ORIGINAL PAPER
A systematic literature review of intracranial hypotension following chiropractic P. Tuchin
Department of Chiropractic, Macquarie University, NorthRyde, NSW, Australia Correspondence to: P. Tuchin, Macquarie University, Waterloo Rd, North Ryde, NSW 2109, Australia Tel.: +612 9850 6384 Fax: +612 9850 9389 Email: [email protected]
Disclosure A/Prof Tuchin declares no conflicts.
SUMMARY
Introduction Intracranial hypotension (IH) is a rare condition, but has been increasingly diagnosed since the introduction of magnetic resonance imaging (MRI). A search of the PubMed database revealed 271 case
396
What’s known
Background: Intracranial hypotension (IH) is caused by a leakage of cerebrospinal fluid (often from a tear in the dura) which commonly produces an orthostatic headache. It has been reported to occur after trivial cervical spine trauma including spinal manipulation. Some authors have recommended specifically questioning patients regarding any chiropractic spinal manipulation therapy (CSMT). Therefore, it is important to review the literature regarding chiropractic and IH. Objective: To identify key factors that may increase the possibility of IH after CSMT. Method: A systematic search of the Medline, Embase, Mantis and PubMed databases (from 1991 to 2011) was conducted for studies using the keywords chiropractic and IH. Each paper was reviewed to examine any description of the key factors for IH, the relationship or characteristics of treatment, and the significance of CSMT to IH. In addition, other items that were assessed included the presence of any risk factors, neck pain and headache. Results: The search of the databases identified 39 papers that fulfilled initial search criteria, from which only eight case reports were relevant for review (after removal of duplicate papers or papers excluded after the abstract was reviewed). The key factors for IH (identified from the existing literature) were recent trauma, connective tissue disorders, or otherwise cases were reported as spontaneous. A detailed critique of these cases demonstrated that five of eight cases (63%) had non-chiropractic SMT (i.e. SMT technique typically used by medical practitioners). In addition, most cases (88%) had minimal or no discussion of the onset of the presenting symptoms prior to SMT and whether the onset may have indicated any contraindications to SMT. No case reports included information on recent trauma, changes in headache patterns or connective tissue disorders. Discussion: Even though type of SMT often indicates that a chiropractor was not the practitioner that delivered the treatment, chiropractic is specifically cited as either the cause of IH or an important factor. There are so much missing data in the case reports that one cannot determine whether the practitioner was negligent (in clinical history taking) or whether the SMT procedure itself was poorly administered. Conclusions: This systematic review revealed that case reports on IH and SMT have very limited clinical details and therefore cannot exclude other theories or plausible alternatives to explain the IH. To date, the evidence that CSMT is not a cause of IH is inconclusive. Further research is required before making any conclusions that CSMT is a cause of IH. Chiropractors and other health practitioners should be vigilant in recording established risk factors for IH in all cases. It is possible that the published cases of CSMT and IH may have missed important confounding risk factors (e.g. a new headache, or minor neck trauma in young or middle-aged adults).
Intracranial hypotension (IH) commonly produces an orthostatic headache which can appear after neck strain. Some papers have reported concerns regarding IH after neck manipulation but this may not be valid.
What’s new This article reviews case reports on neck manipulation and IH which highlights neck manipulation may not be a significant risk factor for IH.
reports published in the last 5 years. IH is caused by a leakage of cerebrospinal fluid (CSF) which is often from a tear in the dura (1). The syndrome of spontaneous IH usually produces an orthostatic headache, but has also been reported without headache (2). In addition to orthostatic headache, other symptoms ª 2013 John Wiley & Sons Ltd Int J Clin Pract, March 2014, 68, 3, 396–402. doi: 10.1111/ijcp.12247
Intracranial hypotension following chiropractic
typically include neck pain and stiffness, diplopia, nausea, vomiting, vertigo, tinnitus, impaired hearing, convulsions and cognitive abnormalities (3). The incidence of IH is estimated at 5 per 100,000 of the population and is most frequent among late middle-aged females, but can occur at any age (4). This means that if 15 million Americans visit a chiropractor each year, up to 750 people may experience IH at some stage during the year (5). IH has been reported to occur after trivial cervical spine trauma including spinal manipulation (6). As a consequence, some authors have recommended specifically questioning patients regarding any chiropractic spinal manipulative therapy in relation to IH (7). Whilst case studies are a low level of evidence, they are often cited to support opinions on treatment safety or adverse effects, including chiropractic and IH (8). However, some articles reviewing the safety of Chiropractic spinal manipulative therapy (SMT) have been shown to have serious errors or flaws (9,10). Chiropractic SMT has good evidence for the treatment of low back pain, neck pain, headache and migraine (11–14). However, some neurologists have expressed concerns regarding safety and articles often are published in neurological journals to support this position (15,16). Therefore, it is important to review the literature regarding chiropractic and IH.
Methods A systematic search of the Medline (PubMed), Embase, and Cumulative Index of Nursing and Allied Health Library (CINAHL) databases (from 1991 to 2011) was conducted for studies using the keywords chiropractic and IH. The search strategy and terms used were ‘chiropractic’ AND ‘intracranial hypotension ‘AND ‘case report’. Abstracts were reviewed for relevance and also hand-searching of reference citations from publications was conducted. Articles that were opinion pieces, hypotheses, extrapolations from basic science research, and other non-observational types of articles were excluded from our review. Further search restrictions were human subjects, English language, peer-reviewed and indexed journals. The description of the search strategy is provided in Table 1. Each included article was critiqued to determine the presence of the key risk factors for IH (recent trauma, connective tissue disorders), the relationship or characteristics of treatment, and the potential significance of CSMT to IH. In addition, other items that were assessed included the presence of any clinical factors, especially neck pain, and headache prior to the delivery of the SMT. The description of clinical factors was reviewed to determine events that ª 2013 John Wiley & Sons Ltd Int J Clin Pract, March 2014, 68, 3, 396–402
Table 1 Search strategy – ‘chiropractic’ AND ‘IH’ AND
‘case report’ Database
Chiropractic
AND ‘IH’
AND ‘case report’
Medline Embase CINAHL Total
5081 3425 17,680
32 28 9
4 5 0 (Non duplicates) 9
may have produced a dural tear prior to any SMT procedures.
Results The search of the databases identified 86 papers that fulfilled initial search criteria, from which only nine case reports were relevant for review (after removal of duplicate papers or papers excluded after the abstract was reviewed). The key factors for IH (identified from the existing literature) were recent trauma, connective tissue disorders, or otherwise cases were reported as spontaneous. A detailed critique of these cases demonstrated that five of nine cases (56%) had non-chiropractic SMT (i.e. SMT technique typically used by medical practitioners). In addition, most cases had minimal or no discussion of the onset of the presenting symptoms prior to SMT and whether the onset may have indicated any contraindications to SMT. No case reports included information on recent trauma, connective tissue disorders, or changes in headache patterns prior to SMT. A detailed critique of these cases is included in the following pages (see Table 2 for a summary). Chung et al. conducted a retrospective review of 30 consecutive patients (10 men, 20 women; mean age 37 years) with the syndrome of CSF hypovolaemia (6). One patient was a 44-year-old female, who was reported to have received chiropractic management, but no other clinical details or pertinent information was recorded. The study ‘… identified possible factors related to CSF leakage in seven patients, which included chiropractic management, playing golf, vigorous physical activity, swimming, yoga exercise, and severe cough associated with upper respiratory infection’. However, unfortunately one table in their article contradicts itself as it reported the 44-year-old female as having no CSF leak, which brings into doubt the conclusion about this case. Jeret reported a 34-year-old man suffered a whiplash injury in a motor vehicle accident (MVA) (17). He consulted a chiropractor for neck pain and was reported to have some improvement. Approximately
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Table 2 Summary of cases
Author
Year
Age
Sex
Presenting symptom
SMT technique
Interval after SMT
Country
Other factors
Chung
2000
44
F
Not described
Not described
Not described
Korea*
Jeret
2001
34
M
Neck pain
Not described
36 h
USA
Beck
2003
40
F
Unknown
Unknown (within 24 h)
Germany*
Suh
2005
37
F
Chronic neck and shoulder pain
‘chiropractioner’ (Axial tension and rotation) Axial tension and rotation
1 day
Korea*
Strauss
2005
54
F
Nuchal pain and neck stiffness
Immediate
Germany*
Mathews Morelli
2006 2006
51 49
F M
HA for several weeks Neck pain
7 days 1 day
USA Italy*
7 day interval Medical SMT
Prasad
2006
37
F
Possibly immediate
USA
Kurbanyan
2007
46
F
Chronic intermittent neck pain Neck stiffness
Orthopaedist(Axial tension and rotation) Not described Rotation and hyperextension Axial tension and rotation Axial tension and rotation
Thoracic and lumbar dural tear Medical SMT
‘several days later’
USA
Lumbar dural tear Similar to Kim (non-SMT) case
No clinical details given MVA- 1 month prior Medical SMT
*Country without legislation for SMT.
1 month after the initial whiplash injury, the chiropractor performed a neck manipulation that caused severe neck pain. Approximately 36 h later the patient noticed severe, throbbing, positional headache, mild dizziness, but no diplopia, otorrhea, rhinorrhea, or other complaints. This case highlights the limitations of case reports on IH and chiropractic. For example, there is no discussion on the severity of the MVA, any other current treatments, any other factors prior to the SMT which may have changed the patient’s condition (i.e. did the neck pain or headache change shortly before the presentation to the chiropractor). This patient had received SMT without incident and then suddenly there was a change, which suggests something had recently changed which affected the outcome of the SMT. Alternatively, there may have been negligence on the part of the chiropractor which affected the outcome of the treatment (e.g. a poor delivery of the SMT, or lack of acknowledgement of a contra-indication to SMT prior to treatment). In the Jeret case, there was no evidence of either dural contrast enhancement or of a CSF leak, even though the author postulated this had occurred. Beck reported a 40-year-old woman had received a spinal chiropractic manipulation (18). They reported
the ‘chiropractioner grasped the head of the supine patient and exerted axial tension while rotating the head’. The patient reported she experienced an immediate sharp pain in her upper neck, and the procedure had to be stopped immediately. Subsequently she complained of headaches and after 24 h she developed nausea and vomiting. Her headaches worsened, and lying down gave the only measure of limited relief. On the sixth day, she developed double vision and presented to the neurology department of a community hospital. This case also highlights similar limitations of case reports reported above. For example, there is no discussion on any other factors prior to the SMT which may have changed the patient’s condition (any change in neck pain or headache change before the presentation to the chiropractor) was the patient having any other current treatments, etc. This patient had received a treatment which is not usually described as chiropractic SMT, and this is also in a country which has no legislation controlling education requirements for people giving SMT. Suh et al. reported a 37-year-old woman (the abstract reported a 36-year old) presented to their hospital with a 4-day history of headache radiating to the occiput and posterior nuchal area (19). It was ª 2013 John Wiley & Sons Ltd Int J Clin Pract, March 2014, 68, 3, 396–402
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reported that she had received a chiropractic manoeuvre 5 days previously because of her chronic neck and shoulder pain. The SMT was reported as delivered in supine position with rotation of her head while exerting axial tension on her neck (not a common chiropractic technique but more associated with orthopaedic spinal manipulation). During the manoeuvre, she felt sharp pain on her posterior neck and upper thoracic spine, and then her headache developed. Once again, there is no discussion of other factors prior to the SMT which may have caused the neck pain and subsequent IH headache. The MRI of thoracic and lumbar spine showed abnormal epidural and subdural fluid collections, spinal epidural venous engorgement, and diffuse spinal dural enhancement, suggesting dural weakness because of some unidentified connective tissue disorder. Also, this case originated in a country which has no legislation controlling education requirements for people giving SMT. Strauss et al. reported a 54-year-old woman developing IH after a chiropractic manoeuvre of her cervical spine (20). The patient was admitted to the Department of Neurology with severe headache radiating from the neck and repeated vomiting. The symptoms were reported to have begun after SMT given by an orthopaedist. The orthopaedist was treating the patient because of moderate nuchal pain and stiffness of her neck. They performed a chiropractic manipulation of the cervical spine by axial tension and rotation of the head. Immediately after this chiropractic manipulation, the patient vomited twice and experienced the severe headache. This case repeats similar weaknesses in case reports previously noted. Again, there is no discussion on any other factors prior to the SMT which may have changed the patient’s condition (e.g. any change in neck pain or headache change before the SMT). Other case reports note trivial events (such as golf, yoga, coughing) as a trigger for IH, but these were not investigated in this case. This case is also in a country which has no legislation controlling education requirements for people giving SMT. Mathews et al. reported a 51 year old woman who had received chiropractic SMT for the treatment of headaches (21). There is no description of the headache, nor any details of onset, previous history, other treatments, etc. One week after her last chiropractic treatment, she developed binocular horizontal diplopia, which was assessed by an ophthalmologist. There was no description of the procedure given, nor any information about the 1-week interval for onset of diplopia. Also there was a 3-week interval before ophthalmologist assessment, in which time many other factors may have caused in the IH. ª 2013 John Wiley & Sons Ltd Int J Clin Pract, March 2014, 68, 3, 396–402
There is also the argument for malpractice, as the patient reported headaches that were not responding to treatment. However, it is not reported in the article whether there was any alteration in the headache pattern after SMT. Interestingly, the patient did not associate any increase in her headaches with chiropractic treatment, which supports other factors as more significant in the onset of IH. Morelli et al. reported a 49-year-old man with neck pain received a single session of chiropractic SMT (22). The following day he reported a severe and throbbing headache which was diagnosed through MRI as IH. Again, there was no discussion on any relevant factors for the onset of the patient’s neck pain (such as trivial activities such as golf, yoga, coughing) in this case. This case is also from a country which has no legislation controlling educational requirements for people performing SMT. This case also does not discuss the experience of the practitioner giving the SMT, and this may indicate a complication from an inexperienced person. The quality of the imaging confirming the dural leak has also been questioned (23). Prasad et al. reported a 37-year-old woman developed IH after a chiropractic treatment for chronic intermittent neck pain (24). The woman complained of a positional headache, which abated only when lying supine. The spinal manipulation manoeuvre was reported as combined axial tension and head rotation. While on the table, she acutely felt a sharp headache that progressed in severity over 2 days. She had never experienced a similar headache. After 1 week, a head CT revealed bilateral subdural hygromas and descent of the cerebellar tonsils. The neurological evaluation occurred 1 month after she underwent the chiropractic SMT. Radionuclide cisternography confirmed the CSF leak caused by dural tear in the lumbar spine, which suggests a prior weakness in this area. Kurbanyan and Lessell reported a generally healthy (my italics) 46-year-old woman with neck stiffness underwent chiropractic SMT involving rotation of the head with axial tension (7). The patient was reported to have been free of neck pain prior to SMT, but experienced neck pain during the manipulation. Several days later, she developed occipital headaches which were relieved by reclining, increased neck stiffness and pain, unsteadiness, and malaise. She also noted horizontal binocular diplopia aggravated on left gaze. As there was very limited clinical history, there are many other plausible alternatives. For example, as neck stiffness is a reported symptom of IH, it is possible the IH was present before the SMT was given. Alternatively, in the ‘several days later’, another event may have occurred which trig-
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gered the IH (e.g. some minor neck strain). As is often the case, there was very limited clinical history of factors prior to the SMT. For example, what had initiated the neck stiffness, did the woman have any history of trauma, was she taking medications, had she had other treatment, etc. This patient also received a treatment which is not usually described as chiropractic SMT.
Discussion Currently the favoured theory for causation of IH is a pre-existing focal weakness of the dural sac which may then exacerbated by the occurrence of a trauma, even trivial, such as coughing, lifting, pushing, sport activities, or even trivial falls (25). Park and Kim reviewed 12 cases of IH who presented to neurosurgical unit from 1995 to 2008 (26). Their study also found 75% reported onset after a trivial activity such as heavy lifting, after coughing from a respiratory infection, dental care, singing and rope skipping, but 25% had no precipitating factor for IH. However, the detailed critique of the case reports associated with CSMT highlighted most had no information (on activities listed above) contained in their report. Almost all case reports had little or no clinical details about the presenting symptom(s) and the onset of these symptoms, which is very relevant in determining when the IH occurred. As a consequence, other plausible causes for IH may have been overlooked. Many cases of IH are reported as spontaneous with few indications prior to the onset of the orthostatic headache. It seems apparent that some people with neck pain or stiffness will present to a chiropractor for treatment, which may then spontaneously develop into IH. For example, Knutson reported a 51-year-old male who sought SMT treatment for headache and neck pain that began 10 days prior because of an injury (27). Challenged to bench press a maximal weight, the patient forced his head, neck and upper torso into flexion to generate momentum. He rated his pain as an 8/10 on a numeric pain scale. The headache was relieved when recumbent and reappeared when upright. The patient had sought medical evaluation at a local emergency department the day after the lifting injury. The diagnosis was a sinus infection and the patient was given a prescription for an antibiotic, which did not have any effect on the headache/neck pain. As a result of the severity of the headache and the recurrence pattern related to increasing by sitting upright, the patient was not given SMT but was referred back to hospital. At the hospital emergency department, a computed tomography scan was negative. The patient was prescribed analgesic medication and was released, but after a
visit with his family physician, a consultation with a neurologist was arranged. The diagnosis by the neurologist was of a dural tear and IH. Radioisotope cisternography confirmed a tear of the dura and leakage of CSF at the T1 level. This case highlights the benefits of taking a detailed clinical history and this enabled the chiropractor to detect a contra-indication to SMT. Clearly, the IH had occurred before the patient attended the chiropractic clinic. Had the patient in the Knutson paper received SMT from the chiropractor for his headache, this case may have also been reported as chiropractic-causing IH (27). Zaatreh and Finkel described a 44-year-old female that presented to her medical practitioner with a 2-week history of headaches which began whilst she was at her office (28). The medical practitioner prescribed NSAIDs which did not give any benefit. The patient presented to hospital 3 days later with a severe headache. Using the logic of previous cases, one might report that this is a case of NSAIDs causing IH. However, it is apparent that this is a case of spontaneous IH unrelated to the NSAID treatment given by the medical practitioner. Alternatively, had this patient gone to a chiropractor for SMT to treat her headache, then this case may also have been reported as chiropractic-causing IH. O’Brien et al. reported a case series of patients with SIH, which had similar clinical features compared with the CSMT cases presented in this article (29). Any one of the O’Brien cases may have presented to a chiropractor for SMT to treat their neck pain or headache, which could subsequently have been reported as chiropractic causing IH. Kim et al. reported a 43-year-old male visited the hospital with a 24-h history of mild headache, neck pain and nausea (30). The patient complained of occipital and temporal headache and tightness in the posterior neck which were aggravated by standing, coughing and shaking of the head. He had a history of hypertension for 2 years and his blood pressure was 145/95 mmHg on his first visit. His symptoms were relieved by lying down, and simple analgesics and muscle relaxants were prescribed, but they did not ease the headache. On the sixth day since the onset of headache, the patient experienced blurred and double vision and this led him to the hospital again. Neurological examination confirmed right sixth cranial nerve palsy, and MRI showed diffuse pachymeningeal thickening and enhancement. A spinal tap was performed and revealed an opening pressure of 11 cmH2O in the right decubitus position. A CT myelogram found contrast leakage in the posterior epidural space from C4 to C6. The diagnosis of spontaneous IH was made despite of the normal CSF pressure. An epidural blood patch was performed ª 2013 John Wiley & Sons Ltd Int J Clin Pract, March 2014, 68, 3, 396–402
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and the patient made a complete recovery from the diplopia. This case is very similar to Kurbanyan and Lessell who reported SIH and abducens palsy following upper spinal manipulation (7). Bhat et al. reported a 35-year-old woman, otherwise healthy, presented with neck stiffness and acuteonset orthostatic headache of 6-week duration which progressed over the next 6 weeks (31). She had similar headache 10 years back just following delivery which subsided with bed rest. Spinal MRI using high resolution T2WI and steady-state imaging revealed a hyper-intense collection in the epidural space from C1 to C2. MR cisternography revealed a distinct tear at the C2 level on the left side with contrast extravasation in the epidural space. This case highlights the similarities to other cases of SIH (with and without spinal manipulation) and demonstrates how illinformed perceptions regarding SMT may occur. Another important point revealed in the critique of SMT and IH case reports was the misuse of the term chiropractic. In most cases, it could be argued that the SMT was not delivered by a chiropractor, but by another healthcare provider, who may not have received adequate training in SMT. Yet the term ‘chiropractic’ was mostly used and was also included as a key word. This has occurred before and distorts the risks associated with chiropractic SMT (32). As the critique of SMT cases also revealed that five of eight cases (63%) had non-chiropractic SMT, and none included information on recent activities and/ or trauma involving the neck, changes in headache patterns or connective tissue disorders, one could argue that chiropractic SMT does not pose a significant threat for IH. In addition, the outcome of most IH cases (including any that may be associated with SMT) is usually complete recovery.
References 1 Schievink WI. Spontaneous spinal cerebrospinal fluid leaks and intracranial hypotension. JAMA 2006; 295: 2286–96. 2 Kawase Y, Ikeda K, Murata K et al. Nonpostural headache in spontaneous intracranial hypotension. Headache 2008; 48: 641–2. 3 Healy DG, Goadsby PJ, Kitchen ND et al. Neurological picture. Spontaneous intracranial hypotension, hygromata and haematomata. J Neurol Neurosurg Psychiatry 2008; 79: 442. 4 Mea E, Chiapparini L, Savoiardo M et al. Headache attributed to spontaneous intracranial hypotension. Neurol Sci 2008; 29(Suppl. 1): S164–5. 5 Davis MA, Sirovich BE, Weeks WB. Utilization and expenditures on chiropractic care in the United States from 1997 to 2006. Health Serv Res 2010; 45: 748–61. 6 Chung SJ, Kim JS, Lee MC. Syndrome of cerebral spinal fluid hypovolemia: clinical and imaging features and outcome. Neurology 2000; 55: 1321–7. ª 2013 John Wiley & Sons Ltd Int J Clin Pract, March 2014, 68, 3, 396–402
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Conclusions This systematic review revealed that case reports on IH and SMT have very limited clinical details and therefore cannot exclude other theories or plausible alternatives to explain the IH. To date, the evidence that CSMT is a cause of IH is inconclusive. Further research is required before making any conclusions that CSMT is a cause of IH. Chiropractors should be vigilant in recording established risk factors for IH in all cases. It is possible that the published cases of CSMT and IH may have missed important confounding risk factors (e.g. a new headache, or minor neck trauma in young or middle-aged adults).
Ethics committee approval The manuscript did not require ethics committee approval as it is a review of previously published papers which had already had ethics approval for their publication.
Funding statement The research received no specific grant from any funding agency in the public, commercial or not-forprofit sectors.
Disclosure The author did not receiving any funding and declares no conflicts.
7 Kurbanyan K, Lessell S. Intracranial hypotension and abducens palsy following upper spinal manipulation. Br J Ophthalmol 2008; 92: 153–5. 8 Ernst E. Adverse effects of spinal manipulation: a systematic review. J R Soc Med 2007; 100: 330–8. 9 Tuchin P. A replication of the study ‘Adverse effects of spinal manipulation: a systematic review’. Chiropr Man Therap 2012; 20: 30. 10 Rosner A. Adverse events in the manipulation of pediatric patients: flaws in a systematic review. Pediatrics 2007; 119: 1261–4. 11 Chaibi A, Tuchin PJ, Russell MB. Manual therapies for migraine: a systematic review. J Headache Pain 2011; 12: 127–33. 12 Bronfort G, Assendelft WJ, Evans R et al. Efficacy of spinal manipulation for chronic headache: a systematic review. J Manipulative Physiol Ther 2001; 24: 457–66. 13 Bronfort G, Evans R, Nelson B et al. A randomized clinical trial of exercise and spinal manipulation for patients with chronic neck pain. Spine 2001; 26: 788–97; discussion 98–9.
14 Chou R, Qaseem A, Snow V et al. Diagnosis and treatment of low back pain: a joint clinical practice guideline from the American College of Physicians and the American Pain Society. Ann Intern Med 2007; 147: 478–91. 15 Lee KP, Carlini WG, McCormick GF, Albers GW. Neurologic complications following chiropractic manipulation: a survey of California neurologists. Neurology 1995; 45: 1213–5. 16 Ernst E. Spinal manipulation: are the benefits worth the risks? Expert Rev Neurother 2007; 7: 1451–2. 17 Jeret JS. More complications of spinal manipulation. Stroke 2001; 32: 1936–7. 18 Beck J, Raabe A, Seifert V, Dettmann E. Intracranial hypotension after chiropractic manipulation of the cervical spine. J Neurol Neurosurg Psychiatry 2003; 74: 821–2. 19 Suh SI, Koh SB, Choi EJ et al. Intracranial hypotension induced by cervical spine chiropractic manipulation. Spine 2005; 30: E340–2. 20 Strauss S, Stemper B, Leis S et al. Intracranial hypotension following chiropraxis. Eur Neurol 2005; 53: 47–50.
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21 Mathews MK, Frohman L, Lee HJ et al. Spinal fluid leak after chiropractic manipulation of the cervical spine. Arch Ophthalmol 2006; 124: 283. 22 Morelli N, Gallerini S, Gori S et al. Intracranial hypotension syndrome following chiropractic manipulation of the cervical spine. J Headache Pain 2006; 7: 211–3. 23 Albayram S. Intracranial hypotension syndrome following chiropratic manipulation of the cervical spine. J Headache Pain 2006; 7: 369–70; author reply 71–2. 24 Prasad S, El-Haddad G, Zhuang H, Khella S. Intracranial hypotension following chiropractic spinal manipulation. Headache 2006; 46: 1456–8. 25 Mokri B. Headaches caused by decreased intracranial pressure: diagnosis and management. Curr Opin Neurol 2003; 16: 319–26.
26 Park E-S, Kim E. Spontaneous intracranial hypotension: clinical presentation, imaging features and treatment. J Korean Neurosurg Soc 2009; 45: 1–4. 27 Knutson GA. Intracranial hypotension causing headache and neck pain: a case study. J Manipulative Physiol Ther 2006; 29: 682–4. 28 Zaatreh M, Finkel A. Spontaneous intracranial hypotension. South Med J 2002; 95: 1342–6. 29 O’Brien M, O’Keeffe D, Hutchinson M, Tubridy N. Spontaneous intracranial hypotension: case reports and literature review. Ir J Med Sci 2012; 181: 171–7. 30 Kim J, Lee S, Ko Y, Lee W. Treatment with epidural blood patch for iatrogenic intracranial hypotension after spine surgery. J Korean Neurosurg Soc 2012; 52: 254–6.
31 Bhat MD, Prasad C, Pruthi N et al. An uncommon site of dural tear in a case of spontaneous intracranial hypotention demonstrated using contrast enhanced magnetic resonance cisternography. Neurol India 2011; 59: 761–2. 32 Terrett AG. Misuse of the literature by medical authors in discussing spinal manipulative therapy injury. J Manipulative Physiol Ther 1995; 18: 203–10.
Paper received June 2013, accepted July 2013
ª 2013 John Wiley & Sons Ltd Int J Clin Pract, March 2014, 68, 3, 396–402
A systematic literature review of intracranial hypotension following chiropractic P. Tuchin
Department of Chiropractic, Macquarie University, NorthRyde, NSW, Australia Correspondence to: P. Tuchin, Macquarie University, Waterloo Rd, North Ryde, NSW 2109, Australia Tel.: +612 9850 6384 Fax: +612 9850 9389 Email: [email protected]
Disclosure A/Prof Tuchin declares no conflicts.
SUMMARY
Introduction Intracranial hypotension (IH) is a rare condition, but has been increasingly diagnosed since the introduction of magnetic resonance imaging (MRI). A search of the PubMed database revealed 271 case
396
What’s known
Background: Intracranial hypotension (IH) is caused by a leakage of cerebrospinal fluid (often from a tear in the dura) which commonly produces an orthostatic headache. It has been reported to occur after trivial cervical spine trauma including spinal manipulation. Some authors have recommended specifically questioning patients regarding any chiropractic spinal manipulation therapy (CSMT). Therefore, it is important to review the literature regarding chiropractic and IH. Objective: To identify key factors that may increase the possibility of IH after CSMT. Method: A systematic search of the Medline, Embase, Mantis and PubMed databases (from 1991 to 2011) was conducted for studies using the keywords chiropractic and IH. Each paper was reviewed to examine any description of the key factors for IH, the relationship or characteristics of treatment, and the significance of CSMT to IH. In addition, other items that were assessed included the presence of any risk factors, neck pain and headache. Results: The search of the databases identified 39 papers that fulfilled initial search criteria, from which only eight case reports were relevant for review (after removal of duplicate papers or papers excluded after the abstract was reviewed). The key factors for IH (identified from the existing literature) were recent trauma, connective tissue disorders, or otherwise cases were reported as spontaneous. A detailed critique of these cases demonstrated that five of eight cases (63%) had non-chiropractic SMT (i.e. SMT technique typically used by medical practitioners). In addition, most cases (88%) had minimal or no discussion of the onset of the presenting symptoms prior to SMT and whether the onset may have indicated any contraindications to SMT. No case reports included information on recent trauma, changes in headache patterns or connective tissue disorders. Discussion: Even though type of SMT often indicates that a chiropractor was not the practitioner that delivered the treatment, chiropractic is specifically cited as either the cause of IH or an important factor. There are so much missing data in the case reports that one cannot determine whether the practitioner was negligent (in clinical history taking) or whether the SMT procedure itself was poorly administered. Conclusions: This systematic review revealed that case reports on IH and SMT have very limited clinical details and therefore cannot exclude other theories or plausible alternatives to explain the IH. To date, the evidence that CSMT is not a cause of IH is inconclusive. Further research is required before making any conclusions that CSMT is a cause of IH. Chiropractors and other health practitioners should be vigilant in recording established risk factors for IH in all cases. It is possible that the published cases of CSMT and IH may have missed important confounding risk factors (e.g. a new headache, or minor neck trauma in young or middle-aged adults).
Intracranial hypotension (IH) commonly produces an orthostatic headache which can appear after neck strain. Some papers have reported concerns regarding IH after neck manipulation but this may not be valid.
What’s new This article reviews case reports on neck manipulation and IH which highlights neck manipulation may not be a significant risk factor for IH.
reports published in the last 5 years. IH is caused by a leakage of cerebrospinal fluid (CSF) which is often from a tear in the dura (1). The syndrome of spontaneous IH usually produces an orthostatic headache, but has also been reported without headache (2). In addition to orthostatic headache, other symptoms ª 2013 John Wiley & Sons Ltd Int J Clin Pract, March 2014, 68, 3, 396–402. doi: 10.1111/ijcp.12247
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typically include neck pain and stiffness, diplopia, nausea, vomiting, vertigo, tinnitus, impaired hearing, convulsions and cognitive abnormalities (3). The incidence of IH is estimated at 5 per 100,000 of the population and is most frequent among late middle-aged females, but can occur at any age (4). This means that if 15 million Americans visit a chiropractor each year, up to 750 people may experience IH at some stage during the year (5). IH has been reported to occur after trivial cervical spine trauma including spinal manipulation (6). As a consequence, some authors have recommended specifically questioning patients regarding any chiropractic spinal manipulative therapy in relation to IH (7). Whilst case studies are a low level of evidence, they are often cited to support opinions on treatment safety or adverse effects, including chiropractic and IH (8). However, some articles reviewing the safety of Chiropractic spinal manipulative therapy (SMT) have been shown to have serious errors or flaws (9,10). Chiropractic SMT has good evidence for the treatment of low back pain, neck pain, headache and migraine (11–14). However, some neurologists have expressed concerns regarding safety and articles often are published in neurological journals to support this position (15,16). Therefore, it is important to review the literature regarding chiropractic and IH.
Methods A systematic search of the Medline (PubMed), Embase, and Cumulative Index of Nursing and Allied Health Library (CINAHL) databases (from 1991 to 2011) was conducted for studies using the keywords chiropractic and IH. The search strategy and terms used were ‘chiropractic’ AND ‘intracranial hypotension ‘AND ‘case report’. Abstracts were reviewed for relevance and also hand-searching of reference citations from publications was conducted. Articles that were opinion pieces, hypotheses, extrapolations from basic science research, and other non-observational types of articles were excluded from our review. Further search restrictions were human subjects, English language, peer-reviewed and indexed journals. The description of the search strategy is provided in Table 1. Each included article was critiqued to determine the presence of the key risk factors for IH (recent trauma, connective tissue disorders), the relationship or characteristics of treatment, and the potential significance of CSMT to IH. In addition, other items that were assessed included the presence of any clinical factors, especially neck pain, and headache prior to the delivery of the SMT. The description of clinical factors was reviewed to determine events that ª 2013 John Wiley & Sons Ltd Int J Clin Pract, March 2014, 68, 3, 396–402
Table 1 Search strategy – ‘chiropractic’ AND ‘IH’ AND
‘case report’ Database
Chiropractic
AND ‘IH’
AND ‘case report’
Medline Embase CINAHL Total
5081 3425 17,680
32 28 9
4 5 0 (Non duplicates) 9
may have produced a dural tear prior to any SMT procedures.
Results The search of the databases identified 86 papers that fulfilled initial search criteria, from which only nine case reports were relevant for review (after removal of duplicate papers or papers excluded after the abstract was reviewed). The key factors for IH (identified from the existing literature) were recent trauma, connective tissue disorders, or otherwise cases were reported as spontaneous. A detailed critique of these cases demonstrated that five of nine cases (56%) had non-chiropractic SMT (i.e. SMT technique typically used by medical practitioners). In addition, most cases had minimal or no discussion of the onset of the presenting symptoms prior to SMT and whether the onset may have indicated any contraindications to SMT. No case reports included information on recent trauma, connective tissue disorders, or changes in headache patterns prior to SMT. A detailed critique of these cases is included in the following pages (see Table 2 for a summary). Chung et al. conducted a retrospective review of 30 consecutive patients (10 men, 20 women; mean age 37 years) with the syndrome of CSF hypovolaemia (6). One patient was a 44-year-old female, who was reported to have received chiropractic management, but no other clinical details or pertinent information was recorded. The study ‘… identified possible factors related to CSF leakage in seven patients, which included chiropractic management, playing golf, vigorous physical activity, swimming, yoga exercise, and severe cough associated with upper respiratory infection’. However, unfortunately one table in their article contradicts itself as it reported the 44-year-old female as having no CSF leak, which brings into doubt the conclusion about this case. Jeret reported a 34-year-old man suffered a whiplash injury in a motor vehicle accident (MVA) (17). He consulted a chiropractor for neck pain and was reported to have some improvement. Approximately
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Table 2 Summary of cases
Author
Year
Age
Sex
Presenting symptom
SMT technique
Interval after SMT
Country
Other factors
Chung
2000
44
F
Not described
Not described
Not described
Korea*
Jeret
2001
34
M
Neck pain
Not described
36 h
USA
Beck
2003
40
F
Unknown
Unknown (within 24 h)
Germany*
Suh
2005
37
F
Chronic neck and shoulder pain
‘chiropractioner’ (Axial tension and rotation) Axial tension and rotation
1 day
Korea*
Strauss
2005
54
F
Nuchal pain and neck stiffness
Immediate
Germany*
Mathews Morelli
2006 2006
51 49
F M
HA for several weeks Neck pain
7 days 1 day
USA Italy*
7 day interval Medical SMT
Prasad
2006
37
F
Possibly immediate
USA
Kurbanyan
2007
46
F
Chronic intermittent neck pain Neck stiffness
Orthopaedist(Axial tension and rotation) Not described Rotation and hyperextension Axial tension and rotation Axial tension and rotation
Thoracic and lumbar dural tear Medical SMT
‘several days later’
USA
Lumbar dural tear Similar to Kim (non-SMT) case
No clinical details given MVA- 1 month prior Medical SMT
*Country without legislation for SMT.
1 month after the initial whiplash injury, the chiropractor performed a neck manipulation that caused severe neck pain. Approximately 36 h later the patient noticed severe, throbbing, positional headache, mild dizziness, but no diplopia, otorrhea, rhinorrhea, or other complaints. This case highlights the limitations of case reports on IH and chiropractic. For example, there is no discussion on the severity of the MVA, any other current treatments, any other factors prior to the SMT which may have changed the patient’s condition (i.e. did the neck pain or headache change shortly before the presentation to the chiropractor). This patient had received SMT without incident and then suddenly there was a change, which suggests something had recently changed which affected the outcome of the SMT. Alternatively, there may have been negligence on the part of the chiropractor which affected the outcome of the treatment (e.g. a poor delivery of the SMT, or lack of acknowledgement of a contra-indication to SMT prior to treatment). In the Jeret case, there was no evidence of either dural contrast enhancement or of a CSF leak, even though the author postulated this had occurred. Beck reported a 40-year-old woman had received a spinal chiropractic manipulation (18). They reported
the ‘chiropractioner grasped the head of the supine patient and exerted axial tension while rotating the head’. The patient reported she experienced an immediate sharp pain in her upper neck, and the procedure had to be stopped immediately. Subsequently she complained of headaches and after 24 h she developed nausea and vomiting. Her headaches worsened, and lying down gave the only measure of limited relief. On the sixth day, she developed double vision and presented to the neurology department of a community hospital. This case also highlights similar limitations of case reports reported above. For example, there is no discussion on any other factors prior to the SMT which may have changed the patient’s condition (any change in neck pain or headache change before the presentation to the chiropractor) was the patient having any other current treatments, etc. This patient had received a treatment which is not usually described as chiropractic SMT, and this is also in a country which has no legislation controlling education requirements for people giving SMT. Suh et al. reported a 37-year-old woman (the abstract reported a 36-year old) presented to their hospital with a 4-day history of headache radiating to the occiput and posterior nuchal area (19). It was ª 2013 John Wiley & Sons Ltd Int J Clin Pract, March 2014, 68, 3, 396–402
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reported that she had received a chiropractic manoeuvre 5 days previously because of her chronic neck and shoulder pain. The SMT was reported as delivered in supine position with rotation of her head while exerting axial tension on her neck (not a common chiropractic technique but more associated with orthopaedic spinal manipulation). During the manoeuvre, she felt sharp pain on her posterior neck and upper thoracic spine, and then her headache developed. Once again, there is no discussion of other factors prior to the SMT which may have caused the neck pain and subsequent IH headache. The MRI of thoracic and lumbar spine showed abnormal epidural and subdural fluid collections, spinal epidural venous engorgement, and diffuse spinal dural enhancement, suggesting dural weakness because of some unidentified connective tissue disorder. Also, this case originated in a country which has no legislation controlling education requirements for people giving SMT. Strauss et al. reported a 54-year-old woman developing IH after a chiropractic manoeuvre of her cervical spine (20). The patient was admitted to the Department of Neurology with severe headache radiating from the neck and repeated vomiting. The symptoms were reported to have begun after SMT given by an orthopaedist. The orthopaedist was treating the patient because of moderate nuchal pain and stiffness of her neck. They performed a chiropractic manipulation of the cervical spine by axial tension and rotation of the head. Immediately after this chiropractic manipulation, the patient vomited twice and experienced the severe headache. This case repeats similar weaknesses in case reports previously noted. Again, there is no discussion on any other factors prior to the SMT which may have changed the patient’s condition (e.g. any change in neck pain or headache change before the SMT). Other case reports note trivial events (such as golf, yoga, coughing) as a trigger for IH, but these were not investigated in this case. This case is also in a country which has no legislation controlling education requirements for people giving SMT. Mathews et al. reported a 51 year old woman who had received chiropractic SMT for the treatment of headaches (21). There is no description of the headache, nor any details of onset, previous history, other treatments, etc. One week after her last chiropractic treatment, she developed binocular horizontal diplopia, which was assessed by an ophthalmologist. There was no description of the procedure given, nor any information about the 1-week interval for onset of diplopia. Also there was a 3-week interval before ophthalmologist assessment, in which time many other factors may have caused in the IH. ª 2013 John Wiley & Sons Ltd Int J Clin Pract, March 2014, 68, 3, 396–402
There is also the argument for malpractice, as the patient reported headaches that were not responding to treatment. However, it is not reported in the article whether there was any alteration in the headache pattern after SMT. Interestingly, the patient did not associate any increase in her headaches with chiropractic treatment, which supports other factors as more significant in the onset of IH. Morelli et al. reported a 49-year-old man with neck pain received a single session of chiropractic SMT (22). The following day he reported a severe and throbbing headache which was diagnosed through MRI as IH. Again, there was no discussion on any relevant factors for the onset of the patient’s neck pain (such as trivial activities such as golf, yoga, coughing) in this case. This case is also from a country which has no legislation controlling educational requirements for people performing SMT. This case also does not discuss the experience of the practitioner giving the SMT, and this may indicate a complication from an inexperienced person. The quality of the imaging confirming the dural leak has also been questioned (23). Prasad et al. reported a 37-year-old woman developed IH after a chiropractic treatment for chronic intermittent neck pain (24). The woman complained of a positional headache, which abated only when lying supine. The spinal manipulation manoeuvre was reported as combined axial tension and head rotation. While on the table, she acutely felt a sharp headache that progressed in severity over 2 days. She had never experienced a similar headache. After 1 week, a head CT revealed bilateral subdural hygromas and descent of the cerebellar tonsils. The neurological evaluation occurred 1 month after she underwent the chiropractic SMT. Radionuclide cisternography confirmed the CSF leak caused by dural tear in the lumbar spine, which suggests a prior weakness in this area. Kurbanyan and Lessell reported a generally healthy (my italics) 46-year-old woman with neck stiffness underwent chiropractic SMT involving rotation of the head with axial tension (7). The patient was reported to have been free of neck pain prior to SMT, but experienced neck pain during the manipulation. Several days later, she developed occipital headaches which were relieved by reclining, increased neck stiffness and pain, unsteadiness, and malaise. She also noted horizontal binocular diplopia aggravated on left gaze. As there was very limited clinical history, there are many other plausible alternatives. For example, as neck stiffness is a reported symptom of IH, it is possible the IH was present before the SMT was given. Alternatively, in the ‘several days later’, another event may have occurred which trig-
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gered the IH (e.g. some minor neck strain). As is often the case, there was very limited clinical history of factors prior to the SMT. For example, what had initiated the neck stiffness, did the woman have any history of trauma, was she taking medications, had she had other treatment, etc. This patient also received a treatment which is not usually described as chiropractic SMT.
Discussion Currently the favoured theory for causation of IH is a pre-existing focal weakness of the dural sac which may then exacerbated by the occurrence of a trauma, even trivial, such as coughing, lifting, pushing, sport activities, or even trivial falls (25). Park and Kim reviewed 12 cases of IH who presented to neurosurgical unit from 1995 to 2008 (26). Their study also found 75% reported onset after a trivial activity such as heavy lifting, after coughing from a respiratory infection, dental care, singing and rope skipping, but 25% had no precipitating factor for IH. However, the detailed critique of the case reports associated with CSMT highlighted most had no information (on activities listed above) contained in their report. Almost all case reports had little or no clinical details about the presenting symptom(s) and the onset of these symptoms, which is very relevant in determining when the IH occurred. As a consequence, other plausible causes for IH may have been overlooked. Many cases of IH are reported as spontaneous with few indications prior to the onset of the orthostatic headache. It seems apparent that some people with neck pain or stiffness will present to a chiropractor for treatment, which may then spontaneously develop into IH. For example, Knutson reported a 51-year-old male who sought SMT treatment for headache and neck pain that began 10 days prior because of an injury (27). Challenged to bench press a maximal weight, the patient forced his head, neck and upper torso into flexion to generate momentum. He rated his pain as an 8/10 on a numeric pain scale. The headache was relieved when recumbent and reappeared when upright. The patient had sought medical evaluation at a local emergency department the day after the lifting injury. The diagnosis was a sinus infection and the patient was given a prescription for an antibiotic, which did not have any effect on the headache/neck pain. As a result of the severity of the headache and the recurrence pattern related to increasing by sitting upright, the patient was not given SMT but was referred back to hospital. At the hospital emergency department, a computed tomography scan was negative. The patient was prescribed analgesic medication and was released, but after a
visit with his family physician, a consultation with a neurologist was arranged. The diagnosis by the neurologist was of a dural tear and IH. Radioisotope cisternography confirmed a tear of the dura and leakage of CSF at the T1 level. This case highlights the benefits of taking a detailed clinical history and this enabled the chiropractor to detect a contra-indication to SMT. Clearly, the IH had occurred before the patient attended the chiropractic clinic. Had the patient in the Knutson paper received SMT from the chiropractor for his headache, this case may have also been reported as chiropractic-causing IH (27). Zaatreh and Finkel described a 44-year-old female that presented to her medical practitioner with a 2-week history of headaches which began whilst she was at her office (28). The medical practitioner prescribed NSAIDs which did not give any benefit. The patient presented to hospital 3 days later with a severe headache. Using the logic of previous cases, one might report that this is a case of NSAIDs causing IH. However, it is apparent that this is a case of spontaneous IH unrelated to the NSAID treatment given by the medical practitioner. Alternatively, had this patient gone to a chiropractor for SMT to treat her headache, then this case may also have been reported as chiropractic-causing IH. O’Brien et al. reported a case series of patients with SIH, which had similar clinical features compared with the CSMT cases presented in this article (29). Any one of the O’Brien cases may have presented to a chiropractor for SMT to treat their neck pain or headache, which could subsequently have been reported as chiropractic causing IH. Kim et al. reported a 43-year-old male visited the hospital with a 24-h history of mild headache, neck pain and nausea (30). The patient complained of occipital and temporal headache and tightness in the posterior neck which were aggravated by standing, coughing and shaking of the head. He had a history of hypertension for 2 years and his blood pressure was 145/95 mmHg on his first visit. His symptoms were relieved by lying down, and simple analgesics and muscle relaxants were prescribed, but they did not ease the headache. On the sixth day since the onset of headache, the patient experienced blurred and double vision and this led him to the hospital again. Neurological examination confirmed right sixth cranial nerve palsy, and MRI showed diffuse pachymeningeal thickening and enhancement. A spinal tap was performed and revealed an opening pressure of 11 cmH2O in the right decubitus position. A CT myelogram found contrast leakage in the posterior epidural space from C4 to C6. The diagnosis of spontaneous IH was made despite of the normal CSF pressure. An epidural blood patch was performed ª 2013 John Wiley & Sons Ltd Int J Clin Pract, March 2014, 68, 3, 396–402
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and the patient made a complete recovery from the diplopia. This case is very similar to Kurbanyan and Lessell who reported SIH and abducens palsy following upper spinal manipulation (7). Bhat et al. reported a 35-year-old woman, otherwise healthy, presented with neck stiffness and acuteonset orthostatic headache of 6-week duration which progressed over the next 6 weeks (31). She had similar headache 10 years back just following delivery which subsided with bed rest. Spinal MRI using high resolution T2WI and steady-state imaging revealed a hyper-intense collection in the epidural space from C1 to C2. MR cisternography revealed a distinct tear at the C2 level on the left side with contrast extravasation in the epidural space. This case highlights the similarities to other cases of SIH (with and without spinal manipulation) and demonstrates how illinformed perceptions regarding SMT may occur. Another important point revealed in the critique of SMT and IH case reports was the misuse of the term chiropractic. In most cases, it could be argued that the SMT was not delivered by a chiropractor, but by another healthcare provider, who may not have received adequate training in SMT. Yet the term ‘chiropractic’ was mostly used and was also included as a key word. This has occurred before and distorts the risks associated with chiropractic SMT (32). As the critique of SMT cases also revealed that five of eight cases (63%) had non-chiropractic SMT, and none included information on recent activities and/ or trauma involving the neck, changes in headache patterns or connective tissue disorders, one could argue that chiropractic SMT does not pose a significant threat for IH. In addition, the outcome of most IH cases (including any that may be associated with SMT) is usually complete recovery.
References 1 Schievink WI. Spontaneous spinal cerebrospinal fluid leaks and intracranial hypotension. JAMA 2006; 295: 2286–96. 2 Kawase Y, Ikeda K, Murata K et al. Nonpostural headache in spontaneous intracranial hypotension. Headache 2008; 48: 641–2. 3 Healy DG, Goadsby PJ, Kitchen ND et al. Neurological picture. Spontaneous intracranial hypotension, hygromata and haematomata. J Neurol Neurosurg Psychiatry 2008; 79: 442. 4 Mea E, Chiapparini L, Savoiardo M et al. Headache attributed to spontaneous intracranial hypotension. Neurol Sci 2008; 29(Suppl. 1): S164–5. 5 Davis MA, Sirovich BE, Weeks WB. Utilization and expenditures on chiropractic care in the United States from 1997 to 2006. Health Serv Res 2010; 45: 748–61. 6 Chung SJ, Kim JS, Lee MC. Syndrome of cerebral spinal fluid hypovolemia: clinical and imaging features and outcome. Neurology 2000; 55: 1321–7. ª 2013 John Wiley & Sons Ltd Int J Clin Pract, March 2014, 68, 3, 396–402
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Conclusions This systematic review revealed that case reports on IH and SMT have very limited clinical details and therefore cannot exclude other theories or plausible alternatives to explain the IH. To date, the evidence that CSMT is a cause of IH is inconclusive. Further research is required before making any conclusions that CSMT is a cause of IH. Chiropractors should be vigilant in recording established risk factors for IH in all cases. It is possible that the published cases of CSMT and IH may have missed important confounding risk factors (e.g. a new headache, or minor neck trauma in young or middle-aged adults).
Ethics committee approval The manuscript did not require ethics committee approval as it is a review of previously published papers which had already had ethics approval for their publication.
Funding statement The research received no specific grant from any funding agency in the public, commercial or not-forprofit sectors.
Disclosure The author did not receiving any funding and declares no conflicts.
7 Kurbanyan K, Lessell S. Intracranial hypotension and abducens palsy following upper spinal manipulation. Br J Ophthalmol 2008; 92: 153–5. 8 Ernst E. Adverse effects of spinal manipulation: a systematic review. J R Soc Med 2007; 100: 330–8. 9 Tuchin P. A replication of the study ‘Adverse effects of spinal manipulation: a systematic review’. Chiropr Man Therap 2012; 20: 30. 10 Rosner A. Adverse events in the manipulation of pediatric patients: flaws in a systematic review. Pediatrics 2007; 119: 1261–4. 11 Chaibi A, Tuchin PJ, Russell MB. Manual therapies for migraine: a systematic review. J Headache Pain 2011; 12: 127–33. 12 Bronfort G, Assendelft WJ, Evans R et al. Efficacy of spinal manipulation for chronic headache: a systematic review. J Manipulative Physiol Ther 2001; 24: 457–66. 13 Bronfort G, Evans R, Nelson B et al. A randomized clinical trial of exercise and spinal manipulation for patients with chronic neck pain. Spine 2001; 26: 788–97; discussion 98–9.
14 Chou R, Qaseem A, Snow V et al. Diagnosis and treatment of low back pain: a joint clinical practice guideline from the American College of Physicians and the American Pain Society. Ann Intern Med 2007; 147: 478–91. 15 Lee KP, Carlini WG, McCormick GF, Albers GW. Neurologic complications following chiropractic manipulation: a survey of California neurologists. Neurology 1995; 45: 1213–5. 16 Ernst E. Spinal manipulation: are the benefits worth the risks? Expert Rev Neurother 2007; 7: 1451–2. 17 Jeret JS. More complications of spinal manipulation. Stroke 2001; 32: 1936–7. 18 Beck J, Raabe A, Seifert V, Dettmann E. Intracranial hypotension after chiropractic manipulation of the cervical spine. J Neurol Neurosurg Psychiatry 2003; 74: 821–2. 19 Suh SI, Koh SB, Choi EJ et al. Intracranial hypotension induced by cervical spine chiropractic manipulation. Spine 2005; 30: E340–2. 20 Strauss S, Stemper B, Leis S et al. Intracranial hypotension following chiropraxis. Eur Neurol 2005; 53: 47–50.
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21 Mathews MK, Frohman L, Lee HJ et al. Spinal fluid leak after chiropractic manipulation of the cervical spine. Arch Ophthalmol 2006; 124: 283. 22 Morelli N, Gallerini S, Gori S et al. Intracranial hypotension syndrome following chiropractic manipulation of the cervical spine. J Headache Pain 2006; 7: 211–3. 23 Albayram S. Intracranial hypotension syndrome following chiropratic manipulation of the cervical spine. J Headache Pain 2006; 7: 369–70; author reply 71–2. 24 Prasad S, El-Haddad G, Zhuang H, Khella S. Intracranial hypotension following chiropractic spinal manipulation. Headache 2006; 46: 1456–8. 25 Mokri B. Headaches caused by decreased intracranial pressure: diagnosis and management. Curr Opin Neurol 2003; 16: 319–26.
26 Park E-S, Kim E. Spontaneous intracranial hypotension: clinical presentation, imaging features and treatment. J Korean Neurosurg Soc 2009; 45: 1–4. 27 Knutson GA. Intracranial hypotension causing headache and neck pain: a case study. J Manipulative Physiol Ther 2006; 29: 682–4. 28 Zaatreh M, Finkel A. Spontaneous intracranial hypotension. South Med J 2002; 95: 1342–6. 29 O’Brien M, O’Keeffe D, Hutchinson M, Tubridy N. Spontaneous intracranial hypotension: case reports and literature review. Ir J Med Sci 2012; 181: 171–7. 30 Kim J, Lee S, Ko Y, Lee W. Treatment with epidural blood patch for iatrogenic intracranial hypotension after spine surgery. J Korean Neurosurg Soc 2012; 52: 254–6.
31 Bhat MD, Prasad C, Pruthi N et al. An uncommon site of dural tear in a case of spontaneous intracranial hypotention demonstrated using contrast enhanced magnetic resonance cisternography. Neurol India 2011; 59: 761–2. 32 Terrett AG. Misuse of the literature by medical authors in discussing spinal manipulative therapy injury. J Manipulative Physiol Ther 1995; 18: 203–10.
Paper received June 2013, accepted July 2013
ª 2013 John Wiley & Sons Ltd Int J Clin Pract, March 2014, 68, 3, 396–402
