22
Medical Management of Spinal Epidural Abscesses: Case Report and Review David Wheeler, Philip Keiser, Daniele Rigamonti, and Susan Keay
From the Division of Infectious Diseases. Department of Medicine. and the Department ofNeurologic Surgery, University ofMaryland Medical Center. and the Department of Veterans Affairs Medical Center, Baltimore. Maryland
The traditionally accepted management of a spinal epidural abscess involves neurological and radiographic staging of the lesion, surgical drainage, identification of the infecting organism, and antibiotic therapy. Before the availability of computerized radiographic imaging, surgery was performed based on neurological and/or myelographic findings. Drainage of the abscess provided neurological decompression as well as a microbiological diagnosis. Because of the development of computed tomography (CT) and magnetic resonance imaging (MRI), the diagnosis of spinal epidural abscess is now possible before the onset of spinal cord compression or neurological dysfunction. For editorial comment see page 28. Reports have appeared in the literature that describe a conservative approach to the treatment of a spinal epidural abscess, and some authors have advocated nonsurgical management in certain clinical settings, particularly for the patient with limited neurological dysfunction. We describe a case of an extensive spinal epidural abscess that involved the anterior cervical, thoracic, and lumbar spine, thus precluding effective surgical drainage, and that
Received 25 November 1991; revised 28 February 1992. The case reported herein will also be included as one of eight cases reported in the article entitled "Spinal Epidural Abscess with Gadolinium Enhanced MRI: Serial Follow-up Studies and Clinical Correlations" by N. Sadato et al. in Neuroradiologv (in press). Reprints or correspondence: Dr. David Wheeler, Division of Infectious Diseases. University of Maryland Hospital, Box 243, 22 South Greene Street, Baltimore, Maryland 2120 I.
Clinical Infectious Diseases 1992;15:22-7 © 1992 by The University of Chicago. All rights reserved. 1058-4838/92/1501-0004$02.00
was successfully managed nonsurgically; no neurological sequelae were reported, and an apparent clinical and radiographic resolution of the infection occurred. We also review the literature and summarize the experience with nonsurgical management of spinal epidural abscesses that has been previously reported.
Case Report A 51-year-old diabetic man who was previously in good health presented to another hospital with lumbar and cervical pain and fever. He was awake and alert but had mild weakness noted in both lower extremities. CT of the spine revealed disease of lumbar disks and compression of nerve roots. A lumbar puncture at the L4-5 interspace yielded puslike material with a white blood cell (WBC) count of 4,500/ mrrr', a protein level of 3,400 mg/dL, and a glucose level of 71 mg/dl.; gram stain of the fluid revealed gram-positive cocci. The patient received a 10-day course of therapy with iv vancomycin; ceftazidime was added to the therapeutic regimen before he was transferred to the University of Maryland Medical Center. The patient's medical history was significant for only adult-onset diabetes mellitus, hypertension, and undocumented rheumatic fever. He denied illicit iv drug use. Two months before admission, he underwent dental manipulation, for which no antibiotic prophylaxis was given. On physical examination, the patient was awake, alert, and cooperative. There was moderate nuchal rigidity and decreased lateral mobility of the neck. A grade 1/6 systolic ejection murmur was heard over the left lower sternal border. Findings of the neurological examination were normal. The peripheral WBC count was 32.5/mm 3 , the serum
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Although the traditional management of spinal epidural abscesses includes antibiotic therapy and surgical drainage, numerous reports have appeared in the literature that describe a nonsurgical approach. We report the successful nonsurgical management of a case of an extensive spinal epidural abscess in which the patient was closely monitored by serial studies with magnetic resonance imaging. Review of the literature from 1970 to 1990 revealed 37 cases that describe conservative management of spinal epidural abscesses. Despite successful conservative management reported for some cases, sudden neurological deterioration of patients receiving appropriate antibiotic therapy has also occurred. A true index of the success of nonsurgical therapy is difficult to discern since cases may have been selectively reported and unsuccessful attempts at conservative management may have never been reported once a laminectomy was performed. A prospective investigation that includes clearly defined indications for conservative management vs. surgical intervention and that can be studied with an intention-to-treat analysis is needed.
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Medical Management of Epidural Abscesses
Methods Literature review. The National Library of Medicine's MEDLINE service was used in the review of the English- and foreign-language literature for cases of pyogenic spinal epidural abscess. Cases that were originally published in a foreign language but subsequently described in the English-language literature were also reviewed. All case series published be-
tween 1970 and 1990 were carefully reviewed for reports of cases managed conservatively, i.e., those managed without laminectomy or other surgical procedure or in which the only intervention was diagnostic needle aspiration. In addition to case series, all individual cases reported between 1970 and 1990 that described the nonsurgical management of spinal epidural abscess were included. Data analysis. Each case was reviewed for the patient's age, sex, presentation, location of abscess, infecting organism, reasons for medical management, and outcome. On the basis of clinical presentation, each case was placed into one of the following categories: (I) back pain; (2) radicular back pain; (3) incomplete neurological symptoms. such as weakness, paresthesias, or urinary or fecal incontinence; (4) paraplegia; and (5) overt sepsis. Each case was also classified according to the following ultimate outcomes: ( 1) total recovery, (2) partial recovery, (3) no improvement, (4) worsening, and (5) death. The results of the classification based on presenting symptoms were then compared with those based on outcome.
Results Fifteen retrospective case series of epidural abscess were published between 1970 and 1990 [I-15]. Of these case series. seven included a total of 25 cases that were managed without surgical intervention [2, 5, 6, 9. II, 12, 15]. Three small case series of epidural abscess treated nonsurgically [16-18] as well as several individual reports [19-21] provided an additional 17 cases for this review. Since no information was reported for the five patients who received nonsurgical management in the case series of Baker et al. [2], these patients were excluded from further consideration. The remaining cases (including our case report) provide a total of 38 for analysis; these are presented in table I. The sex of 23 of the patients was reported; there were 17 men and 6 women. The average age of the patients was 51 years (range, 18-81 years). Sixteen patients had some reported associated illness or other predisposing condition for an epidural abscess. Five patients had a history of spinal injury or surgery, five were iv drug abusers, one had a pleural empyema, three had bacteremia caused by Staphylococcus aureus. and two had overwhelming sepsis. Four had associated conditions that could not be directly related to an epidural abscess, including glomerular nephritis, colonic cancer, sciatica, and cirrhosis. The clinical presentations of the cases were varied. ranging from back pain to paraplegia and sepsis. Of the 34 cases in which presentation was reported, eight patients had localized back pain; three had radicular pain; 15 had signs of incomplete spinal cord impingement, such as weakness, sensory loss, or bladder dysfunction; and seven had paraplegia or quadriplegia. One patient presented with confusion but no neurological deficit.
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glucose level was 264 mg/dL, and the creatinine clearance was normal; results of a urinalysis were unremarkable. Cervical myelography was performed at the C 1-2 level and clear CSF was withdrawn. Analysis of the CSF revealed 2 red blood cells/nun", 58 WBCs/mm 3 (68% lymphocytes, 28% polymorphonuclear neutrophils, and 4 monocytes), a glucose level of 138 mg/dL, and a total protein level of 32 mg/ dL. A block at C2-4 was revealed by injection of contrast medium, and no contrast was noted below this level. CT / myleography demonstrated a low-density area, suggestive of an epidural abscess, anterior to the thecal sac at C2-4. MRI of the spine confirmed the presence of an epidural abscess anterior to the thecal sac and demonstrated that it extended from the upper cervical to the lower lumbar spine with compression at C-2 and a posterior fluid collection at L4-5. Additional fluid collections were also noted in the left psoas and paraspinal muscles with connection to the epidural space via the L4-5 neural foramen. The patient was initially treated with iv vancomycin, nafcillin, and amikacin. Cultures of blood and lumbar epidural fluid (specimens were collected at the first hospital) yielded an a-hemolytic streptococcus. Because he also had an abscess of the psoas muscle, antibiotic therapy was changed to penicillin, metronidazole, and gentamicin. Echocardiography revealed a moderately calcified aortic valve with no visible vegetations. Given the extent of the spinal epidural collection and the normal findings of the neurological examination, the patient underwent drainage of the paraspinal fluid collection only. Culture of the abscess fluid yielded a pure growth of Streptococcus constellatus that was sensitive to penicillin, ampicillin, and vancomycin. Metronidazole therapy was discontinued after 10 days. Serial studies with MRI of his spine revealed a slight decrease in the size of the anterior lumbar collection after I week of treatment at our hospital, and by 3 weeks the cervical collection and the posterior lumbar collection were also notably diminished. The patient was discharged from the hospital and continued to receive iv penicillin and gentamicin; he received a total of 12 weeks ofiv therapy. At 10 weeks, the patient was asymptomatic, findings of his neurological examination remained normal, and MRI of the spine revealed no abnormalities. The patient was evaluated 12 weeks later and had no recurrence of fever or other symptoms suggestive of a relapse of the epidural infection.
23
Wheeler et al.
24
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Table 1. Summary of cases of spinal epidural abscess treated nonsurgically (1970-1990).
I I 6
Not reported Not reported Not reported Not reported Not reported Not reported Not reported Not reported S. aureus bacteremia
Paraplegia Not reported Weakness Weakness Weakness Weakness Paraplegia Paraplegia Back pain
Not reported Not reported Not reported Not reported Not reported Not reported Not reported Not reported L1-2
IVDA/endocarditis
Radicular pain
C7-TI
S. aureus bacteremia Overwhelming sepsis Overwhelming sepsis S. aureus bacteremia Not reported Not reported Glomerular nephritis
Back pain Not reported Not reported Leg weakness Radicular pain Paraplegia Radicular pain
TIO-II Not reported Not reported L-5 T8-9 T2-3 L2-3
Neck trauma Neck fracture Back trauma IVDA Pleural empyema None IVDA Back trauma IVDA Cirrhosis
C6-TI LI-3 T6-8 Lumbar Cervical/lumbar Cervical Lumbar Thoracic Cervical T10-S2 T10-S2
None None
Not reported Confusion Paraplegia Pain Pain Pain Pain Pain Pain Urinary incontinence/ sensory loss Pain/urinary incontinence Weakness/decreased reflexes Decreased reflexes/ loss of sphincter tone Leg weakness Quadraplegia
Refused surgery Not reported Minor neurological signs Poor health Minor neurological signs Extensive abscess Complete paraplegia Complete paraplegia Improved while receiving antibiotic therapy Improved while receiving antibiotic therapy Poor medical condition Sepsis Sepsis Not reported Not reported Missed diagnosis Improved while receiving antibiotic therapy Not reported No neurological deficit Missed diagnosis Minor neurological signs Minor neurological signs Minor neurological signs Minor neurological signs Minor neurological signs Minor neurological signs Poor medical condition
Sciatica [17] [19]
Not reported IVDA
[2 I)
None
[20]
Not reported
[PR]
None
[5] [6] [9]
[I I]
5
[12]
4
[15]
3
[16]
6
[17]
4
None Cancer of the sigmoid colon Disk surgery
[18]
NOTE. report.
3
Diagnostic technique
Outcome Paraplegia Not reported Recovered Recovered Recovered Recovered No change No change Recovered
Not reported Not reported
Recovered
Myelography
Recovered Died Died No change No change No change Recovered
Myelography Autopsy Autopsy CT CT CT CT Not reported Myelography Biopsy CT /myelography CT /rnyelography CT /myelography CT /rnyelography CT/myelography CT /myelography CT
Minor neurological signs
Improved Recovered Paraplegia Recovered Persistent diskitis Recovered Recovered Recovered Recovered Residual sensory deficit Recovered
T4-L5
Poor medical condition
Recovered
CT
L4-5
Minor neurological signs
Recovered
CT
C2-5 C3-5
Not reported Paresis> 18 h
MRI MRI
Decreased reflexes
L2-sacrum
Paraplegia Weakness/urinary symptoms Weakness/sensory loss Transient arm weakness Leg weakness
Not reported L-4
Drainage considered hazardous Not reported Poor medical condition
Recovered Slight regression of paresis in arms Residual leg weakness Recovered Recovered
LP Myelography
Cervical to lumbar C3-5
Extensive abscess
Recovered
Myelography
Minor neurological signs
Recovered
CT
Cervical to lumbar
Extent of abscess
Recovered
MRI
Myelography/LP Myelography/LP Myelography/LP Myelography/LP Myelography/LP Myelography/LP Myelography
CT
MRI
LP = lumbar puncture; IVDA = intravenous drug abuse; CT = computed tomography; MRI = magnetic resonance imaging; and PR = present
An infecting organism was identified in 24 cases. The organism was isolated from the abscess in 10 cases, and a presumptive diagnosis was made on the basis of results of blood cultures alone in 14. S. aureus was cultured in 19 cases, Streptococcus organisms in three (Streptococcus sanguis, S. constellatus, and a viridans streptococcus), Escherichia coli in one, and a Proteus species in one. Two additional patients
had presentations consistent with overwhelming bacterial sepsis and died shortly after admission; in each case autopsy revealed an epidural abscess. The location of the abscess was reported in 27 of the 38 cases. In 20 of the 27 cases, the abscess was reported to involve multiple vertebrae. While 13 of these multilevel abscesses were confined to two or three vertebrae, three were
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Associated conditions
Presentation
Location of abscess
Reason for medial management
No. of cases
[Reference]
25
Medical Management of Epidural Abscesses
CID 1992; 15 (July)
Table 2. Presentation of spinal epidural abscess vs. outcome. No. of patients with indicated outcome Presentation
Died
Localized back pain Radicular pain Incomplete neurological deficit* Paraplegia Clinical syndrome consistent with bacterial sepsis
Worsened
No change
Improved
Recovered
I
7 2 12
5
I
I
I
2
NOTE. Clinical information was available for only 35 of the 38 patients. * Such as sensory loss, weakness, or bowel or bladder dysfunction.
Discussion A pyogenic spinal epidural abscess is a bacterial infection in the epidural space that results in the accumulation ofpuru-
lent fluid or infected granulation tissue. The thoracic spine is reportedly involved in 31%-63% ofcases, the lumbar spine in 21%-44%, and the cervical spine in 14%-26% [2, 5,6, 11, 13]. S. aureus is the etiologic organism most commonly isolated. Reviews from the United States before the availability of antibiotics [22] and from developing countries [8] have revealed isolation rates for S. aureus approaching 100%. While it is still the most common organism isolated, recent reviews in the United States have shown that S. aureus is implicated in only 45%-62% of cases of spinal epidural abscess [11, 13, 14]. Other common organisms include streptococci, Staphylococcus epidermidis, and aerobic gram-negative rods [II]. Incidence rates of --0.2-1.2 cases/ 10,000 hospital admissions were described in both the preantibiotic and the postantibiotic eras [2, 22]; however, recent reviews have cited higher incidence rates of up to 1.96-2.8 casesjlO,OOO hospital admissions [II, 13]. Blunt trauma has been purported to contribute to the formation of spinal epidural abscesses in 17%-30% of cases [2, 11, 22]. According to recent reviews, a localized source for the infecting organism-including the skin, urinary tract, lower respiratory tract, and site of invasive spinal procedures-can be identified in 71%-78% of cases [I I, I 3]. An individual with a spinal epidural abscess usually presents with back pain, localized tenderness, and fever. The presence of radicular pain or a neurological deficit necessitates an emergent diagnostic evaluation. Traditionally, radiography followed by lumbar puncture and myelography were the diagnostic procedures of choice [2, 11]. When CT became available, high resolution CT or CT /myelography provided better anatomical detail [17]. MRI is now the diagnostic procedure of choice in most instances and does not require the intrathecal injection of contrast material [13,
14, 18]. Various authors have used clinical and pathological criteria to classify spinal epidural abscesses as acute or chronic. As defined by some investigators, an acute abscess is one for which symptoms have been present for < 14-16 days and a chronic abscess is one for which symptoms have been present for a longer period [II, 13]. According to other authors, an acute abscess is one in which there is a predominance of
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extensive, stretching from the cervical to the lumbar spine. Eight abscesses were confined to the lumbar area, while five each were exclusively in the cervical or thoracic spine. The reasons for medical management were reported for 32 patients. Twelve patients were reported to have had minor neurological signs and were observed while they were receiving antibiotics, six had surgery deferred because of underlying medical conditions and were considered to be poor surgical candidates, three had epidural abscesses that were so extensive that laminectomy required to drain the abscesses would have potentially destabilized the spinal column, and three had paraplegia that was thought to be irreversible. Three patients had a diagnosis of epidural abscess after their neurological function had improved while receiving antibiotics, two died ofoverwhelming sepsis before the diagnosis of epidural abscess was made, one refused surgery, and two had an incorrect diagnosis until after they were neurologically stable. Outcome after medical management of the spinal epidural abscesses was reported in 37 ofthe 38 cases. Twenty-three of the patients recovered completely, two died, one worsened, and the rest either remained the same or improved. Outcome was compared with presentation (table 2). Those patients who presented with localized pain or with radicular pain were more likely to have improvement or total recovery than those who were paraplegics or in septic shock. Patients with incomplete neurological symptoms, however, did surprisingly well. Twelve of 15 patients with partial neurological symptoms recovered and only one worsened. Five of these 12 patients were managed conservatively because they were believed to have only minor neurological signs. Surgery was deferred for the other seven patients because they either were considered to be poor surgical candidates or had extensive epidural abscesses. Because the etiologic organism was reported for only 63% of the cases and because S. aureus was the organism identified in 79% of those, an analysis of outcome based on etiologic organisms did not reveal any trends.
26
Wheeler et at.
nonsurgical management of spinal epidural abscess; these indications were "poor surgical candidates," "considerable length of the vertebral canal," "patients not suffering severe loss ofspinal cord or cauda equina function," and "complete paralysis for more than 3 days." In 1990 two case series of spinal epidural abscess were published together in the neurosurgical literature in which none of the patients were managed conservatively [13, 14]. Nonetheless, an editorial commentary questioned whether some of the cases managed surgically could have been managed nonsurgically. The author of the commentary went on to suggest that "cases without significant neural compression can be successfully managed with appropriate antimicrobial therapy if the causative organism is cultured" and suggested that "surgery is warranted only if there is: neural compression from mass effect, spinal instability and deformity, or failure to obtain a satisfactory culture ofthe infectious organism" [14]. In light of the fact that nonsurgical management has been shown to be successful in selected cases and that certain practitioners and authors are advocating this approach for patients who are otherwise surgical candidates, it is important to determine whether published literature on the subject would support this approach. Several factors need to be considered in the analysis of the data from these case series. Isolated case reports may reflect success for selected patients, but they may not reflect success in all or even many of the cases that were managed in this fashion. Case series, in which all cases of spinal epidural abscess are included, give a better indication of the success or failure of medical management in a given institution. However, cases may have been reported as surgically managed when, in fact, the patients underwent surgery after nonsurgical management had failed. Danner and Hartman [11] and Hlavin et al. [13] described six and eight cases, respectively, in which emergent laminectomy was required because of'neurological deterioration while the patients were receiving appropriate antibiotic therapy. None ofthe case series were prospectively designed; therefore, intention-to-treat analysis is difficult. Analysis of these cases is also hampered by the fact that (1) diagnosis was made in many of these cases after the patient responded to empirical therapy or that (2) the cases represented instances in which surgery was not an option (either because of medical complications or, as in our case, because the extent of the abscess was so great). Reporting bias is also likely, depending on the group reporting the cases. Some case series described all patients admitted to a hospital [2], while other case series included only those patients referred to a neurosurgical service [14] or to a spinal cord unit [1]. Comparison of all cases from 1970 to 1990 is also difficult since the technology available for the diagnosis of spinal epidural abscess advanced considerably during this period. Heusner [22] relied on subtle neurological dysfunction as an
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purulent material (found during surgical drainage) and a chronic abscess is one that consists of organized granulation tissue [5, 7]. There is not always, however, a close correlation between chronicity of symptoms and the finding of granulation tissue at surgery [13, 14]. Concomitant vertebral osteomyelitis has also been described in -- 35%- 38% of cases of spinal epidural abscess [2, 22]. Complications from pyogenic spinal epidural abscess include a substantial risk of permanent neurological dysfunction. In addition to risk of direct compression of the spinal cord or nerve roots, there may be neurological deterioration caused by vascular compromise ofthe intrinsic circulation to the spinal cord. Neurological deterioration may be sudden and has been described in patients who have received as much as 4 weeks of appropriate antibiotic therapy [13]. Whether sudden vascular thrombosis was responsible for this phenomenon has been debated. In 1948 Heusner [22] described the clinical presentation, treatment, and outcome of spinal epidural abscesses seen at Boston City Hospital, including cases from both before and after the antibiotic era. Heusner's description of the clinical staging of the disease has been referenced in most subsequent literature on epidural abscess. This clinical staging includes four phases through which most patients progress: spinal ache (I), nerve root pain (II), radicular weakness (III), and paralysis (IV). All ofHeusner's cases were managed with laminectomy, although he observed an increased survival rate among patients treated after the availability of sulfonamides and penicillin. References to successful conservative management in previous literature [23] were dismissed by Heusner as probable misdiagnoses, and he stated that the "conception of nonoperative management is mentioned only to be condemned, notwithstanding a recent suggestion that penicillin might sometimes obviate the need for surgery." Two case series published thereafter [24,25] reiterated the need for aggressive surgical intervention and antibiotics. Using historical control data, Dus [25] concluded that successful intervention depends on early diagnosis and surgery combined with antibiotic treatment. In 1975, in a comprehensive review from Massachusetts General Hospital, Baker et al. [2] reported 39 cases of spinal epidural abscess that had been seen between 1947 and 1974. Of 34 patients who underwent surgery, 23 completely recovered, five had residual weakness, and six had paralysis or died. All five patients whose cases were managed without surgery died. Despite such admonitions, 6.6%of the patients in the case series published between 1970 and 1990 received nonsurgical therapy; for 63% of these patients, symptoms abated or disease resolved. Successful nonsurgical management of patients has prompted several authors to suggest this method as an alternative to surgery in some circumstances [16, 17, 19, 20]. Leys et al. [17] proposed a list of four indications for the
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Medical Management of Epidural Abscesses
References I. Hancock DO. A study of ~9 patients with acute spinal extradural abscess. Paraplegia 1973; I0:285-8.
2. Baker AS. Ojemann RG. Swartz MN. Richardson EP Jr. Spinal epidural abscess. N Engl J Med 1975;293:463-8. 3. Phillips GE. Jefferson A. Acute spinal epidural abscess: observations from fourteen cases. Postgrad Med J 1979;55:712-5. 4. Hakin RN. Burt AA, Cook JB. Acute spinal epidural abscess. Paraplegia 1979; 17:330-6. 5. Russell NA, Vaughan R. Morley TP. Spinal epidural infection. Can J Neurol Sci 1979;6:325-8. 6. Kaufman DM, Kaplan JG. Litman N. Infectious agents in spinal epidural abscesses. Neurology 1980;30:844-50. 7. Ravicovitch MA. Spallone A. Spinal epidural abscesses: surgical and parasurgical management. Eur NeuroI1982;21:347-57. 8. Yang SY. Spinal epidural abscess. N Z Med J 1982;95:302-4. 9. Leys D. Lesoin F. Destee A. Jomin M. Christiaens JL. Warot P. Les epidurites aigues a germes banals: vingt-trois observations. Presse Med 1984; 13:597-9. 10. Lasker BR. Harter DH. Cervical epidural abscess. Neurology 1987;37: 1747-53. II. Danner RL. Hartman BJ. Update of spinal epidural abscess: 35 cases and review of the literature. Rev Infect Dis 1987;9:265-74. 12. Koppel BS, Tuchman AJ. Mangiardi JR, Daras M. Weitzner I. Epidural spinal infection in intravenous drug abusers. Arch Neurol 1988;45: 1331-7. 13. Hlavin ML Kaminski HJ, Ross JS. Ganz E. Spinal epidural abscess: a ten-year perspective. Neurosurgery 1990;27: 177-84. 14. Del Curling 0 Jr. Gower DJ, McWhorter JM. Changing concepts in spinal epidural abscess: a report of 29 cases. Neurosurgery 1990;27: 185-92. 15. Ericsson M. Algers G. Schliamser SE. Spinal epidural abscesses in adults: review and report of iatrogenic cases. Scand J Infect Dis 1990;22:249-57. 16. Mampalam TJ, Rosegay H. Andrews BT. Rosenblum ML Pitts LH. Nonoperative treatment ofspinal epidural infections. J Neurosurgery 1989;71 :208-1 O. 17. Leys D, Lesoin F. Viaud C, et al. Decreased morbidity from acute bacterial spinal epidural abscesses using computed tomography and nonsurgical treatment in selected patients. Ann Neurol 1985; 17:350-5. 18. Erntell M. Holtas S. Norlin K. Dahlquist E, Nilsson-Ehle I. Magnetic resonance imaging in the diagnosis of spinal epidural abscess. Scand J Infect Dis 1988;20:323-7. 19. Messer HD. Lenchner GS, Brust JCM, Resor S. Lumbar spinal abscess managed conservatively: case report. J Neurosurg 1977;46:825-9. 20. Bouchez B, Arnott G, Delfosse JM. Acute spinal epidural abscess. J Neurol 1985;231:343-4. 21. Stewart IC Ford MJ. Heading RC Mendelow AD, Harris P. Acute spinal epidural abscess-a cause of meningism. Scott Med J 1981 ;26:348-9. 22. Heusner AP. Nontuberculous spinal epidural infections. N Engl J Med 1948;239:845-54. 23. Grant Fe. Epidural spinal abscess. JAMA 1945; 128:509-12. 24. Hulme A. Dott NM. Spinal epidural abscess. BMJ 1954; I:64-8. 25. Dus V. Spinal peripachymeningitis (epidural abscess): report of 8 cases. J Neurosurg 1960; 17:972-83.
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indication for myelography and subsequent surgery, whereas Leys et al. [17] described management based on findings on CT, making invasive studies unnecessary. Use of MRI in more recent studies has allowed serial evaluation of the size of an epidural abscess with resolution that is equal to that of myelographic imaging and has permitted imaging of inflammation in the disks and paraspinal tissues [18]. To date, there is no consensus in the published literature in regard to nonsurgical approaches to the management of spinal epidural abscess. There are examples of commentary in the neurosurgical literature that call for more liberal use of nonsurgical therapy [14] and from infectious disease specialists who maintain that surgical intervention is the treatment of choice [II]. There will continue to be tremendous temptation on the part of clinicians to treat the patient with a spinal epidural abscess conservatively when there is no neurological dysfunction, the abscess is clearly defined by MRI, the etiologic organism has been identified, and relative contraindications to surgery exist. Undoubtedly, reports such as ours will continue to surface in which this management strategy is successful. Unfortunately, case series ofspinal epidural abscess probably will also be published that include patients for whom this nonsurgical approach does not work. Factors that may have contributed to the successful nonsurgical treatment of our patient include the etiologic organism (s. constellatus), drainage of the extension of the psoas muscle abscess, use of two synergistic antibiotics, and treatment for 12 weeks with periodic assessment by MRI. The current published literature does not support the widespread use of nonsurgical therapy for spinal epidural abscess. Our analysis of 38 reported cases indicates that conservative management indeed appears to be unsuccessful for patients who present with paralysis or septic shock. However, for the remaining patients, the determination of whether surgical therapy is warranted requires that a prospective study be done; this study must have clearly defined indications for surgical or conservative management and must be studied with an intention-to-treat analysis.
27
Medical Management of Spinal Epidural Abscesses: Case Report and Review David Wheeler, Philip Keiser, Daniele Rigamonti, and Susan Keay
From the Division of Infectious Diseases. Department of Medicine. and the Department ofNeurologic Surgery, University ofMaryland Medical Center. and the Department of Veterans Affairs Medical Center, Baltimore. Maryland
The traditionally accepted management of a spinal epidural abscess involves neurological and radiographic staging of the lesion, surgical drainage, identification of the infecting organism, and antibiotic therapy. Before the availability of computerized radiographic imaging, surgery was performed based on neurological and/or myelographic findings. Drainage of the abscess provided neurological decompression as well as a microbiological diagnosis. Because of the development of computed tomography (CT) and magnetic resonance imaging (MRI), the diagnosis of spinal epidural abscess is now possible before the onset of spinal cord compression or neurological dysfunction. For editorial comment see page 28. Reports have appeared in the literature that describe a conservative approach to the treatment of a spinal epidural abscess, and some authors have advocated nonsurgical management in certain clinical settings, particularly for the patient with limited neurological dysfunction. We describe a case of an extensive spinal epidural abscess that involved the anterior cervical, thoracic, and lumbar spine, thus precluding effective surgical drainage, and that
Received 25 November 1991; revised 28 February 1992. The case reported herein will also be included as one of eight cases reported in the article entitled "Spinal Epidural Abscess with Gadolinium Enhanced MRI: Serial Follow-up Studies and Clinical Correlations" by N. Sadato et al. in Neuroradiologv (in press). Reprints or correspondence: Dr. David Wheeler, Division of Infectious Diseases. University of Maryland Hospital, Box 243, 22 South Greene Street, Baltimore, Maryland 2120 I.
Clinical Infectious Diseases 1992;15:22-7 © 1992 by The University of Chicago. All rights reserved. 1058-4838/92/1501-0004$02.00
was successfully managed nonsurgically; no neurological sequelae were reported, and an apparent clinical and radiographic resolution of the infection occurred. We also review the literature and summarize the experience with nonsurgical management of spinal epidural abscesses that has been previously reported.
Case Report A 51-year-old diabetic man who was previously in good health presented to another hospital with lumbar and cervical pain and fever. He was awake and alert but had mild weakness noted in both lower extremities. CT of the spine revealed disease of lumbar disks and compression of nerve roots. A lumbar puncture at the L4-5 interspace yielded puslike material with a white blood cell (WBC) count of 4,500/ mrrr', a protein level of 3,400 mg/dL, and a glucose level of 71 mg/dl.; gram stain of the fluid revealed gram-positive cocci. The patient received a 10-day course of therapy with iv vancomycin; ceftazidime was added to the therapeutic regimen before he was transferred to the University of Maryland Medical Center. The patient's medical history was significant for only adult-onset diabetes mellitus, hypertension, and undocumented rheumatic fever. He denied illicit iv drug use. Two months before admission, he underwent dental manipulation, for which no antibiotic prophylaxis was given. On physical examination, the patient was awake, alert, and cooperative. There was moderate nuchal rigidity and decreased lateral mobility of the neck. A grade 1/6 systolic ejection murmur was heard over the left lower sternal border. Findings of the neurological examination were normal. The peripheral WBC count was 32.5/mm 3 , the serum
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Although the traditional management of spinal epidural abscesses includes antibiotic therapy and surgical drainage, numerous reports have appeared in the literature that describe a nonsurgical approach. We report the successful nonsurgical management of a case of an extensive spinal epidural abscess in which the patient was closely monitored by serial studies with magnetic resonance imaging. Review of the literature from 1970 to 1990 revealed 37 cases that describe conservative management of spinal epidural abscesses. Despite successful conservative management reported for some cases, sudden neurological deterioration of patients receiving appropriate antibiotic therapy has also occurred. A true index of the success of nonsurgical therapy is difficult to discern since cases may have been selectively reported and unsuccessful attempts at conservative management may have never been reported once a laminectomy was performed. A prospective investigation that includes clearly defined indications for conservative management vs. surgical intervention and that can be studied with an intention-to-treat analysis is needed.
CIO 1992;15 (July)
Medical Management of Epidural Abscesses
Methods Literature review. The National Library of Medicine's MEDLINE service was used in the review of the English- and foreign-language literature for cases of pyogenic spinal epidural abscess. Cases that were originally published in a foreign language but subsequently described in the English-language literature were also reviewed. All case series published be-
tween 1970 and 1990 were carefully reviewed for reports of cases managed conservatively, i.e., those managed without laminectomy or other surgical procedure or in which the only intervention was diagnostic needle aspiration. In addition to case series, all individual cases reported between 1970 and 1990 that described the nonsurgical management of spinal epidural abscess were included. Data analysis. Each case was reviewed for the patient's age, sex, presentation, location of abscess, infecting organism, reasons for medical management, and outcome. On the basis of clinical presentation, each case was placed into one of the following categories: (I) back pain; (2) radicular back pain; (3) incomplete neurological symptoms. such as weakness, paresthesias, or urinary or fecal incontinence; (4) paraplegia; and (5) overt sepsis. Each case was also classified according to the following ultimate outcomes: ( 1) total recovery, (2) partial recovery, (3) no improvement, (4) worsening, and (5) death. The results of the classification based on presenting symptoms were then compared with those based on outcome.
Results Fifteen retrospective case series of epidural abscess were published between 1970 and 1990 [I-15]. Of these case series. seven included a total of 25 cases that were managed without surgical intervention [2, 5, 6, 9. II, 12, 15]. Three small case series of epidural abscess treated nonsurgically [16-18] as well as several individual reports [19-21] provided an additional 17 cases for this review. Since no information was reported for the five patients who received nonsurgical management in the case series of Baker et al. [2], these patients were excluded from further consideration. The remaining cases (including our case report) provide a total of 38 for analysis; these are presented in table I. The sex of 23 of the patients was reported; there were 17 men and 6 women. The average age of the patients was 51 years (range, 18-81 years). Sixteen patients had some reported associated illness or other predisposing condition for an epidural abscess. Five patients had a history of spinal injury or surgery, five were iv drug abusers, one had a pleural empyema, three had bacteremia caused by Staphylococcus aureus. and two had overwhelming sepsis. Four had associated conditions that could not be directly related to an epidural abscess, including glomerular nephritis, colonic cancer, sciatica, and cirrhosis. The clinical presentations of the cases were varied. ranging from back pain to paraplegia and sepsis. Of the 34 cases in which presentation was reported, eight patients had localized back pain; three had radicular pain; 15 had signs of incomplete spinal cord impingement, such as weakness, sensory loss, or bladder dysfunction; and seven had paraplegia or quadriplegia. One patient presented with confusion but no neurological deficit.
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glucose level was 264 mg/dL, and the creatinine clearance was normal; results of a urinalysis were unremarkable. Cervical myelography was performed at the C 1-2 level and clear CSF was withdrawn. Analysis of the CSF revealed 2 red blood cells/nun", 58 WBCs/mm 3 (68% lymphocytes, 28% polymorphonuclear neutrophils, and 4 monocytes), a glucose level of 138 mg/dL, and a total protein level of 32 mg/ dL. A block at C2-4 was revealed by injection of contrast medium, and no contrast was noted below this level. CT / myleography demonstrated a low-density area, suggestive of an epidural abscess, anterior to the thecal sac at C2-4. MRI of the spine confirmed the presence of an epidural abscess anterior to the thecal sac and demonstrated that it extended from the upper cervical to the lower lumbar spine with compression at C-2 and a posterior fluid collection at L4-5. Additional fluid collections were also noted in the left psoas and paraspinal muscles with connection to the epidural space via the L4-5 neural foramen. The patient was initially treated with iv vancomycin, nafcillin, and amikacin. Cultures of blood and lumbar epidural fluid (specimens were collected at the first hospital) yielded an a-hemolytic streptococcus. Because he also had an abscess of the psoas muscle, antibiotic therapy was changed to penicillin, metronidazole, and gentamicin. Echocardiography revealed a moderately calcified aortic valve with no visible vegetations. Given the extent of the spinal epidural collection and the normal findings of the neurological examination, the patient underwent drainage of the paraspinal fluid collection only. Culture of the abscess fluid yielded a pure growth of Streptococcus constellatus that was sensitive to penicillin, ampicillin, and vancomycin. Metronidazole therapy was discontinued after 10 days. Serial studies with MRI of his spine revealed a slight decrease in the size of the anterior lumbar collection after I week of treatment at our hospital, and by 3 weeks the cervical collection and the posterior lumbar collection were also notably diminished. The patient was discharged from the hospital and continued to receive iv penicillin and gentamicin; he received a total of 12 weeks ofiv therapy. At 10 weeks, the patient was asymptomatic, findings of his neurological examination remained normal, and MRI of the spine revealed no abnormalities. The patient was evaluated 12 weeks later and had no recurrence of fever or other symptoms suggestive of a relapse of the epidural infection.
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Table 1. Summary of cases of spinal epidural abscess treated nonsurgically (1970-1990).
I I 6
Not reported Not reported Not reported Not reported Not reported Not reported Not reported Not reported S. aureus bacteremia
Paraplegia Not reported Weakness Weakness Weakness Weakness Paraplegia Paraplegia Back pain
Not reported Not reported Not reported Not reported Not reported Not reported Not reported Not reported L1-2
IVDA/endocarditis
Radicular pain
C7-TI
S. aureus bacteremia Overwhelming sepsis Overwhelming sepsis S. aureus bacteremia Not reported Not reported Glomerular nephritis
Back pain Not reported Not reported Leg weakness Radicular pain Paraplegia Radicular pain
TIO-II Not reported Not reported L-5 T8-9 T2-3 L2-3
Neck trauma Neck fracture Back trauma IVDA Pleural empyema None IVDA Back trauma IVDA Cirrhosis
C6-TI LI-3 T6-8 Lumbar Cervical/lumbar Cervical Lumbar Thoracic Cervical T10-S2 T10-S2
None None
Not reported Confusion Paraplegia Pain Pain Pain Pain Pain Pain Urinary incontinence/ sensory loss Pain/urinary incontinence Weakness/decreased reflexes Decreased reflexes/ loss of sphincter tone Leg weakness Quadraplegia
Refused surgery Not reported Minor neurological signs Poor health Minor neurological signs Extensive abscess Complete paraplegia Complete paraplegia Improved while receiving antibiotic therapy Improved while receiving antibiotic therapy Poor medical condition Sepsis Sepsis Not reported Not reported Missed diagnosis Improved while receiving antibiotic therapy Not reported No neurological deficit Missed diagnosis Minor neurological signs Minor neurological signs Minor neurological signs Minor neurological signs Minor neurological signs Minor neurological signs Poor medical condition
Sciatica [17] [19]
Not reported IVDA
[2 I)
None
[20]
Not reported
[PR]
None
[5] [6] [9]
[I I]
5
[12]
4
[15]
3
[16]
6
[17]
4
None Cancer of the sigmoid colon Disk surgery
[18]
NOTE. report.
3
Diagnostic technique
Outcome Paraplegia Not reported Recovered Recovered Recovered Recovered No change No change Recovered
Not reported Not reported
Recovered
Myelography
Recovered Died Died No change No change No change Recovered
Myelography Autopsy Autopsy CT CT CT CT Not reported Myelography Biopsy CT /myelography CT /rnyelography CT /myelography CT /rnyelography CT/myelography CT /myelography CT
Minor neurological signs
Improved Recovered Paraplegia Recovered Persistent diskitis Recovered Recovered Recovered Recovered Residual sensory deficit Recovered
T4-L5
Poor medical condition
Recovered
CT
L4-5
Minor neurological signs
Recovered
CT
C2-5 C3-5
Not reported Paresis> 18 h
MRI MRI
Decreased reflexes
L2-sacrum
Paraplegia Weakness/urinary symptoms Weakness/sensory loss Transient arm weakness Leg weakness
Not reported L-4
Drainage considered hazardous Not reported Poor medical condition
Recovered Slight regression of paresis in arms Residual leg weakness Recovered Recovered
LP Myelography
Cervical to lumbar C3-5
Extensive abscess
Recovered
Myelography
Minor neurological signs
Recovered
CT
Cervical to lumbar
Extent of abscess
Recovered
MRI
Myelography/LP Myelography/LP Myelography/LP Myelography/LP Myelography/LP Myelography/LP Myelography
CT
MRI
LP = lumbar puncture; IVDA = intravenous drug abuse; CT = computed tomography; MRI = magnetic resonance imaging; and PR = present
An infecting organism was identified in 24 cases. The organism was isolated from the abscess in 10 cases, and a presumptive diagnosis was made on the basis of results of blood cultures alone in 14. S. aureus was cultured in 19 cases, Streptococcus organisms in three (Streptococcus sanguis, S. constellatus, and a viridans streptococcus), Escherichia coli in one, and a Proteus species in one. Two additional patients
had presentations consistent with overwhelming bacterial sepsis and died shortly after admission; in each case autopsy revealed an epidural abscess. The location of the abscess was reported in 27 of the 38 cases. In 20 of the 27 cases, the abscess was reported to involve multiple vertebrae. While 13 of these multilevel abscesses were confined to two or three vertebrae, three were
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Associated conditions
Presentation
Location of abscess
Reason for medial management
No. of cases
[Reference]
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Medical Management of Epidural Abscesses
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Table 2. Presentation of spinal epidural abscess vs. outcome. No. of patients with indicated outcome Presentation
Died
Localized back pain Radicular pain Incomplete neurological deficit* Paraplegia Clinical syndrome consistent with bacterial sepsis
Worsened
No change
Improved
Recovered
I
7 2 12
5
I
I
I
2
NOTE. Clinical information was available for only 35 of the 38 patients. * Such as sensory loss, weakness, or bowel or bladder dysfunction.
Discussion A pyogenic spinal epidural abscess is a bacterial infection in the epidural space that results in the accumulation ofpuru-
lent fluid or infected granulation tissue. The thoracic spine is reportedly involved in 31%-63% ofcases, the lumbar spine in 21%-44%, and the cervical spine in 14%-26% [2, 5,6, 11, 13]. S. aureus is the etiologic organism most commonly isolated. Reviews from the United States before the availability of antibiotics [22] and from developing countries [8] have revealed isolation rates for S. aureus approaching 100%. While it is still the most common organism isolated, recent reviews in the United States have shown that S. aureus is implicated in only 45%-62% of cases of spinal epidural abscess [11, 13, 14]. Other common organisms include streptococci, Staphylococcus epidermidis, and aerobic gram-negative rods [II]. Incidence rates of --0.2-1.2 cases/ 10,000 hospital admissions were described in both the preantibiotic and the postantibiotic eras [2, 22]; however, recent reviews have cited higher incidence rates of up to 1.96-2.8 casesjlO,OOO hospital admissions [II, 13]. Blunt trauma has been purported to contribute to the formation of spinal epidural abscesses in 17%-30% of cases [2, 11, 22]. According to recent reviews, a localized source for the infecting organism-including the skin, urinary tract, lower respiratory tract, and site of invasive spinal procedures-can be identified in 71%-78% of cases [I I, I 3]. An individual with a spinal epidural abscess usually presents with back pain, localized tenderness, and fever. The presence of radicular pain or a neurological deficit necessitates an emergent diagnostic evaluation. Traditionally, radiography followed by lumbar puncture and myelography were the diagnostic procedures of choice [2, 11]. When CT became available, high resolution CT or CT /myelography provided better anatomical detail [17]. MRI is now the diagnostic procedure of choice in most instances and does not require the intrathecal injection of contrast material [13,
14, 18]. Various authors have used clinical and pathological criteria to classify spinal epidural abscesses as acute or chronic. As defined by some investigators, an acute abscess is one for which symptoms have been present for < 14-16 days and a chronic abscess is one for which symptoms have been present for a longer period [II, 13]. According to other authors, an acute abscess is one in which there is a predominance of
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extensive, stretching from the cervical to the lumbar spine. Eight abscesses were confined to the lumbar area, while five each were exclusively in the cervical or thoracic spine. The reasons for medical management were reported for 32 patients. Twelve patients were reported to have had minor neurological signs and were observed while they were receiving antibiotics, six had surgery deferred because of underlying medical conditions and were considered to be poor surgical candidates, three had epidural abscesses that were so extensive that laminectomy required to drain the abscesses would have potentially destabilized the spinal column, and three had paraplegia that was thought to be irreversible. Three patients had a diagnosis of epidural abscess after their neurological function had improved while receiving antibiotics, two died ofoverwhelming sepsis before the diagnosis of epidural abscess was made, one refused surgery, and two had an incorrect diagnosis until after they were neurologically stable. Outcome after medical management of the spinal epidural abscesses was reported in 37 ofthe 38 cases. Twenty-three of the patients recovered completely, two died, one worsened, and the rest either remained the same or improved. Outcome was compared with presentation (table 2). Those patients who presented with localized pain or with radicular pain were more likely to have improvement or total recovery than those who were paraplegics or in septic shock. Patients with incomplete neurological symptoms, however, did surprisingly well. Twelve of 15 patients with partial neurological symptoms recovered and only one worsened. Five of these 12 patients were managed conservatively because they were believed to have only minor neurological signs. Surgery was deferred for the other seven patients because they either were considered to be poor surgical candidates or had extensive epidural abscesses. Because the etiologic organism was reported for only 63% of the cases and because S. aureus was the organism identified in 79% of those, an analysis of outcome based on etiologic organisms did not reveal any trends.
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Wheeler et at.
nonsurgical management of spinal epidural abscess; these indications were "poor surgical candidates," "considerable length of the vertebral canal," "patients not suffering severe loss ofspinal cord or cauda equina function," and "complete paralysis for more than 3 days." In 1990 two case series of spinal epidural abscess were published together in the neurosurgical literature in which none of the patients were managed conservatively [13, 14]. Nonetheless, an editorial commentary questioned whether some of the cases managed surgically could have been managed nonsurgically. The author of the commentary went on to suggest that "cases without significant neural compression can be successfully managed with appropriate antimicrobial therapy if the causative organism is cultured" and suggested that "surgery is warranted only if there is: neural compression from mass effect, spinal instability and deformity, or failure to obtain a satisfactory culture ofthe infectious organism" [14]. In light of the fact that nonsurgical management has been shown to be successful in selected cases and that certain practitioners and authors are advocating this approach for patients who are otherwise surgical candidates, it is important to determine whether published literature on the subject would support this approach. Several factors need to be considered in the analysis of the data from these case series. Isolated case reports may reflect success for selected patients, but they may not reflect success in all or even many of the cases that were managed in this fashion. Case series, in which all cases of spinal epidural abscess are included, give a better indication of the success or failure of medical management in a given institution. However, cases may have been reported as surgically managed when, in fact, the patients underwent surgery after nonsurgical management had failed. Danner and Hartman [11] and Hlavin et al. [13] described six and eight cases, respectively, in which emergent laminectomy was required because of'neurological deterioration while the patients were receiving appropriate antibiotic therapy. None ofthe case series were prospectively designed; therefore, intention-to-treat analysis is difficult. Analysis of these cases is also hampered by the fact that (1) diagnosis was made in many of these cases after the patient responded to empirical therapy or that (2) the cases represented instances in which surgery was not an option (either because of medical complications or, as in our case, because the extent of the abscess was so great). Reporting bias is also likely, depending on the group reporting the cases. Some case series described all patients admitted to a hospital [2], while other case series included only those patients referred to a neurosurgical service [14] or to a spinal cord unit [1]. Comparison of all cases from 1970 to 1990 is also difficult since the technology available for the diagnosis of spinal epidural abscess advanced considerably during this period. Heusner [22] relied on subtle neurological dysfunction as an
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purulent material (found during surgical drainage) and a chronic abscess is one that consists of organized granulation tissue [5, 7]. There is not always, however, a close correlation between chronicity of symptoms and the finding of granulation tissue at surgery [13, 14]. Concomitant vertebral osteomyelitis has also been described in -- 35%- 38% of cases of spinal epidural abscess [2, 22]. Complications from pyogenic spinal epidural abscess include a substantial risk of permanent neurological dysfunction. In addition to risk of direct compression of the spinal cord or nerve roots, there may be neurological deterioration caused by vascular compromise ofthe intrinsic circulation to the spinal cord. Neurological deterioration may be sudden and has been described in patients who have received as much as 4 weeks of appropriate antibiotic therapy [13]. Whether sudden vascular thrombosis was responsible for this phenomenon has been debated. In 1948 Heusner [22] described the clinical presentation, treatment, and outcome of spinal epidural abscesses seen at Boston City Hospital, including cases from both before and after the antibiotic era. Heusner's description of the clinical staging of the disease has been referenced in most subsequent literature on epidural abscess. This clinical staging includes four phases through which most patients progress: spinal ache (I), nerve root pain (II), radicular weakness (III), and paralysis (IV). All ofHeusner's cases were managed with laminectomy, although he observed an increased survival rate among patients treated after the availability of sulfonamides and penicillin. References to successful conservative management in previous literature [23] were dismissed by Heusner as probable misdiagnoses, and he stated that the "conception of nonoperative management is mentioned only to be condemned, notwithstanding a recent suggestion that penicillin might sometimes obviate the need for surgery." Two case series published thereafter [24,25] reiterated the need for aggressive surgical intervention and antibiotics. Using historical control data, Dus [25] concluded that successful intervention depends on early diagnosis and surgery combined with antibiotic treatment. In 1975, in a comprehensive review from Massachusetts General Hospital, Baker et al. [2] reported 39 cases of spinal epidural abscess that had been seen between 1947 and 1974. Of 34 patients who underwent surgery, 23 completely recovered, five had residual weakness, and six had paralysis or died. All five patients whose cases were managed without surgery died. Despite such admonitions, 6.6%of the patients in the case series published between 1970 and 1990 received nonsurgical therapy; for 63% of these patients, symptoms abated or disease resolved. Successful nonsurgical management of patients has prompted several authors to suggest this method as an alternative to surgery in some circumstances [16, 17, 19, 20]. Leys et al. [17] proposed a list of four indications for the
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Medical Management of Epidural Abscesses
References I. Hancock DO. A study of ~9 patients with acute spinal extradural abscess. Paraplegia 1973; I0:285-8.
2. Baker AS. Ojemann RG. Swartz MN. Richardson EP Jr. Spinal epidural abscess. N Engl J Med 1975;293:463-8. 3. Phillips GE. Jefferson A. Acute spinal epidural abscess: observations from fourteen cases. Postgrad Med J 1979;55:712-5. 4. Hakin RN. Burt AA, Cook JB. Acute spinal epidural abscess. Paraplegia 1979; 17:330-6. 5. Russell NA, Vaughan R. Morley TP. Spinal epidural infection. Can J Neurol Sci 1979;6:325-8. 6. Kaufman DM, Kaplan JG. Litman N. Infectious agents in spinal epidural abscesses. Neurology 1980;30:844-50. 7. Ravicovitch MA. Spallone A. Spinal epidural abscesses: surgical and parasurgical management. Eur NeuroI1982;21:347-57. 8. Yang SY. Spinal epidural abscess. N Z Med J 1982;95:302-4. 9. Leys D. Lesoin F. Destee A. Jomin M. Christiaens JL. Warot P. Les epidurites aigues a germes banals: vingt-trois observations. Presse Med 1984; 13:597-9. 10. Lasker BR. Harter DH. Cervical epidural abscess. Neurology 1987;37: 1747-53. II. Danner RL. Hartman BJ. Update of spinal epidural abscess: 35 cases and review of the literature. Rev Infect Dis 1987;9:265-74. 12. Koppel BS, Tuchman AJ. Mangiardi JR, Daras M. Weitzner I. Epidural spinal infection in intravenous drug abusers. Arch Neurol 1988;45: 1331-7. 13. Hlavin ML Kaminski HJ, Ross JS. Ganz E. Spinal epidural abscess: a ten-year perspective. Neurosurgery 1990;27: 177-84. 14. Del Curling 0 Jr. Gower DJ, McWhorter JM. Changing concepts in spinal epidural abscess: a report of 29 cases. Neurosurgery 1990;27: 185-92. 15. Ericsson M. Algers G. Schliamser SE. Spinal epidural abscesses in adults: review and report of iatrogenic cases. Scand J Infect Dis 1990;22:249-57. 16. Mampalam TJ, Rosegay H. Andrews BT. Rosenblum ML Pitts LH. Nonoperative treatment ofspinal epidural infections. J Neurosurgery 1989;71 :208-1 O. 17. Leys D, Lesoin F. Viaud C, et al. Decreased morbidity from acute bacterial spinal epidural abscesses using computed tomography and nonsurgical treatment in selected patients. Ann Neurol 1985; 17:350-5. 18. Erntell M. Holtas S. Norlin K. Dahlquist E, Nilsson-Ehle I. Magnetic resonance imaging in the diagnosis of spinal epidural abscess. Scand J Infect Dis 1988;20:323-7. 19. Messer HD. Lenchner GS, Brust JCM, Resor S. Lumbar spinal abscess managed conservatively: case report. J Neurosurg 1977;46:825-9. 20. Bouchez B, Arnott G, Delfosse JM. Acute spinal epidural abscess. J Neurol 1985;231:343-4. 21. Stewart IC Ford MJ. Heading RC Mendelow AD, Harris P. Acute spinal epidural abscess-a cause of meningism. Scott Med J 1981 ;26:348-9. 22. Heusner AP. Nontuberculous spinal epidural infections. N Engl J Med 1948;239:845-54. 23. Grant Fe. Epidural spinal abscess. JAMA 1945; 128:509-12. 24. Hulme A. Dott NM. Spinal epidural abscess. BMJ 1954; I:64-8. 25. Dus V. Spinal peripachymeningitis (epidural abscess): report of 8 cases. J Neurosurg 1960; 17:972-83.
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indication for myelography and subsequent surgery, whereas Leys et al. [17] described management based on findings on CT, making invasive studies unnecessary. Use of MRI in more recent studies has allowed serial evaluation of the size of an epidural abscess with resolution that is equal to that of myelographic imaging and has permitted imaging of inflammation in the disks and paraspinal tissues [18]. To date, there is no consensus in the published literature in regard to nonsurgical approaches to the management of spinal epidural abscess. There are examples of commentary in the neurosurgical literature that call for more liberal use of nonsurgical therapy [14] and from infectious disease specialists who maintain that surgical intervention is the treatment of choice [II]. There will continue to be tremendous temptation on the part of clinicians to treat the patient with a spinal epidural abscess conservatively when there is no neurological dysfunction, the abscess is clearly defined by MRI, the etiologic organism has been identified, and relative contraindications to surgery exist. Undoubtedly, reports such as ours will continue to surface in which this management strategy is successful. Unfortunately, case series ofspinal epidural abscess probably will also be published that include patients for whom this nonsurgical approach does not work. Factors that may have contributed to the successful nonsurgical treatment of our patient include the etiologic organism (s. constellatus), drainage of the extension of the psoas muscle abscess, use of two synergistic antibiotics, and treatment for 12 weeks with periodic assessment by MRI. The current published literature does not support the widespread use of nonsurgical therapy for spinal epidural abscess. Our analysis of 38 reported cases indicates that conservative management indeed appears to be unsuccessful for patients who present with paralysis or septic shock. However, for the remaining patients, the determination of whether surgical therapy is warranted requires that a prospective study be done; this study must have clearly defined indications for surgical or conservative management and must be studied with an intention-to-treat analysis.
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