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205
CASE LETTERS
patient. The focus was on sepsis and psychotropic drug poisoning as potential diagnoses. Failure to consider other causes of high anion gap metabolic acidosis resulted in a delay to diagnosis of iron poisoning. Clinicians should be aware that when intoxication is suspected in the presence of metabolic acidaemia, a systematic rule out of MUDPILES toxicants should be undertaken.
Author contributions JMW: first draft of the manuscript and literature search. MS: supervision manuscript preparation. JGZ: final draft of the manuscript.
Competing interests None declared.
References 1. Kroeker S, Minuk GY. Intentional iron overdose – an institutional review. CMAJ 1994; 150: 45–8. 2. Reynolds LG. Diagnosis and management of acute iron poisoning. Baillieres Clin. Haematol. 1989; 2: 423–33. 3. Tenenbein M. Toxicokinetics and toxicodynamics of iron poisoning. Toxicol. Lett. 1998; 102–103: 653– 6. 4. Tenenbein M, Kowalski S, Sienko A, Bowden DH, Adamson IY. Pulmonary toxic effects of continuous
desferrioxamine administration in acute iron poisoning. Lancet 1992; 339: 699–701.
Johanna M WOLTERS,1 Marije SMIT2 and Jan G ZIJLSTRA2 1 Department of Emergency Medicine, University Medical Centre Groningen, University of Groningen, Groningen, The Netherlands, and 2Department of Critical Care, University Medical Centre Groningen, University of Groningen, Groningen, The Netherlands doi: 10.1111/1742-6723.12194
Pitfalls of triage by imaging in spinal epidural abscess Dear Editor, Spinal epidural abscess (SEA) is a relatively uncommon disorder, which can cause death or persistent neurological deficit if left untreated.1,2 Manifestations include back pain, fever and neurological symptoms.2 However, these symptoms are non-specific, and misdiagnosis is common.3 The current literature emphasises the need for emergency MRI with gadolinium contrast (Gd-MRI) in suspected SEA. We use a recent case to demonstrate that excessive reliance on this technically difficult study to rule out SEA may lead to inappropriate management, resulting in preventable morbidity. A 40-year-old man was transferred from a peripheral hospital with 4 days of increasing back pain and neurological symptoms. The patient had injected methamphetamines 2 weeks earlier. Specifically, the patient described waking up with severe interscapular pain, which spread over days to the lumbar spine and right arm. He was unable to weight bear and micturate.
On examination, the patient had marked lower limb and mild right arm weakness in a pyramidal tract distribution, increased deep tendon reflexes, bilateral positive Babinski reflexes and thoracic vertebral tenderness. No fevers were documented, but the patient reported night sweats. He had a white cell count of 14.6 × 109 and CRP of 307 mg/L, consistent with an infective process. A Gd-MRI was performed on the day of admission. However, the patient was severely claustrophobic and did not tolerate the scan, despite sedation. Therefore, post contrast views and Short T1 Inversion Recovery sequences were limited to the lumbar spine. The scan was reported as normal. In consequence, further neurosurgical input was not offered. Other diagnoses were then considered, including transverse myelitis and anterior spinal artery stroke. However, the patient was given IV flucloxacillin empirically. The GdMRI was repeated under general anaesthesia 5 days later demonstrating an epidural abscess from C7 to T12,
probably arising from infection at the right T1/2 facet and T2 transverse process (Fig. 1). The next day the patient underwent T1/2 laminectomy and evacuation of the phlegmon. Tissue specimens were positive for methicillin sensitive Staphylococcus aureus. The i.v. flucloxacillin was continued for 6 weeks. The patient was then commenced on oral dicloxacillin, aiming to continue for 3–6 months, depending on progress. On transfer to rehabilitation, although limb weakness remained, he was walking. His bowels were working normally, but he had failed multiple trials without a urinary catheter. Here we describe a patient who presented typically for SEA, where inadequate spinal MRI resulted in delayed diagnosis and treatment. In SEA, patients generally present with severe back pain, fevers and neurological symptoms.1 Neurological symptoms range from paraesthesias, radiculopathy, motor weakness and sphincter dysfunction to severe paraplegia.1–3
© 2014 Australasian College for Emergency Medicine and Australasian Society for Emergency Medicine
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206
CASE LETTERS
a
b
imaging and regular neurological review are essential.6 Clinicians should avoid excessive reliance on a single investigation and remain mindful of the pitfalls of diagnosis of this eminently treatable condition.
Competing interests None declared.
References
Figure 1. (a) Sagittal section from the initial spinal MRI where contrast and STIR sequences were limited to the lumbar region and, as a result, the SEA was missed. (b) Post contrast image from the MRI taken 5 days later, showing SEA (arrow) and associated musculoskeletal changes.
Overall, the clinical presentation of SEA is notoriously variable resulting in diagnostic difficulties. However, prompt diagnosis is paramount, as the severity of neurological signs prior to definitive surgery is the best predictor of neurological recovery.1,4 Unfortunately, misdiagnosis and delayed treatment is the rule resulting in substantial morbidity and mortality.4,5 Papers abound recommending early Gd-MRI for suspected SEA, a study
with >90% sensitivity and specificity.1,2,4 However, emergency MRI often presents logistical difficulties, with poor patient tolerance, the need for monitored sedation, poor staffing after hours and the dependence on targeted sequences with axial contrast enhanced views.2 We reiterate that spinal MRI should never be considered in isolation to rule out SEA. According to expert consensus, if MRI is inconclusive, but high suspicion remains, repeat
1. Tompkins M, Panuncialman I, Lucas P, Palumbo M. Spinal epidural abscess. J. Emerg. Med. 2010; 39: 384– 90. 2. El Sayed M, Witting MD. Low yield of ED magnetic resonance imaging for suspected epidural abscess. Am. J. Emerg. Med. 2011; 29: 978–82. 3. Darouiche RO. Spinal epidural abscess. N. Engl. J. Med. 2006; 355: 2012–20. 4. Joshi SM, Hatfield RH, Martin J, Taylor W. Spinal epidural abscess: a diagnostic challenge. Br. J. Neurosurg. 2003; 17: 160–3. 5. Pilkington SA, Jackson SA, Gillett GR. Spinal epidural empyema. Br. J. Neurosurg. 2003; 17: 196–200. 6. Sendi P, Bregenzer T, Zimmerli W. Spinal epidural abscess in clinical practice. QJM 2008; 101: 1–12.
Kate JOHNSON, Shyamini GUNARATNE and Mohamed SHAFFI Neurology Department, Nepean Hospital, Sydney, New South Wales, Australia doi: 10.1111/1742-6723.12205
TASERed during training: An unusual scapular fracture Dear Editor, A 40-year-old policeman presented with acute-onset, severe left chest and shoulder pain following a training exercise at work during which he was voluntarily TASERed in the left shoulder while lying on the ground. He im-
mediately experienced severe shooting pain radiating down his left arm and left chest discomfort. He was brought to the ED for further investigation. His medical history included an excised melanoma in situ on his left shoulder. He had no regular medica-
tions or known drug allergies. He was a heavily muscled man with an endomorphic body type. On examination he had a small 50 cent-sized area of erythema on his left shoulder blade where the TASER had discharged, but no evidence of deeper skin burn. There
© 2014 Australasian College for Emergency Medicine and Australasian Society for Emergency Medicine
205
CASE LETTERS
patient. The focus was on sepsis and psychotropic drug poisoning as potential diagnoses. Failure to consider other causes of high anion gap metabolic acidosis resulted in a delay to diagnosis of iron poisoning. Clinicians should be aware that when intoxication is suspected in the presence of metabolic acidaemia, a systematic rule out of MUDPILES toxicants should be undertaken.
Author contributions JMW: first draft of the manuscript and literature search. MS: supervision manuscript preparation. JGZ: final draft of the manuscript.
Competing interests None declared.
References 1. Kroeker S, Minuk GY. Intentional iron overdose – an institutional review. CMAJ 1994; 150: 45–8. 2. Reynolds LG. Diagnosis and management of acute iron poisoning. Baillieres Clin. Haematol. 1989; 2: 423–33. 3. Tenenbein M. Toxicokinetics and toxicodynamics of iron poisoning. Toxicol. Lett. 1998; 102–103: 653– 6. 4. Tenenbein M, Kowalski S, Sienko A, Bowden DH, Adamson IY. Pulmonary toxic effects of continuous
desferrioxamine administration in acute iron poisoning. Lancet 1992; 339: 699–701.
Johanna M WOLTERS,1 Marije SMIT2 and Jan G ZIJLSTRA2 1 Department of Emergency Medicine, University Medical Centre Groningen, University of Groningen, Groningen, The Netherlands, and 2Department of Critical Care, University Medical Centre Groningen, University of Groningen, Groningen, The Netherlands doi: 10.1111/1742-6723.12194
Pitfalls of triage by imaging in spinal epidural abscess Dear Editor, Spinal epidural abscess (SEA) is a relatively uncommon disorder, which can cause death or persistent neurological deficit if left untreated.1,2 Manifestations include back pain, fever and neurological symptoms.2 However, these symptoms are non-specific, and misdiagnosis is common.3 The current literature emphasises the need for emergency MRI with gadolinium contrast (Gd-MRI) in suspected SEA. We use a recent case to demonstrate that excessive reliance on this technically difficult study to rule out SEA may lead to inappropriate management, resulting in preventable morbidity. A 40-year-old man was transferred from a peripheral hospital with 4 days of increasing back pain and neurological symptoms. The patient had injected methamphetamines 2 weeks earlier. Specifically, the patient described waking up with severe interscapular pain, which spread over days to the lumbar spine and right arm. He was unable to weight bear and micturate.
On examination, the patient had marked lower limb and mild right arm weakness in a pyramidal tract distribution, increased deep tendon reflexes, bilateral positive Babinski reflexes and thoracic vertebral tenderness. No fevers were documented, but the patient reported night sweats. He had a white cell count of 14.6 × 109 and CRP of 307 mg/L, consistent with an infective process. A Gd-MRI was performed on the day of admission. However, the patient was severely claustrophobic and did not tolerate the scan, despite sedation. Therefore, post contrast views and Short T1 Inversion Recovery sequences were limited to the lumbar spine. The scan was reported as normal. In consequence, further neurosurgical input was not offered. Other diagnoses were then considered, including transverse myelitis and anterior spinal artery stroke. However, the patient was given IV flucloxacillin empirically. The GdMRI was repeated under general anaesthesia 5 days later demonstrating an epidural abscess from C7 to T12,
probably arising from infection at the right T1/2 facet and T2 transverse process (Fig. 1). The next day the patient underwent T1/2 laminectomy and evacuation of the phlegmon. Tissue specimens were positive for methicillin sensitive Staphylococcus aureus. The i.v. flucloxacillin was continued for 6 weeks. The patient was then commenced on oral dicloxacillin, aiming to continue for 3–6 months, depending on progress. On transfer to rehabilitation, although limb weakness remained, he was walking. His bowels were working normally, but he had failed multiple trials without a urinary catheter. Here we describe a patient who presented typically for SEA, where inadequate spinal MRI resulted in delayed diagnosis and treatment. In SEA, patients generally present with severe back pain, fevers and neurological symptoms.1 Neurological symptoms range from paraesthesias, radiculopathy, motor weakness and sphincter dysfunction to severe paraplegia.1–3
© 2014 Australasian College for Emergency Medicine and Australasian Society for Emergency Medicine
bs_bs_banner
206
CASE LETTERS
a
b
imaging and regular neurological review are essential.6 Clinicians should avoid excessive reliance on a single investigation and remain mindful of the pitfalls of diagnosis of this eminently treatable condition.
Competing interests None declared.
References
Figure 1. (a) Sagittal section from the initial spinal MRI where contrast and STIR sequences were limited to the lumbar region and, as a result, the SEA was missed. (b) Post contrast image from the MRI taken 5 days later, showing SEA (arrow) and associated musculoskeletal changes.
Overall, the clinical presentation of SEA is notoriously variable resulting in diagnostic difficulties. However, prompt diagnosis is paramount, as the severity of neurological signs prior to definitive surgery is the best predictor of neurological recovery.1,4 Unfortunately, misdiagnosis and delayed treatment is the rule resulting in substantial morbidity and mortality.4,5 Papers abound recommending early Gd-MRI for suspected SEA, a study
with >90% sensitivity and specificity.1,2,4 However, emergency MRI often presents logistical difficulties, with poor patient tolerance, the need for monitored sedation, poor staffing after hours and the dependence on targeted sequences with axial contrast enhanced views.2 We reiterate that spinal MRI should never be considered in isolation to rule out SEA. According to expert consensus, if MRI is inconclusive, but high suspicion remains, repeat
1. Tompkins M, Panuncialman I, Lucas P, Palumbo M. Spinal epidural abscess. J. Emerg. Med. 2010; 39: 384– 90. 2. El Sayed M, Witting MD. Low yield of ED magnetic resonance imaging for suspected epidural abscess. Am. J. Emerg. Med. 2011; 29: 978–82. 3. Darouiche RO. Spinal epidural abscess. N. Engl. J. Med. 2006; 355: 2012–20. 4. Joshi SM, Hatfield RH, Martin J, Taylor W. Spinal epidural abscess: a diagnostic challenge. Br. J. Neurosurg. 2003; 17: 160–3. 5. Pilkington SA, Jackson SA, Gillett GR. Spinal epidural empyema. Br. J. Neurosurg. 2003; 17: 196–200. 6. Sendi P, Bregenzer T, Zimmerli W. Spinal epidural abscess in clinical practice. QJM 2008; 101: 1–12.
Kate JOHNSON, Shyamini GUNARATNE and Mohamed SHAFFI Neurology Department, Nepean Hospital, Sydney, New South Wales, Australia doi: 10.1111/1742-6723.12205
TASERed during training: An unusual scapular fracture Dear Editor, A 40-year-old policeman presented with acute-onset, severe left chest and shoulder pain following a training exercise at work during which he was voluntarily TASERed in the left shoulder while lying on the ground. He im-
mediately experienced severe shooting pain radiating down his left arm and left chest discomfort. He was brought to the ED for further investigation. His medical history included an excised melanoma in situ on his left shoulder. He had no regular medica-
tions or known drug allergies. He was a heavily muscled man with an endomorphic body type. On examination he had a small 50 cent-sized area of erythema on his left shoulder blade where the TASER had discharged, but no evidence of deeper skin burn. There
© 2014 Australasian College for Emergency Medicine and Australasian Society for Emergency Medicine
