Postgrad Med J 2002;78:377–380 377 Postgrad Med J: first published as 10.1136/pmj.78.920.377-a on 1 June 2002. Downloaded from SELF ASSESSMENT ANSWERS Box 1: Aetiology of rhabdomyolysis • Trauma. Back pain and systemic frank septicaemia or those with gross neuro- logical signs do poorly.4 • Seizures. compromise • Ischaemia. Conclusion • Metabolic defects: glycogenoses, carni- Q1: What is the most likely clinical Spinal epidural abscess remains a clinical tine palmitoyltransferase deficiency. diagnosis? diagnosis. A high index of suspicion and rapid • Drugs: clofibrate, gemfibrozil, epsilon- The triad of back pain/tenderness, neurologi- neurosurgical attention are essential to mini- aminocaproic acid, statins, etretinate, cal deficits, and systemic illness are highly mise mortality and long term morbidity. suggestive of a spinal epidural abscess. high dose steroids. Final diagnosis • Alcohol. Q2: What does the MRI scan show? Lumbar spinal epidural abscess. • Infectious diseases. The MRI scan (see p 373) shows a large • Malignant hyperpyrexia: halothane, en- central disc prolapse at the L4/L5 level. There References flurane, isoflurane, succinylcholine, cal- is also, however, loss of cerebrospinal fluid 1 Calderone RR, Larson JM. Overview and cium channel blockers. signal behind the dura from the first lumbar classification of spinal infections. Orthop Clin • Malignant neuroleptic syndrome. vertebral level caudally, suggestive of a com- North Am 1996;27:1–8. Baker AS • Electrolyte imbalance: hypokalaemia, pressive lesion. 2 , Ojemann RG, Swartz MN, et al. Spinal epidural abscess. N Engl J Med hypomagnesaemia, 1975;293:463–8. hypophosphataemia. Q3: Discuss the management of this 3 Verner EF, Musher DM. Spinal epidural condition abscess. Symposium on infections in the Urgent laminectomy was performed. At opera- central nervous system. Med Clin North Am tion free pus was found in the muscular and 1985;69:375–84. 4 Danner RL, Hartmann BJ. Update of spinal always be considered (many would not neces- fascial layers. There was a large epidural epidural abscess: 35 cases and a review of sarily be relevant in this particular age group), abscess which had caused severe compression the literature. Rev Infect Dis 1987;9:265–74. although such an acute, de novo presentation of the lumbar thecal sac posteriorly. The would be unusual. epidural space was debrided and irrigated. In this particular patient, the aetiological Cultures of the specimens as well as blood cul- A bad dose of ’flu agent was a virus, influenza type B, serological tures revealed a staphylococcal infection. The testing indicating a rising antibody titre to 1 Q1: What is the most likely diagnosis patient was started on high dose intravenous in 320. flucloxacillin, metronidazole, and gentamicin. and how would you confirm it? Postoperatively, he was improved neurologi- The most likely diagnosis is one of acute Q3: What potential complications may cally with near normal power in the lower rhabdomyolysis together with myoglobinuria, occur? limbs bilaterally and normal sensation includ- as demonstrated by the generalised oedema, There are several potential complications. ing an improvement in his perianal sensation. muscle tenderness and weakness, and the Massive rhabdomyolysis may result in electro- His subsequent recovery, however, was compli- brown discoloration of the urine. To confirm lyte imbalance, particularly hyperkalaemia, cated by septicaemia, acute respiratory distress the diagnosis, the urine should be tested for hyperphosphataemia, and hypercalcaemia. syndrome, and disseminated intravascular myoglobin (radioimmunoassay is the best Disseminated intravascular coagulation and coagulation, which were successfully treated. technique) and muscle enzymes should be venous thromboses may also occur. Most seri- measured. ously, severe myoglobinuria may cause renal Discussion In this patient, the urine was positive for damage and anuria. The exact mechanism by The risks of developing an abscess in the spine myoglobin and had an acidic pH of 6.0. Mus- which this occurs is uncertain but hypotheses cle enzymes were grossly raised, with creatine are greater in those with diabetes mellitus, include renal tubular obstruction by precipi- http://pmj.bmj.com/ intravenous drug abuse, tuberculosis, malnu- kinase 30 000 U/l, lactate dehydrogenase 2900 tated myoglobin, reduction in renal blood trition, chronic renal failure, and cancer.1 U/l, and aspartate aminotransferase 710 U/l. flow, and direct toxic injury to the tubular Making the diagnosis of an epidural abscess The differential diagnosis of a patient epithelium. can be difficult. Reliance on imaging alone becoming weak on a background of such a may be misleading since the radiological prodromal illness as that described here Q4: How would you manage this changes, as in this case, may be subtle. would normally include an acute inflamma- patient? Furthermore, the condition may be masked by tory demyelinating polyneuropathy (or In general, good nursing and medical care other more common pathologies. In this case, Guillain-Barré syndrome), but the presence of with close monitoring of electrolyte balance, such oedema and muscle tenderness makes there was a large L4/L5 central disc prolapse, renal function, and urinary output are essen- on September 30, 2021 by guest. Protected copyright. although the neurological deficits were far this an unlikely diagnosis even prior to the tial. More specifically, a high fluid intake and more extensive than that expected from such a biochemical results. alkalinisation of the urine by infusion or disc prolapse. It is therefore important to pay A patient presenting in such a manner in ingestion of sodium bicarbonate helps to pro- careful attention to the clinical findings. the postoperative period would lead to suspi- tect the kidney by preventing the formation of Cardinal features of spinal epidural abscess cion of a diagnosis of malignant hyperther- myoglobin casts. This patient received3gof are fever, spinal tenderness, and neurological mia. This is a rare autosomal dominant condi- sodium bicarbonate, every two hours, by deficit. Pain is the most consistent symptom tion, linked to a mutation in the ryanodine intravenous infusion, until the urine pH was 1 and together with fever often precedes the receptor gene on chromosome 19, in which >7.0. He was also treated with 2 mg/kg of development of hard neurological signs.2 This susceptible individuals are endangered by dantrolene by intravenous infusion, daily for natural history contrasts markedly to that of exposure to certain anaesthetic triggering five days. the acute or chronic degenerative pathologies agents (see box 1). of the spine which tend not to exhibit local tenderness or systemic compromise. Most Q2: What is the possible aetiology of patients are thought to have major neurologi- this condition? Box 2: Infectious agents implicated in cal signs prior to surgery.2 When septicaemia The potential aetiology of rhabdomyolysis is rhabdomyolysis dominates the picture as in this case, the wide (see box 1). In this particular patient neurological symptoms may be missed. This is there would appear to be three main possibili- • Influenza A and B. especially true for those patients who may ties. Firstly given the nature of the prodromal • Coxsackie virus. have been confined to bed for some time and symptoms, any one of a range of infectious • Epstein-Barr virus. therefore not regularly assessed.2 agents could be implicated (see box 2). • Cytomegalovirus. Management includes surgical decompres- Secondly, rhabdomyolysis is well recognised sion, debridement, and broad spectrum anti- as a complication of certain types of drug • Echovirus. microbials. Parenteral treatment should be therapy and this patient had been exposed to • Adenovirus. continued for at least four weeks and may be several agents over the 48 hours immediately • Legionella pneumophila. needed for eight weeks if osteomyelitis is before admission, although not before the • Streptococcus pneumoniae. suspected.34 Prognosis is related to the delay time that he first became unwell. Thirdly, the • HIV. in presentation.24 Patients who present with possibility of a primary muscle disease should www.postgradmedj.com 378 Self assessment answers Postgrad Med J: first published as 10.1136/pmj.78.920.377-a on 1 June 2002. Downloaded from myonecrosis but no viral particles, it is postu- Box 3: Learning points Box 1: Causes of osteolysis lated that the virus releases a circulating toxin or stimulates cytokine release. To date how- • Acute rhabdomyolysis represents a ever, no putative toxins have been identified. Trauma medical and neurological emergency. Dantrolene has been used to beneficial • Reflex sympathetic dystrophy. • Rhabdomyolysis may complicate even effect in rhabdomyolysis arising from malig- usually innocent infections. nant hyperpyrexia, malignant neuroleptic Skin • Psoriasis. • Maintenance of high fluid intake and syndrome, exertion, acute alcoholic intoxica- tion, and both cocaine and ecstasy overdose. It alkalinisation of urine are fundamental Infection is known to decrease the release of calcium • Direct. to preserving renal function. from the sarcoplasmic reticulum.6 Calcium • Intravenous dantrolene is a useful thera- may play a part in muscle pain as has been • Indirect—for example, leprosy. peutic option. suggested in McArdle’s disease and in the Tumour • Patients should be monitored for the development of malignant hyperthermia. • Plasmacytoma. possible development of a compartment Muscle cell necrosis