[Backache as the initial symptom of adrenomyeloneuropathy]

Adrenoleukodystrophy is a paroxysmal disorder, with recessive linking to the X chromosome, characterized biochemically by the accumulation of extra-long-chain fatty acids. Six phenotypes are distinguished: pre-symptomatic, infantile, adolescent and adult cerebral forms, adrenomyeloneuropathy and isolated Addison's disease. We describe a patient with adrenomyeloneuropathy in whom the presenting symptom was lumbago.

A 23 year old man with no significant previous clinical history complained of having lumbago for over two years. On examination he had pyramidal signs and reduced epicritic sensitivity of the legs. Laboratory investigations showed adrenal failure, increased plasma extra-long-chain fatty acids concentration, mononuclear cells and fibroblasts. On MR there was a hyperintense lesion of the genu of the corpus callosum. SSEP were pathological while the electroneurogram showed bilateral increase in latency of the F wave. The patient was diagnosed as having adrenomyeloneuropathy and treatment started with hydrocortisone, a diet low in extra-long-chain fatty acids and 'Lorenzo's oil'. The lumbago gradually disappeared while the plasma extra-long-chain fatty acids concentration dropped. The oil was stopped because of moderate thrombocytopenia, and treatment was started with lovastatin 40 mg/day. Two years later the patient has no lumbago and is neurologically stable.

The lumbago associated with adrenomyeloneuropathy is probably due to demyelination of the spinal tracts. Although lumbago is usually a benign condition, a careful history and examination is necessary in all such cases.