[Adrenomyeloneuropathy as a cause of Addison's disease]

A 25-year old male, with a 3-year history of spastic paraparesis and a disturbance of bladder emptying, developed Addison's disease (plasma ACTH 1250 pg/ml, depressed cortisol values with loss of diurnal rhythm, potassium 6.8 mmol/l, sodium 123 mmol/l) associated with a urinary tract infection. The suspected diagnosis of adrenomyeloneuropathy was confirmed by the finding of raised plasma long-chain fatty acid concentrations. The patient was immediately given 0.4 mg fludrocortisone as a bolus, followed by 0.1 mg daily maintenance therapy, the urinary tract infection having already been successfully treated. Substitution therapy with hydrocortisone was also initiated (starting dose 30-20-10 mg daily, maintainance dose 20-10-5 mg daily). As a result, the electrolyte concentrations returned to normal and the neurological features improved. A family study was undertaken to determine whether the adrenomyeloneuropathy was an X-linked recessive form. Both the symptom-free mother (carrier) and the 19-year-old brother, who had suffered from Addison's disease since the third year of life, had raised plasma long-chain fatty acid concentrations. Both brothers were started on a diet low in long-chain fatty acids. Estimation of long-chain fatty acids is indicated in boys or young adult males with peripheral neuropathy or Addison's disease of uncertain aetiology.