ANNUAL DISABILITY PROGRESSION IN PURE ADRENOMYELONEUROPATHY PATIENTS

Objectives: Adrenomyeloneuropathy (AMN) is the adult form of XALD and is the most common, encompassing approximately 40% of all patients. It is a non-inflammatory, distal axonopathy that presents at an average age of 28 and affects mainly the long tracts of the spinal cord. Major manifestations are adrenal impairment, varying degrees of difficulty with walking due to spasticity, urinary disturbances and impotence. Our aim is to determine the rate of disability progression in Pure-AMN in the long term follow-up.

Methods: Disease severity and clinical disability was measured by expanded disability status scale (EDSS). The Annual Progression was computed as the difference of end-of follow-up and baseline EDSS divided by the duration of follow-up in years. A minimum baseline EDSS of one is our studies inclusion criteria, which we believe provides confirmed evidence of spinal cord involvement. Onset date of AMN symptoms is taken as the start point of survival analysis. Results: The study population consisted of 142 pure-AMN patients were followed for a mean of 6±5 years (median: 4.5 years). Baseline EDSS was 3.9±1.6 (median: 3.5) and end of follow-up EDSS was 5.2±1.9 (median: 6). The annual progression was 0.54±1.1 (median: 0.2). Median survival time to reach severe disability was 9.36 years. Almost all patients reach severe disability within 29 years of onset of symptoms.

Conclusion: Pure AMN progresses slower than reported in other phenotypes. These findings furnish an estimate of Pure-AMN progression required for designing clinical trials, which uses EDSS as an outcome measure to assess the efficacy.