The pattern of leprosy-related neuropathy in the AMFES patients in Ethiopia: definitions, incidence, risk factors and outcome

The ALERT MDT Field Evaluation Study (AMFES) began in 1988 and followed pat ients prospectively for up to 10 years after release from treatment (RFT). This paper presents the findings from this cohort with regard to neuropathy and nerve damage. Five hundred and ninety-four new cases of leprosy are in cluded in the study, 300 multibacillary (MB) and 294 paucibacillary (PB) ca ses. Fifty-five percent of patients had some degree of impairment at diagno sis and a further 73 (12%) developed new nerve function impairment (NFI) af ter starting multiple drug therapy (MDT). The overall incidence rate for ne uropathy was 39 episodes per 100 PYAR in the first year after diagnosis, gr adually declining to 12 episodes per 100 PYAR in the sixth year. In those p atients without impairment at diagnosis, the incidence rate of neuropathy w as 25 episodes per 100 PYAR for MB cases and 11 per 100 PYAR for PB cases i n the first year; in 33% of MB cases whose first episode of neuropathy occu rred after diagnosis, that first episode took place after the first year, o r after the normal period of treatment with MDT. Seventy-three patients wit h neuropathy developing after diagnosis are reported more fully: 34 (47%) h ad only one nerve involved and of these 25 (73%) had a single, acute episod e of neuropathy. Nine (27%) had further episodes. Thirty-nine (53%) had mor e than one nerve involved and of these 16 (41%) had a single, acute episode , while 23 (59%) had further episodes. The terms 'chronic' and 'recurrent' neuropathy are defined and used to describe the pattern of neuropathy in th ose with repeated attacks. In patients with no impairment at the start of t he study, treatment with steroids resulted in full recovery in 88% of nerve s with acute neuropathy but only 51% of those with chronic or recurrent neu ropathy. The median time to full recovery from acute neuropathy was approxi mately 6 months, but in a few cases recovery occurred gradually over 2-3 ye ars. Severe neuropathy was less likely to be followed by a complete recover y than mild or moderate neuropathy. Forty-two percent of nerves with acute neuropathy that were not treated with steroids also fully recovered. In the group of patients who were thought to have old, permanent impairments at d iagnosis, full recovery of nerve function occurred in 87/374 (23%) of the n erves involved. The overall outcome is illustrated by examining the average EHF score for groups of patients. Patients with no new neuropathy after di agnosis show a gradual improvement in their EHF score, while those with any episodes of neuropathy after diagnosis show a gradual deterioration after completion of MDT. Possible explanations for these findings are discussed. Risk factors for neuropathy, for chronic and recurrent neuropathy, and for a poor outcome 5 years after release from treatment, are examined. Impairme nt at diagnosis was the main risk factor for a poor outcome, accompanied by the occurrence of chronic/recurrent neuropathy or a reversal reaction.