[The neuropathy epidemic in Cuba: eight years of investigation and follow-up]. / La epidemia de neuropatía en Cuba: ocho años de estudio y seguimiento.

INTRODUCTION: The authors describes the past eight years, since an epidemic started in Cuba which mainly affected the nervous system, particularly the optic nerve and the peripheral nerves. It is thought to have been the biggest epidemic involving the nervous system this century, although there may be over-diagnosis. The cause is controversial but is probably nutritional imbalance with additional toxic elements also in some cases. At the present time the continuous, low, notification of new cases means that it is endemic. DEVELOPMENT: In this paper we consider the clinical and electrophysiological aspects characteristic of the disorder, the degree of involvement, evolution, incidence and annual follow-up of cases from 1992 to date and their differential diagnosis. We describe the national programme of healthcare for control of the disease in Cuba, the measures designed to reduce the number of patients, most of the results of clinical and epidemiological studies and the possible causes. We also discuss the most likely physiopathological hypotheses.

[Leber's hereditary optic neuropathy and its possible relation to a recent epidemic in Cuba]. / Neuropatía óptica hereditaria de Leber y su posible relación con la reciente epidemia de Cuba.

INTRODUCTION: This century, the greatest epidemic affecting the nervous system was notified in Cuba seven years ago. At the present time the epidemic continues although to a lesser extent. The clinical findings of the illness were mainly bilateral optic neuropathy sometimes accompanied by other symptoms and peripheral neuropathy. The similarity of the optic form of the illness with Leber's hereditary optic neuropathy, and their common risk factors, were obvious from the beginning. PATIENTS AND METHODS: Statistics from the national reference department of neuro-ophthalmology of the Instituto de Neurologia de Cuba were reviewed. From these it was evident that the number of cases of Leber's hereditary optic neuropathy had increased in recent years, coinciding with the period of epidemic and endemic Cuban neuropathy. Many of these patients had previously been diagnosed as having epidemic optic neuropathy. RESULTS: We describe the characteristics of a group of these patients and discuss the differences and possible relationship between the two conditions. In the case of epidemic optic neuropathy, there is strikingly simultaneous loss of vision, less visual changes with much smaller cecocentral scotomas, loss of ganglion fibres of the retina around the papillomacular bundle, a good response to multivitamin treatment, and increased frequency of association with peripheral sensory neuropathy. CONCLUSION: This analysis reinforces the hypothesis that many patients with Leber's hereditary optic neuropathy, which started at the time of the epidemic, were incorrectly classified as suffering from this, and also perhaps their condition worsened due to the toxic nutritional features common to both conditions.