Brain barrier dysfunction in Cuban epidemic optic neuropathy

There are practically no references to cerebrospinal fluid (CSF) studies in tropical or nutritional neuropathies. In the present paper we present the results of CSF studies in patients with Cuban Epidemic Optic Neuropathy (CEON) during epidemic and endemic periods, with an appraisal as to the contribution of brain barriers' function in the pathophysiology of this disease.

Two hundred and five patients with CEON were studied during the epidemic period (1992-1993) and 12 patients outside the outbreak (1995-1997). CSF protein determination and electrophoresis were carried out, as well as serum and CSF albumin and immunoglobulin G (IgG) quantitation for calculating IgG and Q(alb) indexes, in order to evaluate intrathecal IgG synthesis and the permeability of the blood-CSF barrier (B-CSF B).

One fourth of the patients had increased permeability of the B-CSF B, but damage was more frequent between 16 and 60 days from onset of disease, disappearing after 120 days. B-CSF B dysfunction was more prevalent in patients with severe neurological impairment, although it was not related to the severity of ophthalmological damage. The group of patients studied outside of the outbreak (endemic period) showed similar results.

The possible association of increased permeability of the B-CSF B with oxidative stress, which lies on the basis of this epidemic outbreak, is discussed.