Evaluation of peripheral nerve conduction and central visual conduction in chronic alcoholics and in chronic alcoholics after prolonged abstention.

Classic statistical method (mean, standard deviation, variance) were used to analyze peripheral nerve conduction tests and visual evoked potentials in 13 chronic alcoholics and in 11 chronic alcoholics who had abstained for at least one year, in order to assess the repercussions of alcohol on the PNS and on the visual pathways and their reversibility. The sensory fibers were more affected than the motor fibers, and while the damage to the motor fibers was transient the damage to the sensory fibers was permanent and also significantly different, at least in the early stages, in the two lower limbs. Our results showed constant involvement, without clinical symptoms, of the visual potential, especially of the earliest component N70 and of the amplitude of the response. This would suggest greater involvement of the peripheral visual nervous structures, that is retino-geniculo-cortical, than of the more properly cortical structures, though these are also affected. For the visual damage too withdrawal of alcohol seems to determine a regression, though only partial, of the neurophysiological changes. The simultaneous involvement of VEP and peripheral nerve function is at variance with the assertion that optic nerve damage is a very rare event in alcoholism.