Impact of Spectral Severity of Alcoholism on Visual-Evoked Potentials: A Neuropsychiatric Perspective

Abstract

ABSTRACT Background: The deleterious effects of alcohol on the brain are replete in literature. Only a few neurophysiologic measures can pick up the neuronal dysfunctions, one of them being visual-evoked potential (VEP). A very limited amount of data exists on the progression of neural abnormalities related to the spectral severity of alcoholism. Aim of the Study: To evaluate the impact of spectral severity of alcoholism through VEP and to understand the emergence of any specific pattern or morphometric abnormalities related to alcohol-induced neuropsychiatric presentations. Methodology: A total of 90 cases were recruited in addition to 180 age- and sex-matched controls using purposive and random sampling. The Structured Clinical Interview for DSM-IV Axis I Disorders, Clinician Version and Campbell Neuropsychiatric Inventory were used to evaluate alcohol disorders and its neuropsychiatric complications apart from the mandatory consultant-specific clinical evaluations of all the cases. Of 90 cases of alcohol dependence, 15 patients were currently abstinent for >6 months, 15 had alcohol intoxication, 15 had signs of alcohol withdrawal, 15 had physical complications, 15 had psychiatric comorbidity, and 15 had neurological complications such as epilepsy. VEP recordings were taken using an Evoked Potential Recorder (RMS EMG. EP MARK II) where the stimulus configuration consisted of transient pattern-reversal method in which a black and white checkerboard was generated full field. Results: Mean age of cases was 37.71 ± 11.49 years compared to 39.43 ± 10.67 years in controls (range 18–65 years). VEP abnormalities comprising of prolonged latencies (62.5%) with a statistically significant difference (P < 0.001) from the healthy controls was observed in cases of alcohol withdrawal syndrome. Predominant amplitude reduction with normal latency was obtained in 37.5% cases of withdrawal. Severe VEP abnormalities, i.e., both latency delay and amplitude reduction, were found in 75% patients with psychiatric comorbidity, 66.67% patients with neurological complications, i.e., epilepsy, and 33.34% patients with physical complications. An explicit finding of prominent interocular differences was a prominent feature present in 25% of patients with complications.