Thursday, March 29, 2007

Wernicke encephalopathy after bariatric surgery

Singh S and Kumar A. Neurology 68; 807-811 . 2007. Clinical description. review of the literature. 27 cases were found. Most had vomiting as a risk factor, presented with the clinical triad of confusion, ataxia and nystagmus, and had a peripheral neuropathy at a median of two months. Most cases occurred at 4-12 weeks. Other neurologic findings included optic neuropathy, seizures, papilledema, deafness, asterixis, eating avoidance and weakness. Prevalence is around eight percent. Some of the patients had hyperintense signal in the periaqueductal gray and dorsal thalamus. Serum thiamine levels and transketolase levels were variably low. Most patients recovered completely with intravenous thiamine. The pathology has been attributed to thiamine deficit, but that is debated. The amblyopia resembles Leber's and tobacco amblyopia. The deafness may be thalamically based. Vasogenic edema due to free radical production and NMDA mediated neuronal injury may be at fault. In Brazil, the presence of thiaminase in river fish has been attributed. MRI is 53 % SENSITIVE AND 93 % SPECIFIC for the diagnosis. Gastroscopy is prudent to evaluate for stasis.