Weight loss may not be the only consequence of bariatric surgery. According to a new study, the surgery could also increase the risk of Wernicke encephalopathy, a serious neurologic problem caused by thiamine deficiency. Usually associated with alcoholism or malnutrition, the disorder produces a classic triad of symptoms: confusion, ataxia, and nystagmus.

Researchers conducted a literature review to identify cases of Wernicke encephalopathy after various types of bariatric surgery. They found 32 patients with the condition. Twenty-seven were women, possibly because 75% of patients who undergo obesity surgery are women.

Neurologic problems were most likely to develop 4 to 12 weeks after the surgery, especially in young women with vomiting. Besides vomiting and the classic triad, signs and symptoms included optic neuropathy, papilledema, deafness, seizures, asterixis, weakness, and sensory motor neuropathy.

Most patients recovered fully after receiving intravenous thiamine, but some continued to have problems with coordination, memory, and vision. Researchers urge providers to evaluate protocols for supplemental thiamine after bariatric surgery to head off Wernicke encephalopathy.

Source: Singh S, Kumar A, Wernicke encephalopathy after obesity surgery: A systematic review, Neurology, March 13, 2007.