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WASHINGTON (Reuters) -- Some obese people who have weight-loss surgery, particularly younger women, develop a neurological condition most often seen in severe alcoholics and linked to a vitamin deficiency, researchers said Monday.
A study in the journal Neurology described the cases of 27 women and five men who developed the condition, Wernicke encephalopathy, after bariatric surgery.
Nearly all had experienced frequent vomiting in the weeks after surgery. Two patients died.
Wernicke encephalopathy can develop when the body does not get enough vitamin B1, also known as thiamine. It affects the brain and nervous system, with symptoms including double vision, eye movement abnormalities, unsteady walking, memory loss and hallucinations.
Lead researcher Dr. Sonal Singh of Wake Forest University School of Medicine in Winston-Salem, North Carolina, said it was unclear how common the condition was in people who have had surgery for obesity.
The researchers said they think it appears in people who have the surgery if they stop taking vitamin supplements or when they vomit so often that it prevents vitamin absorption.
Singh said, when recognized quickly, the condition can be treated easily with injections of thiamine.
People who have the surgery and their doctors should watch for signs of the condition in the first few weeks after the operation, Singh said.
Obesity is a growing problem in the United States and other rich countries, and the popularity of weight-loss surgery has been increasing steadily.
About 170,000 people had the procedure in the United States in 2005, a tenfold rise from the early 1990s. A study last week found that use of the surgery tripled among U.S. adolescents from 2000 to 2003.
'This is a risk'
"We're not saying to people 'Don't get the surgery.' But I think this is a risk that has to be considered now in the equation when people are deciding," Singh said.
Wernicke encephalopathy is usually associated with severe alcoholism or chronic malnutrition.
Singh and co-author Dr. Abhay Kumar of the University of Iowa combed through scientific literature for reported cases of the condition in people after bariatric surgery to figure out its timing, risk factors and symptoms.
They said it appeared most frequently one to three months after surgery, especially in young women, but developed as late as 18 months after surgery in one person.
The study found the condition can appear after all types of weight-loss surgery, including gastric bypass in which surgeons section off a small portion of the stomach into a pouch that bypasses the first part of the small intestine and connects directly to the lower portions.
Other types include surgery to "band" the stomach and gastric partitioning that divides the stomach into two parts.
Thirteen of the 32 people recovered fully. Some of the 32 experienced symptoms not typical of the condition, including seizures, hearing loss, psychosis, muscle weakness and pain or numbness in the extremities, the study found.
"It's really too early to say how common or how rare it is. I think it is more common than people expect," Singh said.
While most of the cases involved women, Singh said it was too soon to say whether women were more susceptible or only appeared to be because about three quarters of weight-loss surgery patients are women.