Gluten Attack: Ataxia
A Controversial Call
Gluten ataxia is a neurologic condition characterized by the loss of balance and coordination. However it can also affect fingers, hands, arms, legs, speech and even eye movements. Typical symptoms include difficulty walking or walking with a wide gait, frequent falls, difficulty judging distances or position, visual disturbances and tremor.
Experts believe gluten ataxia may be a form of gluten sensitivity, a wide spectrum of disorders marked by an abnormal immunological response to gluten.
Different organs can be affected by different types of gluten sensitivity. In celiac disease, sometimes called gluten-sensitive enteropathy, the small bowel is affected. In dermatitis herpetiformis, the skin is targeted, resulting in an itchy rash. With gluten ataxia, damage takes place in the cerebellum, the balance center of the brain that controls coordination and complex movements like walking, speaking and swallowing.
Purkinje cells in the cerebellum, key in maintaining balance, are thought to be lost in gluten ataxia.
“It’s best to describe gluten ataxia using the term gluten sensitivity because it takes one away from the misconception that you must have celiac disease to have any of these diverse manifestations,” says Marios Hadjivassiliou, MD, a neurologist at Royal Hallamshire Hospital in Sheffield, England.
Hadjivassiliou first described gluten ataxia in the 1990s. After seeing a number of patients with unexplained balance and coordination problems, he began systematically testing them for gluten sensitivity using antigliadin antibodies, which point to a heightened immune response to gluten but not necessarily to a diagnosis of celiac disease. Hadjivassiliou found a very high prevalence of antibodies in patients with ataxia, coining the condition, gluten ataxia.
But not all neurologists are on board with gluten ataxia. Although several studies support Hadjivassiliou’s findings, at least one small study, published in Neurology in 2000, failed to find a link between antigliadin antibodies and cerebellar ataxia. None of the 32 patients in the study tested positive for the antibodies.
But this study is just part of the problem. Casting more doubt on the condition is its so-called ‘soft’ diagnostic criteria. Gluten ataxia is currently diagnosed when antigliadin tests suggest gluten sensitivity and other causes of ataxia are ruled out. (Small bowel biopsy is advisable in patients with positive antigliadin and celiac blood tests). It’s a diagnosis of exclusion.
“There’s fairly good evidence why celiacs could have neurologic problems like ataxia,” says Joseph Murray, MD, a gastroenterologist and celiac expert at the Mayo Clinic. Vitamin deficiencies or a phenomenon called molecular mimicry could be to blame. In molecular mimicry, something in the brain may look enough like gluten that antibodies directed at the small bowel cross-react against part of the brain.
“The bottom line is that when celiac disease and gluten ataxia occur together, gluten ataxia can be a robust diagnosis. But when gluten ataxia occurs on its own, we have less certainty of the diagnosis,” says Murray.
A new screening tool may soon help. Hadjivassiliou and his team recently identified an antibody, transglutaminase TG6, which may be a better marker for gluten ataxia. TG6 is similar to the antibody TG2, detected in the widely used tTG screening for celiac disease—but TG6 is primarily expressed in the brain. Although promising, a test for TG6 is not yet ready for clinical use.
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