People who inherit the neurological disease ataxia suffer from balance and coordination problems, seizures, and brain damage. By giving some of these patients a vitamin-like compound that helps the body turn food into energy, these symptoms can be alleviated, according to a small study reported in the 10 April issue of Neurology.
The compound, called coenzyme Q10 (CoQ10), plays an essential role in the series of biochemical reactions by which cells extract energy from sugars. Although CoQ10 is present in every cell in the body, researchers knew that a shortage of CoQ10 is particularly devastating to muscles, which need a lot of energy. Neurologist Salvatore DiMauro of Columbia University was studying a patient with wasted muscles when he discovered an unexpected link to hereditary ataxia.
To test whether his patient's levels of CoQ10 were abnormally low, DiMauro and his colleagues tested CoQ10 levels in 20 control subjects--patients with normal muscle tissue. To their surprise, one of these people also had low CoQ10 levels. The person suffered from severe hereditary ataxia. The disorder can be caused by any of several genes, but although the disease runs in the patient's family, the patient didn't suffer from any of the known genetic subtypes of ataxia. DiMauro put out the word that he was seeking other ataxia patients whose diseases were caused by unknown genes, and soon his colleagues referred six patients.
DiMauro gave the patients 1000 mg of CoQ10 daily, and all six improved. Their scores on a scale assessing balance, speech, and movement rose by 25% after 1 year. The researchers don't know why the CoQ10 helped the patients, and the study didn't have a control group of patients who took placebos. But DiMauro hopes the finding will prompt physicians to try CoQ10 therapy when presented with ataxia of unknown genetic origin. "We may have discovered still another category of genetic ataxia," DiMauro says. "It is clear that if we can diagnose these patients accurately, we can help them."
"I think it's a very important paper," says neurologist Andrew Engel of the Mayo Clinic in Rochester, Minnesota. "It's not a blanket recipe for treating all ... ataxias," he cautions. No one knows how many people suffer from a CoQ10-sensitive type of ataxia, but, Engel says, "it's very important that this form of ataxia is treatable."