The finding provides new evidence that viral infections may cause some forms of ALS, a topic researchers have been debating for decades. Classic ALS is a progressive disorder. There is currently no cure or treatment that stops or reverses the disease; the one current treatment modestly slows the progress of the disease.
"This is exciting news, because if this form of ALS caused by HIV is treatable, then other forms of ALS may be treatable as well," said neurologist Burk Jubelt, MD, of SUNY Upstate Medical University in Syracuse, NY, who wrote an editorial accompanying the Neurology articles. "But more research needs to be done to confirm these results and determine whether there are other viral causes of ALS."
In one of the two articles, French researchers studied 1,700 people infected with HIV and with neurological symptoms seen over a 13-year period. Of those, six people developed symptoms of ALS, or motor neuron disease, which is significantly higher than the rate that motor neuron disease occurs in the general population.
"Causes other than HIV for the motor neuron disease were ruled out," said study author and neurologist Antoine Moulignier, MD, of Adolphe de Rothschild Foundation in Paris.
After treatment with anti-HIV drugs, two of the patients recovered completely from their motor neuron symptoms, three improved and one stabilized.
In the other article, a 32-year-old woman developed ALS-like symptoms and was then found to be HIV positive. Following treatment with anti-HIV drugs, the woman had a complete recovery from the ALS symptoms and HIV could no longer be detected in her blood or cerebrospinal fluid, according to study author and neurologist Daniel MacGowan, MD, of Beth Israel Medical Center in New York, NY. In all seven cases, the rapid course of the disease and the young age of onset, along with other factors, indicate that this is a variant of the classic ALS disease, researchers said.
Moulignier said more research is needed to determine how HIV causes motor neuron disease. "It could be through several mechanisms -- through neuronal infection, by secretion of toxic viral substances, by inducing the immune system to secrete cytokines, or by inducing an autoimmune disease," he said. Moulignier also noted that five of his six patients were seen before the "drug cocktail" of multiple antiretroviral drugs was introduced and the level of HIV in patients' blood could be better controlled. He and his colleagues have not seen any HIV patients with motor neuron disease symptoms since that time.
The American Academy of Neurology, an association of more than 17,500 neurologists and neuroscience professionals, is dedicated to improving patient care through education and research. For more information about the American Academy of Neurology, visit its web site at www.aan.com.
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Neurology