Timothy A. Pedley, MD, presented a summary of research highlights at the conclusion of the meeting, a session which has become one of the more popular events of the long-running meeting. New research in Parkinson’s disease, ALS, West Nile virus and more than a dozen other neurological disorders presented at the meeting was included. "The quality of the science presented this year was very high," said Pedley, chairman of the AAN Scientific Program Subcommittee that selected the studies that were presented from more than 2,500 abstracts submitted. "The competition among submissions was particularly acute this year."
Highlights include:
Multiple Sclerosis – Multiple sclerosis (MS) is an autoimmune disease that attacks the insulation surrounding nerve cells. In a small pilot study, six patients had their immune systems completely ablated and rebuilt from scratch using their own stem cells. Researchers from the Ottawa Health Research Institute found the treatment was safe and well tolerated, and over one year, patients showed no signs of disease progression, suggesting this may be a promising treatment for selected patients. It needs to be replicated in larger trials.
Elevated levels of the protein annexin were shown by researchers from Yale University and University College, London, to increase a type of sodium channel not normally seen in the brain. The number of these channels correlated with worsening ataxia, or loss of coordination, and disease duration. These aberrant sodium channels may contribute to abnormal conduction of impulses, and they represent an attractive therapeutic target.
Two studies examined the role of bacterial infection with Chlamydia pneumoniae in worsening of MS symptoms. In one of these, researchers from the United States, Canada and the Netherlands found that subclinical infection did not cause MS, but it did increase the risk of exacerbations in the relapsing-remitting form of MS. These results suggest that a trial of antibiotic treatment of such infections is warranted because it may help mitigate disease exacerbation in some patients.
Epilepsy – For many patients with epilepsy, surgery that removes pat of the temporal lobe (a portion of the brain above and in front of the ear) effectively reduces the number and severity of seizures. Researchers from Rush Medical College, Chicago, showed that while 25 percent of patients develop post-surgical psychiatric complications, including depression and mania, these respond very well to drug therapy, and were not associated with poorer seizure reduction or type of temporal lobe epilepsy.
The success of epilepsy surgery was examined in children under three years old who had delayed mental development and were not adequately treated by antiseizure medicines. Surgery reduced seizures and the number of antiseizure drugs required, and most infants improved in their rate of mental development, according to researchers from the Cleveland Clinic Foundation.
Investigators at Wayne State University showed that patients with temporal lobe epilepsy who refused surgery had progressive atrophy of the hippocampus if seizures continued. In patients who became seizure-free from medical treatment, the loss of hippocampal tissue was arrested. This is further evidence that temporal lobe epilepsy is a progressive disorder that requires aggressive treatment, including surgery if indicated, to eliminate seizures.
Alzheimer’s disease – The frank dementia of Alzheimer’s disease is often preceded by a long period of slow cognitive decline. Researchers at the Mayo Clinic in Rochester, Minn., showed that the risk for mild cognitive impairment (MCI) or Alzheimer’s disease could be predicted years in advance by a combination of factors, including age, presence of particular forms of the ApoE gene and performance on a battery of neuropsychological tests. Meanwhile, colleagues at the Mayo Clinic in Jacksonville, Fla., showed that the blood protein A-beta-42, which normally increases, declines with the development of MCI, and drops further with Alzheimer’s disease, suggesting it may provide a useful clinical marker for identifying onset of MCI and the transition to Alzheimer’s disease.
Use of statins, which are cholesterol-lowering drugs, were shown by a six-state consortium of researchers to be associated with a slight decrease in the rate of cognitive decline among the elderly, although not in those who had already developed dementia. These results suggest that statins may favorably influence the course of Alzheimer’s disease early on in its progression.
Stroke – Statins also figured favorably in a study of recovery from stroke, conducted by researchers at the University of Massachusetts Medical School. Patients taking statins had significantly better function three months after a stroke compared to those not taking them.
Chlamydia infection and its association with stroke was examined by collaborators from Columbia University and the Centers for Disease Control. They showed that Chlamydia infection increased stroke risk in both men and women independent of other known risks, including high blood pressure and smoking. This suggests that treatment of infection may help lower the risk of stroke.
Elevated blood levels of homocysteine are also associated with increased risk for stroke. Researchers at the Boston University School of Medicine presented data showing such levels are also seen in adults who have not had clinical strokes but whose MRI scans show "silent strokes" and loss of brain volume.
Homocysteine can be reduced by certain vitamins. Whether vitamin therapy can reduce the risk for a second stroke was addressed by a large consortium led by researchers at Wake Forest University School of Medicine in Winston-Salem, North Carolina. They found that while high doses of vitamins B6, B12, and folic acid could reduce homocysteine consistently, stroke risk was not reduced compared to low-dose vitamins, which had no effect on homocysteine concentrations. These results suggest either that more dramatic homocysteine reductions are needed, or that other strategies must be used to reduce the risk of a second stroke.
Sleep apnea, or breathing difficulty, affects half of all stroke victims. Researchers from Zurich showed that stroke patients with sleep apnea have a greater risk of worsening of the effects of their stroke, suggesting that treatment of sleep apnea in these patients may be beneficial.
Finally, researchers at the University of Chicago and Arizona State University compared brain activation of amateur and professional golfers as they visualized performing their swing. Much smaller areas of the brain were activated by the highly trained professionals, and some structures active in the amateurs were entirely silent in the professionals. Not only do these results shed light on the neurological effects of training, they also indicate that post-stroke movement rehabilitation should be tailored to an individual’s previous level of training and expertise in a particular movement.
The American Academy of Neurology, an association of more than 18,000 neurologists and neuroscience professionals, is dedicated to improving patient care through education and research. A neurologist is a doctor with specialized training in diagnosing, treating and managing disorders of the brain and nervous system such as stroke, Alzheimer’s disease, epilepsy, Parkinson’s disease, autism and multiple sclerosis. For more information about the American Academy of Neurology, visit its online press room at www.aan.com/press/index.cfm.