American Academy of Neurology, April 10-17, 2010

American Academy of Neurology 2010 Annual Meeting

The American Academy of Neurology's 2010 Annual Meeting took place April 10 to 17 in Toronto, and attracted about 12,000 attendees from around the world. The meeting featured more than 2,300 abstracts on 26 topics in clinical and basic science research.

"We had six days packed with science and updates," said Carlayne E. Jackson, M.D., of the University of Texas Health Science Center in San Antonio, and a member of the AAN Science Committee. "What was overwhelming was the amount of advances that have taken place in just the past year in every single subspecialty of neurology. There were updates on multiple sclerosis therapies, genetics with Alzheimer's disease, novel treatments for migraine headaches, and updates on new ways to anticoagulate patients with atrial fibrillation to minimize cerebral hemorrhage."

Highlights included the phase 3 PREEMPT 2 Trial presented by David W. Dodick, M.D., of the Mayo Clinic in Scottsdale, Ariz. During the study, which was supported by Allergan Inc., Dodick and colleagues randomly assigned 705 patients with chronic migraine to receive either injections of onabotulinumtoxinA or placebo every 12 weeks for two cycles, followed by three cycles of onabotulinumtoxinA. After 24 weeks, they found that onabotulinumtoxinA was statistically significantly superior to placebo for reduction in the frequency of headache days (−9.0 versus −6.7) and for five secondary variables: headache episodes, migraine/probable migraine days, cumulative hours of headache on headache days, moderate/severe headache days, and the proportion of patients with severe Headache Impact Test-6 scores.

"The results of PREEMPT 2 demonstrate that onabotulinumtoxinA is effective for the prophylaxis of headache in adults with chronic migraine," the authors concluded. "Repeated onabotulinumtoxinA treatments were safe and well tolerated."

Abstract No. P06.251

"The meeting also featured reports about the Mediterranean diet, which has been recommended for reducing the incidence of cerebrovascular disease, and also has been shown to be effective in reducing the risk of Alzheimer's disease," Jackson said.

A study led by Nikolaos Scarmeas, M.D., of the Columbia University Medical Center in New York City, followed 712 adults for an average of six years. Compared to subjects with the lowest adherence to a Mediterranean-like diet, they found that those who either most closely or moderately followed the diet were 36 and 21 percent, respectively, less likely to have brain damage linked to thinking problems.

"The relationship between this type of brain damage and the Mediterranean diet was comparable with that of high blood pressure," Scarmeas said in a statement. "In this study, not eating a Mediterranean-like diet had about the same effect on the brain as having high blood pressure."

The authors speculated that fewer brain infarcts may partially explain their previous findings that a Mediterranean-like diet may be associated with a lower risk of Alzheimer's disease, and may lengthen survival in people with Alzheimer's disease.

Abstract No. S14.004
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During one well-attended program, Leigh R. Hochberg, M.D., of the Massachusetts General Hospital in Boston, discussed the potential of direct brain-computer interfaces, which allow paralyzed patients to control an external device such as a wheelchair simply by modulating their cortical activity. "That was very cool," Jackson said. "The system could conceivably be used for brainstem stroke, advanced amyotrophic lateral sclerosis, or spinal cord injury."

Abstract No. 3AS.005

Other important research presented at the meeting included the RE-LY study presented by Hans-Christoph Diener, M.D., of the University Duisburg-Essen in Germany. During that study, which was supported by Boehringer Ingelheim Pharmaceuticals USA, Diener and colleagues randomly assigned 18,113 patients with atrial fibrillation to receive blinded fixed doses of dabigatran 110 or 150 mg twice daily, or unblinded adjusted warfarin. After a median follow-up of two years, they found that the 150-mg dose of dabigatran was superior to warfarin in reducing the risk of ischemic and hemorrhagic stroke.

Abstract No. PL01.001

Jerry Mendell, M.D., of Ohio State University in Columbus, and colleagues described the immune response after gene therapy for Duchenne muscular dystrophy using adeno-associated virus to transfer the mini-dystrophin gene. Their results showed the potential for a host response to foreign transgene products caused by frame-shifting mutations or large deletions.

"This treatment is very promising, but they're experiencing some challenges with it," Jackson said. "So, although we were very hopeful, it looks like that might not be ready for prime time in the near future."

Abstract No. S06.008

David B. Clifford, M.D., of the Washington University School of Medicine in St. Louis, presented an update on progressive multifocal leukoencephalopathy (PML) in multiple sclerosis patients treated with natalizumab, a drug that was temporarily withdrawn from the market because of PML concerns, and then recently reintroduced. "He reported the incidence of PML increases with duration of exposure to drug," Jackson said. "The rate was about one in a thousand patients treated for two to three years."

"Diagnosis requires clinical vigilance, reliable, sensitive quantitative JC polymerase chain reaction test, and broadened criteria for magnetic resonance recognition of PML lesions, including contrast enhancement," Clifford and colleagues concluded. "Universal immune reconstitution inflammatory syndrome reactions require aggressive management with corticosteroids."

Abstract No. PL01.003

Samuel Goldman, M.D., of the Parkinson's Institute in Sunnyvale, Calif., presented a study suggesting that exposure to the industrial cleaner trichloroethylene may increase the risk of Parkinson's disease. He and his colleagues studied 99 pairs of older male twins in which only one of the twins had Parkinson's disease. The researchers found that subjects exposed to trichloroethylene were five and a half times more likely to have Parkinson's disease than those not exposed to the chemical.

"This is the first time a population-based study has confirmed case reports that exposure to trichloroethylene may increase a person's risk of developing Parkinson's disease," Goldman said in a statement. "Trichloroethylene is a popular industrial solvent that is still widely used to clean grease off metal parts."

Abstract No. S03.005
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Xiang Gao, M.D., of the Harvard School of Public Health in Boston, presented the results of a study which followed 136,474 initially Parkinson's disease-free subjects for six years, during which time 293 of them developed Parkinson's disease. Gao and his colleagues found that regular ibuprofen use was associated with a 40 percent reduced risk of Parkinson's disease compared to non-use, and that subjects who took higher amounts of ibuprofen were less likely to develop Parkinson's disease than those who took smaller amounts of the drug.

"Ibuprofen was the only nonsteroidal anti-inflammatory drug linked to a lower risk of Parkinson's," Gao said in a statement. "Other nonsteroidal anti-inflammatory drugs and analgesics, including aspirin and acetaminophen, did not appear to have any effect on lowering a person's risk of developing Parkinson's. More research is needed as to how and why ibuprofen appears to reduce the risk of Parkinson's disease, which affects up to one million people in the United States."

Abstract No. S03.003
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Robot-Assisted Therapy Somewhat Beneficial in Stroke

FRIDAY, April 16 (HealthDay News) -- In patients with upper-limb impairment six months or more after stroke, 12 weeks of robot-assisted therapy does not significantly improve motor function compared with usual care or intensive therapy. After 36 weeks, however, robot-assisted therapy is associated with improved outcomes compared to usual care but not intensive therapy, according to a study published online April 16 in the New England Journal of Medicine to coincide with the annual meeting of the American Academy of Neurology, held from April 10 to 17 in Toronto.

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AAN: New Gene Associated With Alzheimer's Disease

WEDNESDAY, April 14 (HealthDay News) -- Variation in MTHFD1L -- a gene involved in mitochondrial tetrahydrofolate synthesis associated with risk of neural tube defects and mRNA splicing efficiency -- may be a novel risk factor for late-onset Alzheimer's disease, according to research presented at the annual meeting of the American Academy of Neurology, held from April 10 to 17 in Toronto.

Abstract No. P03.296
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AAN: H1N1 Vaccine Association With Guillain-Barré Studied

WEDNESDAY, April 14 (HealthDay News) -- Few cases of Guillain-Barré syndrome were reported in patients who received the 2009 H1N1 vaccine, according to research presented at the annual meeting of the American Academy of Neurology, held from April 10 to 17 in Toronto.

Abstract No. P02.293 (subscription or payment may be required)
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AAN: Combo Drug Effective for Pseudobulbar Affect

WEDNESDAY, April 14 (HealthDay News) -- Dextromethorphan and low-dose quinidine -- a combination known as DMQ -- shows long-term efficacy in helping control the involuntary episodes of laughing and crying associated with pseudobulbar affect (PBA), according to research presented at the annual meeting of the American Academy of Neurology, held from April 10 to 17 in Toronto.

Abstract No. P02.296
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AAN: Smoking May Counteract Alcohol's Benefit on Stroke Risk

TUESDAY, April 13 (HealthDay News) -- The beneficial effect of moderate alcohol consumption on stroke risk may be counteracted by cigarette smoking, according to research presented at the annual meeting of the American Academy of Neurology, held from April 10 to 17 in Toronto.

Abstract No. P01.297 (subscription or payment may be required)
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AAN: New Guideline Issued on Driving With Dementia

TUESDAY, April 13 (HealthDay News) -- A new guideline issued by the American Academy of Neurology is intended to help physicians decide when a patient with Alzheimer's disease or another type of dementia needs to stop driving. The guideline was published online April 12 in Neurology to coincide with its presentation at the Academy's annual meeting, held from April 10 to 17 in Toronto.

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