The American Academy of Neurology (AAN) held its 2010 annual meeting from April 10 to 17 in Toronto. The features below highlight some of the news emerging from the AAN meeting.

New Driving Recommendations for Dementia Patients [Back to Top]

The Particulars:Although some people with dementia or Alzheimer’s disease (AD) can drive safely for a time, nearly all of these patients will eventually have to forego driving. Evidence shows that driving skills deteriorate with increasing dementia severity. Physicians should discuss this inevita­bility with patients and caregivers soon after their diagnosis as it is likely to affect quality of life and may lead to other health concerns, such as depression. The American Academy of Neurology issued a new guideline to help determine when people with AD or another type of dementia should stop driving.
Data Breakdown: Physicians are recommended to use the Clinical Dementia Rating scale to identify people with dementia or AD who are at an increased risk of unsafe driving. It is recommended that caregivers be encouraged to trust their instincts; caregivers who rate driving as “marginal” or “unsafe” were often correct when patients took on-road driving tests. However, patients who rate their own driving appear to be less accurate in their own assessments. Caregivers and family members play a role in identifying warning signs from unsafe drivers with dementia, including decreased miles being driven; collisions; moving violations; avoiding certain driving situations (eg, driving at night or in inclement weather); and aggressive or impulsive personality traits.
Take Home Pearls:The decision to stop driving should be directed by physicians trained and experienced in working with people who have dementia or AD and their families. Assessing driving ability is a complex process, and guidelines should be used when making decisions. Fur­thermore, physicians, patients, and caregivers must know their state laws to ensure that proper protocols are followed.

New Gene Implicated in Alzheimer’s Disease [Back to Top]

The Particulars: The World Health Organization reported that the incidence of Alzheimer’s disease (AD) will nearly double to 34 million worldwide by 2025. Common variants in genes other than APOE have recently been shown to be associated with a risk of developing late-onset AD. The MTHFD1Lgene is known to be involved in influencing homocysteine levels; high homocysteine levels have been identified as a strong risk factor for late-onset AD.
Data Breakdown: Researchers examined gene variation—including the MTHFD1L gene, which is located on chromosome six—in 2,269 people with late-onset AD and 3,107 people without the disease in a genome-wide association study. Individuals with a particular variation in MTHFD1Lwere almost twice as likely to develop AD as those people without the variation.
Take Home Pearls: The MTHFD1L gene appears to increase a person’s risk of developing late-onset AD. The identification of MTHFD1Las a risk gene for AD may help clinicians better understand how the disease develops and possibly serve as a marker for people considered at increased risk.

A Potential New Treatment for Pseudobulbar Affect [Back to Top]

The Particulars: Pseudobulbar affect (PBA) is a neurologic condition of involuntary, sudden, and frequent episodes of laughing or crying. Research suggests PBA is relatively common among patients with underlying neurologic diseases or injuries, especially those with multiple sclerosis and amyotrophic lateral sclerosis. PBA outbursts, which often occur at inappropriate times, can have a severe impact on patient and caregiver well-being, social functioning, and quality of life. There are no FDA approved treatments for PBA, and currently used off-label treatments are often ineffective or may have unacceptable side effects.
Data Breakdown:Investigators assessed the efficacy of a dextromethorphan/quinidine (DMQ) combination (Avanir Pharmaceuticals, Inc.) in stopping involuntary PBA outbursts. Participants were given daily doses of DMQ, and their frequency and severity of PBA were measured regularly. The average test score was significantly improved (by 2.7 points) from the start to the end of the open-label study. Patients who were taking placebo in a previous clinical trial and switched to DMQ demonstrated the most improvement.
Take Home Pearls: DMQ appears to be effective in helping control PBA outbursts in patients with neurologic diseases or injuries. Findings from the study, in collaboration with additional clinical data, may serve as the basis for an application for FDA approval of the drug for PBA.

Guillain-Barré Syndrome Risk Low After H1N1 Vaccination [Back to Top]

The Particulars: Guillain-Barré syndrome (GBS) is a rare disorder in which the immune system attacks part of the peripheral nervous system, causing tingling and weakness of the extremities. Although the causes of GBS are not fully known, research suggests that about two-thirds of those afflicted with GBS experience it several days or weeks after they have had diarrhea or a res­piratory illness.
Data Breakdown:Researchers analyzed data from the CDC and the FDA’s Vaccine Adverse Event Reporting System (VAERS) to determine if the 2009 H1N1 vaccine was associated with increased risk of GBS. There were 35 reports of GBS following 2009 H1N1 vaccination by the end of 2009, equating to 3.5 reports per 10 million people vaccinated. All cases of GBS except one were reported within 6 weeks of vaccination, with 23 cases reported within the first 2 weeks after vaccine administration. The number of GBS cases reported by the same researcher was only slightly higher after seasonal flu vaccination in 2009: 57 reports of GBS were received by VAERS, equating to 7.3 reports of GBS per 10 million vaccinations.
Take Home Pearls:Reports of GBS appear to have been low following 2009 H1N1 vaccination. It is important for clinicians to continue to closely monitor people after vaccination for GBS.

Alcohol, Smoking, and Stroke [Back to Top]

The Particulars:Heavy alcohol consumption appears to increase the risk of stroke, but the relationship between light-to-moderate drinking and stroke has varied considerably among current studies. The conflicting results could be explained by the interaction between cigarette smoking and alcohol on stroke risk.
Data Breakdown:Scientists followed the drinking and smoking habits of 22,524 people (aged 39 to 79) who did not have a history of heart attack or stroke when the study began. During the 12-year study, 864 strokes occurred. Among non-smokers, people who consumed moderate amounts of alcohol (about two to three glasses of red wine per day) were 37% less likely to develop stroke than non-drinkers. In smokers, this association was not observed, suggesting that smoking may modify the relationship between alcohol intake and stroke risk.
Take Home Pearls: Any beneficial effect of drinking moderate amounts of alcohol on stroke appears to be counteracted by cigarette smoking. Findings could have public health implications as there appears to be a clearer understanding of the dangers of combining smoking and moderate drinking on overall stroke risk.

References

For more information on the news emerging from the 2010 AAN annual meeting, as well as further data on the studies presented in this feature story, go to www.aan.com/go/am10.