"Influenza can worsen symptoms in people with a neurologic disease," says Brendan Kelley, MD, FAAN, associate professor of neurology and psychiatry at Ohio State University Wexner Medical Center in Columbus.
Almost everyone six months and older should get an annual flu shot, says the US Centers for Disease Control and Prevention (CDC). In multiple sclerosis (MS), for example, the flu is associated with an increased risk of an attack. In people with epilepsy, it can increase the risk of seizures, and for people with amyotrophic lateral sclerosis (ALS), an influenza infection can impair critical functions such as breathing or swallowing, says Dr. Kelley.
Children and the elderly are particularly vulnerable. A 2012 study in Neurology that reviewed the records of 506 children in Australia who were hospitalized with influenza A (also known as pandemic flu and one of the flu viruses circulating this year) found that children who had a neurologic condition were 6.5 times more likely to have central nervous system complications, such as seizures, than children without a neurologic condition. A 2013 study in the journal PLOS One found that from 2005 to 2011 between 71 percent and 85 percent of flu-related deaths occurred among people 65 and older. The percentages were slightly lower (between 54 percent and 70 percent) for flu-related hospitalizations. The study was based on a review of data from the CDC, the National Center for Health Statistics, and several U.S. hospitals. And the risk is likely to be higher in older people with neurologic conditions, says John Ferro, MD, FAAN, a neurologist in West Nyack, NY.
Recovery from the flu can take longer if you'd had a stroke, says Melita Petrossian, MD, medical director of the Pacific Movement Disorders Center at Providence Saint John's Health Center in Santa Monica, CA. It can erase gains you've made and even set you back. That's especially true if you have to be hospitalized because of the flu. People with Parkinson's disease may have worse motor symptoms during a hospitalization because of being bedbound, she says. Patients with dementia may experience increased agitation, confusion, or even hallucinations in the evening or at night. "Patients with a neurologic condition may take weeks longer to recover from the flu than those without a condition."
Before getting a flu shot, discuss the benefits and risks with your doctor, especially if you have MS, myasthenia gravis, or once had Guillain-Barre syndrome (GBS), a neurologic condition that can cause temporary paralysis, says Ausim Azizi, MD, professor and chair of the neurology department of the Temple University School of Medicine in Philadelphia. A flu vaccine causes a general inflammatory response, which may temporarily increase some of the symptoms of these diseases, he says. For other neurologic conditions, such as Parkinson's disease, epilepsy, stroke, or Alzheimer's disease, the flu shot may prevent severe illness and even death, says Dr. Azizi. As always, though, if any symptoms worsen after a flu shot, contact your doctor right away.
Peak flu season in the US is between November and March but can last till May. You can get a flu shot at a doctor's office or a pharmacy. Most insurance companies cover the cost if you get it at a doctor's office. At a pharmacy, the staff may process the insurance claim for you. Or they may charge you and leave it to you to file with your insurance company. Some chain stores offer a bonus if you get your shot there. CVS, for example, offers 20 percent off a onetime shopping trip. If you get the flu vaccine in CVS and Minute Clinics in Target stores, you'll receive a $5 gift card. Get your flu shot at Walgreen's and the chain will donate $1 to UNICEF for vaccines in the developing world. To find vaccine locations near you, type in your zip code to the HealthMap vaccine locater funded by the US Department of Health and Human Services.
In the rare instance that your doctor advises against getting a flu shot, take these precautions to avoid getting sick.