Share this article on:

THIS WAY IN: The Risks of H1N1 Flu

Shaw, Gina

doi: 10.1097/01.NNN.0000365448.53465.e3
Departments: the Waiting Room

In all the coverage of the H1N1 (“swine”) flu, you may not have heard that people with a number of neurologic conditions should also be at the top of the list to receive vaccinations first.

The Centers for Disease Control and Prevention (CDC) recommends that people ages 25 and older who have underlying conditions putting them at high risk of complications from influenza be at the front of the line for the vaccine. And many of those “underlying conditions” are neurologic. Children with at least one chronic high-risk neurodevelopmental condition—including epilepsy, cerebral palsy, or developmental delays—make up 67 percent of the at least 36 children who have died from H1N1 complications since the disease first surfaced last spring. Adults with amyotrophic lateral sclerosis (ALS), muscular dystrophy, and multiple sclerosis (MS) also appear to be at higher risk of complications from H1N1, and should therefore receive the vaccine early as well, says Abbigail Tumpey, a spokesperson for the CDC.



People with neurological conditions may be at an increased risk of serious complications from H1N1.

For people with MS, H1N1 has two complicating factors, explains John Richert, M.D., executive vice president for research and clinical programs with the National MS Society. “First, people with advanced MS, or those with less advanced disease who have any breathing difficulties, are at particular risk for complications from H1N1. Second, any viral infection, including H1N1, can precipitate an exacerbation in anyone with MS.”

Approximately one-third of all MS exacerbations are caused by a viral infection, notes Dr. Richert. “The government estimates that about half of people who do not get the H1N1 vaccines are likely to become infected with the flu virus, which means that about half of all unvaccinated people with MS are likely to develop it as well.”

Dr. Richert adds that people with MS should only get the injectable H1N1 vaccine, not the nasal mist, because the mist contains some live attenuated virus and potentially could itself provoke an exacerbation.

The ALS Association recommends that people with ALS—as well as their family members and caregivers—get the H1N1 vaccine as soon as possible. “People with ALS are already at increased risk for respiratory problems associated with viral and bacterial infections,” wrote Edward Karsarskis, M.D., Ph.D., director of the University of Kentucky ALS Association Multidisciplinary Center in Lexington, KY, on the Association's Web site.

Dr. Kasarskis also recommends the injection rather than the nasal spray vaccine for ALS patients, since many people with ALS have problems with thick secretions in their mouth and throat that can make nasal administration difficult and uncomfortable. Indeed, most recommendations are that anyone with an underlying neuromuscular condition not receive the nasal mist vaccine.

The government has ordered a total of 250 million doses of the vaccine. Daniel Kantor, M.D., who is head of the Florida MS Society and agreed to operate an H1N1 vaccine clinic in his community, was still waiting on November 3 for doses of the vaccine that had been promised two weeks earlier. Because of the high demand, Dr. Kantor suggests that people with neurologic conditions that place them at higher risk of complications ask their neurologist to intervene. “Get your neurologist to write a letter to the primary care doctor, or to whoever is operating the vaccine clinic, and try to get pushed to the front of the line,” he says.

Some people considering receiving the vaccine have been concerned about an increased risk of Guillain-Barré Syndrome (GBS), a disorder in which the body's immune system attacks the peripheral nervous system, causing muscle weakness and even paralysis. During the last U.S. outbreak of H1N1, in 1976, a vaccine for the flu appeared to be associated with a small increased risk of GBS.

“The association is still controversial,” says Gary Gronseth, M.D., professor of neurology at the University of Kansas. “Some studies say the vaccine did not increase the risk of Guillain-Barré, some say it did. The implication is that if there is any increased risk of GBS following immunization, the magnitude is extremely small, and it has to be balanced with the significant potential benefit of not getting the flu.”

Today's H1N1 vaccine is made using a very different process than that used in 1976—one similar to the seasonal flu vaccines, which are given every year without any known increased risk of GBS. Even so, neurologists have been asked to monitor their patients for any potential new cases of GBS after vaccination.

That small potential risk, say most neurologists, pales beside the risk of severe complications from H1N1 for many people with neurologic and neuromuscular conditions. “Of course, individuals should consult with their own neurologist first to ensure that there aren't other factors that may be an issue for them,” says Dr. Richert “but in general, we believe our patients should get vaccinated as soon as possible.”

Gina Shaw

Copyright © 2009, AAN Enterprises, Inc.