Narcolepsy and Driving

Patients with narcolepsy often have trouble staying awake, including on the road. Are motorists with sleeping disorders a danger to everyone else?

What is narcolepsy?

According to the National Institutes of Health, narcolepsy is a chronic brain disorder that affects regulation of sleep-wake cycles. People with narcolepsy typically have reduced alertness, a feeling of overwhelming drowsiness during the daytime, and have difficulty staying awake for longer periods of time. More severe symptoms include sleep paralysis (feeling conscious but unable to move, usually while traversing the different stages of sleep) and cataplexy (sudden muscle weakness or paralysis that occurs during the day). The cause of narcolepsy is unknown, but most people with narcolepsy have low levels of hypocretin, a chemical that regulates wakefulness. Less than 10% of individuals with narcolepsy have a family member with a similar condition.

Are narcoleptics allowed to drive?

The short answer is yes, though drowsy driving laws vary by state. Most states do not impose licensing limits on people with sleep disorders, nor do they require physicians to report patients with sleeping disorders. Many states have no specific law against drowsy driving, but a tired driver can be charged under other provisions related to reckless driving. Some states will charge a driver in the result of a motorized vehicle accident, and most will charge a driver in the result of a fatality (for more information, visit here.

Nevertheless, narcolepsy can greatly affect a person’s daily life. People with narcolepsy can fall asleep anywhere and without warning. A person with narcolepsy may encounter dangerous situations when operating machinery. This is why driving can be problematic for someone with narcolepsy, especially if the condition is poorly controlled.

Studies on narcolepsy

Researchers examined the accident risk of drivers who were diagnosed with narcolepsy1. The study found that 66% of patients with narcolepsy reported falling asleep at the wheel, and 67% reported having near- or actual car accidents. Others reported bouts of cataplexy (29%) and sleep paralysis (12%) while driving. When compared with normalized control groups, drivers with narcolepsy reported an increased risk of being in a traffic accident.

A separate study monitored the driving performance of patients with untreated narcolepsy2. The patients operated a driving simulation of a two-lane highway with periodic obstacles. The patients were asked to avoid the obstacles by switching lanes through manual inputs. When normalized to control groups, patients with narcolepsy hit a higher percentage of the obstacles. In another experiment3, patients with narcolepsy and untreated sleep apnea had significantly more collisions that the controls.

Medicating patients

Excessive daytime sleepiness (EDS) is medicinally treatable. Methamphetamine often improves symptoms of EDS and was administered to patients before a simulated driving test. Researchers monitored the patients’ driving performance and compared the results of a control group of healthy drivers. The driving performance of patients with high doses of methamphetamine did not significantly differ from the control group. Similar studies concluded that stimulant drugs (MDMA and methyl-phenidate) can improve driving performance, depending on the type of driving test. Methamphetamine, MDMA, and methyl-phenidate have medicinal properties, but unless administered by a physician, are considered controlled substances that carry criminal penalties.

Despite the findings, the reviewers of the research comment that successful treatment of daytime sleepiness does not necessarily imply that medicated patients are safe drivers4. Since driving is a complex skill, other factors could contribute to driver inattentiveness and increased risk of traffic accidents. Accidents in driving simulations carry no real consequences, and drivers may be aware of this fact. Considering all other circumstances, the researchers concluded that there is little scientific evidence to support that treating narcolepsy improves driving performance in patients.

This conclusion had no bearing on current traffic laws, which aimed to protect people on the road. Driving privileges can be limited for some drivers due to medical conditions, but rarely, and usually not for those whose condition is properly treated. Those with medical conditions leading to temporary incapacitation are few when compared to the majority of drivers, including those from higher-risk groups like new drivers, young drivers, and the elderly. Current laws are designed to allow drivers to determine if and when they are unsafe, and to impose penalties for those who were determined to be reckless. This allows patients with narcolepsy to prioritize receiving medical treatment without fearing that their mobility or independence will be compromised.

References

  1. Broughton R, Ghanem Q, Hishikawa Y, Sugita Y, Nevsimalova S, Roth B. Life effects of narcolepsy in 180 patients from North America, Asia and Europe compared to matched controls. Can J Neurol Sci. 1981;8:299–304.
  1. Findley L, Unverzagt M, Guchu R, Fabrizio M, Buckner J, Suratt P. Vigilance and automobile acci- dents in patients with sleep apnea or narcolepsy. Chest. 1995;108:619–24.
  1. Findley LJ, Suratt PM, Dinges DF. Time-on-task dec- rements in “steer clear” performance of patients with sleep apnea and narcolepsy. Sleep. 1999;22:804–9.
  1. Claire E.H.M. Donjacour, Monique A.J. Mets, Aurora J.A.E. van de Loo, and Joris C. Verster. “Narcolepsy, Driving, and Traffic Safety.” From Narcolepsy, M. Goswami et al. Springer International Publishing Switzerland, 2016.

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