Sleep problems in Parkinsonism

Sudden daytime ''sleep attacks'' among Parkinson's disease victims are not associated with any specific drug or class of drugs they may be taking. Parkinson's disease is a disease that affects the nervous system resulting in muscle stiffness, tremors of the limbs and slowness of movements. There is no cure for Parkinson's disease though the symptoms can be controlled and their progression slowed. This improves the quality of life of patients. The commonly used drugs include levodopa, amantidine, trihexyphenidyl, selegiline, and more recently pramipexole and ropinirole. All these drugs have side effects that must be understood but can often be controlled by careful adjustments of the dose and diet. Researchers at the University of Manitoba, Canada investigated the reports in medical journals suggesting that new drugs called non-ergot dopamine agonists were causing sudden sleep onset and automobile accidents among patients with Parkinson's disease. The survey was conducted between January and April 2000 in 18 clinics and 638 patients with parkinsonism receiving a variety of medications, were enrolled in the study. 420 of these were driving their own vehicles. The study found that falling asleep at the wheel was typically preceded by a warning of sleepiness, rather than occurring suddenly and unpredictably. Only 21 of the drivers reported dozing spells at the wheel and three experienced no warning symptoms. Sudden-onset sleep without warning is infrequent, though daytime excessive sleepiness in general is a recognized symptom of the disease. Sudden onset of sleep during any activity was found to occur with all medications and their combinations. There was no significant difference between the new dopamine agonists and the older agonists. Dopamine agonists mimic the effects of dopamine, a chemical messenger whose decrease in production causes tremors, stiffness and other symptoms of the disease. The observations suggest that sudden onset of sleep is not related to any specific anti-Parkinson drug. Patients should be warned about the nature of excessive daytime sleepiness. They should be educated to recognize the warning symptoms and the associated risk of these episodes occurring while driving, and about the importance of never driving when sleepy.

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