Posted by CCF Neuro MD on August 16, 1997 at 11:47:12:

In Reply to: Too Tired or Too Drugged? posted by Laura on July 23, 1997 at 10:09:46:

: I'm a 42F that has been on lithium for 15 years for BP. Thyroid is tested yearly and is okay; blood level okay for me. Daytime sleepiness is debilitating. I wake up and need a nap to start the day. I have memory lapses, accidents, and can fall asleep anywhere, any time. I was looking up something else and found narcolepsy. I've never had cataplexy, but I've have the hypnagogic hallucinations, and some sleep paralysis. I've taken my ADD son's Ritalin/Dexedrine in emergencies and it helps. My question: Is it the lithium/lithium levels or could it be narcolepsy or something else?

Dear Laura:

I agree. Your symptoms are quite concerning for narcolepsy. Although cataplexy is frequent, it is not a universal symptom of narcolepsy. You do seem to have some of the other symptoms of the disorder. Narcolepsy is not an uncommon condition, but is under-recognised.
Although lithium has effects on sleep architecture and the circadian rhythm, I could not find references of lithium inducing narcolepsy, or causing hypersomnolence at therapeutic levels.
A complete sleep study (MSLT and polysomnography) can help diagnose your problem. Very importantly, it can help exclude other causes of excessive daytime drowsiness, such as obstructive sleep apnea syndrome. Pursuing a diagnostic work-up of your symptom is very appropriate because hypersomnolence can be dangerous (e.g. while driving), and most causes of the problem are eminently treatable.
I certainly do not recommend your taking your son’s prescription medications!
I hope this answers you question. In case you live near Cleveland and want your sleep issues sorted out, I recommend that you see a sleep specialist at the Cleveland Clinic. Drs. Dinner, Foldvary, Geller, and Kotagal are renowned for their expertise in this area of neurology, and we also have a busy state-of-the-art sleep lab.
I wish you the best of luck.
This information is provided for general medical education purposes only. Please consult your physician for diagnostic and treatment options of your specific medical condition.