Somnolence and Periodic Limb Movements due to Treatment with Baclofen

Excessive sleepiness is a common reason for a referral to sleep medicine clinics. The clin-ical picture and context usually suggest the underlying cause; however, all possibilities should be considered and only after sleep studies are done, one can determine the likely cause of the patient’s symptoms.

Case Report: 

We presented the case of a man who was referred for evaluation of hypersomnolence along with snoring and possible apnea during sleep. Obstructive sleep apnea (OSA) was suspected, so home sleep apnea test (HSAT) and later polysomnography (PSG) were performed and both ruled out this possibility. The PSG showed frequent periodic limb movements (PLMs), some associated with arousal; abnormal sleep structure suggested the effect of medication. The patient had been taking baclofen for musculoskeletal pain and it was concluded that baclofen was the cause of the patient’s somnolence and PLMs. The patient’s clinical presentation was compounded by his history of post-traumatic stress disorder (PTSD) and gastroesophageal reflux which probably caused increased arousals and the subjective feeling of poor sleep quality.

Treatment with medications that have sedative effects should be considered in all patients presenting with excessive daytime sleepiness even if the initial clinical picture suggests another possible cause. Baclofen can cause PLMs, sedation, changes in N3 stage, and reduction in rapid eye movement (REM) sleep.