Case 25. Movements Come in Different Ways

Abstract

A 76-year-old man presented with kicking, arm knocking, talking and singing during sleep. A polysomnogram showed hypopneas without oxyhemoglobin desaturation, and nasal continuous positive airway pressure (CPAP) was recommended after titration, without any response. A video-polysomnography showed: (a) frequent, vigorous stereotyped periodic limb movements of sleep (PLMS) involving the lower limbs, upper limbs and trunk inducing arousals associated with hyperventilation followed by relative breathing amplitude decrease with sleep resumption; (b) abnormal behaviors during arousals immediately following PLMS in NREM sleep; and (c) ruled out REM sleep behavior disorder (RBD). Iron deficiency was detected, which could not be improved by iron supplements. A colonoscopy showed an adenocarcinoma of the colon, which was resected. Dopaminergic agents improved abnormal sleep behaviors. Abnormal sleep behaviors simulating REM sleep behavior disorder (RBD) may occur in the context of PLMS. The video-polysomnography allowed to exclude RBD and identified PLMS that caused arousal containing abnormal behaviors with breathing amplitude oscillations mimicking sleep apnea. The identification of the sleep problem helped an early diagnosis of colon cancer.