Altered Cerebral Perfusion of Motor Cortex in Patients with Periodic Limb Movement Disorder

Address for correspondence Seung Bong Hong, MD, PhD Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Irwon-dong, Gangnam-gu, Seoul 135-710, Korea Tel: +82-2-3410-3592 Fax: +82-2-3410-0052 E-mail: ejoo@skku.edu eyuns@paran.com Objectives: The pathophysiology of sleep-related motor diseases and sleep dysfunction in movement disorders is widely unknown as yet. Functional brain imaging, in particular radioisotope techniques, is considered to be powerful tool to investigate pathomechanisms of periodic limb movement disorder (PLMD). Methods: We performed Tc-ethyl cysteinate dimer brain single-photon emission computed tomography in 25 drug-naive patients with PLMD and 23 age-and gender matched normal cotrols during wakefulness. For statistical parametric mapping analysis, single-photon emission computed tomography images were spatially normalized to the standard template and then smoothed using a 14-mm full width at half maximum Gaussian kernel. Results: Mean age of patients and normal controls was 48.6 years and over half of them were male. Most patients reported the sleep onset and maintenance insomnia due to repetitive leg jerks. Average duration of insomnia was 7.5 years. They denied the history of restless leg syndrome and there was no sleep disorders such as obstructive sleep apnea syndrome which was confirmed by polysomnography. Mean PLM during sleep index and movement arousal index were markedly increased to 45.3/hr and 7.5/hr, respectively. Their sleep quality was poorer than that of normal patients. In PLMD patients, cerebral blood flow was significantly increased in the bilateral precentral gyri as compared to normal controls. There was no brain region showing decreased perfusion in patients. Regional cerebral perfusion was not correlated to any polysomnography parameter including PLMS index or movement arousal index. Conclusions: Different perfusion pattern in bilateral primary motor cortices may provide the evidences of motor cortical impairment in patients with PLMD. J Korean Sleep Res Soc 2011;8:35-39