Cortical cerebellar atrophy presenting with central type sleep apnea syndrome

The patient was a 55-year-old man who had shown progressive dysarthria and unsteady gait since 48 years of age. Neurologically, pure cerebellar ataxia without either pyramidal or extrapyramidal signs was seen. He had been diagnosed as having cortical cerebellar atrophy (CCA) at age 53. Polysomnography was carried out at June 17 ^th, 2003, because of snoring and sleep apnea had occurred since January 2003. The results showed central dominant sleep apnea with an apnea index (AI) of 16.6. Apnea occurred during shallow sleep, stages I and II, while the length of REM sleep was almost normal, occupying 17.7% of total sleep time. The rhythm of his sleep was well preserved. Brain MRI showed cerebellar atrophy without any brainstem abnormality. Except for the central type sleep apnea, no other autonomic symptoms were found. We considered that the diagnosis of CCA remained applicable to the patient because of the presence of pure cerebellar symptoms over a 7-year-course, and the absence of brainstem atrophy on MRI. Sleep apnea seen in the present patient was distinct from MSA in which central type sleep apnea dominated, and that the sleeping rhythm including REM was preserved.