Spindle and EEG Sleep Alterations in Subjects Affected by Cortical Cerebellar Atrophy

Abstract

All-night polygraphic records (EEG, EOG and ECG) were performed on 9 subjects. Four of them were affected by Familiar Cerebellar Atrophy (FCA) whereas the others were their blood relatives without clinical signs of cerebellar deficit. In the former FCA was diagnosed clinically and the cerebellar atrophy was confirmed by computer tomography (CT). In all the latter except one who showed slight cerebellar atrophy, the CTs were negative. The EEG sleep records of the FCA patients were characterized by slowly changing phases between synchronized and desynchronized sleep, instability of the synchronized sleep with frequent modifications of EEG activity, subnormal measurement of both REM and slow-wave sleep and presence of spindles in REM sleep (only in 2 patients). The spindle activity was reduced in two FCA subjects. The electroencephalographic sleep records of two BRs, one of which with small cerebellar atrophy, showed qualitative and quantitative alterations similar to those of FCA patients, even if marked to a lesser degree. Increased spindle densities were present in the same BRs who showed sleep abnormalities. The EEG alterations observed in the two BR subjects could show small cerebellar injuries which would be insufficient to induce clinical signs.

Obstructive sleep apnea is related to a thalamic cholinergic deficit in MSA

“…Patients with multiple-system atrophy (MSA) develop many sleep disorders, including obstructive sleep apnea (OSA) with repeated arousals and hypoxemia, 1,2 central sleep apnea, 3 dysrhythmic breathing, 2 phasic swings of systemic arterial pressure, 4 laryngeal abductor paralysis with stridor, 5,6 reduced REM and slowwave sleep, 7 and REM sleep behavior disorder (RBD). 8 OSA occurs frequently in MSA 3 and carries the risk of sudden death.…”

What Is the Involvement of the Cerebellum During Sleep?

“…71 In humans, surgical lesions of different portions of the cerebellum were associated with different disturbances in sleep regulation; in one study, paleocerebellar (anterior lobe) lesions were associated with the reduction of NREM sleep and an increase in REM sleep, whereas neocerebellar (posterior lobe) lesions altered both the transition between wake and sleep and sleep maintenance. 72 Several disorders affecting the cerebellum are associated with sleep disturbances, but the contribution of the cerebellum to these sleep abnormalities are yet to be fully understood. 23,24,73 Genetic disorders associated with cerebellar malformation may manifest with sleep disturbances; the typical example is the Joubert syndrome characterized by cerebellar vermis hypoplasia and sleep apnea.…”