LAUSR

Cerebellar ataxia with neuropathy and vestibular areflexia syndrome (CANVAS) is a rare disorder caused by an autosomal recessive biallelic pentanucleotide repeat expansion in the replication factor C subunit 1 (RFC1) gene. Clinical features include gait disturbances, impaired vibratory sensation, autonomic dysfunction, cough, and slow disease progression. Spinocerebellar ataxias are frequently associated with sleep disturbances, including REM sleep behavior disorders, insomnia, obstructive sleep apnea (OSA), and central sleep apnea. This is thought to be secondary to involvement of several nervous system structures including the cerebellum. OSA is caused by repeated obstruction of the pharyngeal airway leading to sleep disturbances and fatigue. It is likely that cerebellar insults such as CANVAS may play a role in upper airway obstruction and resultant OSA. However, there is little characterization of this relationship in the medical literature. We report a case of a 52-year-old female with a past medical history of CANVAS, anxiety, and depression who was referred to sleep medicine for evaluation of worsening daytime fatigue and fragmented sleep. She reported daytime sleepiness, morning headaches, and gasping arousals. Her Epworth sleepiness scale score was markedly elevated at 19 (normal < 10), and she was subsequently referred for home polysomnography testing for sleep apnea. Home sleep testing revealed an apnea-hypopnea index of 12.5 events/hour and a minimum oxygen saturation of 85%. This patient is at higher risk for sleep disruption due to her diagnosis of CANVAS. She presented with excessive daytime sleepiness and was found to have mild OSA on home sleep testing. Little is known about the presentation of OSA in patients with CANVAS. OSA treatment has the potential to improve sleep symptoms, quality of life, and mood disruption in this patient with an otherwise progressive and disabling neurologic disorder. Therefore early recognition and intervention of OSA are important in the care of patients with CANVAS. Given the disease’s progressive nature and lack of a cure, it is necessary to ameliorate quality of life however possible. OSA leads to persistent fatigue and may result in psychiatric disturbances, therefore, it is necessary to address sleep disturbances secondary to movement disorders to combat these outcomes.