Axonal polyneuropathy in obstructive sleep apnoea

Chronic hypoxaemia in chronic obstructive pulmonary disease is a well known risk factor for polyneuropathy but the impact of intermittent hypoxaemia o n peripheral nerve function has not been established so far. A case-control study was performed to evaluate the prevalence of polyneuropathy in obstru ctive sleep apnoea (OSA). Out of 24 patients with OSA, 17 (71%) had clinica l signs of polyneuropathy versus seven (33%) out of 21 matched controls. Th e mean amplitude of the sural sensory nerve action potential was smaller in the OSA group than in the control group, indicating axonal nerve damage. T he differences were significant and could not be attributed to other known risk factors for polyneuropathy: The severity, of axonal damage in patients with OSA correlated with the percentage of the night time with an O-2 satu ration below 90%. It is assumed that recurrent intermittent hypoxaemia in O SA is an independent risk factor for axonal damage of peripheral nerves.