Sleep apnoea related hypoxia is associated with cognitive disturbances in patients with tetraplegia

Abstract

Sleep disordered breathing is common in patients with tetraplegia. Nocturnal arterial hypoxemia and sleep fragmentation due to sleep apnoea may be associated with cognitive dysfunction. We therefore studied the in¯uence of sleep disordered breathing on neuropsychological function in 37 representative tetraplegic patients (mean age 34+9.7 years). Thirty percent (11 of 37 patients) had clinically signi®cant sleep disordered breathing, de®ned as apnoea plus hypopnoea index (AHI) greater than 15 per hour of sleep. Most apnoeas were obstructive in type. Seven patients (19%) desaturated to 580% during the night. Neuropsychological variables were signi®cantly correlated with measures of sleep hypoxia, but not with the AHI and the frequency of sleep arousals. The neuropsychological functions most aected by nocturnal desaturation were: verbal attention and concentration, immediate and short-term memory, cognitive¯exibility, internal scanning and working memory. There appeared to be a weak association between the presence of severe sleep hypoxia and visual perception, attention and concentration but no association was found between sleep variables and depression scores. We concluded that sleep disordered breathing is common in patients with tetraplegia and may be accompanied with signi®cant oxygen desaturation. The latter impairs daytime cognitive function in these patients, particularly attention, concentration, memory and learning skills. Cognitive disturbances resulting from sleep apnoea might adversely aect rehabilitation in patients with tetraplegia.

Sleep disturbances in the spinal cord injured: an epidemiological questionnaire investigation, including a normal population

“…8 Sleep related hypoxia may be associated with cardiovascular events and a risk of stroke, 50 and cognitive disturbances in patients with tetraplegia. 12 It was a little surprising that only a few in the SCI population reported decreased ability to change position as a sleep problem because many SCI individuals mostly sleep supine, and this position has been shown to be associated with sleep disordered breathing. 51 Adverse sleeping position may even be part of the explanation for the occurrence of periodic leg movements found in patients with SCI.…”

Subjective sleep disturbances and quality of life in chronic tetraplegia

“…5 OSA has been associated with impaired cognition in people with tetraplegia, particularly in the areas of attention, concentration, memory and learning skills. 8 Other serious health consequences of OSA in the able-bodied population include increased risk of cardiovascular disease, diabetes and premature death. 9 This observational study describes the subjective sleep disturbances and quality of life of a chronic tetraplegic population and, where possible, compares the results with the best available published ablebodied (normative) data.…”

Vital capacity in tetraplegics twenty years and beyond

“…Similarly, the incidence of sleep apnea in our study population is slightly less (5.3%) than reported in other tetraplegic populations, with the reported incidence ranging from 15% to 30%. 35,36 Smoking has been known to in¯uence VC in normal persons. Expected results include decline in FEV1, FVC and FEV1/FVC ratio.…”