Sleep Disordered Breathing In Senile Dementia

Background and objectiveAlzheimer's disease (AD) is the most common type of senile dementia, which ischaracterized by progressive deterioration of cognitive functions. Vascular dementia (VD) is the second most common type of senile dementia. Multi-infarct dementia (MID) ranks first among the causes of vascular dementia. It is known that sleep-disordered breathing occur frequently in patients suffered from AD and MID. The objective of this study is to determine the sleep/wake stage variables and the frequency of sleep apneas and hypopneas of these patients.MethodsUsing the polysomnograph of Alice 4, the sleep patterns of two patients with severe MID, one with mild MID and another two with mild AD, who fulfill the including and excluding criteria of this study were recorded. Electroencephalogram,electrooculogram, electrocardiogram, electromyogram in chin, nasal and buccal airflow and nocturnal blood oxygen saturation were monitored. Sleep data were analyzed.Results1. As for the two patients with severe MID, the time spent in REM sleep decreased significantly. Slow wave sleep increased and there were more duration and frequency of wake time. But the changes of total sleep time, stage 1 sleep and stage 2 sleep were unremarkable.2. The patient with mild MID showed no remarkable changes in the architecture of sleep.3. The two patients with mild AD spent more time awake and awoke frequently. One of them had marked decreased slow wave sleep. The same value of the other one increased.4. The two patients with severe MID experienced severe sleep apneas/hypopneas in the night, accompanied by marked reduction of blood oxygen saturation.5. The respiration events of the mild MID patient was not markedly increased.6. There were no significant increase of sleep apneas/hypopneas and reduction of blood oxygen saturation in the two patients with mild AD.Conclusions1. Patients with severe MID had obvious disturbed sleep continuity and architecture, with the significant reduction of REM sleep being characteristic. Their AHI values were particularly high, accompanied by evident decrease of blood oxygen saturation.2. The patient with mild MID showed increased wake time, without much disturbed architecture of sleep.3. Patients with mild AD had less stability during sleep. The incidence of sleep apnea and hypopnea was unremarkable.