Sleep Patterns in a Carbon Monoxide (CO) Poisoning Patient

Importance: The functional anatomy of the brain, especially of the subcortical structures, is one of the least understood areas in neurophysiology. A great deal of the understanding of the functional neuroanatomy is derived from the study of patients whose brain has been damaged under different circumstances. Carbon monoxide (CO) poisoning affects particularly the basal ganglia and subcortical white matter, providing insight into the functional neuroanatomy of this complex region of the central nervous system. Since the regulating mechanisms of the sleepwake cycle depend on multiple brain regions, damage of any of these regions may result in states of vigilance disturbances. Methods: Sleep was recorded and scored using 30-s epochs according to standard methods, including central and occipital EEG (C3-A1, C4-A2, O1-A1 and O2-A2), submental EMG and periorbital EOG. Oronasal airflow and thoracic and abdominal respiratory effort were also monitored throughout the night. Results: In addition to disruption of continuity and alterations in the sleep architecture, total sleep time was significantly reduced in the patient under study; consequently, sleep efficiency was severely affected. Reduction in total time spent in REM sleep was related to the mean duration but not to the number of REM sleep episodes displayed across the recording of sleep. Cardiac and respiratory activities exhibited a tendency across the sleepwake cycle different to that observed in healthy subjects. Conclusions: This report suggests that cortical and subcortical brain damage caused by CO poisoning induces sleep disturbances and functional modification of the autonomic nervous system. Therapies to improve the sleep quality of patients exposed to CO poisoning should be implemented.