Night sleep in patients with vegetative state

Abstract

Summary Polysomnographic recording of night sleep was carried out in 15 patients with the diagnosis vegetative state (syn. unresponsive wakefulness syndrome). Sleep scoring was performed by three raters, and confirmed by means of a spectral power analysis of the electroencephalogram, electrooculogram and electromyogram. All patients but one exhibited at least some signs of sleep. In particular, sleep stage N1 was found in 13 patients, N2 in 14 patients, N3 in nine patients, and rapid eye movement sleep in 10 patients. Three patients exhibited all phenomena characteristic for normal sleep, including spindles and rapid eye movements. However, in all but one patient, sleep patterns were severely disturbed as compared with normative data. All patients had frequent and long periods of wakefulness during the night. In some apparent rapid eye movement sleep episodes, no eye movements were recorded. Sleep spindles were detected in five patients only, and their density was very low. We conclude that the majority of vegetative state patients retain some important circadian changes. Further studies are necessary to disentangle multiple factors potentially affecting sleep pattern of vegetative state patients.

European Academy of Neurology guideline on the diagnosis of coma and other disorders of consciousness

“…Six studies with 153 patients were included . Relative risk for signs of covert consciousness suggesting MCS or better with sleep EEG compared to clinical examination was 1.55 (95% CI 1.24 to 1.94; P = 0.0001).…”

Parametric Description of EEG Profiles for Assessment of Sleep Architecture in Disorders of Consciousness

“…15 Similar relation was observed in DOC-patients, whose sleep recordings revealed spindles, preserved signs of consciousness and had higher chances for recovery. 16 Nevertheless, some researchers have shown that spindles are observed also in unconscious patients, [17][18][19] but the results are ambiguous. 20 Slow wave activity (SWA) defines slow wave sleep (SWS), which relates to stage 3 7 or combined stages 3 and 4.…”

Toward Improving Diagnostic Strategies in Chronic Disorders of Consciousness: An Overview on the (Re-)Emergent Role of Neurophysiology

“…In particular, a study reported that UWS patients with even severe impairment showed residual sleep patterns (including, sometimes, REM sleep), and that the presence of slow-wave sleep was correlated with high Coma Recovery Scale-Revised scores [121]. Similarly, other studies showed a discrimination between DoC categories according to sleep findings [122][123][124][125]. Furthermore, "regular" sleep structure was demonstrated as a good predictor of clinical outcome in sub-acute DoC patients and it was stronger than other known prognostic factors of DoC outcome [126,127].…”