Sleep Features on Continuous Electroencephalography Predict Rehabilitation Outcomes After Severe Traumatic Brain Injury

Abstract

Objective: Sleep characteristics detected by electroencephalography (EEG) may be predictive of neurological recovery and rehabilitation outcomes after traumatic brain injury (TBI). We sought to determine whether sleep features were associated with greater access to rehabilitation therapies and better functional outcomes after severe TBI.

Methods: We retrospectively reviewed records of patients admitted with severe TBI who underwent 24 or more hours of continuous EEG (cEEG) monitoring within 14 days of injury for sleep elements and ictal activity. Patient outcomes included discharge disposition and modified Rankin Scale (mRS).

Results: A total of 64 patients underwent cEEG monitoring for a mean of 50.6 hours. Status epilepticus or electrographic seizures detected by cEEG were associated with poor outcomes (death or discharge to skilled nursing facility). Sleep characteristics were present in 19 (30%) and associated with better outcome (89% discharged to home/acute rehabilitation; P = .0002). Lack of sleep elements on cEEG correlated with a poor outcome or mRS > 4 at hospital discharge (P = .012). Of those patients who were transferred to skilled nursing/acute rehabilitation, sleep architecture on cEEG associated with a shorter inpatient hospital stay (20 days vs 27 days) and earlier participation in therapy (9.8 days vs 13.2 days postinjury). Multivariable analyses indicated that sleep features on cEEG predicted functional outcomes independent of admission Glasgow Coma Scale and ictal-interictal activity.

Conclusion: The presence of sleep features in the acute period after TBI indicates earlier participation in rehabilitative therapies and a better functional recovery. By contrast, status epilepticus, other ictal activity, or absent sleep architecture may portend a worse prognosis. Whether sleep elements detected by EEG predict long-term prognosis remains to be determined.

Figure 1.

Continuous electroencephalography (EEG) findings and functional outcomes. Ictal-interictal EEG patterns (panel A) and EEG sleep features (panel B) correlated with functional outcome, as determined using the mRS score. mRS <4 was considered a favorable outcome. *A statistically significant difference between groups (P < .05).

Figure 2.

Continuous electroencephalography (EEG) findings and discharge disposition. Ictal-interictal EEG patterns (panel A) and EEG sleep features (panel B) and disposition at hospital discharge. Discharges to home or acute rehabilitation were considered favorable outcomes. *A statistically significant difference between the 2 outcome groups (P < .05).

Figure 3.

Sleep features and rehabilitation time course. Number of hospital days before first inpatient therapy visit, ICU length of stay, and hospital length of stay for patients based on the presence of sleep features on continuous electroencephalography. ICU indicates intensive care unit.