Behavioral fluctuation in disorders of consciousness: a retrospective analysis.

Abstract

Objectives: To assess the frequency of behavioral fluctuations in patients with prolonged disorders of consciousness (DoC), characterize the stability of consciousness ratings, and characterize the stability of behavioral signs of consciousness.

Design: Prospective observational analysis.

Setting: Specialized DoC Program in an inpatient rehabilitation facility and a long-term acute care hospital.

Participants: Patients in vegetative state/unresponsive wakefulness state (VS/UWS), minimally conscious state and emerged from MCS followed weekly on the Coma Recovery Scale- Revised (CRS-R) between 28 and 90 days post-injury (N=241).

Main outcome measure: Change in CRS-R subscale scores and consciousness ratings.

Results: Behavioral fluctuation was observed in more than 80% of patients, and was most common on the CRS-R Motor subscale and least common on the Communication subscale (83% and 54% of patients experienced ≥1 fluctuation over the 3-week study period, respectively, with a 1-point change observed most frequently). Among patients who were conscious on baseline assessment, 25% were subsequently rated as unconscious at least once. Localization to pain and object manipulation were the most stable signs of consciousness, recurring at least 3 times after the first occurrence in ≥ 97% of the sample. Reproducible command-following and intelligible verbalization were the least stable, recurring at least 3 times after the first occurrence in ≤ 27% of the sample.

Conclusions: Patients with prolonged DoC who undergo serial assessment demonstrate a high rate of fluctuation in behavioral signs of consciousness. These findings highlight that repeated assessments are essential in this population, both to capture the highest level of consciousness and to help distinguish spontaneous fluctuation from response to treatment in interventional studies.