Behavioral Fluctuation in Disorders of Consciousness: A Retrospective Analysis.

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 a vegetative state/unresponsive wakefulness state, minimally conscious state, and emerging from a minimally conscious state followed weekly by the Coma Recovery Scale-Revised (CRS-R) between 28 and 90days postinjury (N=241).

MAIN OUTCOME MEASURES

Change in CRS-R subscale scores and consciousness ratings.

RESULTS

Behavioral fluctuation was observed in >80% of patients and was most common in the CRS-R motor subscale and least common in the communication subscale (83% and 54% of patients experienced ≥1 fluctuation over the 3wk study period, respectively, with a 1-point change observed most frequently). Among patients who were conscious at 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.