Assessing level of consciousness and cognitive changes from vegetative state to full recovery

Abstract

Although investigations addressing cognitive recovery from the vegetative state have been reported, to date there have been no detailed studies of these patients combining both neuropsychology and functional imaging to monitor and record the recovery of consciousness. This paper describes the recovery of a specific vegetative state (VS) case. The patient (OG) remained in the vegetative state for approximately two months, increasing her level of awareness to a minimally conscious state, where she continued for approximately 70 days. In the course of the ensuing 18 months, she was able to reach an acceptable level of cognitive functioning, with partial levels of independence. Throughout this two year period, she received continuous cognitive evaluation, for which several different tools were applied including coma and low functioning scales, full cognitive batteries, and structural and functional magnetic resonance imaging (MRI). We present here preliminary data on fMRI using a word presentation paradigm before and after recovery; we also discuss the difficulty of how to determine level of consciousness using the tools currently available, and the subsequent improvement in different cognitive domains. We confirm that accurate diagnosis and proper cognitive assessment are critical for the rehabilitation of patients with disorders of consciousness.