“The clinical evaluation of consciousness in Disorder of Consciousness (DOC) patients, based on their exhibited behavior, is difficult and remains erroneous in many cases,” report researchers at the Hadassah Medical Center.
Aiming to determine the plausibility and challenges of implementing a clinical service to evaluate the consciousness level in patients suffering from (DOC), the researchers found via Functional MRI that different patients exhibited different degrees of responsiveness. They explain that recent studies demonstrate different levels of stimulus processing, as well as evidence of some level of awareness in sub-groups of these patients.
The study was composed of 11 patients (ages 11-67), who were diagnosed as being in either vegetative or minimally conscious states. Using Functional MRI, researchers evaluated auditory, language, voice familiarity, imagery, and visual responsiveness.
The authors report: In 9 patients, they found auditory-related activation; however, only in 5 of the subjects was differential activation found for language. Six patients exhibited differential response to their own name. In three patients, a response to visual stimuli was identified. In one patient, the auditory and linguistic systems were clearly activated in a hierarchical pattern and, moreover, willful modulation of brain activity was identified in the imagery test.
Lead Author of the study was Atira S. Bick, coordinator of the clinical service in Hadassah’s Functional MRI Unit. The original research article, entitled “Implementing Novel Imaging Methods for Improved Diagnosis of Disorder of Consciousness Patients”, appears in the Journal of the Neurological Sciences, Volume 334, Issues 1–2, 15 November 2013, Pages 130-138.