Commentary
Video
Exploring Cognitive Motor Dissociation in Consciousness Disorders: Nicholas Schiff, MD
The Jerold B. Katz professor of neurology and neuroscience at Weill Cornell Medicine talked about a recent study that revealed patients who appeared unresponsive to verbal commands in vegetative or minimally conscious states retained high cognitive function. [WATCH TIME: 6 minutes]
WATCH TIME: 6 minutes
"We found that about 25% of those who were unresponsive to command still retained the capacity to carry out high-level cognitive tasks."
Patients with brain injury who are unresponsive to commands may perform cognitive tasks identified through the use of functional MRI (fMRI) and electroencephalography (EEG). This phenomenon, known as cognitive motor dissociation, had not been systematically studied in a large cohort of persons with disorders of consciousness, until recently. Published in the New England Journal of Medicine, a study showed that approximately 1 in 4 patients without an observable response to commands performed a cognitive task on fMRI or EEG as compared with 1 in 3 patients with an observable response to commands.1,2
Conducted by senior author Nicholas Schiff, MD, and colleagues, the study collected clinical, behavioral, and task-based fMRI and EEG data from a convenience sample of 353 adults with consciousness disorders. Researchers detected cognitive motor dissociation in 60 of the 241 patients (25%) without an observable response to commands, of whom 11 were assessed with fMRI only, 13 with EEG only, and 36 with both techniques. Additional findings showed that cognitive motor dissociation was associated with younger age, longer time since injury, and brain trauma as an etiologic factor. Notably, responses on task-based fMRI or EEG were reported in 43 out of 112 patients (38%) with an observable response to verbal commands.
In a recent conversation with NeurologyLive®, Schiff, the Jerold B. Katz professor of neurology and neuroscience in the Feil Family Brain and Mind Research Institute at Weill Cornell Medicine, sat down in an interview to discuss the implications this study has for diagnosing patients with disorders of consciousness. Schiff, who also serves as a neurologist at NewYork-Presbyterian/Weill Cornell Medical Center, talked about how brain-computer interfaces might be used to help patients with cognitive motor dissociation. Furthermore, he spoke about the challenges that exist in accurately assessing cognitive function in patients who appear unresponsive.
