Cognitive Neuromodulation

What is Cognitive Neuromodulation?

Cognitive neuromodulation is an approach under investigation in which neurostimulation, such as deep brain stimulation, is used to try to recover some conscious function in patients who have suffered a brain injury and as a consequence, for some time have been unable to willfully interact or reliably show overt signs of awareness and comprehension.  

What is the Background?

In 2002, researchers published a description of a new clinical designation, minimally conscious state, which defines someone who shows fluctuating, but not reproducible, signs of self-awareness and the surroundings.

Within five years, researchers at Weill Cornell Medical College reported in the Aug. 2, 2007 issue of the journal Nature that a New Jersey man who had been in a minimally conscious state for six years after a head injury regained some ability to feed himself, speak a little when prompted, and brush his teeth and hair, following deep brain stimulation surgery. During the surgery, slender electrical leads were implanted deep within his brain to provide neurostimulation to a network of cells in the thalamus that control arousal and attention, as well as exerting influence over cognitive and motor regions. (1)

What More Recent Research Has Been Done?

In 2012, Takamitsu Yamamoto, MD, PhD, and colleagues at the Division of Applied System Neuroscience, Department of Advanced Medical Science, Nihon University School of Medicine, Tokyo, Japan, reported on patients who were in a minimally conscious state or a more profound persistent vegetative state. Thirty-one study subjects were selected from a group of 128 patients on the basis on resting brain function. Resting brain function differs quite markedly in vegetative state and minimally conscious state, as determined by electrophysiological evaluation. Sixteen of 107 patients who were in vegetative state were included, and 15 of 21 patients who were in a minimally conscious state.

What Were the Results?

Twenty-one patients who had been in a vegetative state for three months, and five who had been in a minimally conscious state, were treated with deep brain stimulation. Another 10 patients who were in a minimally conscious state were treated with spinal cord stimulation.

Of those, eight of the 21 patients recovered from vegetative state and were able to follow verbal instructions. The patients who had been in a minimally conscious state were reported to show marked functional recovery. (2)

What is the Potential?

These early reports created interest in potentially being able to apply neuromodulation to regain some functional ability for communication and self-care in brain-injured patients who retain some residual abilities.

References:

1. Giacino J, Fins J, Machado A, Schiff N. Central Thalamic Deep Brain Stimulation to Promote Recovery from Chronic Posttraumatic Minimally Conscious State: Challenges and Opportunities. Neuromodulation 15 4 339–349 (2012).

2. Yamamoto T, Katayama Y, Obuchi T, et al. DBS and SCS for vegetative and minimally conscious state. World Neurosurgery. (June 2012).


Reviewed Feb. 5, 2013
Takamitsu Yamamoto, MD, PhD
President, International Neuromodulation Society Japan Chapter
Professor of Applied System Neuroscience and Neurological Surgery at Nihon University, School of Medicine, Tokyo, Japan

Last Updated on Tuesday, April 25, 2017 11:16 AM