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Traumatic Brain Injury

Dartmouth-Hitchcock is involved in numerous research projects concerning traumatic brain injury (TBI). We are interested in understanding cognitive and emotional changes after brain injury.

We have been studying impaired memory and attention in prospective, controlled longitudinal experiments funded by the National Institute on Disability and Rehabilitation Research (NIDRR) and the National Institute of Neurological Disorders and Stroke (NINDS) that have focused on individuals one month and one year after TBI. The aim of this work has been to characterize the nature of cognitive deficits after TBI, and to understand the neural mechanisms underlying these deficits.

More recently we have started to characterize the relationship between cognitive function and polymorphisms of specific candidate genes, and to use fMRI to characterize the neural mechanisms underlying these interactions. We plan to use this understanding to develop effective treatment interventions for individuals with disabling cognitive impairments after TBI.

We have several NIH funded projects under this broad umbrella.

Genetic predictors affecting brain injury

In this study, we are seeking to identify genetic predictors of outcome after brain injury. Certain genes may ramp up or reduce the brain's response to trauma and influence resilience of humans to adverse events. An example of this is how protein can influence how rapidly serotonin is taking up by the gene.

People vulnerable in the area of working memory have trouble keeping information "online" while processing other information. There is a particular chemical called COMT. If you have one copy of the gene, you efficiently metabolize dopamine; if you have the other copy of the gene, you metabolize the gene slowly, and therefore do better on some cognitive tasks.

Brain injury with persistent memory/attention complaints

This NIH study is a clinical trial of people with brain injury and persistent memory and attention complaints. We randomize patients 4 to 30 months out from their injury to receive various memory and retention training: an eight-session cognitive training, the drug Rydalin, or a placebo.

We are actively seeking additional participants within one month of injury for this clinical trial. This is a longitudinal study looking at one month and one year from time of injury.

Functional MRI

In partnership with Simbex, a company which makes tiny accelerometers, we are studying athletes pre-season and post-season with MRI cognitive symptom checklists. The accelerometers are embedded in football and ice hockey helmets. Each time they hit their head, the G-force is measured and transmitted to a sideline receiver. If someone sustains a blow, we can measure the force of the concussion. What was the force of the blow? We measure the effect of the blow, direction of blow, what part of the head.

Also we can measure their exposure to biomechanical force.

There is an enormous amount of interest from the NFL, and also from the military.

This study has three parts:

  • The Biomedical Research Project, with Simbex as the lead investigator in a consortium made up of Dartmouth College, Brown University, and Virginia Tech, studies the biomechanics of sports concussion.
  • A larger expanded study of Dartmouth football and ice hockey players is longitudinal, tracking students from freshman year throughout their careers.
  • The third part is funded by Center for Disease Control and studies Hanover High School football players.

Improved state services for TBI

A series of grants with the State of New Hampshire administrative services seeks to improve delivery of services to individuals suffering from traumatic brain injury. The goal is to improve the capacity of local mental health and developmental service agencies to evaluate and treat neurobehavioral consequences of TBI.

Brain injury is the signature wound of the current conflicts in the Middle East due to multiple exposures to highly improvised explosive devices such as bombs planted by the roadside. Soldiers are often exposed to one or more often multiple blast situations, including exposure to pressurized wave, deceleration/acceleration wounds from physical jarring, penetration of matter, exposure to a chemical, or some combination. Application submission for grants to participate in research in this area is ongoing.