Traumatic brain injury-tDCS-Study: Cognitive impairment after repeated concussions

Mild traumatic brain injury (mTBI) occurs frequently, especially in risk sports like soccer, American football or ice hockey. A number of studies have shown that mTBI can lead to permanent cognitive deficits. Furthermore, subjects who had mTBI in earlier life, are more prone to develop dementia in older age. Interestingly, patients after mTBI show advanced neurodegeneration in middle to older age. The exact pathomechanisms are yet unclear, although changes in neurotransmitter activity, especially GABA-activity, are being discussed.

PROJECT 1: The first project investigated the influence of anodal transcranial direct current stimulation (tDCS) on GABA-activity in young patients (< 40 years), who suffered repeated grade 1 mTBI. Neurotransmitter activity was determined by using non-invasive brain stimulation techniques (transcranial magnetic stimulation, TMS). Patients were receive a detailed neuropsychological testing and MRI of the head. Perspectively, tDCS may be a tool to restore GABA-activity in the brain, which may in turn help to prevent cognitive deterioration in these patients before obvious cognitive deficits occur.

PROJECT 2: The second project examined the influence of anodal transcranial direct current stimulation (tDCS) on GABA-activity in older patients (> 55 years) who have suffered grade 1 mTBI before the age of 35. The neurotransmitter activity was determined using TMS as in Project 1. Patients were receive an MRI and a detailed neuropsychological testing. In addition, different biomarkers of cerebral inflammation were determined. Follow-up examinations (TMS, MRI, blood samples) after one and two years should show, whether neurotransmitter acitivity or blood biomarkers are predictors of accelerated neurodegeneration.

Study director: Prof. Dr. Agnes Flöel (WG Cognitive Neurology, NCRC, Neurology CCM)

Course of the study: 2012 - 2014

The study is registered in the database clinicaltrials.gov (NCT01593956).