Altered Intracortical Inhibition in Chronic Traumatic Diffuse Axonal Injury.

Background: Overactivation of NMDA-mediated excitatory processes and excess of GABA-mediated inhibition are attributed to the acute and subacute phases, respectively, after a traumatic brain injury (TBI). However, there are few studies regarding the circuitry during the chronic phase of brain injury.

Objective: To evaluate the cortical excitability (CE) during the chronic phase of TBI in victims diagnosed with diffuse axonal injury (DAI).

Normative data of cortical excitability measurements obtained by transcranial magnetic stimulation in healthy subjects.

Introduction: The assessment of cortical excitability (CE) measurements has been increasingly used in neuropsychiatric research. However, there is scant information on the normative values of these measurements, as well as the possible effect of hemisphere laterality, gender and age on these variables.

Objectives: To obtain normative data for CE measurements by transcranial magnetic stimulation, to assess inter-/intra-investigator variability and the influence of sex, age and oral contraception use.