Convulsions following traumatic brain injury (TBI) represent a diagnostic and therapeutic challenge. They can be differentiated into late (> 7 days after TBI), early (1 - 7 days after TBI), immediate (within the first 24 h after TBI), and impact seizures (within seconds after TBI). Some authors suggest that most impact seizures are non-epileptic in origin and hence coined the term "concussive convulsions" for benign impact seizures. Early and late post-traumatic seizures frequently indicate structural brain damage and transition to chronic, post-traumatic epilepsy. The data for impact seizures or concussive convulsions is less clear: only a small percentage of impact seizures is associated with structural brain damage and the development of post-traumatic epilepsy, rather the majority of cases are benign and associated with an excellent prognosis. Here, we present a case report as a starting point for pathophysiological and clinical considerations regarding convulsions that start within seconds after TBI.