Cavinato et al. report the occurrence of a partial and secondarily generalized tonic-clonic seizure in a 31-year-old male patient who suffered a severe TBI 8 months prior to rTMS intervention. MRIs following the TBI revealed diffuse hematoma in corpus callosum with mass effect over the fourth ventricle and upstream hydrocephalus. Prior to treatment, the patient received medication for gastric disorder and spasticity (2 ml Diazepam), and he had no prior personal or family history of epilepsy or seizure disorder. Treatment began once stable clinical conditions were demonstrated and baseline EEG excluded epileptiform and paroxysmal activity. Three of ten daily sessions at 90% abductor pollicis brevis MT (20 Hz, 1 s train duration, 1 min inter-train interval) applied to the DLPFC were tolerated without adverse effects. Three hours after the fourth rTMS session, the patient experienced an adversive seizure followed by a secondary generalized seizure and a complete loss of consciousness, with no urinary or bladder incontinence or tongue beating. EEG reports following the seizure showed slowing with focal spike discharges in the left fronto-central areas. Reports taken 2 days following the seizure displayed no epileptiform activity and demonstrated a return to baseline levels, with no antiepileptic medication administered at any time.