[Scalp-recorded cortical spreading depolarizations (CSDs) of EEG with time constant of 2 seconds in a patient with acute traumatic brain injury].

An 82-year-old female suffered from head trauma, and developed acute consciousness disturbance 6 days after the event. Head CT showed the acute subdural hematoma in the left temporooccipital area and the patient underwent emergency hematoma evacuation and decompression. However, her consciousness disturbance became worse after surgery. Intermittent large negative infraslow shifts (lasting longer than 40 seconds) were recorded in the right posterior quadrant by scalp EEG with TC of 2 sec, that was defined as cortical spreading depolarizations (CSDs). Clinically consciousness disturbance sustained poor until 1 month after surgery in spite of treatment by anti-epileptic drugs. CSDs were observed on the right side where head injury most likely occurred. It may explain the sustained consciousness disturbance associated with significant prolonged ischemia. Once scalp EEG could record CSDs in this particular patient, the degree and its prognosis of traumatic head injury were estimated.