Prolonged post-traumatic unconsciousness, diffuse brain injury and epilepsy

To investigate whether prolonged post-traumatic unconsciousness should be still considered as a risk factor of epilepsy, we studied a series of sixty pts admitted to the Istituto of Neurosurgery of the University of Milano for immediate traumatic coma associated with diffuse brain lesions and who survived their injury. All pts have been followed-up for a mean time of 4.1 years. The series comprises 31 children (C) and 29 adults (A), 39 males and 21 females with a mean admission Glasgow Coma Scale score: 6.6 (C) and respectively (A) 4.5. All pts have been submitted to repeated CT. According to CT scan appearance we identified three groups of pts: a) 19 pts with well defined, small hyperdense shearing injuries in the corpus callosum and or paramedian white matter, and/or basal ganglia or upper brainstem; b) 29 pts. with 'normal' CT, c) 12 pts with absent 3rd ventricle and basal cisterns. CTs a) and b) have been considered suggestive of diffuse axonal injury, CT c) has been considered indicative of diffuse brain swelling. At follow-up (mean 4.1 years) 34 pts presented a good recovery, 21 moderate disability, 3 severe disability and 2 persistent vegetative state according to the Glasgow Outcome Scale. Only one patient had a single early seizure at admission while no patient presented late seizures during follow up. We therefore conclude that prolonged coma should not be considered as a risk factor for epilepsy whern associated with diffuse brain lesions.