Seizure is a clinical manifestation of abnormal/excessive discharge by a set of neurons.

Type Description
Partial simple if preserved consciousness, complex if impaired consciousness
Generalized grand mal or tonic clonic

Risk factors for late PTS (after 7d):

  • penetrating injury
  • intracranial hematoma
  • early PTS (24hrs to 7d)
  • depressed skull fracture
  • prolonged coma/PTA

Epilepsy: In a non-traumatic setting, recurrent (≥2) seizures unprovoked by any immediate identified cause that are 24hrs apart

Post-traumatic Epilepsy (PTE): recurrent late seizures not attributable to any other etiology other than TBI

Antiepileptic drugs (AEDs) have only proven effective during the first week post-injury at decreasing incidence of early PTS. No benefit seen with prophylaxis >1 week

Therapeutic AEDs are usually started once late seizures occur (there is a high probability of recurrence)

PTE Treatments

  • carbamazepine (for partial) and valproic acid (for generalized) have been preferred to phenobarbital or phenytoin (these are more sedating, associated with cognitive impairment)
  • Recent guidelines suggest comparative effectiveness of valproate vs. phenytoin insufficient, non-significant trend toward higher mortality with valproate
Drug Dosing
Phenytoin (PO=IV) 100mg TID
(can titrate up to 600mg/day but at no less than 7-10 day intervals)
Valproate (PO=IV) 15mg/kg/day
(can titrate up to 60mg/kg/day but at weekly intervals by just 5-10mg/kg/day)
Levetiracetam (PO=IV) 500mg BID
(can titrate up to 1500mg BID but by no more than 500mg/dose q2weeks).

For seizure prophylaxis in SAH (off label use): load with 20mg/kg then maintenance with 1000mg q12h x7 days.

Note: Levetiracetam also is used increasingly for seizure prophylaxis in many conditions including TBI, but comparative studies are insufficient to support superiority over other agents.

  • References

    Elovic E, Baerga E, Galang GF, Cuccurullo SJ, Reyna M, Malone RJ. Physical Medicine and Rehabilitation Board Review. 3rd ed. New York, NY: Demos Medical; 2015. Chapter 2, Traumatic Brain Injury. P.96-146.

    Haltiner AM, Temkin NR, Dikmen SS. Risk of seizure recurrence after the first late posttraumatic seizure. Arch Phys Med Rehabil. 1997;78:835–840.

    Carney N, Totten AM, O'Reilly C, Ullman JS, Hawryluk GW, Bell MJ, Bratton SL, Chesnut R, Harris OA, Kissoon N, Rubiano AM, Shutter L, Tasker RC, Vavilala MS, Wilberger J, Wright DW, Ghajar J; Guidelines for the Management of Severe Traumatic Brain Injury, 4th Edition, Brain Trauma Foundation, September 2016, P.120-129.