Neurophysiologic and neuroradiologic features of intractable epilepsy after traumatic brain injury in adults.
BACKGROUND
There is controversy regarding the precise mechanism by which epilepsy results after traumatic brain injury (TBI). Previous reports have suggested that mesial temporal lobe epilepsy may result from TBI only in young children, while neocortical epilepsy arises from TBI in later life. These conclusions were based on surgical series and may be biased because of patient selection.


OBJECTIVE
To determine the frequency of mesial temporal lobe as opposed to neocortical epilepsy in patients with intractable epilepsy resulting from TBI after the age of 10 years.


METHODS
We identified 23 patients with intractable epilepsy who had TBI after the age of 10 years, preceding the onset of epilepsy. Patients were studied by simultaneous videotape and scalp electroencephalographic recording of typical seizures; magnetic resonance imaging; neuropsychologic studies; and, when appropriate, intracarotid amobarbital testing. Two patients underwent anterior temporal lobectomies.


RESULTS
Of the 23 patients, 8 (35%) had mesial temporal lobe epilepsy, based on the finding of hippocampal sclerosis on a magnetic resonance imaging scan, consistent interictal and ictal electroencephalographic recordings, evidence of temporal lobe dysfunction on neuropsychologic testing, and characteristic seizure semiology. Two of these patients underwent anterior temporal lobectomies with clinical benefit, and hippocampal sclerosis was confirmed pathologically. In 2 cases, patients were not treated surgically because of bilateral temporal lobe dysfunction noted on intracarotid amobarbital testing. Eleven patients had neocortical epilepsy; 1 had primary generalized epilepsy; and, in 3, the site of seizure onset was not localized.


CONCLUSIONS
Mesial temporal lobe epilepsy can result from TBI in adolescents and adults as well as in children, and can often be bilateral and associated with multifocal injury. This information may be useful in developing prophylactic therapy for posttraumatic epilepsy.
Diaz-Arrastia
R
R
Department of Neurology, The University of Texas Southwestern Medical Center at Dallas, 5323 Harry Hines Blvd, Dallas, TX 75235-9036, USA. RdiazA@mednet.swmed.edu
Agostini
M A
MA
Frol
A B
AB
Mickey
B
B
Fleckenstein
J
J
Bigio
E
E
Van Ness
P C
PC
D000328:Adult; D000367:Age Factors; D017668:Age of Onset; D001930:Brain Injuries / Q000150:complications* / Q000000981:diagnostic imaging / Q000503:physiopathology; D004569:Electroencephalography / Q000379:methods; D004827:Epilepsy / Q000000981:diagnostic imaging / Q000503:physiopathology; D004833:Epilepsy, Temporal Lobe / Q000000981:diagnostic imaging* / Q000209:etiology / Q000473:pathology / Q000503:physiopathology* / Q000601:surgery; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D011859:Radiography; D014743:Videotape Recording