Nonconvulsive seizures after traumatic brain injury are associated with hippocampal atrophy.
OBJECTIVE
To determine if posttraumatic nonconvulsive electrographic seizures result in long-term brain atrophy.


METHODS
Prospective continuous EEG (cEEG) monitoring was done in 140 patients with moderate to severe traumatic brain injury (TBI) and in-depth study of 16 selected patients was done using serial volumetric MRI acutely and at 6 months after TBI. Fluorodeoxyglucose PET was done in the acute stage in 14/16 patients. These data were retrospectively analyzed after collection of data for 7 years.


RESULTS
cEEG detected seizures in 32/140 (23%) of the entire cohort. In the selected imaging subgroup, 6 patients with seizures were compared with a cohort of 10 age- and GCS-matched patients with TBI without seizures. In this subgroup, the seizures were repetitive and constituted status epilepticus in 4/6 patients. Patients with seizures had greater hippocampal atrophy as compared to those without seizures (21 +/- 9 vs 12 +/- 6%, p = 0.017). Hippocampi ipsilateral to the electrographic seizure focus demonstrated a greater degree of volumetric atrophy as compared with nonseizure hippocampi (28 +/- 5 vs 13 +/- 9%, p = 0.007). A single patient had an ictal PET scan which demonstrated increased hippocampal glucose uptake.


CONCLUSIONS
Acute posttraumatic nonconvulsive seizures occur frequently after TBI and, in a selected subgroup, appear to be associated with disproportionate long-term hippocampal atrophy. These data suggest anatomic damage is potentially elicited by nonconvulsive seizures in the acute postinjury setting.
Vespa
P M
PM
UCLA Department of Neurosurgery, Los Angeles, CA 90095, USA. Pvespa@mednet.ucla.edu
McArthur
D L
DL
Xu
Y
Y
Eliseo
M
M
Etchepare
M
M
Dinov
I
I
Alger
J
J
Glenn
T P
TP
Hovda
D
D
D000328:Adult; D000368:Aged; D001284:Atrophy; D001930:Brain Injuries / Q000150:complications / Q000473:pathology* / Q000503:physiopathology; D015331:Cohort Studies; D004569:Electroencephalography / Q000639:trends; D004829:Epilepsy, Generalized / Q000209:etiology / Q000473:pathology* / Q000503:physiopathology; D005260:Female; D005500:Follow-Up Studies; D006624:Hippocampus / Q000473:pathology* / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012640:Seizures / Q000209:etiology / Q000473:pathology* / Q000503:physiopathology
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