Overall, the study showed focal slowing in the left frontotemporal head region; frequent epileptiform discharges in the left temporal area; and several seizures starting electrographically from the vertex with spread to the right central head region on surface EEG monitoring.
Clinically, given the patient’s right-sided symptomatology, the seizure focus was presumed to be in the left deep mesial frontal head region. Electrographic findings were consistent with false localization because of encephalomalacia in the left hemisphere.
Because of breakthrough symptoms on her previous antiepileptic medication (valproate), the patient was changed to oxcarbazepine, with dosages increased as seizures persisted.
Image: The MRI is an axial view, T2 weighted image that demonstrates cystic encephalomalacia throughout the left hemisphere, maximum left frontal. The encephalomalacia is residual injury from the left frontal AVM hemorrhage.
In March 2014, the patient underwent an interictal PET scan, which revealed severe encephalomalacia involving the left frontal, left parietal, and the superior aspect of the left occipital lobe, and decreased glucose metabolism/uptake in this region.
A pre-surgical evaluation was initiated, and it was the consensus of the epilepsy specialists that the patient was an excellent epilepsy surgery candidate. We specifically recommended a functional hemispherectomy involving the left hemisphere. We expected the surgery would render the patient seizure-free, without worsening her hemiplegia.
In June 2014, the patient underwent surgery at CHOC Children’s to remove part of her brain’s left side, and disconnect the remaining portion from the right hemisphere. The procedure lasted 6 hours.
The patient spent 16 days recovering in the hospital’s pediatric intensive care unit (PICU), and experienced no further seizures. She did experience fevers, common after a hemispherectomy, most likely central in origin (due to mild bleeding into the cerebral spinal fluid).