Abstracts

Rationale: Memory impairment is a complication of dominant temporal epilepsy surgery. Reoperation has reduced expectations for seizure freedom for 20-45% of patients creating a risk vs benefit decision-making process to determine if further surgery should be pursued. Limited information exists for patients experiencing repeated failed epilepsy surgery. Therefore memory improvement after reoperation is unexpected. Methods: A 39-year-old right-handed Caucasian female had drug- resistant focal epilepsy. Seizure onset was at 19 years during pregnancy. MRI brain and EEG were normal. Recurrent spells characterized as episodic smells were initially misdiagnosed as nonepileptic events. On re-evaluation, left temporal seizures with impaired awareness +/- convulsions were weekly. PET revealed mild left temporal hypometabolism. She was admitted for video-EEG monitoring (VEM). Left mid-temporal IEDs and hemispheric seizures were recorded. Neuropsychology evaluation demonstrated memory dysfunction/ neuropsychological impairment. Invasive combined depth-subdural EEG localized seizures to the left depth. Results: Left mesial temporal lobe surgery was complicated 4 months later by wound infection requiring debridement. Seizures continued following left temporal resection and VEM re-demonstrated similar electroclinical localization. MRI demonstrated retained mesial structures and stereotactic laser ablation was performed. Ablation of mesial structures was unsuccessful. Focal seizure frequency was reduced with continued convulsions. Repeat VEM revealed left temporal seizure onset. Ultimately repeat craniotomy to tailor resection posteriorly used ECoG with high-density grid/stereotactic depth recording. PLEDs Plus was present in the depth. The entirety of the remaining temporal lobe including PLEDs PLUS was resected. The patient subsequently had a second bone infection three months post-surgery resulting in craniectomy. Immediately following surgery, despite infection, the patient and family noted immediate memory improvement. Follow-up neuropsychological evaluation was normal. The patient has remained seizure free. Conclusions: Immediate improvement in her memory was present peri-operatively and was subsequently confirmed on formal neuropsychological testing. PLEDs Plus was present on depth ECoG potentially reflecting ongoing subclinical status epilepticus. The lack of general anesthesia and high-density ECoG may have facilitated identification and resection contributed resolution of chronic memory impairment. Despite multiple failed and complicated epilepsy surgery, patients may have a favorable response to repeat epilepsy surgery following excision of epileptogenic tissue. Funding: None