Pediatric Epilepsy Surgery Outcomes
With new medical and surgical techniques, the outlook for children with repeated epileptic seizures is more promising than ever. At California Pacific, physicians completed three pediatric epilepsy surgeries since 2002, with 100% lack of seizure recurrence in all cases. To determine the best treatment options for patients, neurologists first conduct Phase 2 and 3 Video Telemetry at the Pediatric Epilepsy Monitoring Unit as well as MRI, PET and SPECT scans and a neuropsychological evaluation.
For patients with medically unmanageable epilepsy, surgical excision of the affected hippocampus or other epileptogenic lesion can provide significant, or even complete, seizure relief. Following are case overviews of the four surgeries performed at California Pacific for pediatric epilepsy patients:
Case 1: Left Functional Hemispherectomy
A 4 year-old boy presented with a 2-year history of intractable epilepsy and right hemiparetic cerebral palsy. Previous attempts with more than 6 different antiepileptic medications failed to control his seizures. At evaluation time, he was quite lethargic, drooling and severely ataxic. He was taking only clonazepam, as all other medications had been discontinued due to lack of seizure control and accompanying side effects. An MRI of the brain demonstrated extensive areas of encephalomalacia indicative of left middle cerebral artery (MCA)-occlusive stroke. His parents came to California Pacific’s Pediatric Neurology Team seeking both new opinions and potential treatments. After admission to the Epilepsy Monitoring Unit (EMU) and an ictal SPECT, the left hemisphere was found to be the source of all his seizures. Accordingly, a functional left hemispherectomy was suggested in the team’s Epilepsy Surgical Conference. The child underwent this procedure in December 2001 and, except for a brief post-op seizure, he has been asymptomatic and off medications for the past year. The child has returned to regular school with only mild right hemiparesis.
Case 2: Right Hippocampectomy
An 11 year-old girl presented with a history of focal epilepsy with secondary generalization, neither of which the medications valproic and carbamazepine could control. Because she experienced complex partial seizures almost daily, the girl was quite depressed. The addition of the medication levetiracetam also failed to control her seizures. Her neurological exam was normal. Admission to California Pacific’s EMU in which subdural grid placement was performed demonstrated that all her seizures arose from the right temporal lobe. A Wada test confirmed her language and memory functions resided in the left hemisphere. A right hippocampectomy was performed without complications in June 2002. Since then, the patient remains seizure free and has returned to regular school. She no longer takes any anti-epileptic medications.
Case 3: Lesionectomy
An 8 year-old boy presented with new onset of nocturnal seizures. An EEG suggested benign rolandic epilepsy, however, because his epileptic discharges arose predominantly from the left hemisphere, the Neurology Team obtained an MRI. This demonstrated abnormality consistent with a low grade glioma. Testing in the EMU confirmed his seizures arose from the left temporal region. A lesionectomy was performed in September 2000 and the child has remained asymptomatic since then.
Case 4: Vagus Nerve Stimulator (VNS) Implant
A 14 year-old with severe intractable epilepsy due to Lennox-Gastaut Syndrome was referred to California Pacific’s Pediatric Neurology Team for a second opinion. She was having a mixture of generalized convulsive and atonic seizures about 30 to 50 times daily, which multiple anti-epileptic medications failed to control. After evaluation in the EMU, her EEG findings were shown to be consistent with symptomatic generalized epilepsy. Given this, the team recommended implanting a vagus nerve stimulator, which was successfully performed in February 2000. Since then, the patient’s seizures have dropped to only one every 6 months. She remains on topiramate and clonazepam. Presently, her parents’ only concern is the child’s hyperactivity, which developed after her epileptic encephalopathy resolved.
Review
Several recent studies have demonstrated that epilepsy surgery is the best treatment for patients who have temporal lobe epilepsy, even when performed at older age. The best candidates for epilepsy surgery are:
* Patients who, after comprehensive evaluation, are demonstrated to have concordance in all studies;
* Patients in which the epileptic discharge arises from a specific focus.
Increasing evidence shows that epilepsy surgery at a younger age (under 8 years) can lead to better long-term outcomes since learning disabilities and other cognitive impairment that arise from repetitive seizures can be avoided with better seizure control. Long-term statistical studies also demonstrate that patients who fail more than 3 anti-epileptic medications will not respond to the addition of other anti-epileptic drugs (AED), especially when the seizures are of focal origin. At such a time, a referral for epilepsy surgery consideration should be made.
For further information about California Pacific Medical Center’s Pediatric Neurology Team and our epilepsy services, contact: Luis Bello-Espinosa, M.D. (415) 600-5878
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