Surgical treatment of patients with Lennox-Gastaut syndrome phenotype.

Lennox-Gastaut syndrome (LGS) is a devastating and refractory generalized epilepsy affecting children and adolescents. In this study we report the results of resective surgery in 18 patients with LGS phenotype who underwent single-lobe/lesionectomy or multilobe resection plus multiple subpial transection and/or callosotomy. After surgery, seven patients became completely seizure-free (Engel Class I) and five almost seizure-free (Engel Class II). Additional four had significant seizure control (Engel Class III), and two had no change in seizure frequency (Engel Class IV). Of the 4 patients without any lesion on brain MRI, 2 ended with Engel Class II, 1 with III and the other with IV in Engels' classification. Mean intelligence quotient (IQ) increased from 56.1 ± 8.1 (mean ± SD) before operation to 67.4 ± 8.2 (mean ± SD) after operation, a significant improvement (P = 0.001). Results also indicated that the younger the patient at surgery, or the shorter the interval between onset of seizure and resective operation, the better the intellectual outcome. Our data suggest that resective epilepsy surgery can be successful in patients with LGS phenotype as long as the EEG shows dominance of discharges in one hemisphere and corresponding ipsilateral imaging findings, even with contralateral ictal discharges.

Intraventricular administration of gabapentin in the rat increases flurothyl seizure threshold.

INTRODUCTION: We investigated efficacy of prolonged intraventricular gabapentin (GBP) infusion in the rat flurothyl epilepsy model. METHODS: Sprague-Dawley rats, under anesthesia, were implanted with bilateral Alzet model 2001 osmotic pumps. The pumps infused GBP 80 microg/microL (3.8 mg/day) or isotonic saline control at 1.0 microL/h into each ventricle for 5 days. After 5 days of GBP infusion, seizures were induced by flurothyl dripped onto filter paper. Time to first myoclonic jerk, first partial seizure and first tonic-clonic seizure was recorded by an observer unaware of the treatment group. Determination of seizures was behavioral. RESULTS: Data were obtained from 54 rats. First tonic-clonic seizure was at 295.8+/-58.8s (n=28) for control rats, versus 338.0+/-89.9 s (n=26) for rats with GBP in the pump (p=0.049). First myoclonic jerk occurred at 158.7+/-20.8 versus 164.6+/-33.5 s (p=0.44, n.s.). Regression of time to seizure versus weight was not significant. No animal had measurable serum levels (<1 microg/ml) of GBP. The distribution of GBP in brain was not studied, but qualitative observations of methylene blue dye installed in the pumps showed dye in periventricular white matter and also over cortex, especially ipsilaterally. DISCUSSION: GBP instilled into the lateral ventricles by pump for 5 days delays onset of generalized tonic-clonic seizures produced by flurothyl in the rat. Time to first myoclonic or partial seizure was not influenced. Effects were not due to systemic absorption of GBP. This study provides a proof-in-principle for intraventricular therapy with AEDs.

Experimental Electrical Stimulation Therapy for Epilepsy.

Electrical stimulation of the nervous system is an attractive possible therapy for intractable epilepsy, but only stimulation of the vagus nerve has been subjected to large, controlled, and completed clinical trials. Controlled trials are in progress for intermittent cycling stimulation of the anterior nuclei of the thalamus, and for cortical stimulation at a seizure focus, responsive to detection of seizure onset. Anecdotal experience has been gathered with stimulation of cerebellum, centromedian thalamus, subthalamus, caudate, hippocampus, and brainstem. All stimulation of the central nervous system for epilepsy must be considered experimental.

The relative localizing value of interictal and immediate postictal SPECT in seizures of temporal lobe origin.

UNLABELLED: Although interictal hypoperfusion and ictal hyperperfusion are established localizing findings in partial epilepsy, their relative value is disputed. After a meta analysis of several published articles on SPECT brain imaging in patients with epilepsy (with extractable data on at least 6 patients per article), institutions using SPECT for evaluation of epilepsy have been encouraged to perform ictal scanning or interictal and postictal SPECT studies. METHODS: We compared the relative localizing values of hypoperfusion in video-electroencephalographically (EEG) monitored interictal SPECT (IISPECT) and hyperperfusion in immediate postictal or periictal SPECT (PISPECT) in nonlesional patients who underwent temporal lobectomies in our epilepsy center from 1995 to 1998. We also evaluated the usefulness of combined interpretation of IISPECT and PISPECT when available. RESULTS: Our experience with continuous cerebral blood-flow monitoring, published elsewhere, and SPECT results indicate that these recommendations are valid, but obtaining ictal SPECT is often serendipitous. We found that (a) interictal hypoperfusion was easier to demonstrate by SPECT but was less often concordant with the EEG focus than hyperperfusion in PISPECT, but not significantly (P = 0.11) so; (b) the lower incidence of hyperperfusion in PISPECT in our series was due to the occurrence of hypoperfusion in PISPECT, which was seen in 34.5% of our patients; and (c) hypoperfusion in PISPECT did have localizing value when it occurred on the same side as the hypoperfusion noted in IISPECT. CONCLUSION: On the basis of our findings, we recommend the use of 3 distinct perfusion patterns that emerge from the combined interpretation of IISPECT and PISPECT we proposed earlier (patterns 1-3), for localization purposes when possible, rather than ictal SPECT, IISPECT, or PISPECT by itself.