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H ypotHalamic hamartoma (HH) is a rare congenital abnormality, which presents with a hallmark feature of intractable gelastic seizures (GS). There is now strong evidence that HH involves intrinsic epileptogenesis, [7][8][9][10][11][12]14,17 and surgical treatment of HH itself is considered important for seizure control. Although various surgical treatments are available for epileptic patients with HH, the selection of treatment modalities depends on the type and size of the HH, as well as the surgeons' preference.3 Mittal et al. reported that no single neurosurgical approach is likely to treat all forms of HH, and that a multimodal or staged procedure must be used to treat the lesion. 16 Similarly, the Barrow group commonly use staged and multiple surgical approaches for HH treatment, including microsurgical resection, endoscopic disconnection, and stereotactic radiosurgery. 6,19,24 We previously developed a surgical procedure involving MRI-guided stereotactic radiofrequency thermocoagulation (SRT) of HH and reported an early series of cases in which this technique was used.9,12 In the present study, which was undertaken to determine the invasiveness abbreviatioNs DQ = developmental quotient; EEG = electroencephalography; EFP = emotional facial paresis; FIQ = full-scale IQ; GS = gelastic seizures; HH = hypothalamic hamartoma; SISCOM = subtraction ictal SPECT co-registered to MRI; SMA = supplementary motor area; SPECT = single-photon emission computed tomography; SRT = stereotactic radiofrequency thermocoagulation; WAIS = Wechsler Adult Intelligence Scale; WAIS-R = WAIS-Revised; WAIS-III = WAIS-Third Edition; WISC = Wechsler Intelligence Scale for Children; WISC-R = WISC-Revised; WISC-III = WISC-Third Edition. The median duration of follow-up was 3 years (range 1-17 years). Seventy cases involved pediatric patients. Ninety percent of patients also had other types of seizures (non-GS). The maximum diameter of the HHs ranged from 5 to 80 mm (median 15 mm), and 15 of the tumors were giant HHs with a diameter of 30 mm or more. Comorbidities included precocious puberty (33.0%), behavioral disorder (49.0%), and mental retardation (50.0%). results A total of 140 SRT procedures were performed. There was no adaptive restriction for the giant or the subtype of HH, regardless of any prior history of surgical treatment or comorbidities. Patients in this case series exhibited delayed precocious puberty (9.0%), pituitary dysfunction (2.0%), and weight gain (7.0%), besides the transient hypothalamic symptoms after SRT. Freedom from GS was achieved in 86.0% of patients, freedom from other types of seizures in 78.9%, and freedom from all seizures in 71.0%. Repeat surgeries were not effective for non-GS. Seizure freedom led to disappearance of behavioral disorders and to intellectual improvement. coNclusioNs The present SRT procedure is a minimally invasive and highly effective surgical procedure without adaptive limitations. SRT involves only a single surgical procedure appropriate for all forms of epileptogenic HH and should be...

Researchers have looked for rapidly- and objectively-measurable electrophysiology biomarkers that accurately localize the epileptogenic zone. Promising candidates include interictal high-frequency oscillation and phase-amplitude coupling. Investigators have independently created the toolboxes that compute the high-frequency oscillation rate and the severity of phase-amplitude coupling. This study of 135 patients determined what toolboxes and analytic approaches would optimally classify patients achieving postoperative seizure control. Four different detector toolboxes computed the rate of high-frequency oscillation at ≥ 80 Hz at intracranial EEG channels. Another toolbox calculated the modulation index reflecting the strength of phase-amplitude coupling between high-frequency oscillation and slow-wave at 3-4 Hz. We defined the completeness of resection of interictally-abnormal regions as the subtraction of high-frequency oscillation rate (or modulation index) averaged across all preserved sites from that averaged across all resected sites. We computed the outcome classification accuracy of the logistic regression-based standard model considering clinical, ictal intracranial EEG, and neuroimaging variables alone. We then determined how well the incorporation of high-frequency oscillation/modulation index would improve the standard model mentioned above. To assess the anatomical variability across nonepileptic sites, we generated the normative atlas of detector-specific high-frequency oscillation and modulation index. Each atlas allowed us to compute the statistical deviation of high-frequency oscillation/modulation index from the nonepileptic mean. We determined whether the model accuracy would be improved by incorporating absolute or normalized high-frequency oscillation/modulation index as a biomarker assessing interictally-abnormal regions. We finally determined whether the model accuracy would be improved by selectively incorporating high-frequency oscillation verified to have high-frequency oscillatory components unattributable to a high-pass filtering effect. Ninety-five patients achieved successful seizure control, defined as International League Against Epilepsy class 1 outcome. Multivariate logistic regression analysis demonstrated that complete resection of interictally-abnormal regions additively increased the chance of success. The model accuracy was further improved by incorporating z-score normalized high-frequency oscillation/modulation index or selective incorporation of verified high-frequency oscillation. The standard model had a classification accuracy of 0.75. Incorporation of normalized high-frequency oscillation/modulation index or verified high-frequency oscillation improved the classification accuracy up to 0.82. These outcome prediction models survived the cross-validation process and demonstrated an agreement between the model-based likelihood of success and the observed success on an individual basis. Interictal high-frequency oscillation and modulation index had a comparably additive utility in epilepsy presurgical evaluation. Our empirical data support the theoretical notion that the prediction of postoperative seizure outcomes can be optimized with the consideration of both interictal and ictal abnormalities.