Lack of spontaneous typical seizures during intracranial monitoring with stereo-electroencephalography.

OBJECTIVE: In the presurgical evaluation of patients with drug-resistant epilepsy (DRE), occasionally, patients do not experience spontaneous typical seizures (STS) during a stereo-electroencephalography (SEEG) study, which limits its effectiveness. We sought to identify risk factors for patients who did not have STS during SEEG and to analyze the clinical outcomes for this particular set of patients. METHODS: We conducted a retrospective analysis of all patients with DRE who underwent depth electrode implantation and SEEG recordings between January 2013 and December 2018. RESULTS: SEEG was performed in 155 cases during this period. 11 (7.2%) did not experience any clinical seizures (non-STS group), while 143 experienced at least one patient-typical seizure during admission (STS group). No significant differences were found between STS and non-STS groups in terms of patient demographics, lesional/non-lesional epilepsy ratio, pre-SEEG seizure frequency, number of ASMs used, electrographic seizures or postoperative seizure outcome in those who underwent resective surgery. Statistically significant differences were found in the average number of electrodes implanted (7.0 in the non-STS group vs. 10.2 in STS), days in Epilepsy Monitoring Unit (21.8 vs. 12.8 days) and the number of cases that underwent resective surgery following SEEG (27.3% vs. 60.8%), respectively. The three non-STS patients (30%) who underwent surgery, all had their typical seizures triggered during ECS studies. Three cases were found to have psychogenic non-epileptic seizures. None of the patients in the non-STS group were offered neurostimulation devices. Five of the non-STS patients experienced transient seizure improvement following SEEG. SIGNIFICANCE: We were unable to identify any factors that predicted lack of seizures during SEEG recordings. Resective surgery was only offered in cases where ECS studies replicated patient-typical seizures. Larger datasets are required to be able to identify factors that predict which patients will fail to develop seizures during SEEG.

Role of resective surgery in patients older than 60 years with therapy-resistant epilepsy.

OBJECTIVE: Epilepsy surgery for older adults is controversial owing to their longer duration of epilepsy and perceived higher surgical risk. However, because of an aging population and documented benefit of epilepsy surgery, surgery is considered more frequently for these patients. The authors' objective was to analyze the role of resective surgery in patients older than 60 years and to assess outcomes and safety. METHODS: The authors conducted a retrospective analysis of 595 patients who underwent resective epilepsy surgery at their center from 1999 to 2018. Thirty-one patients aged 60 years or older were identified. Sixty patients younger than 60 years were randomly selected as controls. Population characteristics, results of presurgical evaluations, outcomes, and complications were analyzed. RESULTS: No significant differences were found between the groups in terms of hemisphere dominance, side of surgery, presence of a lesion, and incidence of temporal lobe epilepsy. Epilepsy duration was greater in the older cohort (p = 0.019), and invasive EEG was more commonly employed in younger patients (p = 0.030). The rates of Engel class I outcome at 6 months, 1 year, and 2 years were 89.7%, 96.2%, and 94.7% for the older group and 75% (p = 0.159), 67.3% (p = 0.004), and 75.8% (p = 0.130) for the younger group, respectively. The proportion of seizure-free patients was greatest among those with temporal lobe epilepsy, particularly in the older group. Neurological complication rates did not differ significantly between groups, however medical and other minor complications occurred more frequently in the older group. CONCLUSIONS: Patients older than 60 years had equal or better outcomes at 1 year after epilepsy surgery than younger patients. A trend toward a greater proportion of patients with lesional temporal lobe epilepsy was found in the older group. These results suggest that good seizure outcomes can be obtained in older patients despite longer duration of epilepsy.

Establishment of epilepsy surgery in Peru.

Epilepsy surgery is a well-established treatment for certain types of intractable epilepsy. While there is a relatively high number of epilepsy surgery centers in Canada and the United States, the same cannot be said about many other parts of the world, such as South America. Although there are notable exceptions, such as Brazil and Colombia, formal epilepsy surgery centers have been lacking in many South American countries, including Peru. Although sporadic cases have been performed in Peru, there was no formal epilepsy surgery center in the country as of 2011. Beginning in 2008, with the support of the Partnering Epilepsy Centers in America program of the North American Commission of the International League Against Epilepsy, the Epilepsy Program at Western University in London, Canada, was partnered with the Department of Epilepsy at the Instituto Nacional de Ciencias Neurologicas in Lima. This was the beginning of a long-term relationship that culminated in the establishment of the first 2 formal epilepsy surgery centers in Peru. The purpose of this communication is to briefly summarize the establishment of 2 independent epilepsy surgery programs in Peru and to document the methods with which this accomplishment was achieved.

La cirugía de epilepsia y el establecimiento de programas quirúrgicos en el Perú: El proyecto de colaboración entre Perú y Canadá / Establishing epilepsy surgery programs in Peru: The Peru-Canada collaborative project

El presente artículo define y describe las características clínicas de epilepsia refractaria, la cirugía aplicable al manejo de la misma y la necesidad de establecer centros para el manejo integral de estos pacientes en el Perú. Además, describe los inicios de la cirugía de epilepsia en el Perú, su desarrollo paulatino y el proyecto de colaboración asistencial y educativo entre los programas de epilepsia de la Western University en London, Ontario, Canadá y el Instituto Nacional de Ciencias Neurológicas, así como el Hospital Edgardo Rebagliati en Lima, Perú.

The manuscript describes and defines the clinical characteristics of Refractory Epilepsy, applicable surgical procedures for its management and the need for the establishment of comprehensive epilepsy programs in Peru. It also describes the beginnings of epilepsy surgery in Peru, and the collaborative project between the Epilepsy programs at Western University in London, Canada and the National Neurological Institute and Rebagliati Hospital in Lima, Peru.

Reporte del primer caso de lobectomía para el tratamiento de epilepsia refractaria de lóbulo temporal en el Perú / Report of the first case of lobectomy for the treatment of refractory temporal lobe epilepsy in Peru

Se presenta el caso de una paciente con epilepsia refractaria de lóbulo temporal debida a esclerosis mesial temporal, sometida a la primera lobectomía temporal efectuada en el Perú. El resultado ha sido exitoso, ya que la paciente continúa libre de crisis convulsivas después de más de 4 años de periodo post-operatorio. Se comentan las implicaciones de lo que puede constituir un hito en la historia de la neurología y neurocirugía en el Perú.

The case of a female patient with the diagnosis of refractory temporal lobe epilepsy due to mesial temporal sclerosis is presented. She underwent temporal lobectomy, the first intervention of this type performed in Peru. The outcome has been successful, as the patient remains seizure-free four years into her post-surgical period. The implications of what may be considered a landmark in the history of neurology and neurosurgery in Peru are commented upon.

Timing of early and late seizure recurrence after temporal lobe epilepsy surgery.

PURPOSE: Seizure recurrence after epilepsy surgery has been classified as either early or late depending on the recurrence time after operation. However, time of recurrence is variable and has been arbitrarily defined in the literature. We established a mathematical model for discriminating patients with early or late seizure recurrence, and examined differences between these two groups. METHODS: A historical cohort of 247 consecutive patients treated surgically for temporal lobe epilepsy was identified. In patients who recurred, postoperative time until seizure recurrence was examined using an receiver-operating characteristic (ROC) curve to determine the best cutoff for predicting long-term prognosis, dividing patients in those with early and those with late seizure recurrence. We then compared the groups in terms of a number of clinical, electrophysiologic, and radiologic variables. KEY FINDINGS: Seizures recurred in 107 patients (48.9%). The ROC curve demonstrated that 6 months was the ideal time for predicting long-term surgical outcome with best accuracy, (area under the curve [AUC] = 0.761; sensitivity = 78.8%; specificity = 72.1%). We observed that patients with seizure recurrence during the first 6 months started having seizures at younger age (odds ratio [OR] = 6.03; 95% confidence interval [CI] = 1.06-11.01; p = 0.018), had a worse outcome (OR = 6.85; 95% CI = 2.54-18.52; p = 0.001), needed a higher number of antiepileptic medications (OR = 2.07; 95% CI = 1.16-9.34; p = 0.013), and more frequently had repeat surgery (OR = 9.59; 95% CI = 1.18-77.88; p = 0.021). Patients with late relapse more frequently had seizures associated with trigger events (OR = 9.61; 95% CI = 3.52-26.31; p < 0.01). SIGNIFICANCE: Patients with early or late recurrence of seizures have different characteristics that might reflect diversity in the epileptogenic zone and epileptogenicity itself. These disparities might help explain variable patterns of seizure recurrence after epilepsy surgery.

A collaborative effort to establish a comprehensive epilepsy program in Peru.

We report the achievements obtained, over a period of 4 years, by the collaborative partnering effort of the Epilepsy Program at Western University in Canada and the Instituto of Ciencias Neurologicas in Lima, Peru, building an epilepsy program in Peru.