P. Sarat Chandra, Heri Subianto, Jitin Bajaj, Shabari Girishan, Ramesh Doddamani, Bhargavi Ramanujam, Mahendra Singh Chouhan, Ajay Garg, Madhavi Tripathi, Chandrasekhar S. Bal, Chitra Sarkar, Rekha Dwivedi, Savita Sapra and Manjari Tripathi
Endoscope-assisted hemispherotomy (EH) has emerged as a good alternative option for hemispheric pathologies with drug-resistant epilepsy.
This was a prospective observational study. Parameters measured included primary outcome measures (frequency, severity of seizures) and secondary outcomes (cognition, behavior, and quality of life). Blood loss, operating time, complications, and hospital stay were also taken into account. A comparison was made between the open hemispherotomy (OH) and endoscopic techniques performed by the senior author.
Of 59 cases (42 males), 27 underwent OH (8 periinsular, the rest vertical) and 32 received EH. The mean age was 8.65 ± 5.41 years (EH: 8.6 ± 5.3 years; OH: 8.6 ± 5.7 years). Seizure frequency per day was 7 ± 5.9 (EH: 7.3 ± 4.6; OH: 15.0 ± 6.2). Duration of disease (years since first episode) was 3.92 ± 1.24 years (EH: 5.2 ± 4.3; OH: 5.8 ± 4.5 years). Number of antiepileptic drugs per patient was 3.9 ± 1.2 (EH: 4.2 ± 1.2; OH: 3.8 ± 0.98). Values for the foregoing variables are expressed as the mean ± SD. Pathologies included the following: postinfarct encephalomalacia in 19 (EH: 11); Rasmussen’s syndrome in 14 (EH: 7); hemimegalencephaly in 12 (EH: 7); hemispheric cortical dysplasia in 7 (EH: 4); postencephalitis sequelae in 6 (EH: 2); and Sturge-Weber syndrome in 1 (EH: 1). The mean follow-up was 40.16 ± 17.3 months. Thirty-nine of 49 (79.6%) had favorable outcomes (International League Against Epilepsy class I and II): in EH the total was 19/23 (82.6%) and in OH it was 20/26 (76.9%). There was no difference in the primary outcome between EH and OH (p = 0.15). Significant improvement was seen in the behavioral/quality of life performance, but not in IQ scores in both EH and OH (p < 0.01, no intergroup difference). Blood loss (p = 0.02) and hospital stay (p = 0.049) were less in EH.
EH was as effective as the open procedure in terms of primary and secondary outcomes. It also resulted in less blood loss and a shorter postoperative hospital stay.
Shabari Girishan, Manjari Tripathi, Ajay Garg, Ramesh Doddamani, Jitin Bajaj, Bhargavi Ramanujam and P. Sarat Chandra
The authors sought to analyze the residual connections formed by the temporal stem as a cause for seizure recurrence following endoscopic vertical interhemispheric hemispherotomy and to review and compare lateral approach (perisylvian) with vertical approach surgical techniques to highlight the anatomical factors responsible for residual connections.
This study was a retrospective analysis of patients who underwent endoscopic hemispherotomy for drug-resistant epilepsy. Postoperative MR images were analyzed. Specific attention was given to anatomical 3D-acquired thin-section T1 images to assess the extent of disconnection, which was confirmed with a diffusion tensor imaging sequence. Cadaver brain dissection was done to analyze the anatomical factors responsible for persistent connections.
Of 39 patients who underwent surgery, 80% (31/39) were seizure free (follow-up of 23.61 ± 8.25 months) following the first surgery. Thirty patients underwent postoperative MRI studies, which revealed persistent connections in 14 patients (11 temporal stem only; 3 temporal stem + amygdala + splenium). Eight of these 14 patients had persistent seizures. In 4 of these 8 patients, investigations revealed good concordance with the affected hemisphere, and repeat endoscopic disconnection of the residual connection was performed. Two of the 8 patients were lost to follow-up, and 2 had bihemispheric seizure onset. The 4 patients who underwent repeat endoscopic disconnection had seizure-free outcomes following the second surgery, increasing the good outcome total among all patients to 90% (35/39). Cadaveric brain dissection analysis revealed the anatomical factors responsible for the persistence of residual connections.
In endoscopic vertical approach interhemispheric hemispherotomy (and also vertical approach parasagittal hemispherotomy) the temporal stem, which lies deep and parallel to the plane of disconnection, is prone to be missed, which might lead to persistent or recurrent seizures. The recognition of this limitation can lead to improved seizure outcome. The amygdala and splenium are areas less commonly prone to be missed during surgery.