Christian Dorfer, Thomas Czech, Angelika Mühlebner-Fahrngruber, Aygül Mert, Gudrun Gröppel, Klaus Novak, Anastasia Dressler, Edith Reiter-Fink, Tatjana Traub-Weidinger and Martha Feucht
Outcomes following functional hemispherotomy in patients with drug-resistant epilepsy have been well described. However, studies reporting long-term longitudinal outcomes after subhemispheric disconnective epilepsy surgery are still limited.
The authors conducted a retrospective review of prospectively collected data of 10 children who underwent temporoparietooccipital (TPO) disconnective surgery at the Vienna Pediatric Epilepsy Center.
There were 3 males and 7 females (median age 8.7 years; range 4.2–22.1 years). The affected hemisphere was the left in 3 patients and the right in 7. The patients' median age at seizure onset was 3.0 years (range 0.2–8.3 years). The median duration of epilepsy before surgery was 5.2 years (range 1.3–17.2 years). The underlying pathology was TPO malformation of cortical development in 5 patients, and venous infarction, posterior hemispheric quadrant atrophy, Sturge-Weber syndrome, cortical involvement of a systemic lupus erythematosus, and gliosis after cerebral tumor treatment in 1 each. In 6 children, a pure TPO disconnection was performed; in 2 patients, the temporal lobe was resected and parietooccipital disconnection was performed. The 2 remaining patients had had previous epilepsy surgery that was extended to a TPO disconnection: disconnection of the occipital lobe (n = 1) and resection of the temporal lobe (n = 1). The authors encountered no complications while performing surgery. No patient needed blood replacement therapy. No patient developed CSF disturbances that warranted treatment. Nine of 10 patients are currently seizure free since surgery (Wieser Class 1a) at a median follow-up time of 2.1 years (range 4 months to 8.1 years).
Temporoparietooccipital disconnection is a safe and effective motor-sparing epilepsy surgery in selected cases. Technical adjuncts facilitate a better intraoperative visualization and orientation, thereby enabling a less invasive approach than previously suggested.
Tatjana Traub-Weidinger, Philip Weidinger, Gundrun Gröppel, Georgios Karanikas, Wolfgang Wadsak, Gregor Kasprian, Christian Dorfer, Anastasia Dressler, Angelika Muehlebner, Marcus Hacker, Thomas Czech and Martha Feucht
The objective of this study was to investigate whether fluorine-18 fluorodeoxyglucose PET (18F-FDG PET) can help to predict seizure outcome after hemispherotomy and therefore may be useful in decision making and patient selection.
Children and adolescents less than 18 years of age who underwent 18F-FDG PET studies during presurgical evaluation prior to hemispherotomy and had follow-up data of at least 12 months after surgery were included. Seizure outcome was classified according to the recommendations of the International League Against Epilepsy. PET data were reevaluated by two specialists in nuclear medicine blinded to clinical data and to MRI. MRI studies were also reinterpreted visually by an experienced neuroradiologist blinded to clinical data and PET findings.
Thirty-five patients (17 girls) with a median age of 5 years (range 0.4–17.8 years) were evaluable. Of the 35 patients, 91.4% were seizure free after surgery, including 100% of those with unilateral 18F-FDG-PET hypometabolism compared with only 75% of those with bilateral hypometabolism. With respect to MRI, seizure freedom after surgery was observed in 96.4% of the patients with unilateral lesions compared with only 71.4% in those with bilateral MRI lesions. The best seizure outcomes were noted in patients with unilateral findings in both PET and MRI (100% seizure freedom) whereas only 50% of those with bilateral findings in both imaging techniques were seizure free. Furthermore, 100% of the patients with unilateral PET hypometabolism and bilateral MRI findings were also seizure free, but only 87.5% of those with bilateral PET hypometabolism and unilateral MRI findings.
According to these results, candidate selection for hemispherotomy can be optimized by the use of 18F-FDG PET as part of a multimodal presurgical evaluation program, especially in patients with inconsistent (bilateral) MRI findings.