The validity of 3 Tesla motor functional magnetic resonance imaging (fMRI) in patients with gliomas involving the primary motor cortex was investigated by intraoperative navigated motor cortex stimulation (MCS). Methods: Twenty two patients (10 males, 12 females, mean age 39 years, range 10-65 years) underwent preoperative fMRI studies, performing motor tasks including hand, foot, and mouth movements. A recently developed high field clinical fMRI technique was used to generate pre-surgical maps of functional high risk areas defining a motor focus. Motor foci were tested for validity by intraoperative motor cortex stimulation (MCS) employing image fusion and neuronavigation. Clinical outcome was assessed using the Modified Rankin Scale. Results: FMRI motor foci were successfully detected in all patients preoperatively. In 17 of 22 patients (77.3%), a successful stimulation of the primary motor cortex was possible. All 17 correlated patients showed 100% agreement on MCS and fMRI motor focus within 10 mm. Technical problems during stimulation occurred in three patients (13.6%), no motor response was elicited in two (9.1%), and MCS induced seizures occurred in three (13.6%). Combined fMRI and MCS mapping results allowed large resections in 20 patients (91%) (gross total in nine (41%), subtotal in 11 (50%)) and biopsy in two patients (9%). Pathology revealed seven low grade and 15 high grade gliomas. Mild to moderate transient neurological deterioration occurred in six patients, and a severe hemiparesis in one. All patients recovered within 3 months (31.8% transient, 0% permanent morbidity). Conclusions: The validation of clinically optimised high magnetic field motor fMRI confirms high reliability as a preoperative and intraoperative adjunct in glioma patients selected for surgery within or adjacent to the motor cortex.

Summary: Purpose: We wished to determine the predictive significance of unilateral hippocampal atrophy and interictal spikes on localization of ictal scalp EEG changes and assess whether ictal EEG provides information that might change treatment or influence prognosis in patients with such characteristics of epilepsy.Methods: We analyzed EEG seizure patterns in 11 8 seizures in 24 patients with unilateral mesial temporal lobe epilepsy (MTLE) defined by typical clinical seizure semiology, unilateral hippocampal atrophy on magnetic resonance imaging (MRI) and unitemporal spikes on interictal EEG. Two blinded electroencephalographers independently determined morphology, location, and time course of ictal EEG changes.Results: Lateralization was possible in 88.4-92.0% of seizures and always corresponded to the side of the interictal spike focus and of hippocampal atrophy on MRI. Although only 30.4-33.9% of seizures were lateralized at onset, a later significant pattern emerged (12.6-13.3 s after EEG seizure onset) that allowed lateralization in 82.4-9 1 .O% of seizures with nonlateralized onset. Interobserver reliability for lateralization was excellent, with a K-value of 0.85. In most patients, either all (79.2-83.3%) or >50% (8.3-16.7%) of seizures were lateralized. In only a small proportion of patients (4.2-8.3%) were 4 0 % of seizures lateralized. In 1 patient, no seizure could be lateralized by 1 electroencephalographer. The results of ictal EEG recordings did not alter the surgical approach and did not correlate with surgical outcome.Conclusions: We conclude that unilateral hippocampal atrophy on MRI and unitemporal interictal spikes can predict localization of ictal scalp EEG changes with a high degree of reliability and that ictal EEG provides no additional localizing information in this particular patient group. Key Words: Temporal lobe epilepsy-Epilepsy surgery-Scalp electroencephalogram-Ictal electroencephalogram.Mesial temporal lobe epilepsy (MTLE)-probably the most frequently occurring type of epilepsy-can easily be diagnosed on the basis of clinical history, typical clinical seizure semiology, anterior temporal spikes on scalp EEG, and the appearance of hippocampal attophy or sclerosis on magnetic resonance imaging (MRI) scan (1-3). Patients with MTLE frequently have medically refractory seizures and are considered excellent candidates for epilepsy surgery (3).Presurgical evaluation of epilepsy patients relies on converging evidence from history, clinical seizure semiology, interictal and ictal EEG, neuropsychological testing, and imaging studies evaluating structure (MRI) and function [single photon emission computed tomography (SPECT) and positron emission tomography (PET)] (1, 4-6). Prolonged video-EEG monitoring which records the patient's habitual seizures and the corresponding ictal EEG changes, has been the cornerstone of presurgical

Object 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. Methods 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. Results 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). Conclusions 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.

Object Subtotal resection (STR) of spinal tumors can result in tumor recurrence. Currently, no clinically reliable marker is available for intraoperative visualization of spinal tumor tissue. Protoporphyrin IX (PpIX) fluorescence induced by 5-aminolevulinic acid (5-ALA) is capable of visualizing malignant gliomas. Fluorescence-guided resections of malignant cerebral gliomas using 5-ALA have resulted in an increased rate of complete tumor removal. Recently, the application of 5-ALA has also been described in the first cases of spinal tumors. Therefore, the aim of this observational study was to systematically investigate 5-ALA–induced fluorescence characteristics in different spinal tumor entities. Methods Three hours before the induction of anesthesia, 5-ALA was administered to patients with different intra- and extradural spinal tumors. In all patients a neurosurgical resection or biopsy of the spinal tumor was performed under conventional white-light microscopy. During each surgery, the presence of PpIX fluorescence was additionally assessed using a modified neurosurgical microscope. At the end of an assumed gross-total resection (GTR) under white-light microscopy, a final inspection of the surgical cavity of fluorescing intramedullary tumors was performed to look for any remaining fluorescing foci. Histopathological tumor diagnosis was established according to the current WHO classification. Results Fifty-two patients with 55 spinal tumors were included in this study. Resection was performed in 50 of 55 cases, whereas 5 of 55 cases underwent biopsy. Gross-total resection was achieved in 37 cases, STR in 5, and partial resection in 8 cases. Protoporphyrin IX fluorescence was visible in 30 (55%) of 55 cases, but not in 25 (45%) of 55 cases. Positive PpIX fluorescence was mainly detected in ependymomas (12 of 12), meningiomas (12 of 12), hemangiopericytomas (3 of 3), and in drop metastases of primary CNS tumors (2 of 2). In contrast, none of the neurinomas (8 of 8), carcinoma metastases (5 of 5), and primary spinal gliomas (3 of 3; 1 pilocytic astrocytoma, 1 WHO Grade II astrocytoma, 1 WHO Grade III anaplastic oligoastrocytoma) revealed PpIX fluorescence. It is notable that residual fluorescing tumor foci were detected and subsequently resected in 4 of 8 intramedullary ependymomas despite assumed GTR under white-light microscopy. Conclusions In this study, 5-ALA–PpIX fluorescence was observed in spinal tumors, especially ependymomas, meningiomas, hemangiopericytomas, and drop metastases of primary CNS tumors. In cases of intramedullary tumors, 5-ALA–induced PpIX fluorescence is a useful tool for the detection of potential residual tumor foci.

Summary Purpose The current concept for hemispherotomy includes various lateral techniques and the vertical perithalamic hemispherotomy introduced by Delalande in 1992. We have chosen the vertical approach because of advantages that possibly influence outcome: the possibility to completely disconnect the hemisphere at the level of the thalamus obviating both the need to resect the insula and the need to open and dissect the subarachnoid space of the Sylvian fissure. Methods We retrospectively analyzed prospectively collected data of all patients who underwent vertical hemispherotomy at the Vienna pediatric epilepsy center. Seizure outcome was classified according to the International League Against Epilepsy (ILAE) proposal 2001. Key Findings Follow‐up data of 40 patients (22 male/18 female; median age 5.5 years; range 4.4 months to 20.1 years) were analyzed. Hemispherotomy was left in 26 and right in 14 patients. The underlying pathology was ischemic vascular in 19, malformation of cortical development (MCD) in 11, and other pathology in 10. No serious intraoperative complications were encountered. Only two infants (5.0%) needed blood replacement. There was one death on the fourth day after surgery caused by intractable hyponatremic brain edema. Three patients developed cerebrospinal fluid (CSF) disturbances, but only one needed a permanent ventriculoperitoneal (VP) shunt (2.5%). For outcome analysis we included 37 of 40 children with at least 12 months of follow‐up. Thirty‐four (91.9%) of 37 children were seizure‐free (class 1a) after a median follow‐up time of 3.7 years (range 12 month to 14.8 years). Significance We confirm the efficacy and safety of vertical parasagittal hemispherotomy as described by Delalande in a consecutive series of patients treated at our center since 1998. In addition, complete disconnection of the hemisphere in patients with MCD and/or patients with significant involvement of the insula was possible without the complications usually reported with other techniques.