Vertical perithalamic hemispherotomy: a single-center experience in 40 pediatric patients with epilepsy.

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.

Disconnective surgery in posterior quadrantic epilepsy: experience in a consecutive series of 10 patients.

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.

Temporal Dynamics of MOG Antibodies in Children With Acquired Demyelinating Syndrome.

BACKGROUND AND OBJECTIVE: The spectrum of myelin oligodendrocyte glycoprotein (MOG) antibody-associated disorder (MOGAD) comprises monophasic diseases such as acute disseminated encephalomyelitis (ADEM), optic neuritis (ON), and transverse myelitis and relapsing courses of these presentations. Persistently high MOG antibodies (MOG immunoglobulin G [IgG]) are found in patients with a relapsing disease course. Prognostic factors to determine the clinical course of children with a first MOGAD are still lacking. The objective of the study is to assess the clinical and laboratory prognostic parameters for a risk of relapse and the temporal dynamics of MOG-IgG titers in children with MOGAD in correlation with clinical presentation and disease course. METHODS: In this prospective multicenter hospital-based study, children with a first demyelinating attack and complete data set comprising clinical and radiologic findings, MOG-IgG titer at onset, and clinical and serologic follow-up data were included. Serum samples were analyzed by live cell-based assay, and a titer level of ≥1:160 was classified as MOG-IgG-positive. RESULTS: One hundred sixteen children (f:m = 57:59) with MOGAD were included and initially diagnosed with ADEM (n = 59), unilateral ON (n = 12), bilateral ON (n = 16), myelitis (n = 6), neuromyelitis optica spectrum disorder (n = 8) or encephalitis (n = 6). The median follow-up time was 3 years in monophasic and 5 years in relapsing patients. There was no significant association between disease course and MOG-IgG titers at onset, sex, age at presentation, or clinical phenotype. Seroconversion to MOG-IgG-negative within 2 years of the initial event showed a significant risk reduction for a relapsing disease course. Forty-two/one hundred sixteen patients (monophasic n = 26, relapsing n = 16) had serial MOG-IgG testing in years 1 and 2 after the initial event. In contrast to relapsing patients, monophasic patients showed a significant decrease of MOG-IgG titers during the first and second years, often with seroconversion to negative titers. During the follow-up, MOG-IgG titers were persistently higher in relapsing than in monophasic patients. Decrease in MOG-IgG of ≥3 dilution steps after the first and second years was shown to be associated with a decreased risk of relapses. In our cohort, no patient experienced a relapse after seroconversion to MOG-IgG-negative. DISCUSSION: In this study, patients with declining MOG-IgG titers, particularly those with seroconversion to MOG-IgG-negative, are shown to have a significantly reduced relapse risk.

Clinical and imaging features of children with autoimmune encephalitis and MOG antibodies.

OBJECTIVE: To describe the presentations, radiologic features, and outcomes of children with autoimmune encephalitis associated with myelin oligodendrocyte glycoprotein antibodies (MOG abs). METHODS: Identification of children fulfilling the diagnostic criteria for possible autoimmune encephalitis (AE) and testing positive for serum MOG abs. Chart review and comprehensive analysis of serum MOG abs using live cell assays and rat brain immunohistochemistry. RESULTS: Ten children (4 girls, 6 boys) with AE and serum MOG abs were identified. The median age at onset was 8.0 years (range: 4-16 years). Children presented with a combination of encephalopathy (10/10), headache (7/10), focal neurologic signs (7/10), or seizures (6/10). CSF pleocytosis was common (9/10, median 80 white cell count/µL, range: 21-256). Imaging showed cortical and deep gray matter involvement in all in addition to juxtacortical signal alterations in 6/10 children. No involvement of other white matter structures or contrast enhancement was noted. MOG abs were detected in all children (median titer 1:640; range: 1:320-1:10,540). Nine children had a favorable outcome at discharge (modified Rankin scale of < 2). Five of 10 children had up to 3 additional demyelinating relapses associated with persisting MOG abs. One child had NMDA receptor (NMDAR) abs at initial presentation. A second child had a third demyelinating episode with MOG abs with overlapping NMDAR encephalitis. DISCUSSION: AE associated with serum MOG abs represents a distinct form of autoantibody-mediated encephalitis in children. We therefore recommend including MOG abs testing in the workup of children with suspected AE.

Efficacy and tolerability of the ketogenic diet in Dravet syndrome - Comparison with various standard antiepileptic drug regimen.

UNLABELLED: There is strong evidence for the use of the ketogenic diet (KD) in Dravet syndrome (DS). The purpose of this study was to evaluate both effectiveness and tolerability in comparison with various antiepileptic drugs (AEDs). METHODS: 32 children (19 males) with genetically confirmed DS treated at our center since 1999 were analyzed retrospectively. Data collected from patients' files included type of mutation, age at treatment initiation and treatment lag, overall seizure frequency and frequency of different seizure types, especially prolonged seizures and status epilepticus (SE). Efficacy and safety of the KD were evaluated. In addition, the effect on seizure count was compared with that of various AED regimen and the vagus nerve stimulation (VNS). RESULTS: Overall response to the KD was 70% at 3 months and 60% at 12 months. No SE occurred while patients were on the diet, and the frequencies of prolonged generalized and myoclonic seizures were reduced. No severe side effects requiring withdrawal of the KD were observed. Although the effect of the KD was independent of age at initiation, it had to be withdrawn due to noncompliance more frequently in solid fed older children compared with infants treated with the liquid ketogenic formula. The KD was not significantly inferior to the current gold standard AED triple combination of Stiripentol+Valproate+Clobazam (89%), Bromides (78%), Valproate alone (48%), Topiramate (35%) and VNS (37%) and significantly more effective than Levetiracetam (30%; p=0.037, Pearson's Chi-square). SIGNIFICANCE: These data suggest that the KD ranks among currently used AEDs as an effective treatment for seizures in DS. According to our results (good effect on SE and prolonged seizures, good tolerability, less compliance problems due to formula treatment) the KD should be considered as an early treatment option in infants with DS.

Epilepsy surgery in children and adolescents with malformations of cortical development--outcome and impact of the new ILAE classification on focal cortical dysplasia.

UNLABELLED: To determine long-term efficacy and safety of epilepsy surgery in children and adolescents with malformations of cortical development (MCD) and to identify differences in seizure outcome of the various MCD subgroups. Special focus was set on the newly introduced International League Against Epilepsy (ILAE) classification of focal cortical dysplasia (FCD). STUDY DESIGN: This is a single center retrospective cross-sectional analysis of prospectively collected data. INCLUSION CRITERIA: age at surgery <18 years, pre-surgical evaluation and epilepsy surgery performed at the Vienna pediatric epilepsy center, histologically proven MCD, complete follow-up data for at least 12 months. Clinical variables evaluated: type and localization of MCD, type of surgery and a variety of clinical characteristics reported to be associated with (un-)favorable outcomes. MCD were classified following the existing classification schemes (Barkovich et al., 2012. Brain. 135, 1348-1369; Palmini et al., 2004. Neurology. 62, S2-S8) and the ILAE classification for FCD recently proposed by Blümcke in 2011. Seizure outcome was classified using the ILAE classification proposed by Wieser in 2001. RESULTS: 60 Patients (51.7% male) were included. Follow up was up to 14 (mean 4.4 ± 3.2) years. Mean age at surgery was 8.0 ± 6.0 (median 6.0) years; mean age at epilepsy onset was 2.9 ± 3.2 (median 2.0) years; duration of epilepsy before surgery was 4.8 ± 4.4 (median 3.0) years. 80% of the patients were seizure free at last follow-up. AEDs were successfully withdrawn in 56.7% of all patients. Extended surgery, lesion localization in the temporal lobes and absence of inter-ictal spikes in postsurgical EEG recordings were predictive of favorable seizure outcomes after surgery. However, no association was found between outcome and MCD sub-types. Epilepsy surgery is highly effective in carefully selected drug-resistant children with MCD. Surrogate markers for complete resection of the epileptogenic zone remain the only significant predictors for seizure freedom after surgery.

Long-term outcome and tolerability of the ketogenic diet in drug-resistant childhood epilepsy--the Austrian experience.

PURPOSE: To evaluate the long-term efficacy/tolerability of the ketogenic diet (KD) in paediatric drug-resistant epilepsies. METHODS: Data from children who were treated between 1999 and 2008 and had continuous follow-up of at least 6 months after initiation of the KD were analysed retrospectively. Response was defined as > or = 50% seizure reduction. Treatment effects on EEG, developmental outcome and the "outcome-predictive" value of various clinical factors were also assessed. RESULTS: 50 children (22 boys; mean age 4.5 years+/-3.55) were included. Mean follow-up was 3.93+/-2.95. 50% of the patients were responders, 48% of them became seizure free. 50% were non-responders, 20% of them deteriorated. In responders, EEG background activity improved significantly (p=0.014) and a significantly lower rate of epileptic discharges (p=0.009) was seen after 6 months. In addition, neurological examination findings demonstrated significant developmental progress (p=0.038). Favourable treatment outcome was associated with a shorter disease duration (p=0.025) and generalised tonic clonic seizures (p=0.059). No further significant outcome predictors were detected. However, response was 44% in patients with infantile spasms, 62.5% in those with Dravet syndrome and 50% in Lennox-Gastaut-syndrome. Side effects occurred in 28%, but discontinuation of the KD was not required in any case. They most often observed with concomitant topiramate (p=0.001) and valproate (p=0.046). CONCLUSION: Despite the retrospective nature of the study and the inhomogeneous patient sample, we found good long-term effects of the KD on seizure frequency, EEG and neurological development.