Correlates of intellectual development before and after hemispherotomy: an analysis of 75 children and adolescents.

This study describes the intellectual development of 75 children and adolescents who underwent hemispherotomy. Furthermore, we aimed to reveal predicting factors on pre- and postsurgical development with a focus on the role of aetiology. We analysed presurgical and six-month postsurgical developmental and intellectual data of 75 patients (age range: 0.87-19.78 years) and divided them into two groups: a not severely impaired group in which outcome of intellectual functioning was reported based on FSIQ score, and a severely impaired group (not testable by IQ tests) in which intellectual developmental outcome was described based on developmental quotients instead. In the not severely impaired group (n = 31), the preoperative level of intellectual functioning was a strong predictor of postoperative intellectual outcome; for 22/31 (71%) patients, postoperative FSIQ and its subscales were similar to preoperative levels. Improvements were observed for FSIQ in five patients, only for Verbal IQ in one patient and only for Performance IQ in one further patient; significant losses occurred in two patients, only for Performance IQ in both. In the severely impaired group, 30/40 (75%) patients showed further development after surgery, nine (23%) patients had the same results as before surgery, and one (2%) patient showed regression. Longer duration of presurgical epilepsy was related to a marginally lower presurgical developmental level, and good seizure outcome was a predictor of better postoperative development. For all patients, early age at seizure onset and early lesion origin correlated with poorer presurgical intellectual development. Although an entire hemisphere was disconnected, most patients exhibited ongoing development after hemispherotomy or had at least the same preoperative intellectual status; deterioration was rare.

Sacrificing one visual hemifield during pediatric epilepsy surgery: Effects on visual search.

OBJECTIVES: To investigate early and late effects of planned surgically acquired homonymous hemianopias on visual search in children and adolescents. METHODS: This prospective study included five patients (5y 5 m-18y 0 m; 2 girls) with pharmaco-refractory epilepsies in whom one visual hemifield was sacrificed as part of the surgical strategy, and, as controls, seven patients (5y 11 m-18y 0 m; 6 girls) undergoing epilepsy surgeries not affecting the visual fields. Visual search was studied using the "Table Test", which is an everyday life-like visual search test. General processing speed was studied using a standard IQ subtest. RESULTS: All five patients with newly acquired homonymous hemianopias showed a relative disadvantage of visual search times for objects in their newly blind hemifields immediately after the surgery. Six months later, this relative disadvantage had recovered completely in all patients. Nevertheless, compared with the preoperative situation, overall search times were still prolonged in the hemianopic patients, but this effect could be mitigated or even overcompensated by improvements in processing speed. CONCLUSIONS: Children with homonymous hemianopias inflicted by epilepsy surgery develop effective compensation strategies to minimize the relative disadvantage of visual search in their blind hemifields. For changes in overall visual search times between the preoperative and the six-month follow-up examination, we could demonstrate overlapping effects of (a) deterioration by hemianopia and (b) amelioration by improved processing speed as part of the cognitive improvements achieved by amelioration of the epilepsy.

Neuropeptide S Receptor Gene Variation Differentially Modulates Fronto-Limbic Effective Connectivity in Childhood and Adolescence.

The neuropeptide S (NPS) system contributes to the pathogenesis of anxiety. The more active T allele of the functional rs324981 variant in the neuropeptide S receptor gene (NPSR1) is associated with panic disorder (PD) and distorted cortico-limbic activity during emotion processing in healthy adults and PD patients. This study investigated the influence of NPSR1 genotype on fronto-limbic effective connectivity within the developing brain. Sixty healthy subjects (8-21 years) were examined using an emotional go-nogo task and fMRI. Fronto-limbic connectivity was determined using Dynamic Causal Modeling. In A allele carriers, connectivity between the right middle frontal gyrus (MFG) and the right amygdala was higher in older (≥14 years) than that in younger (<14 years) probands, whereas TT homozygotes ≥14 years showed a reduction of fronto-limbic connectivity between the MFG and both the amygdala and the insula. Fronto-limbic connectivity varied between NPSR1 genotypes in the developing brain suggesting a risk-increasing effect of the NPSR1T allele for anxiety-related traits via impaired top-down control of limbic structures emerging during adolescence. Provided robust replication in longitudinal studies, these findings may constitute valuable biomarkers for early targeted prevention of anxiety disorders.