Frequency, Predictors, and Outcome of Seizures in Patients With Myelomeningocele: Single-Center Retrospective Cohort Study.

To determine the frequency, predictors, and outcomes of seizures in patients with myelomeningocele, we retrospectively analyzed the data from patients with myelomeningocele followed longitudinally at a single center from 1975 to 2013. We identified a total of 122 patients (61% female). The mean follow-up duration was 11.1 years (minimum-maximum = 0-34.5 years, SD = 8.8, median = 9.1 years). A total of 108 (88.5%) patients had hydrocephalus, and 98 (90.7%) of those patients required a ventriculoperitoneal shunt procedure. Twenty-four (19.7%) patients manifested with seizures, 23 of whom had hydrocephalus. The average age of seizure onset was 4.8 years (median 2 years of age). Falx dysgenesis (P = .004), lumbar myelomeningocele (P = .007), and cortical atrophy (P = .028) were significantly associated with epileptic seizure development. The average seizure-free period at the last follow-up in patients with a history of myelomeningocele and seizures was 8.1 years. We conclude that myelomeningocele patients with seizures have an overall good prognosis with considerable long-term seizure freedom.

Perception of phosphenes and flashed alphabetical characters is enhanced by single-pulse transcranial magnetic stimulation of anterior frontal lobe: the thalamic gate hypothesis.

Single pulses of transcranial magnetic stimulation (sTMS) restricted locally to the primary cortical areas for somatosensory and visual input, unlike the effects of repetitive stimulation, usually fail to elicit projected sensations. We tested the effect of sTMS over anterior frontal cortex in facilitating phosphenes from preceding sTMS over calcarine cortex, which alone was rarely effective in eliciting phosphenes. The combined sTMS elicited complex phosphenes, which changed with the site of frontal sTMS and the interstimulus interval. Our results show that sTMS over anterior frontal cortex also improved reporting of weakly illuminated, flashed four-letter stimuli, which permitted its statistical validation. We propose that the present demonstration of frontal cortical facilitation of visual awareness, when combined with the previous finding of projected paresthesias and sense of movement (Amassian et al, 1991 Brain 114 2505-2520), provide evidence of a general frontal opening effect on a thalamic gate. Opening this gate facilitates entry of information from primary cortical receiving areas to thalamus. Thereby, the reciprocal thalamocortical interrelations that subserve conscious awareness of sensory stimuli could be fostered.

Protein synthesis-dependent LTP in isolated dendrites of CA1 pyramidal cells.

Local dendritic protein synthesis provides a mechanism by which the effects of gene expression can be spatially restricted within synaptodendritic compartments of neurons. In the present study, we show that long-term potentiation (LTP), induced by two strong tetanic trains, can be produced in isolated CA1 apical dendrites and that new protein synthesis is critical for this dendritic LTP. LTP in isolated dendrites is also blocked by rapamycin, an inhibitor of growth-related protein synthesis, similar to that observed for LTP in the intact hippocampal slice. These results show that increased dendritic translation of proteins is a critical molecular mechanism for hippocampal LTP.