The authors describe 12 pregnancies in women with epilepsy using lamotrigine (LTG) monotherapy. A seizure increase in nine pregnancies was probably related to a gradual decline of LTG level-to-dose ratio to 40% of baseline. After delivery, LTG kinetics returned swiftly to baseline, causing toxic side effects in some women. Frequent LTG level monitoring and appropriate dose adjustments are advised in the period before and during pregnancy and after delivery, especially in women on LTG monotherapy.

We performed a multicenter retrospective study in 166 consecutive patients shunted for presumed normal-pressure hydrocephalus (NPH) in the four neurosurgical departments of Amsterdam. Overall improvement occurred in 36%, substantial improvement in 21%. In the subgroup of idiopathic NPH (N = 127), marked improvement was only 15%. The incidence of shunt-responsive NPH in our area was 2.2/million/year. The rate of severe and moderate shunt-related complications was 28%, leading to death or severe residual morbidity in 7%. The substantial benefit/serious harm ration in the whole group was only three (21%/7%), decreasing to 1.7 in idiopathic NPH. By excluding patients at high surgical risk, this ratio might have risen to 10 in the whole group and to six in idiopathic NPH. Our experience is much less favorable than that encountered in the literature, reporting overall improvement in 74% and marked improvement in 55% of the shunted patients. We conclude that NPH is probably a very rare and still overdiagnosed syndrome and that the overall morbidity rate for each patient demonstrating meaningful improvement is high.

Ring chromosome 20 mosaicism is associated with dysmorphic features, mental retardation, and intractable seizures, including recurrent episodes of nonconvulsive status epilepticus. The authors' findings in four children, all without dysmorphic features, indicate that mental deterioration and frequent subtle nocturnal frontal lobe seizures, associated with a characteristic EEG pattern, represent prominent additional clinical features not previously described in this syndrome. This emphasizes the importance of full-night video-EEG in children with frontal lobe seizures and cognitive deterioration.

Pathogenic variants in the PCDH19 gene are associated with epilepsy, intellectual disability (ID) and behavioural disturbances. Only heterozygous females and mosaic males are affected, likely due to a disease mechanism named cellular interference. Until now, only four affected mosaic male patients have been described in literature. Here, we report five additional male patients, of which four are older than the oldest patient reported so far. All reported patients were selected for genetic testing because of developmental delay and/or epilepsy. Custom-targeted next generation sequencing gene panels for epilepsy genes were used. Clinical data were collected from medical records. All patients were mosaic in blood for likely pathogenic variants in the PCDH19 gene. In most, clinical features were very similar to the female phenotype, with normal development before seizure onset, which occurred between 5 and 10 months of age, clustering of seizures and sensitivity to fever. Four out of five patients had mild to severe ID and behavioural problems. We reaffirm the similarity between male and female PCDH19-related phenotypes, now also in a later phase of the disorder (ages 10–14 years).Electronic supplementary materialThe online version of this article (doi:10.1007/s10048-017-0517-5) contains supplementary material, which is available to authorized users.

Relatively few SCN1A mutations associated with genetic epilepsy with febrile seizures plus (GEFS+) and Dravet syndrome (DS) have been functionally characterized. In contrast to GEFS+, many mutations detected in DS patients are predicted to have complete loss-of-function. However, functional consequences are not immediately apparent for DS missense mutations. Therefore, we performed biophysical analysis of three SCN1A missense mutations (R865G, R946C, and R946H) we detected in six patients with DS. Furthermore, we compared the functionality of the R865G DS mutation with that of a R859H mutation detected in a GEFS+ patient; both mutations reside in the same voltage sensor domain of Nav1.1. The four mutations were co-expressed with β1 and β2-subunits in tsA201 cells and characterized using the whole-cell patch clamp technique. The two DS mutations, R946C and R946H, were non-functional. However, the novel voltage sensor mutants R859H (GEFS+) and R865G (DS) produced sodium current densities comparable to wild-type channels. Both mutants had negative shifts in the voltage dependence of activation, slower recovery from inactivation, and increased persistent current. Only the GEFS+ mutant exhibited a loss-of-function in voltage dependent channel availability. Our results suggest that the R859H mutation causes GEFS+ by a mixture of biophysical defects in Nav1.1 gating. Interestingly, while loss of Nav1.1 function is common in DS, the R865G mutation may cause DS by overall gain-of-function defects.