Alternating hemiplegia of childhood: evolution over time and mouse model corroboration.

Alternating hemiplegia of childhood is a rare neurodevelopmental disorder caused by ATP1A3 mutations. Some evidence for disease progression exists, but there are few systematic analyses. Here, we evaluate alternating hemiplegia of childhood progression in humans and in the D801N knock-in alternating hemiplegia of childhood mouse, Mashlool, model. This study performed an ambidirectional (prospective and retrospective data) analysis of an alternating hemiplegia of childhood patient cohort (n = 42, age 10.24 ± 1.48 years) seen at one US centre. To investigate potential disease progression, we used linear mixed effects models incorporating early and subsequent visits, and Wilcoxon Signed Rank test comparing first and last visits. Potential early-life clinical predictors were determined via multivariable regression. We also compared EEG background at first encounter and at last follow-up. We then performed a retrospective confirmation study on a multicentre cohort of alternating hemiplegia of childhood patients from France (n = 52). To investigate disease progression in the Mashlool mouse, we performed behavioural testing on a cohort of Mashlool- mice at prepubescent and adult ages (n = 11). Results: US patients, over time, demonstrated mild worsening of non-paroxysmal disability index scores, but not of paroxysmal disability index scores. Increasing age was a predictor of worse scores: P < 0.0001 for the non-paroxysmal disability index, intellectual disability scale and gross motor scores. Earliest non-paroxysmal disability index score was a predictor of last visit non-paroxysmal disability index score (P = 0.022), and earliest intellectual disability score was a predictor of last intellectual disability score (P = 0.035). More patients with EEG background slowing were noted at last follow-up as compared to initial (P = 0.015). Similar worsening of disease with age was also noted in the French cohort: age was a significant predictor of non-paroxysmal disability index score (P = 0.001) and first and last non-paroxysmal disability index score scores significantly differed (P = 0.002). In animal studies, adult Mashlool mice had, as compared to younger Mashlool mice, (i) worse balance beam performance; (ii) wider base of support; (iii) higher severity of seizures and resultant mortality; and (iv) no increased predisposition to hemiplegic or dystonic spells. In conclusion, (i) non-paroxysmal alternating hemiplegia of childhood manifestations show, on average over time, progression associated with severity of early-life non-paroxysmal disability and age. (ii) Progression also occurs in Mashlool mice, confirming that ATP1A3 disease can lead to age-related worsening. (iii) Clinical findings provide a basis for counselling patients and for designing therapeutic trials. Animal findings confirm a mouse model for investigation of underlying mechanisms of disease progression, and are also consistent with known mechanisms of ATP1A3-related neurodegeneration.

Mowat-Wilson syndrome: growth charts.

BACKGROUND: Mowat-Wilson syndrome (MWS; OMIM #235730) is a genetic condition caused by heterozygous mutations or deletions of the ZEB2 gene. It is characterized by moderate-severe intellectual disability, epilepsy, Hirschsprung disease and multiple organ malformations of which congenital heart defects and urogenital anomalies are the most frequent ones. To date, a clear description of the physical development of MWS patients does not exist. The aim of this study is to provide up-to-date growth charts specific for infants and children with MWS. Charts for males and females aged from 0 to 16 years were generated using a total of 2865 measurements from 99 MWS patients of different ancestries. All data were collected through extensive collaborations with the Italian MWS association (AIMW) and the MWS Foundation. The GAMLSS package for the R statistical computing software was used to model the growth charts. Height, weight, body mass index (BMI) and head circumference were compared to those from standard international growth charts for healthy children. RESULTS: In newborns, weight and length were distributed as in the general population, while head circumference was slightly smaller, with an average below the 30th centile. Up to the age of 7 years, weight and height distribution was shifted to slightly lower values than in the general population; after that, the difference increased further, with 50% of the affected children below the 5th centile of the general population. BMI distribution was similar to that of non-affected children until the age of 7 years, at which point values in MWS children increased with a less steep slope, particularly in males. Microcephaly was sometimes present at birth, but in most cases it developed gradually during infancy; many children had a small head circumference, between the 3rd and the 10th centile, rather than being truly microcephalic (at least 2 SD below the mean). Most patients were of slender build. CONCLUSIONS: These charts contribute to the understanding of the natural history of MWS and should assist pediatricians and other caregivers in providing optimal care to MWS individuals who show problems related to physical growth. This is the first study on growth in patients with MWS.

Infantile spasms followed by childhood absence epilepsy: A case series.

PURPOSE: Infantile spasms (IS) represent a severe seizure disorder of infancy and early childhood characterized by epileptic spasms along with hypsarrhythmia often accompanied by intellectual disability. According to the current classification and terminology (3) IS can be categorized as known etiology, formerly known as "symptomatic", when an underlying cause has been observed prior to the onset of spasms, or of "unknown cause" with "unfavorable" and "favorable" outcome (previously referred as "cryptogenic" or "idiopathic", respectively). Single reports described children with "unknown cause and favorable outcome" (UC/FO) IS who later developed childhood absence epilepsy (CAE). This study aims to determine the prevalence of CAE following IS. METHODS: a multicenter retrospective chart review was performed; children with UC/FO IS who subsequently developed CAE during follow-up were identified. Eight Italian pediatric epilepsy centers participated in this study. RESULTS: seven out of 24 (29 %) children (3 males) showing a favorable outcome (UC/FO) IS received a second diagnosis of CAE during follow-up. Mean age at IS presentation was 5.8 months (SD ± 0.9). All achieved seizure control of IS at a mean age of 8.5 months (SD ± 1.3) (3 monotherapy, 4 polytherapy). CAE was diagnosed at a mean age of 8.0 years (SD ± 3.0). Six children achieved sustained remission of CAE with valproic acid, whereas 1 child required dual therapy by adding ethosuximide. CONCLUSION: although it is not possible to determine whether the association between UC/FO IS and CAE implies a causality relationship, the later occurrence of CAE in patients with UC/FO IS might support a possible role of thalamo-cortical dysfunction.

Expanding the phenotype of MED 17 mutations: Description of two new cases and review of the literature.

We report the case of two siblings presenting with failure to thrive in early years, progressive microcephaly, moderate intellectual disability, developmental delay, ataxic gait and seizures with an identical EEG pattern, and minimal cerebellar atrophy. We ruled out the syndromic and metabolic causes of microcephaly and subsequently conducted a panel of genetic diagnostic tests, including the clinical exome sequencing which revealed compound heterozygous mutations in MED 17 gene in both patients. p.Glu16fs was found to be inherited from the mother and p.Gly253Arg from the father. This case along with review of the literature suggests that mutations in MED17 may define a phenotype characterized by progressive microcephaly, intellectual disability, seizures, cerebellar atrophy of variable degree, and ataxia. More cases are needed to define the phenotype-genotype correlation in MED17 mutations. However, basing on our findings, we recommend testing MED17 mutations in any patient presenting with two or more of the aforementioned signs and symptoms.

Transcutaneous vagal nerve stimulatio (t-VNS): An adjunctive treatment option for refractory epilepsy.

PURPOSE: The aim of this trial was to investigate the efficacy and safety of transcutaneous vagal nerve stimulation (t-VNS) in the palliative treatment of drug resistant epileptic patients ineligible for surgery. METHODS: Twenty adult patients received four hours of t-VNS per day for six months (T1), followed by a two-month washout period (T2). The frequency and type of seizures recorded at T1 and T2 were compared with those occurring in the three months preceding study entry (T0). Responders (>30% reduction in the total number of seizures) subsequently received two hours of t-VNS per day for further six months (T3). All patients underwent electroencephalography (EEG) and completed the Quality of Life in Epilepsy questionnaire at baseline and T1. RESULTS: At T1 six patients were considered responders. In these patients, at T3 the average reduction in seizure frequency was 60% compared to T0 (p = 0.043), and 51% compared to T2 (p = 0.043). Responders had more often seizures with falls (5 of 6; 83.3%) compared with non-responders (3 of 14; 21.4%) (p = 0,010) and t-VNS reduced their frequency by a percentage ranging from 47.5 to 100%. There was no change in responders' EEG findings after stimulation. At the end of the trial, three responders continued t-VNS, one implanted VNS. CONCLUSIONS: t-VNS had no or minimal side effects and significantly reduced seizures in about one third of the enrolled patients. Further studies should be planned to assess whether t-VNS is a suitable tool to predict the efficacy of implanted VNS.