Progressive Myoclonus Epilepsy in Congenital Generalized Lipodystrophy type 2: Report of 3 cases and literature review

PURPOSE

A small case series with a neurodegenerative disorder involving central nervous system and related to Seipin mutations was recently reported. Herein we describe clinical and EEG features of three patients presenting with Progressive Myoclonus Epilepsy (PME) and Congenital Generalized Lipodystrophy type 2 (CGL2) related to novel Seipin mutations.

METHODS

The EEG-clinical picture was evaluated at epilepsy onset and in the follow-up period. The molecular analysis of BSCL2, Laforin and Malin genes was performed to patients and/or their parents by Denaturing High Performance Liquid Chromatography and automated nucleotide sequencing. Skin specimens collected from a patient were processed for histochemical and ultrastructural analysis.

RESULTS

The CGL2-PME syndrome co-segregated with two different BSCL2 genotypes: the homozygosity for c.782_783dupG involving exon 8 (two cases), or the compound heterozygosity for c.782_783dupG/c.828_829delAA (one case). Periodic-Acid Schiff positive osmiophilic material in the cytoplasm of fibrocytes and eccrine-gland cells were found in skin specimens. The lack of Lafora's bodies in skin specimens and the molecular analysis excluding mutations in Laforin and Malin genes ruled out Lafora disease.

CONCLUSION

The spectrum of CGL2 associated to BSCL2 gene mutations may include PMEs. Selected mutations in BSCL2 gene seem to be related to PMEs in patients with CGL2 phenotype.

Pediatric epilepsy following neonatal seizures symptomatic of stroke

BACKGROUND

Neonatal seizures are a risk factor for later epilepsy and their etiology is known to be implicated in the outcome but, little is known about this issue in the subgroup of seizures symptomatic of perinatal arterial ischemic stroke. The aim of this study was to describe the long term risk of epilepsy after electroencephalographic confirmed neonatal seizures symptomatic of perinatal arterial ischemic stroke.

DESIGN/SUBJECT

Fifty-five patients with electroclinical ictal data, vascular territory confirmed by neuroimaging and a minimum follow up of 3.5 years were identified from a multi-centre prospective neonatal seizures registry. Primary outcome was occurrence of post-neonatal epilepsy. The association of outcome with family history of epilepsy, gender, location of the infarct, neonatal clinical and electroencephalogram data were also studied.

RESULTS

During a mean follow up of 8 years and 5 months, 16.4% of the patients developed post neonatal epilepsy. The mean age at first post neonatal seizure was 4 years and 2 months (range 1-10 years and 6 months). Location of the infarct was the only statistically significant risk factor (p=0.001); epilepsy was more represented in males but the difference was not statistically significant.

CONCLUSIONS

Neonatal seizures symptomatic of perinatal arterial ischemic stroke had lower risk and later onset of post-neonatal epilepsy, compared to seizures described in the setting of other perinatal brain insults. Our data have implications for counseling to the family at discharge from neonatal intensive care unit.

Paediatric anti-N-methyl-D-aspartate receptor encephalitis: The first Italian multicenter case series

BACKGROUND

Given the rarity of this condition, especially in children, there is a paucity of large reported paediatric case series of anti-N-methyl-d-aspartate receptor encephalitis.

METHODS

To contribute to define the features of this condition, we describe retrospectively a new nationwide case series of 20 children (50% females), referred by 13 Italian centres.

RESULTS

Mean age at onset was 8 years (range 3-17). Prodromal symptoms were reported in 31.6%; onset was with neurological symptoms in 70%, and with behavioural/psychiatric disturbances in 30%. Most patients developed a severe clinical picture (90%), and 41% experienced medical complications; children 12-18 years old seemed to be more severe and symptomatic than younger patients. All children received first-line immune therapy; second-line treatment was administered to 45%. Relapses occurred in 15%. At last follow-up (mean 23.9 months, range 5-82), 85% patients had mRS 0-1; this rate was higher among older patients, and in those receiving first immune therapy within 1 month.

CONCLUSIONS

Our case series confirms a symptomatologic core of paediatric anti-N-methyl-d-aspartate receptor encephalitis, even though displaying some distinctive features that may be explained by a specific genetic background or by the limited number of patients. The growing incidence of this condition, the relative age-dependent variability of its manifestations, the availability of immunotherapy and the possible better outcome with early treatment impose a high index of clinical suspicion be maintained. In the absence of data suggesting other specific etiologies, paediatricians should consider this diagnosis for children presenting with neurological and/or behavioural or psychiatric disturbances, regardless of age and gender.

Epilepsy in Menkes disease: an electroclinical long-term study of 28 patients

BACKGROUND

Epilepsy is a frequent and severe feature of Menkes disease (MD) but only few studies described the long-term evolution of these children. We report a series of 28 epileptic MD patients, with clinical characteristics, EEG abnormalities, brain malformations and long-term outcome.

METHODS

EEG, clinical characteristics and neuroimaging features in 28 MD patients were analyzed at the onset of epilepsy and after long-term follow-up (at least 4 years). We subdivided the patients into two groups: Group 1, 16 patients who received a subcutaneous copper-histidine treatment, and Group 2 including 12 patients who did not get any therapies.

RESULTS

The large majority of our patients presented at the onset of epilepsy focal seizures (FS) and infantile spasms (IS). Five patients had recurrent status epilepticus (SE). During the follow-up, patients showed multiple seizure types: 6 patients had generalized tonic clonic seizures (GCT), 6 patients presented IS, 10 children had FS, 11 had myoclonic jerks and 3 had SE. Therapy with various antiepileptic drugs had poor efficacy, except in three patients who showed seizure disappearance with consequent discontinuation of antiepileptic therapy. There was no difference of neurological outcome among the two groups analyzed.

CONCLUSIONS

Epilepsy in MD is a difficult to treat problem. At the onset, the most frequent type of seizures are FC and IS; in the next months, other kinds of seizures can appear. Many children are drug resistant. Institution of replacement therapy with copper-histidine seems to be not beneficial for epilepsy.

Epilepsy-related brain networks in ring chromosome 20 syndrome: an EEG-fMRI study

OBJECTIVE

To identify the brain networks that are involved in the different electroencephalography (EEG) abnormalities in patients with ring chromosome 20 [r(20)] syndrome. We hypothesize the existence of both distinctive and common brain circuits for the paroxysmal high voltage sharp waves (hSWs), the seizures, and the slow-wave 3-7 Hz rhythm that characterize this condition.

METHODS

Thirteen patients with [r(20)] syndrome were studied by means of EEG simultaneously recorded with functional magnetic resonance imaging (EEG-fMRI). EEG traces were reviewed in order to detect the pathologic interictal (hSWs) and ictal activities; the 3-7 Hz theta-delta power was derived using a fast Fourier transform. A group-level analysis was performed for each type of EEG abnormality separately using a fixed-effect model and a conjunction analysis. Finally, a second-level random-effect model was applied considering together the different EEG abnormalities, without distinction between hSW, seizures, or theta-delta rhythms.

RESULTS

Subcontinuous theta-delta rhythm was recorded in seven patients, seizures in two, and hSWs in three patients. The main results are the following: (1) the slow-wave rhythm was related to blood oxygen level-dependent (BOLD) increases in the premotor, sensory-motor, and temporoparietal cortex, and to BOLD decrements involving the default mode (DMN) and the dorsal attention networks (DANs); (2) the ictal-related BOLD changes showed an early involvement of the prefrontal lobe; (3) increases in BOLD signal over the basal ganglia, either for interictal and ictal activities, were observed; (4) a common pattern of positive BOLD changes in the bilateral perisylvian regions was found across the different EEG abnormalities.

SIGNIFICANCE

The BOLD increment in the perisylvian network and the decrease of the DMN and DAN could be the expression of the [r(20)] syndrome-related cognitive and behavioral deficits. The observed BOLD patterns are similar to the ones detected in other epileptic encephalopathies, suggesting that different epileptic disorders characterized by neurobehavioral regression are associated with dysfunction in similar brain networks. A PowerPoint slide summarizing this article is available for download in the Supporting Information section here.

Low frequency mu-like activity characterizes cortical rhythms in epilepsy due to ring chromosome 20

OBJECTIVES

To evaluate the spectral and spatial features of the cortical rhythms in patients affected by ring chromosome 20 - [r(20)]-syndrome.

METHODS

Twelve patients with [r(20)] syndrome were studied. As controls we enrolled 12 patients with idiopathic generalized epilepsy (IGE) and 12 healthy volunteers (HV). Blind source separation, spectral analyses and source reconstruction were applied in all cases in order to identify reliable spatio-temporal patterns of cortical activity.

RESULTS

A theta-delta EEG rhythm was identified in [r(20)] patients, with spectral peak ranging between 3 and 7Hz and whose generators mapped over the sensory-motor cortices. A second peak laying at a frequency about double with respect to the first one was present in 6 cases. Analogue methodological approach in HV and IGE groups failed to show similar findings.

CONCLUSIONS

EEG of [r(20)] patients reveals the existence of a highly reproducible EEG pattern arising from the sensory-motor system.

SIGNIFICANCE

The recognition of this peculiar EEG pattern could help the diagnostic work-up. Additionally, our findings supports the existence of a parallelism between this EEG trait and the physiological "mu" rhythm which is generate by the sensory-motor system. Such link suggests a sensory-motor system dysfunction in [r(20)] patients.

Molecular epidemiology of childhood neuronal ceroid-lipofuscinosis in Italy

Background

To review the descriptive epidemiological data on neuronal ceroid lipofuscinoses (NCLs) in Italy, identify the spectrum of mutations in the causative genes, and analyze possible genotype-phenotype relations.

Methods

A cohort of NCL patients was recruited through CLNet, a nationwide network of child neurology units. Diagnosis was based on clinical and pathological criteria following ultrastructural investigation of peripheral tissues. Molecular confirmation was obtained during the diagnostic procedure or, when possible, retrospectively.

Results

One hundred eighty-three NCL patients from 156 families were recruited between 1966 and 2010; 124 of these patients (from 88 families) were tested for known NCL genes, with 9.7% of the patients in this sample having not a genetic diagnosis. Late infantile onset NCL (LINCL) accounted for 75.8% of molecularly confirmed cases, the most frequent form being secondary to mutations in CLN2 (23.5%). Juvenile onset NCL patients accounted for 17.7% of this cohort, a smaller proportion than found in other European countries. Gene mutations predicted severe protein alterations in 65.5% of the CLN2 and 78.6% of the CLN7 cases. An incidence rate of 0.98/100,000 live births was found in 69 NCL patients born between 1992 and 2004, predicting 5 new cases a year. Prevalence was 1.2/1,000,000.

Conclusions

Descriptive epidemiology data indicate a lower incidence of NCLs in Italy as compared to other European countries. A relatively high number of private mutations affecting all NCL genes might explain the genetic heterogeneity. Specific gene mutations were associated with severe clinical courses in selected NCL forms only.

Individually tailored extratemporal epilepsy surgery in children: anatomo-electro-clinical features and outcome predictors in a population of 53 cases

Surgery for refractory extratemporal lobe epilepsy (ETLE) in the pediatric age group has been reported to be associated with a high percentage of failure and relapse. We performed a retrospective study of 53 consecutive patients with epilepsy onset before 12 years of age, who underwent, mostly at a pediatric age, an individually tailored ETLE surgery (32 in frontal and 21 in posterior cerebral areas) for pharmacoresistant seizures; these patients were selected and followed by a single national tertiary care pediatric center. Mean age at seizure onset was 3.14 years, and mean age at surgery was 11.23 years. Complete seizure freedom was achieved in 75% of the subjects. Short duration of illness before surgery, MRI features, no invasive pre-surgical evaluation, a localized interictal and ictal pattern as well as the presence of ictal fast activity on scalp EEG, localized interictal fast rhythms and absence of a diffuse initial ictal modification during SEEG, a complete resection of the epileptogenic zone, a type II FCD, and the absence of acute postoperative seizures correlated in a statistically significant way with a seizure-free outcome. We conclude that the seizure outcome of ETLE surgery in a carefully selected pediatric population can be excellent.

PRRT2 mutations are the major cause of benign familial infantile seizures

Mutations in PRRT2 have been described in paroxysmal kinesigenic dyskinesia (PKD) and infantile convulsions with choreoathetosis (PKD with infantile seizures), and recently also in some families with benign familial infantile seizures (BFIS) alone. We analyzed PRRT2 in 49 families and three sporadic cases with BFIS only of Italian, German, Turkish, and Japanese origin and identified the previously described mutation c.649dupC in an unstable series of nine cytosines to occur in 39 of our families and one sporadic case (77% of index cases). Furthermore, three novel mutations were found in three other families, whereas 17% of our index cases did not show PRRT2 mutations, including a large family with late-onset BFIS and febrile seizures. Our study further establishes PRRT2 as the major gene for BFIS alone.

Oxidative stress-related biomarkers in autism: systematic review and meta-analyses

Autism spectrum disorders (ASDs) are rarely diagnosed in children younger than 2 years, because diagnosis is based entirely on behavioral tests. Oxidative damage may play a central role in this pathogenesis, together with the interconnected transmethylation cycle and transsulfuration pathway. In an attempt to clarify and quantify the relationship between oxidative stress-related blood biomarkers and ASDs, a systematic literature review was carried out. For each identified study, mean biomarker levels were compared in cases and controls providing a point estimate, the mean ratio, for each biomarker. After meta-analysis, the ASD patients showed decreased blood levels of reduced glutathione (27%), glutathione peroxidase (18%), methionine (13%), and cysteine (14%) and increased concentrations of oxidized glutathione (45%) relative to controls, whereas superoxide dismutase, homocysteine, and cystathionine showed no association with ASDs. For the C677T allele in the methylene tetrahydrofolate reductase gene (MTHFR), homozygous mutant subjects (TT) showed a meta-OR of 2.26 (95% CI 1.30-3.91) of being affected by ASD with respect to the homozygous nonmutant (CC). Case-control studies on blood levels of vitamins suggest a lack of association (folic acid and vitamin B12) or rare association (vitamins A, B6, C, D, E). Sparse results were available for other biomarkers (ceruloplasmin, catalase, cysteinylglycine, thiobarbituric acid-reactive substances, nitric oxide) and for polymorphisms in other genes. Existing evidence is heterogeneous and many studies are limited by small sample size and effects. In conclusion, existing evidence suggests a role for glutathione metabolism, the transmethylation cycle, and the transsulfuration pathway, although these findings should be interpreted with caution, and larger, more standardized studies are warranted.

Juxtaposition of heterochromatic and euchromatic regions by chromosomal translocation mediates a heterochromatic long-range position effect associated with a severe neurological phenotype

Background

The term "position effect" is used when the expression of a gene is deleteriously affected by an alteration in its chromosomal environment even though the integrity of the protein coding sequences is maintained. We describe a patient affected by epilepsy and severe neurodevelopment delay carrying a balanced translocation t(15;16)(p11.2;q12.1)dn that we assume caused a position effect as a result of the accidental juxtaposition of heterochromatin in the euchromatic region.

Results

FISH mapped the translocation breakpoints (bkps) to 15p11.2 within satellite III and the 16q12.1 euchromatic band within the ITFG1 gene. The expression of the genes located on both sides of the translocation were tested by means of real-time PCR and three, all located on der(16), were found to be variously perturbed: the euchromatic gene NETO2/BTCL2 was silenced, whereas VPS35 and SHCBP1, located within the major heterochromatic block of chromosome 16q11.2, were over-expressed. Pyrosequencing and chromatin immunoprecipitation of NETO2/BTCL2 and VPS35 confirmed the expression findings. Interphase FISH analysis showed that der(16) localised to regions occupied by the beta satellite heterochromatic blocks more frequently than der(15).

Conclusions

To the best of our knowledge, this is the first report of a heterochromatic position effect in humans caused by the juxtaposition of euchromatin/heterochromatin as a result of chromosomal rearrangement. The overall results are fully in keeping with the observations in Drosophila and suggest the occurrence of a human heterochromatin position effect associated with the nuclear repositioning of the der(16) and its causative role in the patient's syndromic phenotype.

Brain iron levels in attention-deficit/hyperactivity disorder: a pilot MRI study

OBJECTIVE

Brain iron deficiency has been supposed to be involved in the pathophysiology of ADHD. Available studies assessing iron in ADHD are based on serum ferritin, a peripheral marker of iron status. To what extent serum ferritin correlates with brain iron (BI) is unclear. The main aim of this study was to compare BI, estimated with magnetic resonance imaging (MRI) in the putamen, pallidum, caudate, and thalamus, between children with and without ADHD. The secondary aim was to assess the correlation between serum ferritin and BI levels.

METHODS

Thirty-six children (18 with and 18 without ADHD, the latter including nine healthy controls and nine psychiatric controls) completed MRI and blood sampling. Brain iron levels were estimated by imaging T2*.

RESULTS

Children with ADHD showed significantly lower estimated BI in right and left thalamus compared to healthy controls. Estimated BI did not differ significantly between children with ADHD and psychiatric controls. Children with ADHD had significantly lower levels of serum ferritin than healthy as well as psychiatric controls. Serum ferritin and T2* values did not correlate significantly in most regions.

CONCLUSIONS

Low iron in the thalamus may contribute to ADHD pathophysiology.

Molecular mechanisms generating and stabilizing terminal 22q13 deletions in 44 subjects with Phelan/McDermid syndrome

In this study, we used deletions at 22q13, which represent a substantial source of human pathology (Phelan/McDermid syndrome), as a model for investigating the molecular mechanisms of terminal deletions that are currently poorly understood. We characterized at the molecular level the genomic rearrangement in 44 unrelated patients with 22q13 monosomy resulting from simple terminal deletions (72%), ring chromosomes (14%), and unbalanced translocations (7%). We also discovered interstitial deletions between 17-74 kb in 9% of the patients. Haploinsufficiency of the SHANK3 gene, confirmed in all rearrangements, is very likely the cause of the major neurological features associated with PMS. SHANK3 mutations can also result in language and/or social interaction disabilities. We determined the breakpoint junctions in 29 cases, providing a realistic snapshot of the variety of mechanisms driving non-recurrent deletion and repair at chromosome ends. De novo telomere synthesis and telomere capture are used to repair terminal deletions; non-homologous end-joining or microhomology-mediated break-induced replication is probably involved in ring 22 formation and translocations; non-homologous end-joining and fork stalling and template switching prevail in cases with interstitial 22q13.3. For the first time, we also demonstrated that distinct stabilizing events of the same terminal deletion can occur in different early embryonic cells, proving that terminal deletions can be repaired by multistep healing events and supporting the recent hypothesis that rare pathogenic germline rearrangements may have mitotic origin. Finally, the progressive clinical deterioration observed throughout the longitudinal medical history of three subjects over forty years supports the hypothesis of a role for SHANK3 haploinsufficiency in neurological deterioration, in addition to its involvement in the neurobehavioral phenotype of PMS.

Pathogenic role of the X-linked cyclin-dependent kinase-like 5 and aristaless-related homeobox genes in epileptic encephalopathy of unknown etiology with onset in the first year of life

Two genes causally involved in refractory epilepsy with mental retardation, cyclin-dependent kinase-like 5 and aristaless-related homeobox, could account for at least some forms of early onset epileptic encephalopathy that still lack etiological explanation. With the aim of investigating the specific pathogenic involvement of the 2 genes, we have conducted a clinical and molecular study in 80 patients with epileptic encephalopathy of unknown etiology and onset within the first year of life, regardless of the presence of other clinical features or the definition of a precise epileptologic syndrome. A total of 8 different disease-causing mutations were detected in our population, confirming the pivotal role of these genes in the pathogenesis of the epileptic encephalopathies in infancy. Early key clinical and electroencephalographic phenotypical features identified in these patients can contribute to more precise and early diagnoses. This work provides a better phenotypic characterization and more stringent clinical indications for the molecular test.

Electroclinical findings in four patients with karyotype 47,XYY

47,XYY karyotype is a Y chromosome aneuploidy characterized by an extra copy of the Y chromosome in each of the male cells, with an incidence of 1/1000 males. Most studies about 47,XYY have focused on growth, cognitive development, academic performance, behavioural problems, speech and language skills and neuromuscular status. Up-to-date reports on seizures and EEG characteristics concerning 47,XYY men have been sporadic and poorly detailed. The aim of this study is to describe the particular electroclinical patterns in a group of four subjects with 47,XYY karyotype. We performed neurological examinations, psychometric tests, brain MRIs, prolonged EEG recordings during awake and sleep on four unselected males 47,XYY. All four patients presented various degrees of neuropsychological impairment. An incidence of familial antecedents for epilepsy was confirmed by three families. When present, seizures were very similar to that of benign epilepsy with central-temporal spikes, (BECTS), for age of onset, clinical picture, evolution and good response to antiepileptic drugs. EEG recordings in all four subjects showed normal background activity and sleep organization, particular focal spikes and sharp-waves localized mostly over the vertex and/or central-temporal regions, which increased during sleep. In our opinion, these 47,XYY patients present a particular electroclinical pattern.

Spectrum of phenotypes in female patients with epilepsy due to protocadherin 19 mutations

PURPOSE

To describe clinical and neuropsychological features of six consecutive sporadic girls with protocadherin 19 (PCDH19) mutations.

METHODS

Following recent descriptions of PCDH19 mutation in girls with epilepsy, we sequenced this gene in patients with infantile or early childhood seizures onset, either focal or generalized, without an obvious etiology.

KEY FINDINGS

Mean age at the time of the study was 13.5 ± 11 years. Mean age at seizure onset was 15.5 ± 11 months (range 9-38). All patients experienced clusters of either focal or generalized seizures, precipitated during febrile illness in five patients. Attacks were very frequent at onset, but they became less numerous during follow-up. Ictal electroencephalography (EEG) showed temporal lobe involvement in five patients. Periictal EEG showed focal or multifocal epileptiform and slow abnormalities. Cognitive impairment became obvious after seizure onset in three patients and was associated with autistic features in two. Genetic analysis revealed five new and one known de novo PCDH19 mutation that were missense in four and frameshift in two. Variants are clustered in the large exon 1, corresponding to the extracellular domain of the PCDH19 protein.

SIGNIFICANCE

Our findings emphasize that de novo PCDH19 mutations are associated with infantile or early childhood onset of febrile or afebrile seizures often occurring in clusters. Cognitive impairment is not constantly present and autistic features are observed in some patients. Most patients have a "stormy" seizure onset, often related to fever; however, seizure severity does not clearly correlate with the degree of cognitive deficit. PCDH19 is likely a major epilepsy gene; phenotypes associated with mutations of this gene range from epileptic encephalopathies to mild epilepsy, yet large series of patients will be necessary to fully delineate phenotypic spectrum.