The rare rs769301934 variant in NHLRC1 is a common cause of Lafora disease in Turkey.

Lafora disease (LD) is a severe form of progressive myoclonus epilepsy inherited in an autosomal recessive fashion. It is associated with biallelic pathogenic variations in EPM2A or NHLRC1, which encode laforin and malin, respectively. The disease usually starts with adolescent onset seizures followed by progressive dementia, refractory status epilepticus and eventually death within 10 years of onset. LD is generally accepted as having a homogenous clinical course with no considerable differences between EPM2A or NHLRC1 associated forms. Nevertheless, late-onset and slow progressing forms of the disease have also been reported. Herein, we have performed clinical and genetic analyses of 14 LD patients from 12 different families and identified 8 distinct biallelic variations in these patients. Five of these variations were novel and/or associated with the LD phenotype for the first time. Interestingly, almost half of the cases were homozygous for the rare rs769301934 (NM_198586.3(NHLRC1): c.436 G > A; p.(Asp146Asn)) allele in NHLRC1. A less severe phenotype with an onset at a later age may be the reason for the biased inflation of this variant, which is already present in the human gene pool and can hence arise in the homozygous form in populations with increased parental consanguinity.

Panayiotopoulos syndrome and Gastaut syndrome are distinct entities in terms of neuropsychological findings.

BACKGROUND: Although the courses of self-limited focal epilepsies of childhood are considered as benign, a handful of studies suggested that these children may suffer from cognitive problems. Implementing tailor-made educational strategies would aid these children to reach their full potentials. Therefore, it is crucial to understand and differentiate the complete neuropsychological and behavioral profiles of these rather common syndromes. We aimed to examine the distinct cognitive and behavioral profiles of the Panayiotopoulos syndrome (PS) and the Gastaut syndrome (GS), comparatively. METHOD: Twenty patients with PS, 20 patients with GS, and 20 healthy controls have been recruited. The testing protocol included Wechsler Intelligence Scale for Children-Revised, Conner's Continuous Performance Test, Verbal Fluency Test, Stroop Color and Word Test, Color Trails Test, Tower of London Test, Symbol Digit Modalities Test, California Verbal Learning Test-Children's Version, Rey Complex Figure Test, Benton Face Recognition Test, Benton Judgment of Line Orientation, Peabody Picture Vocabulary Test, Reading and Writing Test, Child Behavior Checklist, Conner's Parent Rating Scale-48, and Behavior Rating Inventory of Executive Function. Demographical, clinical, electrophysiological data, and imaging findings have also been evaluated. RESULTS: With regard to intelligence, the patients with PS scored less in all scales compared to the healthy controls. However, only the performance IQ (intelligence quotient) scores differed significantly between the patient groups, with the patients with PS scoring lower than the patients with GS. Verbal memory problems were eminent in both of the patient groups; whereas, visual memory was impaired only in the group with PS. Psychomotor speed was affected in both groups. Reading problems were prominent only in the patients with PS. Writing and arithmetic skills were defective in both patient groups. There were no noteworthy behavioral problems in comparison to healthy subjects. CONCLUSION: Using neuropsychological profiles, this study demonstrated that the GS and the PS are two distinct entities. Cognitive dysfunction is a more prominent and widespread feature of the patients with PS; whereas, the patients with GS suffer only from milder and isolated cognitive problems.

Increased photosensitivity following short sleep in sleep deprived patients.

INTRODUCTION: We aimed to determine the effect of short day-time sleep on photoparoxysmal epileptic activity in sleep-deprived patients. METHODS: We retrospectively reviewed video-EEG recordings performed between 2003 and 2015. All recordings following at least four hours of sleep deprivation, including intermittent photic stimulation (IPS) both before and after sleep with any form of epileptiform activity were included. The study group was divided into four subgroups: (1) no photoparoxysmal response (PPR) group, with epileptiform activities other than PPRs; (2) increment group, with PPR duration increased by ≥200% after vs. before sleep; (3) no significant change group, with PPR duration increased between 50% and 200% after vs. before sleep; (4) decrement group, with PPR duration increased ≤50% after vs. before sleep. RESULTS: A total number of 5805 EEG recordings from 459 patients was analyzed. Photosensitivity was present in 98 patients (21.4%). The PPRs after sleep were increased in 70% of the photosensitive patients, did not change in 23%, and were decreased in 7%. The increase in duration of PPRs was statistically significant (P<0.001). In our cohort, photosensitivity would have been detected in 67 patients if IPS was applied only before sleep and in 91 patients if IPS was applied only after awakening (P<0.05). CONCLUSIONS: This study demonstrates that photosensitivity is enhanced after awakening from a short sleep following sleep deprivation. Thus, we recommend performing IPS after awakening to increase sensitivity to detect photoparoxysmal epileptiform discharges.

Visually evoked startle response in a patient with epilepsy: a case report and review of the literature.

Both symptomatic and genetic, cases with hyperekplexia or startle seizures induced by acoustic stimuli, are previously reported. By contrast, startle response induced by visual stimuli is rare. While visual stimuli are more commonly associated with startle seizures, here we present an 11-year-old girl with epilepsy, motor-mental retardation, and spastic tetraparesis, who had repetitive startle responses by photic stimulation during the electroencephalogram recording, without any spike-and-wave discharges associated with the startles. We report this unique case with startle responses induced both by acoustic and photic stimuli and review the literature related to this exceptionally rare combination of symptoms.

Long-Term Clinical and Electroencephalography (EEG) Consequences of Idiopathic Partial Epilepsies.

BACKGROUND Idiopathic partial epilepsies of childhood (IPE) affect a considerable proportion of children. Three main electroclinical syndromes of IPE are the Benign Childhood Epilepsy with Centro-temporal Spikes (BECTS), Panayiotopoulos Syndrome (PS), and Childhood Epilepsy with Occipital Paroxysms (CEOP). In this study we investigated the long-term prognosis of patients with IPE and discussed the semiological and electroencephalography (EEG) data in terms of syndromic characteristics. MATERIAL AND METHODS This study included a group of consecutive patients with IPE who had been followed since 1990. Demographic and clinical variables were investigated. Patients were divided into 3 groups - A: Cases suitable for a single IPE (BECTS, PS and CEOP); B: cases with intermediate characteristics within IPEs; and C: cases with both IPE and IGE characteristics. Long-term data regarding the individual seizure types and EEG findings were re-evaluated. RESULTS A total of 61 patients were included in the study. Mean follow-up duration was 7.8 ± 4.50 years. The mean age at onset of seizures was 7.7 years. There were 40 patients in group A 40, 14 in group B, and 7 in group C. Seizure and EEG characteristics were also explored independently from the syndromic approach. Incidence of autonomic seizures is considerably high at 2-5 years and incidence of oromotor seizures is high at age 9-11 years. The EEG is most abnormal at 6-8 years. The vast majority (86%) of epileptic activity (EA) with parietooccipital is present at 2-5 years, whereas EA with fronto-temporal or multiple sites become more abundant between ages 6 and 11. CONCLUSIONS Results of the present study provide support for the age-related characteristics of the seizures and EEGs in IPE syndromes. Acknowledgement of those phenomena may improve the management of IPEs and give a better estimate of the future consequences.

Epilepsy Surgery in Children with Lesional Partial Epilepsies.

AIM: Surgery for epilepsy is a significant treatment alternative with favorable outcomes in the pediatric age group. In this study we present the surgical outcomes of pediatric population referred to our center. MATERIAL AND METHODS: The clinical data of 126 patients (≤18 years) with lesional partial epilepsies operated in our center between 1995- 2011 were evaluated retrospectively. Parameters investigated were gender, age at seizure onset, duration of epilepsy, etiology, type and location of operation and outcome. Seizure outcome was classified according to Engel's classification. RESULTS: The study group consisted of 70 males (55,6%) and 56 females (44.4%). The most common etiology was malformation of cortical development followed by tumors and hippocampal sclerosis. Overall 73.8% of patients had Engel I, 13.5% Engel II and 11.9% Engel III+IV postoperative seizure outcome. CONCLUSION: The results of our pediatric patients who underwent surgery were similar to previous reports in the literature. The seriousness of the clinical picture should tempt physicians to refer the patients as soon as possible to avoid long term complications like epileptic encephalopathies and the side effects of antiepileptic drugs during the development of the young brains.

Long-term outcomes in patients with West syndrome: an outpatient clinical study.

PURPOSE: Nearly half of all patients with seizure onset in the first year of life suffer from West syndrome (WS). The prognosis of epilepsy and psychosocial outcomes in children with WS are variable. This study was performed to examine the factors influencing the outcome of this patient population. METHODS: A total of 109 patients with WS followed up regularly for at least 3 years were included in the study. Relevant clinical, laboratory, and imaging data were collected. RESULTS: The male/female ratio was 65/44 (59.6%/40.4%). The mean age at onset of infantile spasm (IS) was 6 ± 6 (1-36) months. With regard to neuro-developmental and social conditions during the final evaluation, 29.4% of the patients were socially dependent on caregivers, 61.8% needed assistance, and 8.8% were normal. Among the patients, 5.9% were free of epilepsy and antiepileptic drugs (AED) for at least 2 years, 49.0% had no seizures with AEDs, and 45.1% had uncontrollable seizures. Parameters with significant negative effects on the long-term outcomes included symptomatic etiology, presence of developmental retardation before the onset of IS, persistence of active epilepsy, and male gender. CONCLUSION: In this study, 37 (33.9%) patients had severe consequences as a result of WS. The majority of the rest could cope with daily life with varying degrees of assistance. Eight percent of the patients had a normal development. These results draw attention to the two-thirds of patients with WS who have the chance of an acceptable quality of life (QoL) with early diagnosis and therapeutic measures.

Panayiotopoulos syndrome and symptomatic occipital lobe epilepsy of childhood: a clinical and EEG study.

AIM: Panayiotopoulos syndrome (PS) is an age-related seizure susceptibility syndrome that affects the central autonomic system. Although the majority of the few ictal recordings obtained so far suggest an occipital origin, semiological and interictal EEG data appear to favour more extensive involvement. In this study, the characteristics (including those based on semiology and EEG) of children with Panayiotopoulos syndrome (n=24) and those with lesion-related, symptomatic occipital lobe epilepsy (SOLE) (n=23) were compared. METHODS: Detailed semiological information and EEG parameters including the localisation, distribution, density (n/sec), reactivity, and morphological characteristics of spike-wave foci and their relationship with different states of vigilance were compared between the two groups. RESULTS: The age at seizure onset was significantly younger in patients with symptomatic occipital lobe epilepsy than in those with PS (mean age at onset: 3.4 versus 5.6 years, respectively; p=0.044). Autonomic seizures (p=0.001) and ictal syncope (p=0.055) were more frequent in PS than in symptomatic occipital lobe epilepsy (87.5% and 37.5% versus 43.5% and 13%, respectively). The interictal spike-wave activity increased significantly during non-rapid eye movement (non-REM) sleep in both groups. The spike waves in non-REM seen in PS tended to spread mainly to central and centro-temporal regions. CONCLUSIONS: The results indicate that although common features do exist, Panayiotopoulos syndrome differs from symptomatic occipital lobe epilepsy and has a unique low epileptogenic threshold related to particular brain circuits.

A close look at EEG in subacute sclerosing panencephalitis.

PURPOSE: To define atypical clinical and EEG features of patients with subacute sclerosing panencephalitis that may require an overview of differential diagnosis. METHODS: A total of 66 EEGs belonging to 53 (17 females and 36 males) consecutive patients with serologically confirmed subacute sclerosing panencephalitis were included in this study. Patient files and EEG data were evaluated retrospectively. EEGs included in the study were sleep-waking EEGs and/or sleep-waking video-EEG records with at least 2 hours duration. Cranial MRIs of the patients taken 2 months before or after the EEG records were included. RESULTS: Age range at the onset of the disease was 15 to 192 months (mean age: 80.02 months). Epilepsy was diagnosed in 21 (43%) patients. Among epileptic seizures excluding myoclonic jerks, generalized tonic-clonic type constituted the majority (58%). Tonic seizures were documented during the video-EEG recordings in four patients. Epileptogenic activities were found in 56 (83%) EEG recordings. They were localized mainly in frontal (58%), posterior temporal, parietal, occipital (26%), and centrotemporal (8%) regions. Multiple foci were detected in 26 recordings (39%). Epileptiform activities in the 39 (59%) EEGs appeared as unilateral or bilateral diffuse paroxysmal discharges. CONCLUSIONS: Recognition of uncommon clinical and EEG findings of subacute sclerosing panencephalitis, especially in countries where subacute sclerosing panencephalitis has not been eliminated yet, could be helpful in prevention of misdiagnosis and delay in the management of improvable conditions.

A novel X-linked disorder with developmental delay and autistic features.

OBJECTIVE: Genomic duplications that lead to autism and other human diseases are interesting pathological lesions since the underlying mechanism almost certainly involves dosage sensitive genes. We aim to understand a novel genomic disorder with profound phenotypic consequences, most notably global developmental delay, autism, psychosis, and anorexia nervosa. METHODS: We evaluated the affected individuals, all maternally related, using childhood autism rating scale (CARS) and Vineland Adaptive scales, magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS) brain, electroencephalography (EEG), electromyography (EMG), muscle biopsy, high-resolution molecular karyotype arrays, Giemsa banding (G-banding) and fluorescent in situ hybridization (FISH) experiments, mitochondrial DNA (mtDNA) sequencing, X-chromosome inactivation study, global gene expression analysis on Epstein-Barr virus (EBV)-transformed lymphoblasts, and quantitative reverse-transcription polymerase chain reaction (qRT-PCR). RESULTS: We have identified a novel Xq12-q13.3 duplication in an extended family. Clinically normal mothers were completely skewed in favor of the normal chromosome X. Global transcriptional profiling of affected individuals and controls revealed significant alterations of genes and pathways in a pattern consistent with previous microarray studies of autism spectrum disorder patients. Moreover, expression analysis revealed copy number-dependent increased messenger RNA (mRNA) levels in affected patients compared to control individuals. A subset of differentially expressed genes was validated using qRT-PCR. INTERPRETATION: Xq12-q13.3 duplication is a novel global developmental delay and autism-predisposing chromosomal aberration; pathogenesis of which may be mediated by increased dosage of genes contained in the duplication, including NLGN3, OPHN1, AR, EFNB1, TAF1, GJB1, and MED12.

Challenges in diagnosing SSPE.

PURPOSE: The typical clinical presentation of subacute sclerosing panencephalitis (SSPE) includes behavioral and intellectual changes followed by myoclonia. However, there are a considerable number of SSPE cases which present with distinct clinical features that can lead to a diagnostic difficulty. In this report, we summarize the clinical features of patients with SSPE who have uncommon presentations or features of the disease or coexisting medical conditions which may lead to diagnostic difficulties. METHODS: We studied 173 patients, all under the age of 17. Patients were included in the study group according to following criteria: onset of the disease before age 2 years, seizures occurring before the onset of myoclonia and/or behavioral symptoms, extrapyramidal or cerebellar signs and ocular manifestations as initial presenting symptoms, fulminant course including coma or death within 6 months. Additionally, patients with onset of SSPE at the setting of a known neurological disorder are defined as another group in the study. RESULTS: Out of 173 patients with SSPE who were followed in two neurology centers, 31 (17.9%) met our criteria. CONCLUSIONS: We found a relative high frequency of these clinical features. Our findings suggest that clinicians should be aware of this clinical characteristics and rule out the disease in cases were other common causes have been excluded, especially in countries with insufficient measles immunization.

A case imitating Panayiotopoulos syndrome.

Panayiotopoulos syndrome is one of the most common childhood-specific epileptic disorders. It is characterized by autonomic symptoms; the most common being emesis. However, the presence of emetic symptoms may cause misdiagnosis, for example with some organic disorders which have similar autonomic features. On the other hand, since this syndrome has been recently well documented, the tendency for early recognition may lead to overdiagnosis. Here, we present a case which could be mistaken for Panayiotopoulos syndrome based on anamnesis, however, with the aid of ictal video-EEG monitoring, the patient was shown to present with a non-epileptic psychogenic seizure. This report is an example of careful evaluation in order to avoid over- or underdiagnosis of this benign disorder. [Published with video sequences].

Four novel SCN1A mutations in Turkish patients with severe myoclonic epilepsy of infancy (SMEI).

Severe myoclonic epilepsy of infancy (SMEI) (OMIM #607208), also known as Dravet syndrome, is a rare genetic disorder characterized by frequent generalized, unilateral clonic or tonic-clonic seizures that begin during the first year of life. Heterozygous de novo mutations in the SCN1A gene, which encodes the neuronal voltage-gated sodium channel α subunit type 1 (Nav1.1), are responsible for Dravet syndrome, with a broad spectrum of mutations and rearrangements having been reported. In this study, the authors present 4 novel mutations and confirm 2 previously identified mutations in the SCN1A gene found in a cohort of Turkish patients with Dravet syndrome. Mutational analysis of other responsible genes, GABRG2 and PCDH19, were unrevealing. The authors' findings add to the known spectrum of mutations responsible for this disease phenotype and once again reinforce our understanding of the allelic heterogeneity of this disease.

Autonomic status epilepticus in Panayiotopoulos syndrome and other childhood and adult epilepsies: a consensus view.

PURPOSE: To discuss and propose a definition of autonomic status epilepticus (SE), describe its clinical and EEG features, and review what is known about its epidemiology, pathophysiology, differential diagnosis, and management. METHODS: An international consortium of established researchers in the field was identified from their published work, agreed the purpose of the project, searched the literature, and, by use of e-mail communication, agreed the consensus document. RESULTS: Autonomic SE is a condition lasting at least 30 min and characterized by epileptic activity causing altered autonomic function of any type at seizure onset or in which manifestations consistent with altered autonomic function are prominent (quantitatively dominant or clinically important) even if not present at seizure onset. It is best described, and probably most commonly encountered in children, with Panayiotopoulos syndrome. However, it also occurs in children with symptomatic epilepsies and, exceptionally, in adults. Its pathogenesis and most appropriate management are poorly understood. CONCLUSIONS: It is hoped that this document will help clinical recognition of Autonomic SE, reduce misdiagnosis, and promote further interest and studies into what has been a relatively neglected area.

A novel missense mutation (N258S) in the KCNQ2 gene in a Turkish family afflicted with benign familial neonatal convulsions (BFNC).

Benign familial neonatal convulsions (BFNC) is a rare monogenic subtype of idiopathic epilepsy exhibiting autosomal dominant mode of inheritance. The disease is caused by mutations in the two homologous genes KCNQ2 and KCNQ3 that encode the subunits of the voltage-gated potassium channel. Most KCNQ2 mutations are found in the pore region and the cytoplasmic C domain. These mutations are either deletions/insertions that result in frameshift or truncation of the protein product, splice-site variants or missense mutations. This study reveals a novel missense mutation (N258S) in the KCNQ2 gene between the S5 domain and the pore of the potassium channel in two BFNC patients in a Turkish family. The absence of the mutation both in the healthy members of the family and in a control group, and the lack of any other change in the KCNQ2 gene of the patients indicate that N258S substitution is a pathogenic mutation leading to epileptic seizures in this family.

EEG abnormalities in West syndrome: correlation with the emergence of autistic features.

Autism may develop in children with West syndrome. This study was conducted to determine if EEG abnormalities in patients with West syndrome predict the later onset of autism. Two groups of patients with West syndrome, older than 6 years of age, were studied. One group consisted of those with a past history of West syndrome plus autism (N=14); the control group consisted of those with a past history of West syndrome but without autism (N=14). Patients were followed at regular intervals and video-EEG recordings were done. A total of 108 (autistic group) and 123 (non-autistic group) video-EEGs were examined. The two groups were compared with respect to age, presence or absence of hypsarrhythmia, and characteristics and localization of the epileptogenic foci. chi2 and Fisher's exact tests were used. The number of patients with at least one hypsarrhythmic EEG at the age of one year or later was significantly higher in autistic subjects (86%) than in non-autistic controls (29%). The incidence of EEGs with hypsarrhythmia was also higher in the autistic group, especially in older children (autistic, 49% versus non-autistic, 18% at age 3 years and later). Frontal predominance of the primary foci on EEGs with or without hypsarrhythmia was seen in 95.3% of the autistic group and 28.8% of the non-autistic group (p=0.001). Frontal abnormalities on the EEGs, which were mainly bilateral, and the persistence of hypsarrhythmia were significantly related to the emergence of autistic behavior in patients with West syndrome. These findings suggest that paroxysmal discharges in the cortical areas undergoing rapid maturation may be involved in the development of autistic features.

The consequences of idiopathic partial epilepsies in relation to neuropsychological functioning: a closer look at the associated mathematical disability.

Although the seizure prognosis is mostly favorable in idiopathic partial epilepsies, there is some empirical evidence showing that subtle neuropsychological impairments, with a consequent risk of academic underachievement, are not rare. We investigated neuropsychological functioning including attention, memory, visuomotor ability, and executive functioning with a closer look at the associated mathematical ability in patients with idiopathic partial epilepsies. A battery of age-appropriate, neuropsychological and mathematics achievement tests was administered to 30 participants with idiopathic partial epilepsy [13 children with benign epilepsy with centrotemporal spikes (BECTS), 17 children with idiopathic childhood occipital epilepsies (ICOE)], and to 30 healthy participants matched for age, sex, handedness, and socioeconomic status. Results did not support any impairment in overall neuropsychological functioning in participants with idiopathic partial epilepsies, whereas, isolated deficits did exist. The mean performance of the IPE group was significantly lower than the control group in six out of 12, neuropsychological measures: drawing (p < 0.01), digit span (p < 0.05), verbal learning (p < 0.01), object assembly (p < 0.01), similarities (p < 0.05), and vocabulary (p < 0.001). Results suggested that one should be cautious regarding neuropsychological and academic prognosis in the so-called benign idiopathic partial epilepsies of childhood.

Panayiotopoulos syndrome: a consensus view.

The aim of this paper is to promote the correct classification of, and provide guidelines on, the diagnosis and management of Panayiotopoulos syndrome (PS). An international consortium of established researchers in the field collaborated to produce a consensus document. The resulting document defines PS, characterizes its electro-clinical features, considers its likely pathogenesis, and provides guidance on appropriate management. We conclude that PS is a common idiopathic, benign seizure disorder of childhood, which should be classified as an autonomic epilepsy, rather than an occipital epilepsy.

A study on visual evoked responses in children with chronic renal failure.

AIMS OF THE STUDY: Nervous involvement is frequent in patients with renal failure. Early recognition of the condition by electrophysiological tests may provide means for protective measures before irreversible damage of nervous system (NS) structures takes place. This study has two objectives: (1) examining whether pattern-reversal visual evoked potential (PR-VEP) studies may provide information relating to possible subclinical NS involvement in pediatric patients with chronic renal failure (CRF) and (2) looking for a possible relationship between serum parathormone (PTH) and creatinine levels and PR-VEP parameters. METHODS: PR-VEP recordings at low spatial frequencies were performed and peak-to-peak amplitudes and latencies of the P100 component were measured in 19 neurologically asymptomatic children with CRF, 15 of whom were on continuous ambulatory peritoneal dialysis (CAPD) and four on hemodialysis (HD). A similar procedure was applied to 29 healthy, age- and sex-matched, subjects. Patients were sub-grouped according to the serum PTH and creatinine levels. Student's-t and one-way ANOVA tests were used for comparisons within patient and control groups and sub-groups relating to serum PTH and creatinine levels. RESULTS: We did not demonstrate any statistically significant differences in PR-VEP parameters in patients vs. controls. PR-VEP amplitudes were higher in patients with low serum creatinine levels as compared to group with high creatinine values and to controls. No other relationship was found between PR-VEP parameters and serum PTH and creatinine levels in this pediatric population. CONCLUSION: Young patients with CRF and under dialysis do not necessarily show pathologic alterations in PR-VEPs when they are neurologically intact. This fact suggests that either PR-VEPs are not sensitive enough to detect clinically silent NS involvements in such patients, or it could be related to positive effects of the currently improving standards in the management of dialysis and supportive nutrition. Additional factors such as the age of the patient during examination, the latency between dialysis and visual evoked potential (VEP) assessment, or the selected check size may have some impact on the results and justify further studies.