Genotype-phenotype correlations in SCN8A-related disorders reveal prognostic and therapeutic implications.

We report detailed functional analyses and genotype-phenotype correlations in 392 individuals carrying disease-causing variants in SCN8A, encoding the voltage-gated Na+ channel Nav1.6, with the aim of describing clinical phenotypes related to functional effects. Six different clinical subgroups were identified: Group 1, benign familial infantile epilepsy (n = 15, normal cognition, treatable seizures); Group 2, intermediate epilepsy (n = 33, mild intellectual disability, partially pharmaco-responsive); Group 3, developmental and epileptic encephalopathy (n = 177, severe intellectual disability, majority pharmaco-resistant); Group 4, generalized epilepsy (n = 20, mild to moderate intellectual disability, frequently with absence seizures); Group 5, unclassifiable epilepsy (n = 127); and Group 6, neurodevelopmental disorder without epilepsy (n = 20, mild to moderate intellectual disability). Those in Groups 1-3 presented with focal or multifocal seizures (median age of onset: 4 months) and focal epileptiform discharges, whereas the onset of seizures in patients with generalized epilepsy was later (median: 42 months) with generalized epileptiform discharges. We performed functional studies expressing missense variants in ND7/23 neuroblastoma cells and primary neuronal cultures using recombinant tetrodotoxin-insensitive human Nav1.6 channels and whole-cell patch-clamping. Two variants causing developmental and epileptic encephalopathy showed a strong gain-of-function (hyperpolarizing shift of steady-state activation, strongly increased neuronal firing rate) and one variant causing benign familial infantile epilepsy or intermediate epilepsy showed a mild gain-of-function (defective fast inactivation, less increased firing). In contrast, all three variants causing generalized epilepsy induced a loss-of-function (reduced current amplitudes, depolarizing shift of steady-state activation, reduced neuronal firing). Functional effects were known for 170 individuals. All 136 individuals carrying a functionally tested gain-of-function variant had either focal (n = 97, Groups 1-3) or unclassifiable (n = 39) epilepsy, whereas 34 individuals with a loss-of-function variant had either generalized (n = 14), no (n = 11) or unclassifiable (n = 6) epilepsy; only three had developmental and epileptic encephalopathy. Computational modelling in the gain-of-function group revealed a significant correlation between the severity of the electrophysiological and clinical phenotypes. Gain-of-function variant carriers responded significantly better to sodium channel blockers than to other anti-seizure medications, and the same applied for all individuals in Groups 1-3. In conclusion, our data reveal clear genotype-phenotype correlations between age at seizure onset, type of epilepsy and gain- or loss-of-function effects of SCN8A variants. Generalized epilepsy with absence seizures is the main epilepsy phenotype of loss-of-function variant carriers and the extent of the electrophysiological dysfunction of the gain-of-function variants is a main determinant of the severity of the clinical phenotype in focal epilepsies. Our pharmacological data indicate that sodium channel blockers present a treatment option in SCN8A-related focal epilepsy with onset in the first year of life.

Adverse life events in patients with functional seizures: Assessment in clinical practice and association with long-term outcome.

BACKGROUND: A history of adverse life events (ALE) is a risk factor for functional seizures (FS). Their influence on long-term outcome remains unclear. International guidelines recommend assessing ALE in patients presenting with associated disorders. It is not clear to what extent patients evaluated for FS are regularly asked about ALE. OBJECTIVES: We hypothesised that the presence of ALE would relate to worse outcome at follow-up and, that the rate of detection of ALE in clinical work-up would be inferior to that based on self-report questionnaires. METHODS: 53 patients with FS from the National Centre for Epilepsy in Norway, aged 16-62 years were included. Symptom severity, health-related quality of life (HRQoL), and antecedent ALE were assessed at baseline. Medical records were examined for disclosure of ALE. At a mean of 70.45 (SD 29.0, range 22-130) months after inclusion, participants were inquired about FS status, FS-related health care utilization and HRQoL. FINDINGS: A history of emotional abuse documented in the medical record was an independent risk factor for worse HRQoL at follow-up. Prevalence of ALE documented in medical records was lower compared with rates measured by a self-report questionnaire. CONCLUSIONS: These findings indicate an association between antecedent ALE and HRQoL years after diagnosis. A substantial proportion of the adverse life events by a self-report questionnaire had not been documented in the clinical records. CLINICAL IMPLICATIONS: The supplemental use of a self-report questionnaire in the diagnostic work-up of patients with FS may be valuable for detecting ALE.

The effect of attachment style on long-term outcomes in psychogenic nonepileptic seizures: Results from a prospective study.

INTRODUCTION: Insecure and fearful attachment styles have been reported in psychogenic nonepileptic seizures (PNES). We have investigated associations between long-term clinical outcome in PNES, parenting and attachment styles and demographic, clinical, and neuropsychiatric factors. MATERIAL AND METHODS: Patients aged at least 16 years and with documented PNES, according to criteria from the International League Against Epilepsy, were prospectively recruited to this study. They were assessed at baseline to determine clinical characteristics, experience of attachment and perceptions of experienced parenting styles, trauma history, dissociation, and health-related quality of life. At a mean of 70.45 (SD 29.0, range 22-130) months after inclusion, participants were contacted by telephone and asked about their current medical status and psychiatric/psychological interventions. RESULTS: Of 53 patients included in the study, 51 (96 %) provided follow-up data. Most (84.9 %) patients were female, and the mean age of PNES onset was 25.6 years. At follow-up, 20 patients (39 %) were free of PNES. Those patients that had achieved PNES freedom at follow-up had lower levels of attachment anxiety (p = 0.01) and reported to have experienced their fathers as less controlling (p = 0.02) and their mothers as more caring (p = 0.04) at baseline compared with those patients still suffering from PNES. Seizure freedom at follow-up was predicted by male gender, younger age at PNES onset, and less attachment anxiety. CONCLUSION: In our cohort from a tertiary epilepsy center the long-term prognosis of PNES is poor. Attachment anxiety is a risk factor for persistent PNES. It may be of therapeutic relevance to assess attachment patterns in patients with PNES.

Pharmacokinetic Variability During Long-Term Therapeutic Drug Monitoring of Valproate, Clobazam, and Levetiracetam in Patients With Dravet Syndrome.

BACKGROUND: The use of therapeutic drug monitoring (TDM) for antiseizure medications (ASMs) may contribute to treatment optimization in individual patients. This study included patients with Dravet syndrome as they often require close monitoring because of polypharmacy with various ASMs. The aim was to use long-term TDM to investigate pharmacokinetic variability of ASMs in these patients. METHODS: Retrospective data from patients with Dravet syndrome were collected from the TDM database at the Section for Clinical Pharmacology, National Center for Epilepsy in Norway (2008-2018). Concentration/(dose/kg)ratios (C/D ratios) were calculated for the ASMs and the concentration (C/C ratio) for N-desmethylclobazam. In patients with at least 3 measurements, the CV for C/D ratios for intrapatient and interpatient variability was calculated. RESULTS: Fifty-three patients (30 male patients/23 female patients) between 2 and 50 years of age (mean, 16 years) were included. Pharmacokinetic variability of the total number of measurements of valproate (n = 417), clobazam and N-desmethylclobazam (n = 328), and levetiracetam (n = 238) was determined. Interpatient variability was more pronounced than intrapatient variability (coefficient of variations: valproate, 65% vs. 24%; levetiracetam, 71% vs. 27%; and clobazam/N-desmethylclobazam, 47%/77% vs. 35%/55%) (P < 0.01). Comedication with stiripentol (n = 16) increased the C/D ratio of valproate by 63% and of clobazam by 133% and the C/C ratio of N-desmethylclobazam/clobazam by 104% (P < 0.05). Younger age also contributed to pharmacokinetic variability. CONCLUSIONS: Long-term TDM revealed extensive variability in serum concentrations over time; the variability was lowest for levetiracetam, moderate for valproate, and highest for clobazam. Pharmacokinetic variability and interactions can thus be identified and adjusted to facilitate decision making to achieve the optimal treatment outcome.

Aicardi syndrome and cognitive abilities: A report of five cases.

Aicardi syndrome is a rare neurodevelopmental disorder with agenesis of corpus callosum, chorioretinal lacunae, and infantile spasms as the main features. The outcome is in general severe, with poor cognitive development and difficult-to-treat epilepsy. In this study, we assessed the level of cognitive function of five girls with Aicardi syndrome, using normed population based tests and questionnaires. Their cognitive abilities varied from mild to profound intellectual disabilities. The more severe the epilepsy, the poorer were the cognitive skills. To the best of our knowledge, this is the first study that systematically applies validated cognitive assessment tools to study patients with this syndrome. Knowledge about cognitive functioning is crucial for providing optimal special education and finding appropriate alternative communication with parents and caregivers.

Skeletal muscle fiber characteristics and oxidative capacity in hemiparetic stroke survivors.

INTRODUCTION: Skeletal muscle is changed after stroke, but conflicting data exist concerning muscle morphology and oxidative enzyme capacity. METHODS: In 36 chronic stroke patients bilateral rectus femoris muscle biopsies were analyzed, and fiber type proportions and cross-sectional areas were determined by ATPase histochemistry. Enzymatic concentrations of citrate synthase (CS) and 3-Hydroxyacyl-coenzymeA-dehydrogenase (HAD) were determined using freeze-dried muscle tissue. Findings were correlated with clinical outcomes. RESULTS: In the paretic muscles the mean fiber area was smaller (P = 0.0004), and a lower proportion of type 1 fibers (P = 0.0016) and a higher proportion of type 2X fibers (P = 0.0002) were observed. The paretic muscle had lower CS (P = 0.013) and HAD concentrations (P = 0.037). Mean fiber area correlated with muscle strength (r = 0.43; P = 0.041), and CS concentration correlated with aerobic capacity (r = 0.47; P = 0.01). CONCLUSIONS: In stroke survivors there is a phenotypic shift toward more fatigable muscle fibers with reduced oxidative enzymatic capacity that relates to clinical outcomes.

Failure in closure of the anterior neural tube causes left isomerization of the zebrafish epithalamus.

Differences between the left and right sides of the brain are present in many animal species. For instance, in humans the left cerebral hemisphere is largely responsible for language and tool use and the right for processing spatial information. Zebrafish have prominent left-right asymmetries in their epithalamus that have been associated with differential left and right eye use and navigational behavior. In wild-type (WT) zebrafish embryos, Nodal pathway genes are expressed in the left side of the pineal anlage. Shortly thereafter, a parapineal organ forms to the left of the pineal. The parapineal organ causes differences in gene expression, neuropil density, and connectivity of the left and right habenula nuclei. In embryos that have an open neural tube, such as embryos that are deficient in Nodal signaling or the cell adhesion protein N-cadherin, the left and right sides of the developing epithalamus remain separated from one another. We find that the brains of these embryos often become left isomerized: both sides of the brain develop morphology and gene expression patterns that are characteristic of the left side. However, other aspects of epithalamic development, such as differentiation of specific neuronal cell types, are intact. We propose that there is a mechanism in embryos with closed neural tubes that prevents both sides from developing like the left side. This mechanism fails when the two sides of the epithalamus are widely separated from one another, suggesting that it is dependent upon a signaling protein with limited range.

CHD2 mutations in Lennox-Gastaut syndrome.

Lennox-Gastaut syndrome (LGS) is an epileptic encephalopathy with a heterogeneous etiology. In this study, we aimed to explore the role of CHD2 in LGS, as CHD2 mutations have been described recently in various epileptic encephalopathies. We have previously identified one patient with a large deletion affecting the CHD2 gene in a group of 22 patients with LGS or LGS-like epilepsy. In the remaining 17 patients without known etiology, Sanger sequencing revealed a de novo 1-bp duplication in the CHD2 gene in another patient. This mutation leads to a frameshift and, consequently, a premature stop codon 49bp downstream of the mutation. The patient had prominent myoclonic seizures and photosensitivity, thus, sharing phenotypic features with previously reported patients with CHD2-related epilepsy. In our original material of 22 patients with LGS features, we have now found two (9%) with mutations in the CHD2 gene. Our findings suggest that CHD2 mutations are important in the etiological spectrum of LGS.

Effectiveness and safety of everolimus treatment in patients with tuberous sclerosis complex in real-world clinical practice.

BACKGROUND: The randomised double-blinded placebo-controlled EXIST-1-3 studies have showed everolimus effective with adverse effects reported as acceptable in treatment of symptoms in patients with tuberous sclerosis complex (TSC), although evidence of outcomes in clinical practice remains limited. This study aimed to investigate, in clinical practice, the effectiveness and safety of everolimus for epilepsy, renal angiomyolipoma (rAML), and subependymal giant cell astrocytoma (SEGA) in patients with TSC. RESULTS: The study included 64 patients with TSC (median age: 19, range 0.9-54 years) receiving everolimus treatment (Norway: n = 35; Denmark: n = 29). Among 45 patients with epilepsy, 14 (31%) were responders experiencing ≥ 50% reduction in seizure frequency in the last 3 months of treatment compared with the last 3 months before treatment. Nineteen (42%) patients changed their anti-seizure medications (ASMs). Responders were more common among patients < 18 years (46%) than among patients ≥ 18 years (14%, p = 0.03). In 29 patients with rAML, everolimus reduced (≥ 30% decrease) and stabilized (< 20% increase, ≤ 30% decrease) longest diameter of rAML in 38% and 59%, respectively, after a mean treatment duration of 37 months. SEGA volume was reduced in three patients by 71%, 43%, and 48% after 39, 34, and 82 months. Adverse effects were reported in 61 of 64 patients (95%) after a median treatment duration of 31 months (range 0-106), with oral ulceration/stomatitis (63%) and upper respiratory tract infections (38%) being the most common. The most common laboratory abnormalities were increased cholesterol (41%), anaemia (30%), and leucopoenia (25%). Grade 3-4 adverse effects were reported in 36% of cases, and life-threatening conditions were reported in two patients. Nine patients discontinued everolimus treatment. CONCLUSIONS: Seizure reduction in this study sample was consistent with results from EXIST, but might be lower than expected, given that changes in concomitant ASMs are part of clinical practice. Seizure reduction was associated with younger age. As with EXIST, everolimus reduced or stabilised rAML size in most patients. SEGA volume was reduced in all three patients. Close follow-up is needed for this group, especially for children and patients who may not be able to report adverse effects.

[Dravet syndrome as a cause of epilepsy and learning disability]. / Dravets syndrom som årsak til epilepsi og utviklingshemning.

BACKGROUND: Dravet syndrome is a severe, genetic epileptic encephalopathy with seizures starting during the first year of life. We present a review of the genetic and clinical picture along with treatment aspects. MATERIAL AND METHODS: This review is based on a non-systematic literature search in PubMed until April 2011 and the personal experiences of the authors. RESULTS: Dravet syndrome should be suspected in children with febrile hemiconvulsions or tonic-clonic seizures in the first year of life. Non-febrile seizures also occur, and other seizure types gradually appear, e.g. myoclonic jerks, atypical absences or focal seizures. In adulthood the clinical picture is less characteristic. The clinical diagnosis is supported by genetic testing; 70-80% of the patients have mutations in the sodium channel subunit gene SCN1A. Seizure control is difficult to achieve, but valproate, benzodiazepines and stiripentol may cause improvement, whereas sodium channel blockers, such as lamotrigine and carbamazepine may aggravate the tendency towards seizures. INTERPRETATION: Dravet syndrome appears to be an under-recognised condition among both children and adults with severe epilepsy and learning disability. Clinical information from the first years of life is essential in making the diagnosis. A correct diagnosis at an early age is essential for appropriate treatment and genetic counselling.

[Lennox-Gastaut syndrome--course and treatment]. / Lennox-Gastauts syndrom--forløp og behandling.

BACKGROUND: Lennox-Gastaut syndrome (LGS) is a severe epileptic encephalopathy, which starts in childhood with various seizure types. The children develop cognitive impairment and a typical EEG pattern. The aim of this article is to describe the clinical presentation of LGS, with particular emphasis on the course in adulthood. MATERIAL AND METHODS: The article is based on literature (up to November 2009) identified through a non-systematic search in PubMed and our own clinical experience. RESULTS: There are cases with unknown etiology and symptomatic cases with a wide spectrum of etiologies. While children with LGS have a high frequency of generalized seizures, seizure activity tends to decrease somewhat in adulthood and the seizures may become more focal. The prognosis is usually poor. The adult patient with LGS is clearly affected by global encephalopathy and is typically characterized by bluntness, apathy, progressive cognitive failure and motoric deficits. Valproate has been the first-line treatment for many years, but newer antiepileptic drugs; such as lamotrigine, topiramate and rufinamide, have shown efficacy as add-on therapy. Overtreatment with antiepileptic drugs is common. INTERPRETATION: For optimal treatment, a specialist should follow LGS patients at all ages. New treatment options with milder side effects may improve the quality of life for these patients.

A retrospective review of changes and challenges in the use of antiseizure medicines in Dravet syndrome in Norway.

OBJECTIVE: Dravet syndrome is a developmental and epileptic encephalopathy characterized by severe and drug-resistant seizures in early childhood, followed by developmental delay. The purpose of this study was to investigate aspects of pharmacological treatment of Norwegian patients with Dravet syndrome, focusing on the use of antiseizure medicines (ASMs) and identifying treatment challenges. METHODS: Patients were identified through medical registries at the National Center for Epilepsy in Norway and National Center for Rare Epilepsy Related Disorders during 2008-2018. Additional clinical data were obtained from medical records and laboratory request forms. RESULTS: We identified 53 patients with Dravet syndrome, 30/23 males/females, aged 2-50 years. The majority of patients with known seizure frequency experienced frequent seizures, 80% (n = 35/44). Only two patients were seizure-free. Valproate (n = 48), clobazam (n = 45), levetiracetam (n = 30), and stiripentol (n = 38) were most commonly used, previous or current use. More than one-third (n = 20) had tried sodium channel blockers (including lamotrigine), but these drugs were used less during the last decade. Polytherapy was common, 81% (n = 43) used two or more ASMs, and eight of these patients used 4-5 drugs (15%). Several challenges were identified: high seizure frequency, comorbidities, treatment changes with a wide range of ASMs, common use of oral gastro-tubes, extensive polypharmacy, and drug interactions. SIGNIFICANCE: The use of ASMs has changed over the last decade, in accordance with updated international recommendations. Various treatment challenges were identified. This vulnerable group of patients needs close follow-up for an optimal treatment outcome.

SCN1A mutation screening in adult patients with Lennox-Gastaut syndrome features.

Mutations in the SCN1A gene have been identified in a variety of epilepsy phenotypes, from severe encephalopathies such as Dravet syndrome to milder familial forms such as generalized epilepsy with febrile seizures plus. In a previous study, an SCN1A mutation was also identified in a patient with Lennox-Gastaut syndrome (LGS), and the aim of our study was to investigate the importance of mutations in the SCN1A gene in Norwegian patients with clinical features of LGS. We screened 22 adult patients for SCN1A mutations by direct sequencing of DNA and for micro-rearrangements with multiplex ligation-dependent probe amplification. In one patient a mutation was found, which demonstrates a clinical overlap between LGS and Dravet syndrome. This finding emphasizes the significance of SCN1A mutations also in epileptic disorders with features of LGS, particularly in the myoclonic variant of the disorder.

[Psychogenic non-epileptic seizures]. / Psykogene ikke-epileptiske anfall.

BACKGROUND: Psychogenic non-epileptic seizure is the term used for epilepsy-like seizures assumed to have psychological causes. Many patients with such seizures are misdiagnosed with epilepsy, and are consequently treated with antiepileptic drugs for many years. Assessment of a thorough medical history and ictal EEG-recordings will lead to the right diagnosis in most cases. The article provides an overview of this condition, which often represents large diagnostic and therapeutic challenges and is the most frequent differential diagnosis in epilepsy. MATERIAL AND METHODS: The article is based on literature identified through a non-systematic search in PubMed up to January 2009. RESULTS: Much literature is available in the field. 10-20 % of those referred to epilepsy centers because of therapy-resistant epilepsy, have psychogenic non-epileptic seizures. 70-80 % of these patients are women. The attacks may resemble all types of epileptic seizures, from absence-like episodes to tonic-clonic-like seizures. INTERPRETATION: Such seizures may have a wide spectre of causes, including chronic psychological conflicts and psychotraumas. Treatment should therefore be tailored to individuals.

Balance and walking performance are improved after resistance and aerobic training in persons with chronic stroke.

PURPOSE: To investigate the effect of different types of physical training on balance performance and whether improved balance correlates with improved walking performance. METHODS: Forty eight participants with chronic stroke were randomly assigned to aerobic training on cycle ergometer (AT-group), resistance training of the lower extremities (RT-group), or sham training of upper extremities (ST-group). Participants exercised 3 d/week for 12 weeks. Balance (Berg Balance Scale), peak oxygen uptake rate, isometric knee extensor strength, maximal gait speed, and 6 minute walk test were measured at baseline and after 12 weeks. RESULTS: Training specific effects were observed; the AT-group improved peak oxygen uptake rate by 15.5 (6.0-25.0)%, the RT-group improved non-paretic knee extensor strength by 35.1 (18.3-51.9)% and the ST-group improved non-paretic knee extensor strength by 8.9 (0.7-17.1)%. All groups improved balance (6.0 (95% CI: 3.2-8.8)%), maximal gait speed (10.2 (6.5-14.0)%), and 6 minute walk distance (12.4 (8.8-15.9)%) but balance improvements did not correlate with improvements in muscle strength, peak oxygen uptake rate, or walking. CONCLUSIONS: Physical exercise improves balance and walking performance, but improved balance is not a prerequisite for functional improvements in chronic stroke. Implications for Rehabilitation Aerobic training and progressive resistance training show small significant improvements in balance and walking, indicating a possible clinical relevance of these training modalities. Improvements in balance may not be a prerequisite for improvements in walking distance when assistive devices are allowed during walking tests.

Histopathological and clinical findings in leprosy patients with chronic neuropathic pain: a study from Hyderabad, India.

BACKGROUND: Chronic neuropathic pain in leprosy patients after completion of multi-drug therapy (MDT) is an under-researched problem. The reason why some leprosy patients develop it is unknown. In this study we evaluated the role of ongoing inflammation and small-fibre neuropathy as possible contributing factors for neuropathic pain. METHODS: We assessed chronic neuropathic pain in 17 leprosy patients who had completed MDT and were attending a referral clinic in Hyderabad, India. All patients had a clinical assessment, intraepidermal nerve (IENF) assessment and quantitative sensory testing (QST), which included the testing of tactile and pinprick sensations using Semmes-Weinstein monofilaments and weighted needles method. Nine patients had a sural nerve biopsy (SNB). RESULTS: Thirteen patients had a glove and stocking pattern of neuropathy. All nerve biopsies showed inflammation with intraneural inflammation and perineural thickening, and intraneural acid fast bacilli were observed in five biopsies. IENF analysis of the skin biopsy specimens in 16/17 patients showed a statistically significant reduction in IENF density (P < 0.001, Mann Whitney test) compared to control skin biopsies. Complete depletion of intraepidermal nerves was observed in six patients. QST also showed marked abnormalities. In 11 patients total sensory loss for all modalities was found, and in the other six patients the sensory function was seriously impaired. DISCUSSION: There is evidence of ongoing intraneural inflammation in leprosy patients who have completed MDT. This may explain the occurrence of chronic neuropathic pain. Using IENF density measurement we have found significant small-fibre neuropathy in leprosy patients and the use of this tool could be expanded.

Exome Sequencing Fails to Identify the Genetic Cause of Aicardi Syndrome.

Aicardi syndrome (AS) is a well-characterized neurodevelopmental disorder with an unknown etiology. In this study, we performed whole-exome sequencing in 11 female patients with the diagnosis of AS, in order to identify the disease-causing gene. In particular, we focused on detecting variants in the X chromosome, including the analysis of variants with a low number of sequencing reads, in case of somatic mosaicism. For 2 of the patients, we also sequenced the exome of the parents to search for de novo mutations. We did not identify any genetic variants likely to be damaging. Only one single missense variant was identified by the de novo analyses of the 2 trios, and this was considered benign. The failure to identify a disease gene in this study may be due to technical limitations of our study design, including the possibility that the genetic aberration leading to AS is situated in a non-exonic region or that the mutation is somatic and not detectable by our approach. Alternatively, it is possible that AS is genetically heterogeneous and that 11 patients are not sufficient to reveal the causative genes. Future studies of AS should consider designs where also non-exonic regions are explored and apply a sequencing depth so that also low-grade somatic mosaicism can be detected.

Aicardi syndrome: an epidemiologic and clinical study in Norway.

BACKGROUND: Aicardi syndrome is a rare neurodevelopmental disorder. The main diagnostic features are agenesis of corpus callosum, chorioretinal lacunae, and infantile spasms. The outcome is in general severe, with poor cognitive development and difficult-to-treat epilepsy. The aim of this study was to perform a nationwide epidemiologic survey of patients with Aicardi syndrome and describe their clinical features. Norway is a small country with a well-developed health system, making epidemiologic studies of rare diseases feasible and reliable. METHODS: We aimed at identifying all patients diagnosed with Aicardi syndrome in Norway. Prevalence of Aicardi syndrome was calculated for January 1, 2011. All available patients were examined, and their medical records were scrutinized. RESULTS: Six females aged 7 to 27 years with the diagnosis of Aicardi syndrome were identified. With a female population of 949,578 in ages 0 to 29 years, we found an age-adjusted prevalence of 0.63 per 100,000 females. One patient never had epileptic seizures. The other five had all experienced infantile spasms, all had at some point hypsarrhythmia in electroencephalography, two had a clear picture of suppression burst, whereas three had periods of suppression. Four of the five patients with seizure disorders experienced a marked improvement with time. CONCLUSION: We found an age-adjusted prevalence of 0.63 per 100,000 females with Aicardi syndrome and that their seizure disorder appeared to improve with age.

Copy number variants in adult patients with Lennox-Gastaut syndrome features.

PURPOSE: Lennox-Gastaut syndrome (LGS) is a severe epileptic encephalopathy with complex etiology. To explore possible genetic predispositions and causes of LGS, we have searched for copy number variants (CNVs). METHODS: We studied 21 patients with LGS or LGS-like epilepsy for CNVs using whole-genome array comparative genomic hybridization (aCGH). KEY FINDINGS: Eight patients (38%) carried rare CNVs that might contribute to their phenotype. The pathogenicity could be questioned in some of them, but in four patients (19%) a causative role was considered highly probable. Three had CNVs and clinical features consistent with known genetic syndromes: 22q13.3 deletion, 2q23.1 deletion, and MECP2 duplication. SIGNIFICANCE: There is a high frequency of rare CNVs in adult patients with LGS-like epilepsy. The phenotypes of these background disorders may be obscured by the effects of intractable seizures and massive antiepileptic drug treatment. Previously, syndromic disorders were primarily identified by their clinical features; however, a genome wide approach with identification of the genotype might shed light on the phenotype.