Breath analysis in detecting epilepsy.

The aim of this proof of concept study is to investigate if an electronic nose (eNose) is able to make a distinction between breath profiles of diagnosed epilepsy patients and epilepsy-free control subjects. An eNose is a non-invasive device, with a working mechanism that is based on the presence of volatile organic compounds (VOCs) in exhaled breath. These VOCs interact with the sensors of the eNose, and the eNose has to be trained to distinguish between breath patterns from patients with a specific disease and control subjects without that disease. During the measurement participants were asked to breathe through the eNose for five minutes via a disposable mouthpiece. Seventy-four epilepsy patients and 110 control subjects were measured to train the eNose and create a classification model. To assess the effects of anti-epileptic drugs (AEDs) usage on the classification, additional test groups were measured: seven patients who (temporarily) did not use AEDs and 11 patients without epilepsy who used AEDs. The results show that an eNose is able to make a distinction between epilepsy and control subjects with a sensitivity of 76%, a specificity of 67%, and an accuracy of 71%. The results of the two additional groups of subjects show that the created model classifies one out of seven epilepsy patients without AEDs and six out of 13 patients without epilepsy but with AEDs correctly. In this proof of concept study, the AeonoseTM is able to differentiate between epilepsy patients and control subjects. However, the number of false positives and false negatives is still high, which suggests that this first model is still mainly based on the usage of various AEDs.

De Novo Pathogenic Variants in CACNA1E Cause Developmental and Epileptic Encephalopathy with Contractures, Macrocephaly, and Dyskinesias.

Developmental and epileptic encephalopathies (DEEs) are severe neurodevelopmental disorders often beginning in infancy or early childhood that are characterized by intractable seizures, abundant epileptiform activity on EEG, and developmental impairment or regression. CACNA1E is highly expressed in the central nervous system and encodes the α1-subunit of the voltage-gated CaV2.3 channel, which conducts high voltage-activated R-type calcium currents that initiate synaptic transmission. Using next-generation sequencing techniques, we identified de novo CACNA1E variants in 30 individuals with DEE, characterized by refractory infantile-onset seizures, severe hypotonia, and profound developmental impairment, often with congenital contractures, macrocephaly, hyperkinetic movement disorders, and early death. Most of the 14, partially recurring, variants cluster within the cytoplasmic ends of all four S6 segments, which form the presumed CaV2.3 channel activation gate. Functional analysis of several S6 variants revealed consistent gain-of-function effects comprising facilitated voltage-dependent activation and slowed inactivation. Another variant located in the domain II S4-S5 linker results in facilitated activation and increased current density. Five participants achieved seizure freedom on the anti-epileptic drug topiramate, which blocks R-type calcium channels. We establish pathogenic variants in CACNA1E as a cause of DEEs and suggest facilitated R-type calcium currents as a disease mechanism for human epilepsy and developmental disorders.

Psychogenic nonepileptic seizures in adults with epilepsy and intellectual disability: A neglected area.

PURPOSE: To describe the main characteristics of psychogenic nonepileptic seizures (PNES) in adults with epilepsy and intellectual disability (ID), and to analyse the differences regarding psychosocial functioning, epilepsy severity and ID between patients with PNES and a control group without PNES. METHODS: Medical records of adults with ID and epilepsy living at an epilepsy care facility (N = 240) were screened for PNES and evaluated by a neurologist. A control group consisting of patients with epilepsy and ID, without PNES, was matched according to age, sex and level of ID. Characteristics of PNES and epilepsy were provided by the subject's nursing staff or retrieved from patient charts, psychosocial data were collected by standardised questionnaires and level of ID was individually assessed using psychometric instruments. RESULTS: The point prevalence of PNES was 7.1%. The patients with PNES (n = 15) were most often female and had a mild or moderate level of ID. Compared to controls, they showed more depressive symptoms, experienced more negative life events and had more often an ID discrepancy (ID profile with one domain particularly more impaired than another). Stress-related triggers were recognised in a large majority by the nursing staff. CONCLUSION: PNES appears to be a relatively rare diagnostic entity among inpatients with both epilepsy and ID. However, the complexity of diagnosing PNES in this population, and the similarities in stress-related triggers for PNES in patients with and without ID, suggest that PNES may be underdiagnosed in the ID population. Diagnostic challenges of PNES and, as subcategory, reinforced behavioural patterns are discussed.

Phenytoin as a last-resort treatment in SCN8A encephalopathy.

SCN8A encodes Nav1.6, one of the main voltage-gated sodium channel subunits in the brain, and SCN8A mutations lead to epileptic encephalopathy. Particular mutations render the mutant channel more susceptible to inhibition by phenytoin. Yet, the potentially severe side effects of phenytoin maintenance therapy, especially cognitive impairment, are undesirable in these already cognitively impaired patients. We describe a 5-year-old patient with SCN8A encephalopathy in whom phenytoin proved successful as emergency treatment to prevent clustering of seizures and status epilepticus, thus hospital stays. The ketogenic diet, levetiracetam, zonisamide, topiramate, and phenytoin maintenance therapy resulted in adverse reactions not previously documented in SCN8A encephalopathy.

A LRSAM1 mutation links Charcot-Marie-Tooth type 2 to Parkinson's disease.

LRSAM1 mutations have been found in recessive and dominant forms of Charcot-Marie-Tooth disease. Within one generation of the original Dutch family in which the dominant LRSAM1 mutation was identified, three of the five affected family members have developed Parkinson's disease between ages 50 and 65 years, many years after neuropathy onset. We speculate that this late-onset parkinsonism is part of the LRSAM1 phenotype, thus associating a hitherto peripheral nerve disease with a central nervous system phenotype. How the mutated Lrsam1 protein, which normally has E3 ubiquitin ligase activity and is expressed in the nervous system, impacts on substantia nigra neurons is unclear.

Effect of Presymptomatic Body Mass Index and Consumption of Fat and Alcohol on Amyotrophic Lateral Sclerosis.

IMPORTANCE: Because dietary intake may influence pathophysiologic mechanisms in sporadic amyotrophic lateral sclerosis (ALS), the association between premorbid dietary intake and the risk of sporadic ALS will provide insight into which mechanisms are possibly involved in ALS pathophogenesis. OBJECTIVE: To systematically determine the association between premorbid dietary intake and the risk of sporadic ALS. DESIGN, SETTING, AND PARTICIPANTS: A population-based case-control study was conducted in a general community setting in the Netherlands from January 1, 2006, to September 30, 2011. Analysis was conducted April 1, 2013, to November 15, 2014. All patients with a new diagnosis of possible, probable (laboratory supported), or definite ALS according to the revised El Escorial criteria were included and multiple sources were used to ensure complete case ascertainment. Of 986 eligible patients, 674 gave informed consent and returned a complete questionnaire; 2093 controls randomly selected from the general practitioners' registers and frequency matched to the patients for sex and age were included. MAIN OUTCOMES AND MEASURES: We studied the premorbid intake of nutrients in association with the risk of ALS by using a 199-item food frequency questionnaire adjusted for confounding factors and corrected for multiple comparisons while minimizing recall bias. RESULTS: Presymptomatic total daily energy intake in patients, reported as mean (SD), was significantly higher compared with controls (2258 [730] vs 2119 [619] kcal/day; P < .01), and presymptomatic body mass index (calculated as weight in kilograms divided by height in meters squared) was significantly lower in patients (25.7 [4.0] vs 26.0 [3.7]; P = .02). With values reported as odds ratio (95% CI), higher premorbid intake of total fat (1.14; 1.07-1.23; P < .001), saturated fat (1.43; 1.25-1.64; P < .001), trans-fatty acids (1.03; 1.01-1.05; P < .001), and cholesterol (1.08; 1.05-1.12; P < .001) was associated with an increased risk of ALS; higher intake of alcohol (0.91; 0.84-0.99; P = .03) was associated with a decreased risk of ALS. These associations were independent of total energy intake, age, sex, body mass index, educational level, smoking, and lifetime physical activity. No significant associations between dietary intake and survival were found. CONCLUSIONS AND RELEVANCE: The combination of independent positive associations of a low premorbid body mass index and a high fat intake together with prior evidence from ALS mouse models transgenic for SOD1 and earlier reports on premorbid body mass index support a role for increased resting energy expenditure before clinical onset of ALS.

Cumulative effect of 5 daily sessions of θ burst stimulation on corticospinal excitability in amyotrophic lateral sclerosis.

INTRODUCTION: Excitotoxicity plays an important role in the pathogenesis of the preferential motor neuron death observed in amyotrophic lateral sclerosis (ALS). Continuous theta burst stimulation (cTBS) by transcranial magnetic stimulation has an inhibitory effect on corticospinal excitability (CSE). We characterized the neurophysiological changes induced by cTBS in ALS. METHODS: The patients received 5 daily sessions of cTBS. CSE was assessed at baseline and after each session of cTBS. RESULTS: The amplitude of a single pulse motor evoked potential was significantly decreased (34%) over the days. The amplitude returned to baseline a week after the last session. The resting motor threshold increased significantly, whereas intracortical inhibition and facilitation did not change over the sessions. CONCLUSIONS: Daily cTBS has a cumulative depressing effect on CSE in patients with ALS. These results suggest that modulation of CSE in ALS is possible, but repetitive sessions are needed to maintain the effect.

Parental age and the risk of amyotrophic lateral sclerosis.

Sporadic ALS is a multifactorial disease for which there are probably multiple genetic risk factors. An association with increased parental age might suggest there is a role for specific (epi)genetic changes. Previous studies have shown conflicting results on the association between parental age and the risk of ALS. A large, population based study might help in the search for specific (epi)genetic risk factors. We performed a population based, case-control study in the Netherlands. Date of birth of both mother and father was retrieved from the National Register. Multivariate logistic regression analysis was performed in 769 patients with sporadic ALS, 49 patients with a hexanucleotide repeat expansion in C9orf72, and 1929 age-, gender- and geographically-matched controls. Multivariate analyses showed no difference in either paternal or maternal age at delivery (adjusted for age of subject, age of other parent at delivery, and level of education) in patients with sporadic ALS, nor in patients with a hexanucleotide repeat expansion in C9orf72 compared to controls. In conclusion, parental age was not associated with an increased risk of ALS in our study. (Epi)genetic alterations that are associated with increased parental age are not, therefore, likely to contribute to the aetiology of sporadic ALS.

Is the Frontal Assessment Battery reliable in ALS patients?

The assessment of frontal functions in ALS patients is important because of the overlap with the behavioural variant of frontotemporal dementia (bvFTD). We investigated the applicability and reliability of the Frontal Assessment Battery (FAB) within a cohort of predominantly prevalent ALS patients. The FAB was administered to 85 ALS patients and eight ALS-bvFTD patients. Original scores and the percentage of items that could be performed were recorded. Item-adjusted scores of the FAB were calculated. The ALS Functional Rating Scale-Revised version (ALSFRS-R) was used to assess disease severity. Eighty-seven patients (94%) had ALS symptoms of more than one year. Twenty patients (21.5%) were not able to perform one or more FAB items. The original FAB score correlated with the ALSFRS-R score (r = 0.30; p < 0.01), while the item-adjusted FAB score did not. In contrast to the original FAB scores, the item-adjusted FAB score was lower in ALS-bvFTD patients (66.7, range 33.3-100) compared to ALS patients without bvFTD (94.4, range 38.9-100; p < 0.01). In summary, 20% of prevalent ALS patients could not complete the FAB, which limits its use in ALS and emphasizes the importance of disease specific instruments and adjusting for motor impairment in cognitive and behavioural examinations of ALS patients.

H63D polymorphism in HFE is not associated with amyotrophic lateral sclerosis.

The H63D polymorphism in HFE has frequently been associated with susceptibility to amyotrophic lateral sclerosis (ALS). Regarding the role of HFE in iron homeostasis, iron accumulation is considered an important process in ALS. Furthermore, novel therapeutic strategies are being developed targeting this process. Evidence for this genetic association is, however, limited to several small studies. For this reason we studied the H63D polymorphism in a large European cohort including 3962 ALS patients and 5072 control subjects from 7 countries. After meta-analysis of previous studies and current findings we conclude that the H63D polymorphism in HFE is not associated with susceptibility to ALS, age at disease onset, or survival.

The ALS-FTD-Q: a new screening tool for behavioral disturbances in ALS.

OBJECTIVE: The assessment of behavioral disturbances in amyotrophic lateral sclerosis (ALS) is important because of the overlap with the behavioral variant of frontotemporal dementia (ALS-bvFTD). Motor symptoms and dysarthria are not taken into account in currently used behavioral questionnaires. We examined the clinimetric properties of a new behavioral questionnaire for patients with ALS (Amyotrophic Lateral Sclerosis-Frontotemporal Dementia-Questionnaire [ALS-FTD-Q]). METHODS: In addition to other clinimetric properties, we examined reliability, clinical validity, and construct validity of the ALS-FTD-Q, using data from patients with ALS (n = 103), ALS-bvFTD (n = 10), bvFTD (n = 25), muscle disease control subjects (n = 39), and control subjects (n = 31). Construct validity of the ALS-FTD-Q was assessed using the Frontal Systems Behavior scale (FrSBe), Frontal Behavioral Inventory (FBI), Hospital Anxiety and Depression Scale, ALS Functional Rating Scale-Revised, Frontal Assessment Battery, Mini-Mental State Examination, and a fluency index. In addition, the point prevalence of behavioral disturbances according to the ALS-FTD-Q was compared with those obtained with the FrSBe and FBI. RESULTS: The internal consistency of the ALS-FTD-Q was good (Cronbach α = 0.92). The ALS-FTD-Q showed construct validity because it correlated highly with other behavioral measures (r = 0.80 and 0.79), moderately with measures of frontal functions and global cognitive functioning (r = 0.37; r = 0.32), and poorly with anxiety/depression and motor impairment (r = 0.18 for both). The ALS-FTD-Q discriminated between patients with ALS-bvFTD, patients with ALS, and control subjects. The point prevalence of behavioral disturbances in patients with ALS measured with the ALS-FTD-Q was lower than that for the FrSBe and FBI. CONCLUSION: The ALS-FTD-Q is a feasible and clinimetrically validated instrument for the screening of behavioral disturbances in ALS.

TDP-43 plasma levels are higher in amyotrophic lateral sclerosis.

Our objective was to investigate TDP-43 plasma levels in patients with amyotrophic lateral sclerosis (ALS). TDP-43 has been identified as a major component of protein inclusions in the brain of patients with ALS; mutations in the corresponding gene (TARDBP) have also been identified. Although increased TDP-43 levels have been reported in the cerebrospinal fluid, plasma levels have not yet been assessed in patients with ALS. TDP-43 levels were quantified by sandwich ELISA in plasma of 219 patients and 100 controls. In addition, we sequenced exon 6 of TARDBP, and performed longitudinal TDP-43 plasma measurements in a subset of patients. Results showed that TDP-43 plasma levels were significantly increased in patients with ALS (p=0.023) and we found a positive correlation with age in patients and controls. Longitudinal measurements of TDP-43 plasma levels showed an increase in only one patient, with stable levels in five others. Three TARDBP variations were identified in the ALS group (1.7%), but the association with TDP-43 plasma levels was ambiguous. In conclusion, our data indicate that TDP-43 plasma levels may have potential as a marker for ALS. A genotype-phenotype relationship could not, however, be established in this cohort.

Lithium lacks effect on survival in amyotrophic lateral sclerosis: a phase IIb randomised sequential trial.

OBJECTIVES: To determine the safety and efficacy of lithium for the treatment of amyotrophic lateral sclerosis (ALS) in a randomised, placebo controlled, double blind, sequential trial. METHODS: Between November 2008 and June 2011, 133 patients were randomised to receive lithium carbonate (target blood level 0.4-0.8 mEq/l) or placebo as add-on treatment with riluzole. The primary endpoint was survival, defined as death, tracheostomal ventilation or non-invasive ventilation for more than 16 h/day. Secondary outcome measures consisted of the revised ALS Functional Rating Scale and forced vital capacity. Analysis was by intention to treat and according to a sequential trial design. RESULTS: 61 patients reached a primary endpoint, 33 of 66 in the lithium group and 28 of 67 patients in the placebo group. Lithium did not significantly affect survival (cumulative survival probability of 0.73 in the lithium group (95% CI 0.63 to 0.86) vs 0.75 in the placebo group (95% CI 0.65 to 0.87) at 12 months and 0.62 in the lithium group (95% CI 0.50 to 0.76) vs 0.67 in the placebo group (95% CI 0.56 to 0.81) at 16 months). Secondary outcome measures did not differ between treatment groups. No major safety concerns were encountered. CONCLUSIONS: This trial, designed to detect a modest effect of lithium, did not demonstrate any beneficial effect on either survival or functional decline in patients with ALS. TRIAL REGISTRATION NUMBER: NTR1448. Name of trial registry: Lithium trial in ALS.

Fasciculations and their F-response revisited: high-density surface EMG in ALS and benign fasciculations.

OBJECTIVE: To compare the prevalence of fasciculation potentials (FPs) with F-responses between patients with amyotrophic lateral sclerosis (ALS) and patients with benign fasciculations. METHODS: In seven patients with ALS and seven patients with benign fasciculations, high-density surface EMG was recorded for 15 min from the gastrocnemius muscle. Template matching was used to search for pairs of FPs with a repetition within 10-110 ms. RESULTS: Interspike interval (ISI) histograms were constructed from 282 pairs of benign fasciculations and from 337 FP pairs in ALS. Peaks attributable to F-waves were found at latencies of 32 ms (benign) and 35 ms (ALS). Five patients with benign fasciculations and four patients with ALS had FPs with F-waves. CONCLUSIONS: F-waves of FPs occur in both conditions - therefore they are not diagnostically helpful. SIGNIFICANCE: F-waves confirm the distal origin of FPs for an individual axon. The occurrence of these FPs in a benign condition suggests that the generation of ectopic discharges in the distal axons is not specific to progressive neurodegeneration.

Structural MRI reveals cortical thinning in amyotrophic lateral sclerosis.

OBJECTIVES: Amyotrophic lateral sclerosis (ALS) is a fatal disease characterised by combined upper and lower motor neuron degeneration. An early and accurate diagnosis is important for patient care and might facilitate the search for a more effective therapy. MRI was used to study the whole cortical mantle, applying an unbiased surface based approach to identify a marker of upper motor neuron involvement in ALS. METHODS: Surface based cortical morphology analyses were performed on structural, 3T MRI data of 45 patients with ALS and 25 matched healthy controls in a case control study design. These analyses consisted of measuring cortical thickness, surface area and volume. The effects of disease progression were examined by correlating cortical measures with progression rate and by longitudinal measures in 20 patients. RESULTS: Cortical morphology analyses revealed specific thinning in the precentral gyrus, considered the primary motor cortex, in patients with ALS compared with controls (p=6.3×10(-8)). Surface area was reduced in the right inferior parietal region (p=0.049) and volume--the product of cortical thickness and surface area--was reduced in the right precentral gyrus (p=0.031). From these findings, it appears that cortical thickness is superior in detecting the degenerative effects of ALS. Relative cortical thinning in temporal regions was related to faster clinical progression (right inferior temporal gyrus: p=3.3×10(-4)). CONCLUSIONS: Cortical thinning of the primary motor cortex might be a diagnostic marker for upper motor neuron degeneration in ALS. Relative thinning in temporal regions was associated with a rapidly progressive disease course.

A frameshift mutation in LRSAM1 is responsible for a dominant hereditary polyneuropathy.

Despite the high number of genes identified in hereditary polyneuropathies/Charcot-Marie-Tooth (CMT) disease, the genetic defect in many families is still unknown. Here we report the identification of a new gene for autosomal dominant axonal neuropathy in a large three-generation family. Linkage analysis identified a 5 Mb region on 9q33-34 with a LOD score of 5.12. Sequence capture and next-generation sequencing of the region of interest identified five previously unreported non-synonymous heterozygous single nucleotide changes or indels, four of which were confirmed by Sanger sequencing. Two sequence variants co-segregated with the disease, and one, a 2 bp insertion in the last exon of LRSAM1, was also absent in 676 ethnicity-matched control chromosomes. This frameshift mutation (p.Leu708Argfx28) is located in the C-terminal RING finger motif of the encoded protein. Ubiquitin ligase activity in transfected cells with constructs carrying the patient mutation was affected as measured by a higher level of abundance of TSG101, the only reported target of LRSAM1. Injections of morpholino oligonucleotides in zebrafish embryos directed against the ATG or last splice site of zebrafish Lrsam1 disturbed neurodevelopment, showing a less organized neural structure and, in addition, affected tail formation and movement. LRSAM1 is highly expressed in adult spinal cord motoneurons as well as in fetal spinal cord and muscle tissue. Recently, a homozygous mutation in LRSAM1 was proposed as a strong candidate for the disease in a family with recessive axonal polyneuropathy. Our data strongly support the hypothesis that LRSAM1 mutations can cause both dominant and recessive forms of CMT.