Insertion and deletion variants (indels) within poly glycine tracts of fused in sarcoma (FUS) were initially reported as causative of disease in amyotrophic lateral sclerosis (ALS). Subsequent studies identified similar indels in controls and suggested that these indels may confer susceptibility to ALS. We aimed to elucidate the role of previously published and novel exonic indels in FUS in an extensive cohort of 630 ALS patients and 1063 controls. We detected indels in FUS exons 5, 6, 12 and 14 with similar frequencies in patients (0.95%) and controls (0.75%). Exonic indels in poly glycine tracts were also observed with similar frequencies. The largest indel (p.Gly138_Tyr143del) was observed in one control. In one patient, a 3 base pair deletion in exon 14 (p.Gly475del) was identified, however in-vitro studies did not reveal abnormal localization of p.Gly475del mutant FUS. These findings suggest that not all exonic indels in FUS cause disease.

Pathological laughing and crying is a disorder of emotional expression seen in a number of neurological diseases. The aetiology is poorly understood, but clinical descriptions suggest a disorder of emotion regulation. The goals of this study were: (i) to characterize the subjective, behavioural and physiological emotional reactions that occur during episodes of pathological laughing and crying; (ii) to compare responses during these episodes to those that occur when emotions are elicited under standard conditions (watching sad and amusing emotional films, being startled); and (iii) to examine the ability of patients with this disorder to regulate their emotions under standardized conditions. Twenty-one patients with pathological laughing and crying due to amyotrophic lateral sclerosis and 14 with amyotrophic lateral sclerosis but no pathological laughing and crying were studied. Emotional measures included self-reported emotional experience, video recordings of facial reactivity and peripheral physiological responses (skin conductance, heart rate and somatic activity). Nineteen of the 21 patients with histories of pathological laughing and crying had at least one episode in the laboratory that they agreed constituted pathological laughing or crying (a total of 56 episodes were documented). Compared with viewing sad and amusing films, the episodes were associated with greater facial and physiological activation. Contrary to many clinical descriptions, episodes were often induced by contextually appropriate stimuli and associated with strong experiences of emotion that were consistent with the display. When instructed to regulate their facial responses to emotion-eliciting films, patients with pathological laughing and crying showed impairments compared with patients who did not have a history of this disorder. These findings support the idea that pathological laughing and crying represents activation of all channels of emotional responding (i.e. behavioural, physiological and subjective). Furthermore, they support previously advanced theories that, rather than being associated with general emotional hyperreactivity, this disorder may be due to dysfunction in frontal neural systems that support voluntary regulation of emotion.

Expanded glutamine repeats of the ataxin-2 (ATXN2) protein cause spinocerebellar ataxia type 2 (SCA2), a rare neurodegenerative disorder. More recent studies have suggested that expanded ATXN2 repeats are a genetic risk factor for amyotrophic lateral sclerosis (ALS) via an RNA-dependent interaction with TDP-43. Given the phenotypic diversity observed in SCA2 patients, we set out to determine the polymorphic nature of the ATXN2 repeat length across a spectrum of neurodegenerative disorders. In this study, we genotyped the ATXN2 repeat in 3919 neurodegenerative disease patients and 4877 healthy controls and performed logistic regression analysis to determine the association of repeat length with the risk of disease. We confirmed the presence of a significantly higher number of expanded ATXN2 repeat carriers in ALS patients compared with healthy controls (OR = 5.57; P= 0.001; repeat length >30 units). Furthermore, we observed significant association of expanded ATXN2 repeats with the development of progressive supranuclear palsy (OR = 5.83; P= 0.004; repeat length >30 units). Although expanded repeat carriers were also identified in frontotemporal lobar degeneration, Alzheimer's and Parkinson's disease patients, these were not significantly more frequent than in controls. Of note, our study identified a number of healthy control individuals who harbor expanded repeat alleles (31–33 units), which suggests caution should be taken when attributing specific disease phenotypes to these repeat lengths. In conclusion, our findings confirm the role of ATXN2 as an important risk factor for ALS and support the hypothesis that expanded ATXN2 repeats may predispose to other neurodegenerative diseases, including progressive supranuclear palsy.

Juvenile amyotrophic lateral sclerosis (ALS) with basophilic inclusions is a well-recognized entity. However, the molecular underpinnings of this devastating disease are poorly understood. Here, we present genetic and neuropathological characterizations in two young women with fatal rapidly progressive ALS with basophilic inclusions. In one case, a germline mutation (P525L) was detected in the FUS/TLS (fused in sarcoma/translocated in liposarcoma) gene, whereas no mutation was identified in the other case. Postmortem examination in both cases revealed severe loss of spinal motor neurons with remaining neurons showing basophilic inclusions that contain abnormal aggregates of FUS proteins and disorganized intracellular organelles, including mitochondria and endoplasmic reticulum. In both patients, the FUS-positive inclusions were also detected in neurons in layers IV–V of cerebral cortex and several brainstem nuclei. In contrast, spinal motor neurons in patients with late-onset sporadic ALS showed no evidence of abnormal accumulation of FUS protein. These results underscore the importance of FUS mutations and pathology in rapidly progressive juvenile ALS. Furthermore, our study represents the first detailed characterizations of neuropathological findings in rapidly progressive juvenile ALS patients with a mutation in the FUS/TLS gene.

Frontotemporal dementia (FTD) is a progressive neurological condition caused by degeneration of the frontal and/or anterior temporal lobes resulting in personality, behavioral, and cognitive changes. Amyotrophic lateral sclerosis (ALS) is caused by degeneration of lower motor and pyramidal neurons, leading to loss of voluntary muscle movement. The common molecular pathological and anatomical overlap between FTD and ALS, suggest that the two disorders are strongly linked. In some patients FTD precedes ALS, in others ALS occurs first, while in still others the two disorders begin simultaneously. The association between ALS and FTD create unique challenges for family caregivers. This paper provides a guide for healthcare providers caring for patients with FTD-ALS exhibiting behavioral, cognitive, and emotional symptoms. Strategies are suggested to help minimize the impact of negative symptoms.

Objective

Amyotrophic lateral sclerosis (ALS) is a devastating, and currently incurable, neuromuscular disease in which oxidative stress and mitochondrial impairment are contributing to neuronal loss. Coenzyme Q10 (CoQ10), an antioxidant and mitochondrial cofactor, has shown promise in ALS transgenic mice, and in clinical trials for neurodegenerative diseases other than ALS. Our aims were to choose between two high doses of CoQ10 for ALS, and to determine if it merits testing in a Phase III clinical trial.

Methods

We designed and implemented a multi-center trial with an adaptive, two-stage, bias-adjusted, randomized, placebo-controlled, double-blind, Phase II design (n=185). The primary outcome in both stages was decline in the ALS Functional Rating Scale-revised (ALSFRSr) score over 9 months. Stage 1 (dose selection, 35 participants per group) compared CoQ10 doses of 1,800 and 2,700 mg/day. Stage 2 (futility test, 75 patients per group) compared the dose selected in Stage 1 against placebo.

Results

Stage 1 selected the 2,700 mg dose. In Stage 2, the pre-specified primary null hypothesis that this dose is superior to placebo was not rejected. It was rejected, however, in an accompanying pre-specified sensitivity test, and further supplementary analyses. Pre-specified secondary analyses showed no significant differences between CoQ10 at 2,700 mg/day and placebo. There were no safety concerns.

Interpretation

CoQ10 at 2,700 mg daily for 9 months shows insufficient promise to warrant Phase III testing. Given this outcome, the adaptive Phase II design incorporating a dose selection and a futility test avoided the need for a much larger conventional Phase III trial.