Genetic factors affecting survival in Japanese patients with sporadic amyotrophic lateral sclerosis: a genome-wide association study and verification in iPSC-derived motor neurons from patients.

BACKGROUND: Several genetic factors are associated with the pathogenesis of sporadic amyotrophic lateral sclerosis (ALS) and its phenotypes, such as disease progression. Here, in this study, we aimed to identify the genes that affect the survival of patients with sporadic ALS. METHODS: We enrolled 1076 Japanese patients with sporadic ALS with imputed genotype data of 7 908 526 variants. We used Cox proportional hazards regression analysis with an additive model adjusted for sex, age at onset and the first two principal components calculated from genotyped data to conduct a genome-wide association study. We further analysed messenger RNA (mRNA) and phenotype expression in motor neurons derived from induced pluripotent stem cells (iPSC-MNs) of patients with ALS. RESULTS: Three novel loci were significantly associated with the survival of patients with sporadic ALS-FGF1 at 5q31.3 (rs11738209, HR=2.36 (95% CI, 1.77 to 3.15), p=4.85×10-9), THSD7A at 7p21.3 (rs2354952, 1.38 (95% CI, 1.24 to 1.55), p=1.61×10-8) and LRP1 at 12q13.3 (rs60565245, 2.18 (95% CI, 1.66 to 2.86), p=2.35×10-8). FGF1 and THSD7A variants were associated with decreased mRNA expression of each gene in iPSC-MNs and reduced in vitro survival of iPSC-MNs obtained from patients with ALS. The iPSC-MN in vitro survival was reduced when the expression of FGF1 and THSD7A was partially disrupted. The rs60565245 was not associated with LRP1 mRNA expression. CONCLUSIONS: We identified three loci associated with the survival of patients with sporadic ALS, decreased mRNA expression of FGF1 and THSD7A and the viability of iPSC-MNs from patients. The iPSC-MN model reflects the association between patient prognosis and genotype and can contribute to target screening and validation for therapeutic intervention.

Mutation screening of the DNAJC7 gene in Japanese patients with sporadic amyotrophic lateral sclerosis.

DNAJC7 has recently been identified as an amyotrophic lateral sclerosis (ALS) gene via large-scale exome analysis, and its involvement in ALS is still unclear in various populations. This study aimed to determine the frequencies and characteristics of the DNAJC7 variants in a Japanese ALS cohort. A total of 807 unrelated Japanese patients with sporadic ALS were screened via exome analysis. In total, we detected six rare missense variants and one splice-site variant of the DNAJC7 gene, which are not reported in the Japanese public database. Furthermore, the missense variants are located around the TPR domain, which is important for the function of DNAJC7. The total frequency of the DNAJC7 variants in Japanese ALS patients was estimated at 0.87%. Collectively, these results suggest that variants of DNAJC7 are rare cause of Japanese patients with sporadic ALS.

Genetic and functional analysis of KIF5A variants in Japanese patients with sporadic amyotrophic lateral sclerosis.

Two recent genetic studies reported that loss-of-function mutation of the C-terminal cargo-binding tail domain of the KIF5A gene cause amyotrophic lateral sclerosis (ALS). The aim of this study is to investigate the frequency of KIF5A variants in Japanese patients with sporadic ALS. In total, 807 sporadic ALS patients and 191 normal controls from a multicenter ALS cohort in Japan were included. Whole exome sequencing on an Illumina HiSeq 2000/2500 sequencer was used to identify and select variants within the KIF5A gene. Thirteen patients harbored a nonsynonymous variant in the KIF5A gene; These were considered variants of uncertain significance. One patient harbored a novel splice-site variant (c.2993-3C>A) in the C-terminal cargo-binding tail domain of the KIF5A gene. Functional analysis of this variant revealed that it caused skipping of exon 27. The frequency of KIF5A mutations in Japanese patients with sporadic ALS was 0.12% (1/807). This study reports a novel loss-of-function variant in KIF5A, and indicates that loss-of-function variant in KIF5A is a rare cause of sporadic ALS in Japanese patients.

A multi-ethnic meta-analysis identifies novel genes, including ACSL5, associated with amyotrophic lateral sclerosis.

Amyotrophic lateral sclerosis (ALS) is a devastating progressive motor neuron disease that affects people of all ethnicities. Approximately 90% of ALS cases are sporadic and thought to have multifactorial pathogenesis. To understand the genetics of sporadic ALS, we conducted a genome-wide association study using 1,173 sporadic ALS cases and 8,925 controls in a Japanese population. A combined meta-analysis of our Japanese cohort with individuals of European ancestry revealed a significant association at the ACSL5 locus (top SNP p = 2.97 × 10-8). We validated the association with ACSL5 in a replication study with a Chinese population and an independent Japanese population (1941 ALS cases, 3821 controls; top SNP p = 1.82 × 10-4). In the combined meta-analysis, the intronic ACSL5 SNP rs3736947 showed the strongest association (p = 7.81 × 10-11). Using a gene-based analysis of the full multi-ethnic dataset, we uncovered additional genes significantly associated with ALS: ERGIC1, RAPGEF5, FNBP1, and ATXN3. These results advance our understanding of the genetic basis of sporadic ALS.

[Role of the liaison officer in disaster countermeasures implemented by the Japanese Society of Neurology: Hope for the best and prepare for the worst].

Disaster countermeasures have been implemented by the Japanese Society of Neurology based on the experience of support to the areas affected by the Great East Japan Earthquake on March 11, 2011. The countermeasures activity began at the end of 2011. We, the Committee for Measures Against Disaster, officially started work in 2014. We developed a support network to urgently deal with patients with intractable neurological disease at the time of disaster and strengthen disaster measures, including effective disaster countermeasure training. During the 2016 Kumamoto earthquake, we realized the need to prepare for natural disasters, leading to a state of emergency, at normal times. A list of vulnerable people should be prepared and the individual support plan for disaster should be confirmed during normal times. Furthermore, during disaster, livelihood support is required for patients with intractable neurological disease living in evacuation centers in affected areas. Therefore, we compiled and published the book, titled "The manual of disaster countermeasures," in 2017. The Committee for Measures Against Disaster in the Japanese Society of Neurology has appointed a liaison officer for patients with intractable neurological disease in each prefecture. The liaison's role of is gathering and disseminating information on the disaster-hit areas, arranging medical support, and coordinating health activities, when natural disasters occur. It is hoped that the liaison officer will play an active role both at normal times and during disaster, even unforeseen ones. Although we hope for the best, we aim to be prepared for the worst.

[A case of motor and sensory polyneuropathy and respiratory failure with novel heterozygous mutation of the senataxin gene].

The patient was a 29-year-old male. He took his first steps at two-and-a-half years old, but his physical strength deteriorated and he became non-ambulatory at 12 years old. He had respiratory failure at the age of 20, and finally underwent tracheostomy with invasive positive-pressure ventilation (TPPV). He showed distal dominant muscle weakness and atrophy, including the face. Spinal scoliosis was recognized. He had peripheral predominance of sensory disorders. Nerve conduction studies showed a decrease of compound muscle action potential and a reduction of motor nerve conduction velocity. Sensory nerve action potential was not evoked. In genetic analysis, c.23 C> T (p. T8M) heterozygous mutation was found in the senataxin gene (SETX). Although SETX is a causative gene of familial amyotrophic lateral sclerosis type 4 (ALS4), this case suggests that SETX mutation can also cause motor and sensory polyneuropathy.

[Intractable Neurological Disease].

Subacute intractable neurological diseases sometimes require patients to make various choices in life without accepting the disease. Therefore, doctors need to be diagnose these diseases early. However, in clinical settings, diagnosis is often sought only from the localized history and symptoms and not the overall picture of the disease. In addition, there are many findings that are difficult to interpret, and depending on the combination of findings, the diagnostic criteria or guidelines may be met. As a result, the disease fits only seemingly to the findings. Therefore, I would like to urge physicians to be aware of pitfalls by referring to the cases refferred to our neurology department for us to assess them.

Prognosis of amyotrophic lateral sclerosis patients undergoing tracheostomy invasive ventilation therapy in Japan.

OBJECTIVE: The aim of this study is to describe and clarify the factors affecting the prognosis of Japanese patients with amyotrophic lateral sclerosis (ALS) undergoing tracheostomy invasive ventilation (TIV) therapy. METHODS: We conducted a prospective longitudinal observational case-control study using a multicentre registry. ALS patients who started TIV therapy after registration (TIV group) and those who did not receive TIV (non-TIV group) were included. We compared the survival time between the TIV group and the non-TIV group using a propensity score matching analysis and evaluated the prognostic factors in the TIV group. RESULTS: From February 2006 to January 2018, 190 patients in the TIV group and 1093 patients in the non-TIV group were included in this study. The mean age of disease onset and usage rate of gastrostomy and non-invasive ventilation therapy differed between the groups. In the propensity score matching analysis using known prognostic factors, the median overall survival time of the TIV group was significantly greater than that of the non-TIV group (11.33 years vs 4.61 years; p<0.001). Analysis using the Cox proportional hazard model suggested that older age of onset and respiratory onset was an independent factor for poor prognosis after starting TIV therapy. CONCLUSION: We showed that there was a significant difference of approximately 7 years in life expectancy between Japanese ALS patients who did and did not receive TIV therapy.

Increase of arginine dimethylation correlates with the progression and prognosis of ALS.

OBJECTIVE: To investigate whether arginine methylation is altered in patients with amyotrophic lateral sclerosis (ALS) and how it affects disease severity, progression, and prognosis. METHODS: We compared the immunoreactivity of protein arginine methyltransferase 1 (PRMT1) and its products, asymmetric dimethylated proteins (ASYM), in postmortem spinal cord. We also measured the concentrations of total l-arginine and methylated arginine residues, including asymmetric dimethyl l-arginine (ADMA), symmetric dimethyl arginine, and monomethyl arginine, in CSF samples from 52 patients with ALS using liquid chromatography-tandem mass spectrometry, and we examined their relationship with the progression and prognosis of ALS. RESULTS: The immunoreactivity of both PRMT1 (p < 0.0001) and ASYM (p = 0.005) was increased in patients with ALS. The concentration of ADMA in CSF was substantially higher in patients with ALS than in disease controls. The ADMA/l-arginine ratio was correlated with the change of decline in the ALS Functional Rating Scale at 12 months after the time of measurement (r = 0.406, p = 0.010). A Cox proportional hazards model showed that the ADMA/l-arginine ratio was an independent predictor for overall survival. Moreover, a high ADMA/l-arginine ratio predicted poor prognosis, even in a group with normal percentage forced vital capacity. CONCLUSION: There was an enhancement of arginine dimethylation in patients with ALS, and the ADMA/l-arginine ratio predicted disease progression and prognosis in such patients.

Early use of donepezil against psychosis and cognitive decline in Parkinson's disease: a randomised controlled trial for 2 years.

OBJECTIVES: Brain acetylcholine is decreased even in patients with cognitively preserved Parkinson's disease (PD). We investigated whether early and long-term use of donepezil prevents psychosis in non-demented PD patients. METHODS: A double-blinded, placebo-controlled trial was conducted. A total of 145 non-demented PD patients were randomly assigned to receive 5 mg/day donepezil (n=72) or placebo (n=73) for 96 weeks. Medications for PD were not restricted, but antipsychotic drugs were not permitted throughout the study. The primary outcome measure was survival time to psychosis that was predefined by Parkinson's Psychosis Questionnaire (PPQ) B score ≥2 or C score ≥2. Secondary outcome measures included psychosis developing within 48 weeks, total PPQ score, Mini-Mental State Examination (MMSE), Wechsler Memory Scale (WMS) and subgroup analysis by apolipoprotein ε4 genotyping. RESULTS: Kaplan-Meier curves for psychosis development were very similar between the two groups, and the Cox proportional hazard model revealed an adjusted HR of 0.87 (95%CI 0.48 to 1.60). The changes in MMSE and WMS-1 (auditory memory) were significantly better with donepezil than in placebo. In the subgroup analysis, donepezil provided an HR of 0.31 (0.11-0.86) against psychosis in 48 weeks for apolipoprotein ε4 non-carriers. CONCLUSIONS: Although donepezil provided beneficial effects on PPQ, MMSE and auditory WMS score changes in 2 years, it had no prophylactic effect on development of psychosis in PD. Apolipoprotein ε4 may suppress the antipsychotic effect of donepezil. TRIAL REGISTRATION NUMBER: UMIN000005403.

Frequency and characteristics of the TBK1 gene variants in Japanese patients with sporadic amyotrophic lateral sclerosis.

Amyotrophic lateral sclerosis (ALS) is a devastating neurological disease, and the etiology of sporadic ALS is generally unknown. The TANK-binding kinase 1 (TBK1) gene was identified as an ALS gene contributing to a predisposition toward ALS. To reveal the frequency and characteristics of variants of the TBK1 gene in sporadic ALS patients in Japan, we analyzed the TBK1 gene by exome sequencing in a large Japanese cohort of 713 sporadic ALS patients and 800 controls. We identified known or potentially toxic rare variants of TBK1 gene in 9 patients (1.26%) with sporadic ALS, including 4 novel missense variants (p.V23I, p.H322R, p.R358C, and p.T478I) and 3 loss-of-function variants (p.R357X, p.P378_I379del, and p.T419_G420del). The odds ratio between sporadic ALS patients and controls was 10.2 (p = 0.008, 95% confidence interval = 1.67-62.47). These findings support the contribution of TBK1 to the etiology of sporadic ALS in Japanese patients.

Frontal assessment battery and frontal atrophy in amyotrophic lateral sclerosis.

OBJECTIVES: To determine the potential utility of the frontal assessment battery (FAB) in assessing cognitive impairments in amyotrophic lateral sclerosis (ALS), we investigated the association between the FAB score and regional gray matter volume, and ascertained whether the regional brain alterations related to cognitive impairments occur in relatively mild stage of ALS. MATERIALS AND METHODS: Twenty-four ALS patients with a Mini-Mental State Examination score of >23, a normal score on the Self-Rating Depression Scale, little or no disturbance in speech and handling utensils on the ALS Functional Rating Scale (ALSFRS), and normal measures on respiratory tests (respiratory function test and arterial blood gas analysis), and two age-matched normal control groups (one for FAB assessment and the other for brain morphometry) underwent FAB testing and structural magnetic resonance imaging. We applied voxel-based morphometry to investigate the relationship between the FAB score and regional brain alteration, and assessed the relationship between the altered regional brain volume and ALSFRS or respiratory tests. RESULTS: Frontal assessment battery scores were significantly lower in ALS patients than in normal controls. Volume reduction in the right orbitofrontal gyrus in ALS was correlated with a lower FAB score. There was no correlation between the right orbitofrontal gyrus volume and ALSFRS or respiratory tests. CONCLUSIONS: The results suggest that the FAB is an adequate tool for detecting cognitive impairments related to frontal lobe pathology in the relatively mild stage of ALS, independent of physical dysfunctions.

Age of onset differentially influences the progression of regional dysfunction in sporadic amyotrophic lateral sclerosis.

The clinical courses of sporadic amyotrophic lateral sclerosis (ALS) show extensive variability. Our objective was to elucidate how age of onset influences the progression of regional symptoms and functional losses in sporadic ALS. We included 648 patients with sporadic ALS from a multicenter prospective ALS cohort. We investigated the distribution of initial symptoms and analyzed the time from onset to events affecting activities of daily living (ADL) as well as the longitudinal changes in each regional functional rating score among four groups with different ages of onset. The frequencies of dysarthria and dysphagia as initial symptoms were higher in the older age groups, whereas weakness of upper limbs was the most common initial symptom in the youngest age group. The survival times and the times from onset to loss of speech and swallowing were significantly shorter in the older age group (p < 0.001), although the times from onset to loss of upper limb function were not significantly different among the age groups. According to joint modeling analysis, the bulbar score declined faster in the older age groups (<50 vs. 60-69 years: p = 0.029, <50 vs. ≥70 years: p < 0.001), whereas there was no significant correlation between the age of onset and decline in the upper limb score. Our results showed that age of onset had a significant influence on survival time and the progression of bulbar symptoms, but had no influence on upper limb function in sporadic ALS.

Next-generation sequencing of 28 ALS-related genes in a Japanese ALS cohort.

We investigated the frequency and contribution of variants of the 28 known amyotrophic lateral sclerosis (ALS)-related genes in Japanese ALS patients. We designed a multiplex, polymerase chain reaction-based primer panel to amplify the coding regions of the 28 ALS-related genes and sequenced DNA samples from 257 Japanese ALS patients using an Ion Torrent PGM sequencer. We also performed exome sequencing and identified variants of the 28 genes in an additional 251 ALS patients using an Illumina HiSeq 2000 platform. We identified the known ALS pathogenic variants and predicted the functional properties of novel nonsynonymous variants in silico. These variants were confirmed by Sanger sequencing. Known pathogenic variants were identified in 19 (48.7%) of the 39 familial ALS patients and 14 (3.0%) of the 469 sporadic ALS patients. Thirty-two sporadic ALS patients (6.8%) harbored 1 or 2 novel nonsynonymous variants of ALS-related genes that might be deleterious. This study reports the first extensive genetic screening of Japanese ALS patients. These findings are useful for developing genetic screening and counseling strategies for such patients.

The characteristics of camptocormia in patients with Parkinson's disease: A large cross-sectional multicenter study in Japan.

PURPOSE: The goal of the present study was to clarify the clinical characteristics and laboratory results of parkinsonian symptoms among patients with and without camptocormia. METHODS: Seventy-eight Parkinson's disease (PD) patients with camptocormia and 78 PD patients without camptocormia underwent a neurological examination, a blood test, and spinal magnetic resonance imaging (MRI). PD with camptocormia group and PD with non-camptocormia group were matched on age, age at PD onset, and sex. PRINCIPAL RESULTS: Camptocormia group had significantly higher prevalence of compression fractures, more severe parkinsonian symptoms, and a greater incidence of dementia than those without camptocormia. Serum creatine kinase levels in camptocormia group significantly elevated compared with non-camptocormia group. There were higher prevalence of abnormal findings in spine MRI including compression fractures and paravertebral muscle changes in camptocormia group compared with non-camptocormia group. MAJOR CONCLUSIONS: Camptocormia is associated with a greater prevalence of compression fractures and associated with greater UPDRS part II, part III score, axial score, and lower MMSE in this cross-sectional study. Thus, it can be concluded that camptocormia in PD is predominantly myopathic.

Factors affecting longitudinal functional decline and survival in amyotrophic lateral sclerosis patients.

Our objective was to elucidate the clinical factors affecting functional decline and survival in Japanese amyotrophic lateral sclerosis (ALS) patients. We constructed a multicenter prospective ALS cohort that included 451 sporadic ALS patients in the analysis. We longitudinally utilized the revised Amyotrophic Lateral Sclerosis Functional Rating Scale (ALSFRS-R) as the functional scale, and determined the timing of introduction of a tracheostomy for positive-pressure ventilation and death. A joint modelling approach was employed to identify prognostic factors for functional decline and survival. Age at onset was a common prognostic factor for both functional decline and survival (p < 0.001, p < 0.001, respectively). Female gender (p = 0.019) and initial symptoms, including upper limb weakness (p = 0.010), lower limb weakness (p = 0.008) or bulbar symptoms (p = 0.005), were related to early functional decline, whereas neck weakness as an initial symptom (p = 0.018), non-use of riluzole (p = 0.030) and proximal dominant muscle weakness in the upper extremities (p = 0.01) were related to a shorter survival time. A decline in the ALSFRS-R score was correlated with a shortened survival time (p < 0.001). In conclusion, the factors affecting functional decline and survival in ALS were common in part but different to some extent. This difference has not been previously well recognized but is informative in clinical practice and for conducting trials.

Frontal lobe-mediated behavioral changes in amyotrophic lateral sclerosis: are they independent of physical disabilities?

OBJECTIVE: Several studies have indicated that frontal cognitive impairment is present in patients with amyotrophic lateral sclerosis (ALS). However, it remains to be elucidated whether the behavioral change is a direct consequence of ALS pathology or the measurements are confounded by the physical impairments. We examined frontal lobe-mediated behavioral dysfunction in daily living in patients with ALS by using the family- and self-rating forms of the Frontal Systems Behavior Scale (FrSBe) and assessed the relationship between the scores and motor impairments or ventilatory status. METHODS: We examined 24 patients with sporadic ALS, who were aged 65.7 ± 10.5 years with mean disease duration of 2.3 ± 1.7 years, Mini-Mental State Examination score of ≥ 24, normal Self-rating Depression Scale, no need of assistance in daily life, normal respiratory function, and normal arterial blood gas analytes. We examined the relationship between FrSBe scores and ALS Functional Rating Scale (ALSFRS), respiratory function, and arterial blood gas analytes. RESULTS: The scores of family- and self-rating FrSBe were significantly higher after onset of ALS than before onset, most notably in apathy. The family-rating FrSBe scores after onset were not correlated with ALSFRS, respiratory function, or arterial blood gas analytes. CONCLUSION: The frontal-lobe-related behavioral dysfunction is present after the onset of ALS, but is independent of physical impairments.

[Assessing frontal lobe function in patients with amyotrophic lateral sclerosis by frontal assessment battery].

Frontal Assessment Battery (FAB) is short neuropsychological battery for the bed side screening of frontal lobe function. Several studies have indicated that frontal lobe dysfunction is the main neuropsychological feature in Amyotrophic lateral sclerosis (ALS). We examined frontal lobe function in patients with ALS and in age-matched normal subjects by using the FAB. We examined 24 patients with sporadic ALS aged 66.0 +/- 10.1 years, with a mean disease duration of 2.0 +/- 0.7 years, a Mini-Mental State Examination score of > or = 24, a normal self-rating depression score, no dyspnea, and no or only slight disturbances in speech, cutting food, and handling utensils on the ALS Functional Rating Scale. Total FAB score, similarity score, and lexical fluency score were significantly lower in ALS patients. Total FAB score did not correlate with age, disease duration, ALS Functional Rating Scale, spirometry, or blood gas analyses. These results suggest frontal lobe dysfunction in ALS patients.

[A nationwide survey of ALS patients on trachoestomy positive pressure ventilation (TPPV) who developed a totally locked-in state (TLS) in Japan].

We conducted a nationwide survey of ALS patients on tracheostomy positive pressure ventilation (TPPV) who had developed a totally locked-in state (TLS) during the period from August to November 2006, in Japan. TLS occurred in 89 of 709 (13%) ALS patients on TPPV. On the second investigation, 29 of 41 patients with TLS showed complete palsy of more than two voluntary motor systems out of 4 motor systems [respiratory, pontine and medullar (bulbar), limb and external ocular motor systems] successively during a certain six months. The conventional classification of ALS based on the initial symptoms (bulbar, upper limb and lower limb type) was not found to be useful for predicting the onset of TLS. Seventy percent the patients developed TLS within 5 years after the start of TPPV. Thirty-seven (90%) patients finally developed total ophthalmoplegia at the onset of TLS, while one patient eventually developed complete bulbar palsy. One of 11 ALS patients with TLS, whom we experienced at Tokyo Metropolitan Neurological Hospital, also eventually showed complete palsy of the pontine (bulbar) motor system (inability to pull back the jaw). Due to the fact that TLS is a state of complete palsy of the voluntary motor systems for communication, which may occur during the course of ALS in around 15% of patients, further clinical investigation of TLS including cognition is thus considered to be essential for improving the palliative care of ALS patients on TPPV.

Conduction velocities of Adelta-fibers and C-fibers in human peripheral nerves and spinal cord after CO2 laser stimulation.

Conduction velocities (CVs) in two nociceptive afferents were estimated to clarify the mechanism of pain transmission. Late and ultra-late laser evoked potentials (LEPs) were recorded by stimulating Adelta- and C-nociceptive nerve endings at different skin sites (the hand, foot, and skin overlying the 7th cervical and 12th thoracic vertebrae), by which data CVs of the arm (CVA), leg (CVL), and spinothalamic tract (CVSTT) were estimated. In late LEPs, Adelta-CVA and Adelta-CVL respectively were between 6.7 and 23.7 (mean +/- SD, 12.8 +/- 5.2) m/s, and 9.0 and 26.7 (17.2 +/- 5.6) m/s. Adelta-CVSTT was between 4.1 and 22.1 m/s (10.6 +/- 5.8). In ultra-late LEPs, C-CVA and C-CVL respectively varied between 1.0 and 2.1 (mean +/- SD, 1.5 +/- 0.3) m/s, and 1.0 and 1.9 (1.4 +/- 0.2) m/s. C-CVSTT was between 1.0 and 3.9 (1.8 +/- 0.8) m/s. No significant difference was found among CVA, CVL, and CVSTT values calculated from late or ultra-late LEP latencies. Nociceptive signals of the primary Adelta- and C-afferents therefore may be conveyed separately by myelinated (Adelta-) and unmyelinated (C) axons through peripheral nerves and spinal cord.