Neurogenic intermittent claudication caused by vasculitis in the cauda equina: an autopsy case report.

PURPOSE: Intermittent claudication (IC) refers to leg pain that is induced by walking and relieved by rest. Neurogenic IC is usually associated with lumbar canal stenosis (LCS). We present rare findings from an autopsied patient who had neurogenic IC caused by vasculitis in the cauda equina. METHODS: We performed antemortem neurological and electrophysiological assessments, sural nerve biopsy, and post-mortem examination of the spinal cord and brain. RESULTS: A 61-year-old man noted sudden-onset leg pain that was not associated with any traumatic trigger. His leg pain consistently appeared when the patient walked and quickly faded on stopping. Spine surgery and cardiovascular departments both made a diagnosis of IC. However, magnetic resonance imaging (MRI) did not show LCS, and all ankle-brachial pressure indices were normal. He subsequently developed diffuse muscle weakness of the legs a month after disease onset. Myeloperoxidase antineutrophil cytoplasmic autoantibody was seropositive (140 IU/mL), and a sural nerve biopsy revealed axonal injury and angiitis. MRI showed multiple cerebral infarctions. He was diagnosed with microscopic polyangiitis (MPA) and underwent corticosteroid therapy. He died from complications two months after the onset. A post-mortem study revealed vasculitis in the subarachnoid space of the cauda equina, spinal cord, and brain parenchyma. The cauda equina showed a combined loss of small and large axonal fibres. The lumbar cord displayed central chromatolysis of the lower motor neurons. CONCLUSION: MPA is a rare cause of neurogenic IC when the symptom is acute and multimodal. Small-vessel vasculitis affecting the cauda equina may underlie MPA-associated IC.

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.

Acute Unilateral Isolated Oculomotor Nerve Palsy in an Adult Patient with Influenza A.

An otherwise healthy 44-year-old woman exhibited isolated unilateral oculomotor nerve palsy accompanied by an influenza A infection. An intra-orbital MRI scan revealed that her right third intracranial nerve was enlarged and enhanced. She recovered completely during the first month after treatment with oseltamivir phosphate. Although intracranial nerve disorders that result from influenza infections are most frequently reported in children, it is noteworthy that influenza can also cause focal intracranial nerve inflammation with ophthalmoparesis in adults. These disorders can be diagnosed using intra-orbital MRI scans with appropriate sequences and through immunological assays to detect the presence of antiganglioside antibodies.

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.

Structural MRI correlates of amyotrophic lateral sclerosis progression.

PURPOSE: Amyotrophic lateral sclerosis (ALS) presents with varying degrees of brain degeneration that can extend beyond the corticospinal tract (CST). Furthermore, the clinical course and progression of ALS varies widely. Brain degeneration detected using structural MRI could reflect disease progression. SUBJECTS AND METHODS: On study registration, 3-Tesla volumetric MRI and diffusion tensor imaging scans were obtained at baseline in 38 healthy controls and 67 patients with sporadic ALS. Patients had Amyotrophic Lateral Sclerosis Functional Rating Scale-Revised (ALSFRS-R) scores of ≥36 and did not have the chromosome 9, open reading frame 72 repeat expansion. Six months later, changes in ALSFRS-R (ΔALSFRS-R) scores were calculated and patients were grouped into three categories, namely, patients with slow progression with ΔALSFRS-R scores ≤3 (n=19), intermediate progression with ΔALSFRS-R scores =4, 5 and 6 (n=36) and rapid progression with ΔALSFRS-R scores ≥7 (n=12). We analysed voxel-based morphometry and tract-based spatial statistics among these subgroups and controls. RESULTS: In comparison with controls, patients with ALS showed grey matter atrophy and decreased fractional anisotropy beyond the motor cortex and CST, especially in the frontotemporal lobes and basal ganglia. Moreover, the degree of change was highly proportional to ΔALSFRS-R at the 6-month assessment. CONCLUSION: A more rapid disease progression and poorer functional decline were associated with greater involvement of the extra-motor cortex and basal ganglia, suggesting that the spatial extent of brain involvement can be an indicator of the progression in ALS.

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.

A rapid functional decline type of amyotrophic lateral sclerosis is linked to low expression of TTN.

OBJECTIVE: To classify the patterns of functional decline in patients with sporadic amyotrophic lateral sclerosis (ALS) and explore the genetic backgrounds that modified these patterns. METHODS: We included 465 patients with sporadic ALS in the analysis and clustered the longitudinal functional scores in the registered patients, using a mixture approach of a non-linear mixed-effects model. We conducted a genome-wide analysis of 572 983 single nucleotide polymorphisms (SNPs). We then assessed the association between the clusters of longitudinal functional scores and SNPs. RESULTS: We identified the following four clusters of longitudinal functional decline in the cases: a rapid decline cluster, an intermediate decline cluster, a sigmoidal decline cluster and a moderate decline cluster. We identified seven SNPs associated with the rapid decline cluster, using a recessive model (p=3.47-8.34×10(-8)). The OR for the probabilities of the rapid decline cluster ranged from 5.5 to 5.84. Homozygosity for the minor alleles in the seven SNPs, which constituted a linkage disequilibrium (LD) block, was associated with decreased expression of TTN (encoding Titin, a large sarcomere protein) in the expression quantitative trait loci database of a large-scale Japanese genetic variation database (p=8.6×10(-10)-1.1×10(-7)). TTN expression in immortalised lymphocyte lines was decreased in patients who were homozygous for the minor alleles compared with those who were homozygous for the major alleles (n=19 in each group, p=0.002). CONCLUSIONS: We detected an LD block associated with a rapid functional decline in patients with sporadic ALS, which is linked to decreased expression of TTN.

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.

Distinct phenotypes of speech and voice disorders in Parkinson's disease after subthalamic nucleus deep brain stimulation.

OBJECTIVES: To elucidate the phenotypes and pathophysiology of speech and voice disorders in Parkinson's disease (PD) with subthalamic nucleus deep brain stimulation (STN-DBS). METHODS: We conducted a cross-sectional study on 76 PD patients treated with bilateral STN-DBS (PD-DBS) and 33 medically treated PD patients (PD-Med). Speech and voice functions, electrode positions, motor function and cognitive function were comprehensively assessed. Moreover, speech and voice functions were compared between the on-stimulation and off-stimulation conditions in 42 PD-DBS patients. RESULTS: Speech and voice disorders in PD-DBS patients were significantly worse than those in PD-Med patients. Factor analysis and subsequent cluster analysis classified PD-DBS patients into five clusters: relatively good speech and voice function type, 25%; stuttering type, 24%; breathy voice type, 16%; strained voice type, 18%; and spastic dysarthria type, 17%. STN-DBS ameliorated voice tremor or low volume; however, it deteriorated the overall speech intelligibility in most patients. Breathy voice did not show significant changes and stuttering exhibited slight improvement after stopping stimulation. In contrast, patients with strained voice type or spastic dysarthria type showed a greater improvement after stopping stimulation. Spastic dysarthria type patients showed speech disorders similar to spastic dysarthria, which is associated with bilateral upper motor neuron involvement. Strained voice type and spastic dysarthria type appeared to be related to current diffusion to the corticobulbar fibres. CONCLUSIONS: Stuttering and breathy voice can be aggravated by STN-DBS, but are mainly due to aging or PD itself. Strained voice and spastic dysarthria are considered corticobulbar side effects.

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.

[Japanese Consortium for Amyotrophic Lateral Sclerosis research (JaCALS)].

To investigate the longitudinal course of Japanese patients with amyotrophic lateral sclerosis (ALS), we have designed a multicenter registration and follow-up system called Japanese Consortium for Amyotrophic Lateral Sclerosis research (JaCALS). Genomic DNA samples and B-cell lines from patients with ALS were stored and linked to their clinical information. We designed a telephone survey system involving clinical research coordinators to check the patients' scores on the ALS Functional Rating Scale-revised and their prognoses every 3 months. In February 2006, we began registering patients with ALS. Currently, 30 neurology institutions are participating in the JaCALS, and 905 patients with ALS are registered. The JaCALS has established an efficient registration and follow-up system linking genomic information from patients with ALS. We believe this consortium will contribute to clinical research in ALS.

Potential of a new MRI for visualizing cerebellar involvement in progressive supranuclear palsy.

OBJECTIVES: We assessed the usefulness of differential diagnosis of parkinsonism by evaluating lesions of the decussation of the superior cerebellar peduncle (SCP) in patients with progressive supranuclear palsy (PSP) using a new MRI procedure known as readout segmentation of long variable echo-trains (RESOLVE). METHODS: We evaluated 100 cases, consisting of 20 with PSP, 24 with Parkinson's disease (PD), 13 with multiple system atrophy with predominant parkinsonism (MSA-P), 18 with multiple system atrophy with predominant cerebellar ataxia (MSA-C), and 24 controls. All patients were scored on the Unified Parkinson's Disease Rating Scale Part III and the Scale for the Assessment and Rating Scale of Ataxia, and MRI using RESOLVE was conducted. RESULTS: Images acquired by this MRI procedure clearly showed high intensity areas corresponding to the decussation of the SCP in all controls, PD, and MSA patients. In contrast, ten of the 20 PSP patients exhibited abnormal iso intensities of the decussation of the SCP, while the other 10 showed high intensity signals. Among the PSP patients, there were no differences in clinical features between those with and those without visualization of the decussation of the SCP. Iso intensity signals had a sensitivity of 50% and a specificity of 100% for differentiating PSP from PD, MSA, and controls. CONCLUSION: This MRI procedure (RESOLVE) shows a potential for detecting the involvement of the decussation of the SCP in PSP, and can be used for discriminating PSP from PD and MSA-P.

[Cutting-edge MRI techniques for studying neurological diseases focusing on spinocerebellar degeneration].

This symposium discusses the utility of the different MR techniques in the diagnosis and management of spinocerebellar degeneration (SCD). Conventional MRI is widely used and can show characteristic signal abnormalities such as putaminal hyperintensity, hyperintense putaminal rim, putaminal hypointensity, hot cross bun sign in the pontine base, and hyperintensity in the middle cerebellar peduncles strengthening a diagnosis of multiple system atrophy (MSA). However, the diagnostic utility of these signal abnormalities in early MSA remains restricted. In addition, it should be considered that different magnetic field strengths and sequences could be influenced on the findings resulting false negative. On the other hand, proton magnetic resonance spectroscopy, diffusion weighted imaging (DWI), diffusion tensor imaging (DTI) and voxel based morphometry (VBM) in the pontine base, cerebellum, and putamen will be informative in the early diagnosis of MSA and other SCD prior to conventional MRI changes and even before any clinical manifestation of symptoms. Particularly, DWI, DTI, and VBM are expected to have potential as surrogate markers of disease progression. Further prospective and large studies including earlier disease stages will be needed to clarify whether these novel MR techniques will aid in the future sets of diagnostic criteria and therapeutic trials.

Neck weakness is a potent prognostic factor in sporadic amyotrophic lateral sclerosis patients.

OBJECTIVE: To clarify the emergence of muscle weakness in regions of the body that affect survival, and deterioration in activities of daily living (ADL) in amyotrophic lateral sclerosis (ALS) patients. METHODS: We conducted a multicentre-based prospective cohort study of patients with ALS. We enrolled 401 sporadic patients with ALS. Death or the introduction of invasive ventilation was defined as the primary endpoint, and the time to five clinical markers of ADL deterioration associated with bulbar paralysis or limb weakness were defined as ADL milestones. Muscle weakness was assessed in the neck flexor muscles; the bilateral abductors of the shoulders; the bilateral wrist extensor muscles; the bilateral flexor muscles of the hips; and the bilateral ankle dorsiflexion muscles. We performed Cox proportional hazards regression analyses for the primary endpoint and the five ADL milestones, adjusting for known covariate prognostic factors for ALS. RESULTS: The Medical Research Council (MRC) score for the neck flexors was the most significant prognostic factor for the primary endpoint (HR 0.74, p<0.001), loss of speech (HR 0.66, p<0.001), and loss of swallowing function (HR 0.73, p<0.001), and was one of the significant prognostic factors for loss of upper limb function, difficulty turning in bed, and loss of walking ability (p=0.001, 0.002, and 0.008, respectively). The MRC score for the neck flexors was also a significant prognostic factor for covariates of the previously reported prognostic factors. CONCLUSIONS: Neck weakness is an independent prognostic factor for survival and deterioration in ADL in Patients with ALS.

Analysis of C9orf72 repeat expansion in 563 Japanese patients with amyotrophic lateral sclerosis.

Recently, a hexanucleotide repeat expansion in C9orf72 was identified as the most common cause of both sporadic and familial amyotrophic lateral sclerosis (ALS) and frontotemporal dementia in Western populations. We analyzed 563 Japanese patients with ALS (552 sporadic and 11 familial) using fluorescent fragment-length analysis of C9orf72 and repeat-primed polymerase chain reaction analysis. Haplotype analysis was performed for 42 single nucleotide polymorphisms in patients with C9orf72 repeat expansion. C9orf72 repeat expansion was found in 2 patients with sporadic ALS (2/552 = 0.4%) and no patients with familial ALS (0/11 = 0%). In the probands' families, 1 primary progressive aphasia patient and 1 asymptomatic 76-year-old individual exhibited C9orf72 repeat expansion. All of the patients with the C9orf72 repeat expansion carried the 20-single nucleotide polymorphism consensus risk haplotype. The frequency of the C9orf72 repeat expansion among Japanese patients is much lower than in Western populations. The existence of a 76-year-old asymptomatic carrier supported the notion of incomplete penetrance. The C9orf72 mutation should be analyzed in sporadic ALS patients after determining their family histories not only of frontotemporal dementia but also of primary progressive aphasia.

MRI mean diffusivity detects widespread brain degeneration in multiple sclerosis.

We investigated the magnetic resonance imaging (MRI) findings of 32 multiple sclerosis (MS) patients using voxel-based morphometry (VBM) and voxel-based analysis of white matter fluid-attenuated inversion recovery image (FLAIR) high-intensity lesions and diffusion tensor imaging (DTI). Compared with 18 healthy controls, MS patients showed gray matter volume reduction in the thalamus, hypothalamus, caudate, limbic lobe, and frontal lobe. A marked volume reduction of white matter was evident along the ventriculus lateralis and corpus callosum. FLAIR high-intensity lesions were observed beside the ventriculus lateralis. DTI revealed reduced fractional anisotropy areas similar to those of the FLAIR high-intensity lesions. Changes in the volume of increased mean diffusivity (MD) were the most widespread and extended to normal-appearing white matter (p<0.001). Multiple regression analysis revealed that MD values were significantly correlated with both disease duration (r=0.381, p=0.032) and expanded disability status scale scores (EDSS) (r=0.393, p=0.026). This study demonstrated that combined voxel-based analysis for volumetry, FLAIR high-intensity lesions, and DTI could reveal widespread brain abnormalities in MS patients. Furthermore, DTI, especially MD, showed far more widespread brain degeneration than other MRI parameters, and was significantly correlated with both severity and disease duration.

[JaCALS: a prospective multicenter ALS cohort study].

To investigate the longitudinal course of Japanese patients with Amyotrophic Lateral Sclerosis (ALS), we constructed a multicenter registration and follow-up system called Japanese Consortium for Amyotrophic Lateral Sclerosis research (JaCALS). Genomic DNA samples of ALS patients were stored and linked to the clinical information. We designed a telephone survey system using a clinical research coordinator (CRC) to check the score of the ALS Functional Rating Scale-R (ALSFRS-R) and the prognosis every 3 months. In January 2006, we began registering ALS patients, and, at present, 22 neurology facilities are participating in the JaCALS. Currently, 571 Japanese ALS patients are registered. From the longitudinal data of the 279 patients who were registered before September 2009, the older age at onset was a significant risk factor for not only earlier death or introduction of mechanical ventilation, but also earlier loss of speech, loss of swallowing function and loss of upper limb function. In collaboration with the RIKEN Center for Genomic Medicine, genome-wide association studies (GWAS) using 1,305 ALS samples from the JaCALS and BioBank Japan were conducted, which showed that ZNF512B gene was associated with susceptibility to ALS. The JaCALS has established an efficient registration and follow-up system with genomic DNA resources of ALS patients, and will contribute to identify ALS-associated genes and to promote clinical researches.