Makito Hirano

Overlapping demyelinating syndromes and anti–N-methyl-D-aspartate receptor encephalitis.

To report the clinical, radiological, and immunological association of demyelinating disorders with anti–N‐methyl‐D‐aspartate receptor (NMDAR) encephalitis.

VCP gene analyses in Japanese patients with sporadic amyotrophic lateral sclerosis identify a new mutation

Accumulating evidence has proven that mutations in the VCP gene encoding valosin-containing protein (VCP) cause inclusion body myopathy with Paget disease of the bone and frontotemporal dementia. This gene was later found to be causative for amyotrophic lateral sclerosis (ALS), a fatal neurodegenerative disease, occurring typically in elderly persons. We thus sequenced the VCP gene in 75 Japanese patients with sporadic ALS negative for mutations in other genes causative for ALS and found a novel mutation, p.Arg487His, in 1 patient. The newly identified mutant as well as known mutants rendered neuronal cells susceptible to oxidative stress. The presence of the mutation in the Japanese population extends the geographic region for involvement of the VCP gene in sporadic ALS to East Asia.

Rotigotine Transdermal Patch Improves Swallowing in Dysphagic Patients with Parkinson's Disease.

Abnormal swallowing, dysphagia, is a potentially fatal symptom in Parkinson’s disease (PD) and is characterized by frequent silent aspiration, an unrecognized risk of suffocation and aspiration pneumonia. Several studies have reported that the injection of apomorphine, a dopamine agonist, alleviated dysphagia in some patients with PD. The effects of other antiparkinson medications against dysphagia remain controversial. Rotigotine is another dopamine agonist with non-oral administration, i.e., a transdermal patch. Its noninvasiveness seems to render this medicine even more suitable than apomorphine for dysphasic patients. However, no direct evidence has been reported. In the present retrospective open-label study, we for the first time objectively showed that rotigotine improved swallowing on videofluoroscopic examination in dysphagic patients with PD.

Differences in Dysphagia Between Spinocerebellar Ataxia Type 3 and Type 6

Spinocerebellar ataxias (SCAs) are a group of neurodegenerative disorders frequently associated with autosomal dominant inheritance. SCA type 3 (SCA3) and SCA type 6 (SCA6) are the most common forms in Japan as well as the rest of the world. SCA3 affects multiple nervous systems while SCA6 affects mainly the cerebellar system. Dysphagia is clinically important since aspiration pneumonia is the most common cause of death in patients with SCA. We retrospectively studied dysphagia in 7 patients with SCA3 and 13 with SCA6 by videofluoroscopic examination of swallowing (VF). This is a larger series of patients with SCA6 than in previous studies, which had inconsistent results. Dysphagia was evaluated according to the scale established by the Japanese Society of Dysphagia Rehabilitation and the dysphagia outcome severity scale, an internationally used scale. The former separately evaluates oral and pharyngeal phases, while the latter concurrently grades both phases. Dysphagia according to the Japanese scale was mild but statistically significant in SCA6 and severe in SCA3. DOSS indicated abnormalities in SCA3 but not in SCA6. The swallowing abnormalities in SCA3 or SCA6 did not parallel the duration of disease or physical disability, suggesting that even patients with early disease or with well-preserved physical functions were at risk for aspiration. Our patients with dysphagia received percutaneous endoscopic gastrostomy-tube feeding at an appropriate time and underwent rehabilitation of swallowing. No patient had aspiration pneumonia. In conclusion, evaluation of swallowing ability by VF is essential for preventing aspiration in patients with SCA.

Binding specificity of anti-HNK-1 IgM M-protein in anti-MAG neuropathy: Possible clinical relevance

Anti-myelin-associated-glycoprotein (MAG) neuropathy is an intractable autoimmune polyneuropathy. The antigenic region of MAG is the human natural killer-1 (HNK-1) carbohydrate. We and others previously suggested that the extension of antibody reactivities to HNK-1-bearing proteins other than MAG was associated with treatment resistance, without statistical analyses. In this study, we established an ELISA method with recombinant proteins to test binding specificities of currently available monoclonal antibodies to MAG and another HNK-1-bearing protein, phosphacan. Using this system, we found the distinct binding specificities of anti-MAG antibody in 19 patients with anti-MAG neuropathy. Their clinical relevance was then determined retrospectively with the adjusted 10-points INCAT disability score (0 = normal and 10 = highly disable). The results showed that strong reactivities of anti-MAG antibodies to phosphacan were significantly associated with treatment resistance or progressive clinical courses, indicating a possible clinical relevance of the binding specificities.

A Case of Severe Ganciclovir-Induced Encephalopathy

Background: Ganciclovir, a drug against cytomegalovirus (CMV) infection, is generally well tolerated, but can cause neurotoxicity such as encephalopathy. Although ganciclovir-induced encephalopathy has been described in several reports, a literature search revealed that ganciclovir concentrations in the blood or cerebrospinal fluid were previously measured in only 3 patients with encephalopathy. Symptoms usually include confusion and disturbed consciousness, which mimic CMV encephalitis. Prompt and accurate diagnosis is thus sometimes difficult, and is derived solely from accumulated clinical information of definite cases, since ganciclovir concentrations, not routinely measured, become available after several days or a few weeks. Case Presentation: Here, we summarize clinical information of all patients with definite ganciclovir-induced encephalopathy including our own patient, who had severe symptoms, with the highest reported trough concentration of ganciclovir in the blood, and underwent therapeutic dialysis with complete recovery. Conclusion: Our summary of patients with definite encephalopathy could lead to prompt and accurate diagnoses.

Multiple system involvement in a Japanese patient with a V31A mutation in the SOD1 gene.

Abstract The superoxide dismutase-1 (SOD1) gene is the first gene for familial amyotrophic lateral sclerosis (ALS) with autosomal dominant inheritance. We describe a Japanese patient who had slowly progressive motor neuron disease with autonomic and sensory disturbances, urine incontinence and sensory neuropathy. This patient was found to have V31A mutation in the SOD1 gene. Although slow progression has been previously observed in patients with ALS caused by several mutations in the SOD1 gene, symptoms unrelated with motor systems are very rare. In addition, MRI showed cerebellar and brainstem atrophy, a finding previously unreported in SOD1-related ALS. The COQ2 gene, a gene very recently reported to be associated with multiple system atrophy, as well as genes for spinocerebellar ataxias was analyzed, the result of which showed no mutation in this patient. The V31A mutation is thus likely to be associated with atypical ALS affecting multiple systems.

The First Nationwide Survey and Genetic Analyses of Bardet-Biedl Syndrome in Japan

Bardet-Biedl syndrome (BBS) is an autosomal recessive disorder characterized by central obesity, mental impairment, rod-cone dystrophy, polydactyly, hypogonadism in males, and renal abnormalities. The causative genes have been identified as BBS1-19. In Western countries, this disease is often reported, but remains undiagnosed in many patients until later in life, while only a few patients with no mutations identified have been reported in Japan. We thus conducted the first nationwide survey of BBS in Japan by sending questionnaires to 2,166 clinical departments with board-certified specialists and found 7 patients with clinically definite BBS. We performed exome analyses combined with analyses of mRNA and protein in these patients. We identified 2 novel mutations in the BBS5 gene (p.R89X and IVS7-27 T>G) in 2 sibling patients. The latter mutation that resided far from the authentic splicing site was associated with skipping of exon 8. We also found 3 previously reported mutations in the BBS2 (p.R413X and p.R480X) and BBS7 (p.C243Y) genes in 2 patients. To our knowledge, a nationwide survey of BBS has not been reported in any other country. In addition, this is the first study to identify genetic alterations in Japanese patients with BBS. Our results indicate that BBS in Japan is genetically heterogeneous and at least partly shares genetic features with BBS in other countries.

Differential Progression of Dysphagia in Heredity and Sporadic Ataxias Involving Multiple Systems

Sporadic ataxia affecting multiple systems, such as cerebellar, extrapyramidal, and autonomic systems, is known as multiple system atrophy cerebellar type (MSA-C), while similar multisystem involvements are seen in certain types of hereditary ataxia, such as spinocerebellar ataxia type 3 (SCA3). Dysphagia is a common symptom that can predispose to aspiration pneumonia, a major cause of death in patients with these diseases. Although the progressions of dysphagia in patients with MSA-C have been reported sporadically, those in SCA3 have not been reported. We retrospectively compared the results of repetitive videofluoroscopic examinations in patients with SCA3 (n = 6) and in those with MSA-C (n = 7). The result showed that the gross progression of dysphagia was significantly slower in patients with SCA3 than in those with MSA-C, but the maximum progression speeds were not significantly different. The dysphagia severities were not associated with impaired activity of daily living evaluated by the Barthel index in MSA-C, but were associated in SCA3. Despite the small number of patients enrolled, these data suggest that physicians should monitor swallowing functions in patients with SCA3 after mild dysphagia develops because it may progress as rapidly as it does in MSA-C.