[Clinical characteristics of seizure-predominant autoimmune encephalitis and utility of anti-neuronal antibody scores for early treatment]

We analyzed 20 patients diagnosed with autoimmune neurological diseases with seizure predominance. In these patients, we examined the usefulness of Antibody Prevalence in Epilepsy and Encephalopathy (APE2) score and Antibodies Contributing to Focal Epilepsy Signs and Symptoms (ACES) score in autoimmune encephalitis (AE) for facilitating early treatment. APE2 score was positive in 19 of 20 patients. ACES score was positive in 15 of 20 patients, and 4 of 5 of the patients with negative ACES score did not have AE. Comprehensive assessment including the use of the above scores is desirable in the early stage of AE.

The Movement Disorder Society Criteria: Its Clinical Usefulness in Multiple System Atrophy

Objective In 2022, Wenning et al. proposed the Movement Disorder Society Criteria (MDS Criteria) for the Diagnosis of Multiple System Atrophy (MSA). These criteria were expected to provide useful alternatives to the second consensus statement. We examined trends in these diagnostic criteria. Methods We used patient data registered with the Hokkaido Rare Disease Consortium for Multiple System Atrophy, which has been recruiting patients with MSA through medical facilities in Hokkaido since November 2014. Patients were evaluated according to the MDS criteria based on neurological examinations and imaging findings at three separate times: the first evaluation, the time of enrollment (diagnosis), and the most recent evaluation (final evaluation). Results The MDS criteria were examined in 68 of 244 patients enrolled between November 2014 and July 2022. At the initial evaluation, the classifications were as follows: clinically established (n=27; 39.7%); clinically probable (n=13; 19.1%); possible prodromal (n=12; 17.6%); and negative (did not meet criteria (n=16; 23.5%). At the time of diagnosis, the classifications were as follows: clinically established (n=45; 66.2%); clinically probable (n=12; 17.6%); possible prodromal (n=4; 5.9%); and negative (n=7; 10.3%). At the final evaluation, the classifications were as follows: clinically established (n=52; 76.5%); clinically probable (n=9; 13.2%); possible prodromal (n=2; 2.9%); and negative (n=5; 7.4%). Conclusions We were able to clarify the changes in the criteria values and transition of patients due to the clarification of imaging and supportive findings in the MDS criteria.

Transthyretin Variant Amyloidosis with a TTR A97D (p.A117D) Mutation Manifesting Remarkable Asymmetric Neuropathy

We herein report a 68-year-old Japanese man with sporadic variant transthyretin (ATTRv) amyloidosis harboring the novel variant A97D (p.A117D) in TTR. He had slow development of asymmetric neuropathy, unintentional weight loss, mild autonomic failure and mild cardiomyopathy. TTR amyloid deposition on the gastric duodenal mucosa was detected. In silico analyses predicted that TTR A97D (p.A117D) altered the structure and function of the TTR protein. ATTRv amyloidosis is often difficult to diagnose in non-endemic regions due to its diverse phenotypes, such as atypical peripheral nerve involvement and a rare family history.

Anti-signal Recognition Particle Antibody-positive Immune-mediated Myopathy after mRNA-1273 SARS-CoV-2 Vaccination

A 26-year-old Japanese woman developed a fever, myalgia and gait disturbance one day after receiving the second dose of the mRNA-1273 severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine. A neurological examination revealed symmetrical weakness and myalgia in proximal lower limbs, and a blood examination showed prominent elevation of creatinine kinase. Magnetic resonance imaging (MRI) revealed a high signal intensity in the thigh muscles on short-tau inversion recovery images, and antibody testing revealed positive findings for anti-signal recognition particle (SRP) antibody. Thus, anti-SRP antibody-positive immune-mediated myopathy was diagnosed. We initiated immunotherapy, and she was ultimately able to walk stably.

A Case of Cerebral Tuberculoma Diagnosed by Nested Polymerase Chain Reaction of a Formalin-fixed Paraffin-embedded Brain Biopsy Sample

A 38-year-old man was taken to hospital with generalized clonic seizure. Brain magnetic resonance imaging (MRI) showed multiple ring-enhancing lesions centered in the left frontoparietal lobe. A histopathological examination of a brain biopsy sample revealed granulomatous lesions with caseous necrosis. We extracted DNA from a formalin-fixed paraffin-embedded (FFPE) brain specimen, and nested polymerase chain reaction (PCR) of the DNA sample detected the Mycobacterium tuberculosis-specific insertion sequence IS6110. The lesions worsened after anti-tuberculosis drugs were administered, which we considered to be a paradoxical response and continued treatment. A genetic diagnosis of M. tuberculosis using FFPE specimens is useful for diagnosing tuberculoma.

Ubiquitin-dependent rapid degradation conceals a cell-protective function of cytoplasmic SIRT3 against oxidative stress

SIRT3 is an NAD+-dependent protein deacetylase localized in mitochondria. Several studies reported localization of SIRT3 in the cytoplasm or nucleus, but data of these studies were not consistent. We detected expression of mitochondrial (SIRT3mt) and cytoplasmic (SIRT3ct) Sirt3 mRNAs in the mouse brain, and we also found SIRT3 immunostaining of mitochondria and cytoplasm in the brain and cultured neural cells. However, expression levels of SIRT3ct in COS cells transfected with SIRT3ct cDNA were much lower than those of SIRT3mt. We found that SIRT3ct but not SIRT3mt was promptly degraded by ubiquitin-dependent degradation, in which SIRT3ct degradation was mediated mainly by ubiquitination of NH2-terminal methionine and partly by that of lysine residues of SIRT3ct. SIRT3ct expression level was significantly enhanced by treatment of cells with staurosporine or H2O2. H2O2 treatment promoted nuclear translocation of SIRT3ct and induced histone H3 deacetylation and superoxide dismutase 2 expression. Overexpression of SIRT3ct decreased cell death caused by H2O2 at levels similar to those achieved by overexpression of SIRT3mt. Knockdown of Sirt3 mRNA increased cell death caused by amyloid-β (Aβ), and overexpression of SIRT3ct suppressed the toxic function of Aβ in PC12 cells. These results indicate that SIRT3ct promotes cell survival under physiological and pathological conditions.

Abrupt Onset of Cardiac Tamponade in Sarcoidosis

Sarcoidosis is a systemic inflammatory disease characterized by the formation of noncaseating epithelioid granulomas. Multiple organs, including the lung, eyes, and skin, are involved in this disorder, and cardiac involvement is a major cause of morbidity and mortality in patients with this disorder. We present the case history of a 22-year-old man with neurosarcoidosis complicated by abrupt onset of cardiac tamponade. Cardiac tamponade is a rare but potentially fatal manifestation of sarcoidosis, which is treatable with glucocorticoid therapy. Including the present case, previously reported cases of sarcoidosis with cardiac tamponade are reviewed to delineate its clinical characteristics.

Sporadic Amyotrophic Lateral Sclerosis Due to a FUS P525L Mutation with Asymmetric Muscle Weakness and Anti-ganglioside Antibodies

Amyotrophic lateral sclerosis (ALS) due to a fused in sarcoma (FUS) P525L mutation is characterized by a rapidly progressive course. Multifocal motor neuropathy (MMN) may resemble ALS in early stage and is associated with anti-ganglioside antibodies. A 38-year-old woman was admitted to our hospital because of progressive muscle weakness in the right limbs. She had mild mental retardation and minor deformities. Initially, we suspected MMN given the asymmetric muscle weakness and detection of anti-ganglioside antibodies. However, physical and electrophysiological tests did not support MMN, instead suggesting ALS. We confirmed a heterozygous P525L mutation and finally diagnosed this case as ALS due to an FUS mutation.

[A case of Charcot-Marie-Tooth disease type 2Z caused by MORC2 S87L mutation mimicking spinal muscular atrophy]

A 33-year-old man with an unremarkable family history has had limb muscle weakness, joint contracture and skeleton deformation from early childhood. He was diagnosed with spinal muscular atrophy (SMA) by a pediatrician. He needed assistance and used orthoses in his daily life. There was no subjective sensory disturbance. However, physical examination showed slight sensory impairment, and nerve conduction study indicated sensory motor axonal neuropathy. This finding suggested Charcot-Marie-Tooth disease (CMT). Gene analysis detected MORC2 S87L mutation, leading to a diagnosis of CMT type 2Z. Patients with MORC2 S87L mutation are known to exhibit a severe phenotype, and may mimic SMA. It is important to demonstrate subclinical sensory neuropathy in patients with MORC2 S87L mutation mimicking SMA.

[A case of facial-onset sensory and motor neuronopathy (FOSMN) with cerebellar ataxia and abnormal decrement in repetitive nerve stimulation test]

A 59-year-old woman presented with a 7-year history of facial numbness on the left side, and gradual worsening of symptoms. Over several years, facial muscle weakness, dysarthria, tongue atrophy and fasciculation had progressed. Then, she developed cerebellar ataxia affecting the left extremities, in addition to earlier symptoms. Brain MRI revealed cerebellar atrophy, and ^99mTc-SPECT depicted cerebellar hypoperfusion. A repetitive nerve stimulation test (RNS) indicated abnormal decrement in the nasalis and trapezius muscles on the left side. Facial-onset sensory and motor neuronopathy (FOSMN) was diagnosed. Administration of intravenous immunoglobulin resulted in improvement of some symptoms. Although cerebellar ataxia is not a common symptom of FOSMN, a case showing TDP-43-positive glial cytoplasmic inclusions in cerebellar white matter has been reported. Therefore, it is possible that FOSMN may cause cerebellum impairment in some patients. Furthermore, RNS positive rate in the trapezius muscle is known to be high in amyotrophic lateral sclerosis (ALS) patients. It is speculated that RNS of the affected muscles in FOSMN may show abnormal decrement by the same mechanisms as ALS.

SIRT1 decelerates morphological processing of oligodendrocyte cell lines and regulates the expression of cytoskeleton-related oligodendrocyte proteins

SIRT1 is involved in the regulation of a variety of biological processes such as metabolism, stress response, autophagy and differentiation. Although progenitor cells of oligodendrocytes (OPCs) express high level of SIRT1, its function on differentiation is unknown. Because we have shown that SIRT1 plays a pivotal role in differentiation of neural precursor cells, we hypothesized that SIRT1 may also participate in the differentiation of oligodendrocytes (OLGs). We examined whether SIRT1 was expressed in two human oligodendrocyte cell lines: KG-1-C and MO 3.13 OLG. Transfection of cell lines with SIRT1-siRNA and SIRT2-siRNA promoted the extension of cellular processes. SIRT1-siRNA and SIRT2-siRNA increased acetyl-α-tubulin level, conversely, over expression of SIRTs resulted in decreased the ratio of acetyl-α-tubulin to α-tubulin. We also found knockdown of SIRT1 and SIRT2 induced overexpression of βIV-tubulin and tubulin polymerization promoting protein (TPPP) (OLG-specific cytoskeleton-related molecules) that distributed widely in cell bodies. Taken together, SIRT1 may play a role in oligodenroglial differentiation and myelinogenesis.

Transplantation of Mesenchymal Stem Cells Improves Amyloid-β Pathology by Modifying Microglial Function and Suppressing Oxidative Stress

Mesenchymal stem cells (MSC) are increasingly being studied as a source of cell therapy for neurodegenerative diseases, and several groups have reported their beneficial effects on Alzheimer’s disease (AD). In this study using AD model mice (APdE9), we found that transplantation of MSC via the tail vein improved spatial memory in the Morris water maze test. Using electron paramagnetic resonance imaging to evaluate the in vivo redox state of the brain, we found that MSC transplantation suppressed oxidative stress in AD model mice. To elucidate how MSC treatment ameliorates oxidative stress, we focused on amyloid-β (Aβ) pathology and microglial function. MSC transplantation reduced Aβ deposition in the cortex and hippocampus. Transplantation of MSC also decreased Iba1-positive area in the cortex and reduced activated ameboid shaped microglia. On the other hand, MSC transplantation accelerated accumulation of microglia around Aβ deposits and prompted microglial Aβ uptake and clearance as shown by higher frequency of Aβ-containing microglia. MSC transplantation also increased CD14-positive microglia in vivo, which play a critical role in Aβ uptake. To confirm the effects of MSC on microglia, we co-cultured the mouse microglial cell line MG6 with MSC. Co-culture with MSC enhanced Aβ uptake by MG6 cells accompanied by upregulation of CD14 expression. Additionally, co-culture of MG6 cells with MSC induced microglial phenotype switching from M1 to M2 and suppressed production of proinflammatory cytokines. These data indicate that MSC treatment has the potential to ameliorate oxidative stress through modification of microglial functions, thereby improving Aβ pathology in AD model mice.

Hyperemesis-induced Wernicke-Korsakoff Syndrome due to Hypergastrinemia during Long-term Treatment with Proton Pump Inhibitors

We herein report a patient with Wernicke-Korsakoff syndrome (WKS) who had neither a history of alcoholism or of history of gastric surgery. A 56-year-old woman was transferred to our hospital because of the loss of consciousness and she was diagnosed to have Wernicke encephalopathy. She showed proton pump inhibitor-induced refractory hypergastrinemia with the subsequent development of hyperemesis and a vitamin B1 deficiency.

Evaluation of Mitochondrial Oxidative Stress in the Brain of a Transgenic Mouse Model of Alzheimer's Disease by in vitro Electron Paramagnetic Resonance Spectroscopy

Alzheimer's disease (AD) is one of the most common neurodegenerative diseases responsible for progressive dementia. Deposition of amyloid-β (Aβ) in the brain is the most important pathophysiological hallmark of AD. In addition, recent evidence indicates that reactive oxygen species (ROS) derived from mitochondria contribute to progression of AD pathology. We thus hypothesized that Aβ accumulates and oxidative stress increases in the brain mitochondria of a transgenic mouse model of AD (APdE9). We measured the quantity of Aβ and the activity of the antioxidant enzyme superoxide dismutase (SOD) in brain mitochondrial fractions prepared from APdE9 and wild-type (WT) mice aged 6, 9, 15, and 18 months. We also quantified the age-related changes in redox status in the mitochondrial fractions obtained from both APdE9 and WT mouse brains by electron paramagnetic resonance (EPR) spectrometry using a paramagnetic nitroxide "Mito-Tempo" [(2-(2,2,6,6-Tetramethylpiperidin-1-oxyl-4-ylamino)-2-oxoethyl) triphenylphosphonium chloride monohydrate] as a mitochondria-targeted redox-sensitive probe. In APdE9 mice, Aβ accumulated in brain mitochondria earlier than in the non-mitochondrial fraction of the brain. Furthermore, increased oxidative stress was demonstrated in brain mitochondria of APdE9 mice by in vitro SOD assay as well as EPR spectroscopy. EPR combined with a mitochondria-targeted redox-sensitive nitroxide probe is a potentially powerful tool to elucidate the etiology of AD and facilitate the development of new therapeutic strategies for AD.

Severe Mononeuritis Multiplex due to Rheumatoid Vasculitis in Rheumatoid Arthritis in Sustained Clinical Remission for Decades

Rheumatoid vasculitis (RV) usually occurs in patients with refractory rheumatoid arthritis (RA). An 80-year-old woman was transferred to our hospital because of muscle weakness and paresthesia in all 4 limbs. She had been diagnosed with RA 30 years ago and achieved sustained clinical remission. At presentation, polyarthritis and drop foot were observed, and rheumatoid factor was prominently elevated. A peripheral nerve conduction test revealed mononeuritis multiplex in her limbs. We suspected that RV had developed rapidly despite RA having been stable for many years and started immunosuppression therapy with steroids combined with azathioprine. The treatment prevented worsening of muscle weakness and paresthesia.

Early administration of galantamine from preplaque phase suppresses oxidative stress and improves cognitive behavior in APPswe/PS1dE9 mouse model of Alzheimer's disease

Alzheimer's disease (AD) is a common neurodegenerative disease that progressively impairs memory and cognition. Deposition of amyloid-β (Aβ) peptides is the most important pathophysiological hallmark of AD. Oxidative stress induced by generation of reactive oxygen species (ROS) is a prominent phenomenon in AD and known to occur early in the course of AD. Several reports suggest a relationship between change in redox status and AD pathology including progressive Aβ deposition, glial cell activation, and inflammation. Galantamine is an acetylcholinesterase inhibitor and has been reported to have an oxidative stress inhibitory function. In the present study, galantamine was administered orally to AD model mice from before the appearance of Aβ plaques (preplaque phase), and in vivo change in redox status of the brain was measured using electron paramagnetic resonance (EPR) imaging. Administration of galantamine from the preplaque phase ameliorated memory decline in Morris water maze test and novel object recognition test. Monitoring of the redox status of the brain using EPR imaging showed that galantamine treatment improved the unbalanced redox state. Additionally, galantamine administration enhanced microglial function to promote Aβ clearance, reducing the Aβ-positive area in the cortex and amount of insoluble Aβ in the brain. In contrast, galantamine treatment from the preplaque phase suppressed the production of proinflammatory cytokines through neurotoxic microglial activity. Therefore, galantamine administration from the preplaque phase may have the potential of clinical application for the prevention of AD. In addition, our results demonstrate the usefulness of EPR imaging for speedy and quantitative evaluation of the efficacy of disease-modifying drugs for AD.

[Sporadic adult-onset neuronal intranuclear inclusion disease with abnormal electroretinogram, nerve conduction studies and somatosensory evoked potential]

A 70-year-old man, a urinary retention of unknown origin from 10 years ago, decreased cognitive function from 4 years ago, vision impairment advanced a year ago. Brain MRI with DWI showed high intensity erea in the cortico-medullary junction. We diagnosed as intranuclear inclusion body disease (NIID) because of p62-positive intranuclear inclusion bodies by skin biopsy. Electroretinogram revealed amplitude reduction in the cone response superiority. Nerve conduction test showed mild conduction velocity reduction. Furthermore, in the somatosensory evoked potential of the lower limb, latency of the first cortical component was prolonged. These electrophysiological abnormalities were considered to be associated with the pathological features of NIID.

Role of Suppressor of Cytokine Signaling 3 (SOCS3) in Altering Activated Microglia Phenotype in APPswe/PS1dE9 Mice

In response to changes of the central nervous system environment, microglia are capable of acquiring diverse phenotypes for cytotoxic or immune regulation and resolution of injury. Alzheimer's disease (AD) pathology also induces several microglial activations, resulting in production of pro-inflammatory cytokines and reactive oxygen species or clearance of amyloid-β (Aβ) through phagocytosis. We previously demonstrated that microglial activation and increase in oxidative stress started from the middle age in APPswe/PS1dE9 mice, and hypothesized that M1 activation occurs in middle-aged AD mice by Aβ stimulation. In the present study, we analyzed in vivo expressions of pro-inflammatory cytokines (M1 microglial markers), M2 microglial markers, and suppressor of cytokine signaling (SOCS) family, and examined the microglial phenotypic profile in APPswe/PS1dE9 mice. Then we compared the in vitro gene expression patterns of Aβ- and lipopolysaccharide (LPS)-stimulated primary-cultured microglia. Microglia in APPswe/PS1dE9 mice exhibited an M1-like phenotype, expressing tumor necrosis factor α (TNFα) but not interleukin 6 (IL6). Aβ-stimulated primary-cultured microglia also expressed TNFα but not IL6, whereas LPS-stimulated primary-cultured microglia expressed both pro-inflammatory cytokines. Furthermore, both microglia in APPswe/PS1dE9 mice and Aβ-stimulated primary-cultured microglia expressed SOCS3. Reduction of SOCS3 expression in Aβ-challenged primary-cultured microglia resulted in upregulation of IL6 expression. Our findings indicate that SOCS3 suppresses complete polarization to M1 phenotype through blocking IL6 production, and Aβ-challenged primary-cultured microglia replicate the in vivo gene expression pattern of microglia in APPswe/PS1dE9 mice. Aβ may induce the M1-like phenotype through blocking of IL6 by SOCS3.

Latitude and HLA-DRB1*04:05 independently influence disease severity in Japanese multiple sclerosis: a cross-sectional study

Background

Higher latitude and human leukocyte antigen (HLA)-DRB1*04:05 increase susceptibility to multiple sclerosis (MS) in the Japanese population, but their effects on disease severity are unknown. We aimed to clarify the effects of latitude and the HLA-DRB1 and HLA-DPB1 genes on disease severity in Japanese patients with MS.

Methods

We enrolled 247 MS patients and 159 healthy controls (HCs) from the northernmost main island of Japan, Hokkaido Island (42–45° north), and 187 MS patients and 235 HCs from the southern half (33–35° north) of the Japanese archipelago (33–45° north). We genotyped HLA-DRB1 and HLA-DPB1 alleles, compared demographic features, and analyzed factors contributing to differences in clinical and laboratory findings between MS patients from southern and northern Japan. The Multiple Sclerosis Severity Score (MSSS), which adjusts the Kurtzke’s Expanded Disability Status Scale score according to disease duration, was used to estimate disease severity.

Results

The HLA-DRB1*04:05 and DRB1*15:01 alleles conferred susceptibility to MS in our Japanese population (p^corr = 0.0004 and p^corr = 0.0019, respectively). Southern patients had higher MSSS scores than northern patients (p = 0.003). Northern patients had higher frequencies of brain lesions meeting the Barkhof criteria (Barkhof brain lesions) and cerebrospinal fluid (CSF) IgG abnormalities than southern patients (p = 0.0012 and p < 0.0001, respectively). DRB1*04:05-positive MS patients had lower MSSS scores and lower frequencies of Barkhof brain lesions and CSF IgG abnormalities than DRB1*04:05-negative MS patients (p = 0.0415, p = 0.0026, and p < 0.0001, respectively). Multivariate analyses revealed that latitude and DRB1*04:05 were independently associated with the lowest quartile of MSSS and that latitude was positively associated with Barkhof brain lesions and CSF IgG abnormalities. DRB1*04:05 was negatively associated with these parameters. MSSS was decreased by 0.57 per DRB1*04:05 allele (p = 0.0198).

Conclusions

Living at a higher latitude and carrying the DRB1*04:05 allele independently lessens MS symptom severity as defined by MSSS. However, these factors influence the frequency of Barkhof brain lesions and CSF IgG abnormalities in opposite ways; higher latitude increases the frequency of Barkhof brain lesions and CSF IgG abnormalities, whereas DRB1*04:05 decreases them.

Electronic supplementary material

The online version of this article (doi:10.1186/s12974-016-0695-3) contains supplementary material, which is available to authorized users.

Impaired post-tetanic potentiation of muscle twitch in myasthenia gravis

OBJECTIVE

The aim of this study was to evaluate post-tetanic potentiation of muscle twitch in myasthenia gravis (MG).

METHODS

Post-tetanic potentiation was evaluated by recording the compound muscle action potential (CMAP) of abductor pollicis brevis and movement-related potential (MRP) of the thumb using an accelerometer after tetanic stimulation of the median nerve at the wrist. After baseline recording, tetanic stimulation was delivered to the median nerve at a frequency of 10 Hz for 10s. The CMAP and MRP were successively recorded at baseline and at 5, 10, 30, 60, 90 and 120 s after tetanic stimulation. The chronological changes of CMAPs and MRPs were recorded bilaterally in 11 patients with MG, 9 patients with myopathies (disease controls), and 25 healthy control subjects.

RESULTS

Maximal acceleration of MRP was significantly elevated during 10s after tetanic stimulation without any CMAP changes in all groups. However, statistical analysis detected a significant decrease in post-tetanic potentiation of maximal acceleration of MRP in MG patients only compared to healthy controls, but not in myopathy patients, which may imply impairment of excitation-contraction coupling in MG.

CONCLUSIONS

Post-tetanic potentiation of muscle twitch is significantly diminished in MG, suggesting impaired excitation-contraction coupling.

SIGNIFICANCE

Measurement of post-tetanic potentiation using an accelerometer is a simple and sensitive method to detect impairment of excitation-contraction coupling in MG.

Evaluation of oxidative stress in the brain of a transgenic mouse model of Alzheimer disease by in vivo electron paramagnetic resonance imaging

Alzheimer disease (AD) is a neurodegenerative disease clinically characterized by progressive cognitive dysfunction. Deposition of amyloid-β (Aβ) peptides is the most important pathophysiological hallmark of AD. Oxidative stress induced by reactive oxygen species is prominent in AD, and several reports suggest the relationship between a change in redox status and AD pathology containing progressive Aβ deposition, the activation of glial cells, and mitochondrial dysfunction. Therefore, we performed immunohistochemical analysis using a transgenic mouse model of AD (APdE9) and evaluated the activity of superoxide dismutase in brain tissue homogenates of APdE9 mice in vitro. Together with those analyses, in vivo changes in redox status with age in both wild-type (WT) and APdE9 mouse brains were measured noninvasively by three-dimensional electron paramagnetic resonance (EPR) imaging using nitroxide (3-methoxycarbonyl-2,2,5,5-tetramethylpyrrolidine-1-yloxy) as a redox-sensitive probe. Both methods found similar changes in redox status with age, and in particular a significant change in redox status in the hippocampus was observed noninvasively by EPR imaging between APdE9 mice and age-matched WT mice from 9 to 18 months of age. EPR imaging clearly visualized the accelerated change in redox status of APdE9 mouse brain compared with WT. The evaluation of the redox status in the brain of AD model rodents by EPR imaging should be useful for diagnostic study of AD.

A novel lamin A/C gene mutation causing spinal muscular atrophy phenotype with cardiac involvement: report of one case

BACKGROUND

Mutations of the lamin A/C gene have been associated with several diseases such as Emery-Dreifuss muscular dystrophy, dilated cardiomyopathy and Charcot-Marie-Tooth disease, referred to as laminopathies. Only one report of spinal muscular atrophy and cardiomyopathy phenotype with lamin A/C gene mutations has been published. The concept that lamin A/C gene mutations cause spinal muscular atrophy has not been established.

CASE PRESENTATION

We report a man aged 65 years who presented with amyotrophy of lower limbs, arrhythmia and cardiac hypofunction. He showed gait disturbance since childhood, and his family showed similar symptoms. Neurological and electrophysiological findings suggested spinal muscular atrophy type 3. Gene analysis of lamin A/C gene showed a novel nonsense mutation p.Q353X (c.1057C > T). Further investigations revealed that he and his family members had cardiac diseases including atrioventricular block.

CONCLUSIONS

We report the first Japanese case of spinal muscular atrophy phenotype associated with lamin A/C mutation. When a patient presents a spinal muscular atrophy phenotype and unexplained cardiac disease, especially when the family history is positive, gene analysis of lamin A/C gene should be considered.

Latitude and HLA-DRB1 alleles independently affect the emergence of cerebrospinal fluid IgG abnormality in multiple sclerosis

BACKGROUND

It is unclear whether the prevalence of oligoclonal IgG bands (OCBs) in multiple sclerosis (MS) is different between northern and southern regions of Asia.

OBJECTIVE

This study aimed to compare the prevalence of OCBs and positive cerebrospinal fluid (CSF) findings between northern and southern regions of Japan and to investigate the association of these CSF findings with HLA-DRB1 alleles.

METHODS

The study included 180 MS patients from Hokkaido (northern Japan) and 184 patients from Kyushu (southern Japan). The IgG index was defined as increased if it was >0.658. Presence of CSF OCBs and/or increased IgG index was defined as positive CSF findings.

RESULTS

Positive CSF findings and OCB positivity were significantly higher in MS patients from Hokkaido than in those from Kyushu (p < 0.0001 for both). Logistic regression analysis revealed that after adjusting for covariates that can be related to abnormal CSF IgG production, the geographic region (Hokkaido) showed odds ratios (ORs) of 4.08 and 2.57, whereas the HLA-DRB1*04:05 allele showed ORs of 0.36 and 0.30 for positive CSF findings and OCB positivity, respectively.

CONCLUSIONS

The results indicate that latitude and HLA-DRB1 alleles independently affect the emergence of CSF IgG abnormalities in Japanese patients with MS.

[Treatment outcome of patients with cranial base lesions of unknown etiology: focusing on infectious cases with multiple cranial nerve disorders]

Involvement of cranial nerves caused by cranial base lesions manifests diverse symptoms according to the localization of lesions. These localization-related symptoms are classified into syndromes such as orbital apex syndrome, cavernous sinus syndrome, and jugular foramen syndrome. Since the lesions may have various etiologies including infection, inflammation and tumor, etiological diagnosis should be performed simultaneously if possible. However, previous reports have described poor and/or fatal outcome following inappropriate treatment mainly due to difficulties in making a definitive pathological diagnosis. Nineteen patients with multiple cranial nerve involvement caused by skull base lesions were enrolled over the past 12 years. The patients were divided into an "infectious" group (n=11) and a "noninfectious" group (n=8) based on the final diagnosis. Chi-square analysis was conducted to examine the sensitivity and specificity of various factors including patient characteristics, clinical course and treatment response in infectious and noninfectious groups. Consequently, we identified some patients with good outcome irrespective of infectious or noninfectious etiology, even though a pathological diagnosis was not reached before the initial treatment. These patients with good outcome consistently received antifungal therapy in the early stage if infectious etiologies were suspected. We recommend conducting diagnostic therapy with antifungal drugs in patients with skull base lesions of unknown origin although infection cannot be excluded, when a pathological diagnosis is difficult due to various patient conditions.

Early effect of tacrolimus in improving excitation-contraction coupling in myasthenia gravis

OBJECTIVES

Tacrolimus (FK506) is a macrolide T-cell immunomodulator used to treat myasthenia gravis (MG). Besides immunosuppression, tacrolimus has been reported to have the potential to increase muscle strength by enhancing ryanodine receptor (RyR) function. However, few attempts have been made to demonstrate the early effect of tacrolimus as an RyR enhancer in clinical investigation.

METHODS

In 20 MG patients, masseteric compound muscle action potential (CMAP) and mandibular movement-related potentials (MRPs) were recorded simultaneously after stimulating the trigeminal motor nerve with a needle electrode. The excitation-contraction (E-C) coupling time (ECCT) was calculated by the latency difference between CMAP and MRP. Bite force was measured using a pressure-sensitive sheet. Serial assessments of % decrement in masseteric repetitive nerve stimulation (RNS), ECCT and bite force were performed before and within 4 weeks of tacrolimus (3 mg day(-1)) treatment. The median (mean, range) interval of assessment was 2 (2.4, 1-4) weeks. We also measured serum antibodies against RyR, acetylcholine receptor and muscle-specific receptor tyrosine kinase.

RESULTS

Bite force increased after tacrolimus treatment accompanying clinical improvement assessed by Myasthenia Gravis Foundation of America classification, but the bite force difference did not reach statistical significance. Wilcoxon matched-pairs signed-ranks test detected a significant ECCT shortening in 12 patients assessed after 1-2 weeks of tacrolimus treatment as well as in eight patients assessed after 3-4 weeks. In contrast, masseteric CMAP and % decrement showed no significant changes after short-term tacrolimus treatment.

CONCLUSIONS

Tacrolimus induces ECCT shortening accompanying clinical improvement despite no improvement in % decrement within 2 weeks.

SIGNIFICANCE

This early effect of tacrolimus may imply a pharmacological enhancement of RyR function to improve E-C coupling in MG.

The spectrum of clinicopathological features in pure autonomic neuropathy

We assessed the clinicopathological features of nine patients with pure autonomic neuropathy, that is, neuropathy without sensory or motor deficits. The duration from symptom onset to diagnosis ranged from 1 month to 13 years. Of eight patients in whom serum antiganglionic acetylcholine receptor antibody was determined, four were positive. All patients who tested positive for this antibody manifested widespread autonomic dysfunction, with the exception of one patient who only experienced orthostatic hypotension. However, patients who were negative for the antiganglionic acetylcholine receptor antibody presented with partial autonomic failure. One of these patients had diffuse parasympathetic failure and generalized hypohidrosis but no orthostatic hypotension, which is clinically compatible with postganglionic cholinergic dysautonomia. Electron microscopic examination revealed a variable degree of reduction in unmyelinated fibers. Compared with normal controls, the patients had a significantly increased density of collagen pockets (p < 0.05). Additionally, the percentage of Schwann cell subunits with axons (out of the total number of Schwann cell subunits associated with unmyelinated fibers) was significantly decreased (p < 0.01). The density of unmyelinated fibers tended to decrease with increasing time between the onset of autonomic symptoms and biopsy (p < 0.05). In conclusion, the clinical and pathological features of pure autonomic neuropathy vary in terms of progression, autonomic involvement, presence of the antiganglionic acetylcholine receptor antibody, and loss of unmyelinated fibers.

Relationship between dysphagia and depressive states in patients with Parkinson's disease

Aspiration pneumonia related to dysphagia is known to be the leading cause of death in patients with Parkinson's disease (PD). We investigated the relationship between depressive states and dysphagia in patients with PD. A hundred and twenty-seven PD patients gave their informed consent and were enrolled in this study. We used the Beck Depression Inventory (BDI) questionnaire to determine the participants' depressive states, and also used a questionnaire to assess participants' state of dysphagia. Participants were divided into four groups according to their BDI score. We compared the PD patients with Swallowing Disturbances Questionnaire (SDQ) scores of more than or equal to 11 with the SDQ scores of less than 11 regarding depressive categories. A logistic regression analysis was conducted to calculate odds ratios (ORs) and their 95% confidence intervals (95%CI) adjusting for age, sex, disease duration, wearing-off phenomenon and severity of movement disorder. OR (95%CI) of depressive categories, in which the trivial class was set as a reference group, were 3.28 (0.93-11.55), 13.44 (3.10-58.16), 30.35 (5.65-162.97) in the mild class, the moderate class and the severe class, respectively. This study suggests that there may be a strong relationship between depressive states and dysphagia in patients with PD.

Toxin-induced and genetic animal models of Parkinson's disease

Parkinson's disease (PD) is a common progressive neurodegenerative disorder. The major pathological hallmarks of PD are the selective loss of nigrostriatal dopaminergic neurons and the presence of intraneuronal aggregates termed Lewy bodies (LBs), but the pathophysiological mechanisms are not fully understood. Epidemiologically, environmental neurotoxins such as pesticides are promising candidates for causative factors of PD. Oxidative stress and mitochondrial dysfunction induced by these toxins could contribute to the progression of PD. While most cases of PD are sporadic, specific mutations in genes that cause familial forms of PD have led to provide new insights into its pathogenesis. This paper focuses on animal models of both toxin-induced and genetically determined PD that have provided significant insight for understanding this disease. We also discuss the validity, benefits, and limitations of representative models.

Induction of manganese superoxide dismutase by nuclear translocation and activation of SIRT1 promotes cell survival in chronic heart failure

Oxidative stress plays a pivotal role in chronic heart failure. SIRT1, an NAD(+)-dependent histone/protein deacetylase, promotes cell survival under oxidative stress when it is expressed in the nucleus. However, adult cardiomyocytes predominantly express SIRT1 in the cytoplasm, and its function has not been elucidated. The purpose of this study was to investigate the functional role of SIRT1 in the heart and the potential use of SIRT1 in therapy for heart failure. We investigated the subcellular localization of SIRT1 in cardiomyocytes and its impact on cell survival. SIRT1 accumulated in the nucleus of cardiomyocytes in the failing hearts of TO-2 hamsters, postmyocardial infarction rats, and a dilated cardiomyopathy patient but not in control healthy hearts. Nuclear but not cytoplasmic SIRT1-induced manganese superoxide dismutase (Mn-SOD), which was further enhanced by resveratrol, and increased the resistance of C2C12 myoblasts to oxidative stress. Resveratrol's enhancement of Mn-SOD levels depended on the level of nuclear SIRT1, and it suppressed the cell death induced by antimycin A or angiotensin II. The cell-protective effects of nuclear SIRT1 or resveratrol were canceled by the Mn-SOD small interfering RNA or SIRT1 small interfering RNA. The oral administration of resveratrol to TO-2 hamsters increased Mn-SOD levels in cardiomyocytes, suppressed fibrosis, preserved cardiac function, and significantly improved survival. Thus, Mn-SOD induced by resveratrol via nuclear SIRT1 reduced oxidative stress and participated in cardiomyocyte protection. SIRT1 activators such as resveratrol could be novel therapeutic tools for the treatment of chronic heart failure.

Response of serum carboxylated and undercarboxylated osteocalcin to risedronate monotherapy and combined therapy with vitamin K(2) in corticosteroid-treated patients: a pilot study

OBJECTIVE

The aim of this study was to investigate the responses of serum osteocalcin (OC), undercarboxylated osteocalcin (ucOC) and N-terminal telopeptide of type I collagen (NTx) to corticosteroids, and to examine the effects of risedronate therapy with or without vitamin K(2) supplementation on bone metabolic markers in corticosteroid-treated patients.

METHODS

Sixteen patients on corticosteroid therapy for neuromuscular disorders were assigned randomly to 2 groups (A: risedronate monotherapy, n=8; B: combined risedronate and vitamin K(2) therapy, n=8) and treated for 1 year. Another 6 patients who received intravenous steroid pulse therapy were assigned to group C for investigation of the effects of corticosteroids on OC and ucOC 1 month after pulse therapy.

RESULTS

Serial measurements revealed that significant decreases of OC, ucOC and NTx persisted with a similar time course profile during 1 year of treatment in groups A and B, and between-group analysis failed to demonstrate any additional effects of vitamin K(2) on risedronate therapy. Intravenous steroid pulse therapy induced a transient depression of OC and ucOC within 1 week in group C.

CONCLUSION

These results indicate that serum concentrations of OC and ucOC become consistently low during corticosteroid administration despite risedronate therapy with or without vitamin K(2) supplementation, and the serum ucOC level may not be a reliable indicator of vitamin K status under corticosteroid administration.

Transcriptional activation of NAD+-dependent protein deacetylase SIRT1 by nuclear receptor TLX

An orphan nuclear receptor TLX is a transcriptional repressor that promotes the proliferation and self-renewal of neural precursor cells (NPCs). SIRT1, an NAD(+)-dependent protein deacetylase, is highly expressed in the NPCs and participates in neurogenesis. Here, we found that TLX colocalized with SIRT1 and knockdown of TLX by small interfering RNAs decreased SIRT1 levels in NPCs. TLX increased the SIRT1 expression by binding to the newly identified TLX-activating element in the SIRT1 gene promoter in HEK293 cells. Thus, TLX is an inducer of SIRT1 and may contribute to neurogenesis both as a transactivator and as a repressor.

Thyrotoxic myopathy mimicking myasthenic syndrome associated with thymic hyperplasia

A 41-year-old man with progressive limb weakness manifested fluctuating muscle weakness as seen in myasthenia gravis (MG). Laboratory investigations revealed hyperthyroidism without the complication of MG. Electrophysiological studies demonstrated abnormal features of neuromuscular transmissions resembling those of the Lambert-Eaton myasthenic syndrome rather than those of MG. A CT scan showed a mediastinal mass that suggested thymic hyperplasia which often complicates MG or hyperthyroidism. Medical treatment of hyperthyroidism resulted in resolution of MG-like symptoms and regression of thymic hyperplasia on CT concomitant with normalization of thyroid function. This case highlights the fact that careful investigations are needed to differentiate MG-like symptoms from genuine MG in cases of hyperthyroidism with thymic lesions.