The Responsiveness of Triaxial Accelerometer Measurement of Gait Ataxia Is Higher than That of the Scale for the Assessment and Rating of Ataxia in the Early Stages of Spinocerebellar Degeneration

We reported previously that the average medial-lateral gait amplitude while walking on a straight path determined using triaxial accelerometers fixed on the middle of the upper back may be a quantitative and concise indicator for the severity of cerebellar ataxia. Considering that gait ataxia is a typical initial symptom in a variety of spinocerebellar degeneration (SCD), we aimed to develop quantitative biomarkers for cerebellar ataxia as metric variables. We used triaxial accelerometers to analyze gait parameters in 14 patients with SCD at 3 points over 3 years (at baseline, 1.5 years and 3 years). Analysis of covariance (ANCOVA) models adjusted for the baseline scores were used to estimate sample sizes. The mean medial-lateral amplitude (ML) gained by a triaxial accelerometer fixed on upper back could detect the each 1.5-year change. In the 14 patients, the mean ML(m) was 0.032 +/- 0.007(SD) at entry, 0.037 +/- 0.008 after 1.5-year follow, and 0.042 +/- 0.020 after 3-year follow. In contrast, SARA gait scores were 2.9, 2.9, and 3.0, respectively. The responsiveness of the quantitative evaluation of gait ataxia by triaxial accelerometers is higher than that of the SARA within a 1.5-year follow-up period. Gait analysis by triaxial accelerometers will be complementary to the evaluation of scales like SARA in the assessment of clinical severity of SCD patients in early stage

Progressive multifocal leukoencephalopathy with mild clinical conditions and detection of archetype-like JC virus in cerebrospinal fluid

Progressive multifocal leukoencephalopathy (PML) is a demyelinating disease of the central nervous system with a poor prognosis and is primarily caused by JC virus (JCV) with a mutation called prototype. We encountered a case of PML with moderate progression and analyzed the mutational patterns of JCV in the cerebrospinal fluid (CSF). A 19-year-old Japanese woman with mild neurological symptoms was diagnosed with combined immunodeficiency following pneumocystis pneumonia. Brain magnetic resonance imaging scan showed multiple brain lesions, and real-time polymerase chain reaction testing detected JCV in the CSF, leading to the diagnosis of PML. The disease course of PML was stable after administration of mefloquine and mirtazapine with immunoglobulin replacement therapy. In the JCV genome cloned from the patient CSF, DNA sequences of the gene encoding the capsid protein (VP1) and the non-coding control region exhibited small mutations. However, they were quite similar to those of the archetype JCV, which persists asymptomatically in healthy individuals. These findings provide insight into the mutational characteristics of JCV in PML with mild symptoms and progression

A Retrospective Epidemiological Study of Tick-Borne Encephalitis Virus in Patients with Neurological Disorders in Hokkaido, Japan

Tick-borne encephalitis (TBE) is a zoonotic disease that usually presents as a moderate febrile illness followed by severe encephalitis, and various neurological symptoms are observed depending on the distinct central nervous system (CNS) regions affected by the TBE virus (TBEV) infection. In Japan, TBE incidence is increasing and TBEV distributions are reported in wide areas, specifically in Hokkaido.However, an extensive epidemiological survey regarding TBEV has not been conducted yet. In this study, we conducted a retrospective study of the prevalence of antibodies against TBEV in patients with neurological disorders and healthy populations in a TBEV-endemic area in Hokkaido. Among 2000 patients, three patients with inflammatory diseases in the CNS had TBEV-specific IgM antibodies and neutralizing antibodies. The other four patients diagnosed clinically with other neurological diseases were positive for TBEV-specific IgG and neutralizing antibodies, indicating previous TBEV infection. In a total of 246 healthy residents in a TBEV-endemic region, one resident had TBEV-specific antibodies. These results demonstrated undiagnosed TBEV infections in Japan. Further surveys are required to reveal the actual epidemiological risk of TBE and to consider preventive measures, such as a vaccine program, for the control of TBE in Japan

Gait video-based prediction of unified Parkinson’s disease rating scale score: a retrospective study

Abstract Background The diagnosis of Parkinson’s disease (PD) and evaluation of its symptoms require in-person clinical examination. Remote evaluation of PD symptoms is desirable, especially during a pandemic such as the coronavirus disease 2019 pandemic. One potential method to remotely evaluate PD motor impairments is video-based analysis. In this study, we aimed to assess the feasibility of predicting the Unified Parkinson’s Disease Rating Scale (UPDRS) score from gait videos using a convolutional neural network (CNN) model. Methods We retrospectively obtained 737 consecutive gait videos of 74 patients with PD and their corresponding neurologist-rated UPDRS scores. We utilized a CNN model for predicting the total UPDRS part III score and four subscores of axial symptoms (items 27, 28, 29, and 30), bradykinesia (items 23, 24, 25, 26, and 31), rigidity (item 22) and tremor (items 20 and 21). We trained the model on 80% of the gait videos and used 10% of the videos as a validation dataset. We evaluated the predictive performance of the trained model by comparing the model-predicted score with the neurologist-rated score for the remaining 10% of videos (test dataset). We calculated the coefficient of determination (R 2) between those scores to evaluate the model’s goodness of fit. Results In the test dataset, the R 2 values between the model-predicted and neurologist-rated values for the total UPDRS part III score and subscores of axial symptoms, bradykinesia, rigidity, and tremor were 0.59, 0.77, 0.56, 0.46, and 0.0, respectively. The performance was relatively low for videos from patients with severe symptoms. Conclusions Despite the low predictive performance of the model for the total UPDRS part III score, it demonstrated relatively high performance in predicting subscores of axial symptoms. The model approximately predicted the total UPDRS part III scores of patients with moderate symptoms, but the performance was low for patients with severe symptoms owing to limited data. A larger dataset is needed to improve the model’s performance in clinical settings

MM2 cortical form of sporadic Creutzfeldt-Jakob disease without progressive dementia and akinetic mutism : A case deviating from current diagnostic criteria

Sporadic Creutzfeldt-Jakob disease (sCJD) is classified into six types based on codon 129 polymorphism in the PRNP gene and the protease-resistant prion-related protein, PrP [1,2]. This classification corresponds well with the clinical course and the pathological findings. MM2-cortical type sCJD (MM2C-sCJD) is clinically characterized by slow progressive dementia, increased levels of 14-3-3 protein in the cerebrospinal fluid (CSF), and no periodic synchronous discharge (PSD) in electroencephalography [3]. We report the case of a patient presented with chronic progressive cortical symptoms. Based on the initial clinical findings, corticobasal syndrome (CBS) was suspected although he did not develop akinetic mutism during the lifetime. The postmortem pathological and anatomical findings confirmed MM2C-sCJD. As per the existing diagnostic criteria, our case was difficult to diagnose during the patient’s lifetime. Therefore, this is an important case for considering future revisions of the diagnostic criteria for MM2C-sCJD

Clinical factors affecting evoked magnetic fields in patients with Parkinson's disease

Studies on evoked responses in Parkinson's disease (PD) may be useful for elucidating the etiology and quantitative evaluation of PD. However, in previous studies, the association between evoked responses and detailed motor symptoms or cognitive functions has not been clear. This study investigated the characteristics of the visual (VEF), auditory (AEF), and somatosensory (SEF) evoked magnetic fields in patients with Parkinson's disease (PD), and the correlations between evoked fields and the patient's clinical characteristics, motor symptoms, and cognitive functions. Twenty patients with PD and 10 healthy controls (HCs) were recruited as participants. We recorded VEF, AEF, and SEF, collected clinical characteristics, performed physical examinations, and administered 10 cognitive tests. We investigated differences in the latencies of the evoked fields between patients with PD and HCs. We also evaluated the correlation of the latencies with motor symptoms and cognitive functioning. There were significant differences between the two groups in 6 of the cognitive tests, all of which suggested mild cognitive impairment in patients with PD. The latencies of the VEF N75m, P100m, N145m, AEF P50m, P100m, and SEF P60m components were greater in the patients with PD than in the HCs. The latencies mainly correlated with medication and motor symptoms, less so with cognitive tests, with some elements of the correlations remaining significant after Bonferroni correction. In conclusion, the latencies of the VEF, AEF, and SEF were greater in PD patients than in HCs and were mainly correlated with medication and motor symptoms rather than cognitive functioning. Findings from this study suggest that evoked fields may reflect basal ganglia functioning and are candidates for assessing motor symptoms or the therapeutic effects of medication in patients with PD