Hitoshi Mochizuki

Background,Freezing of gait (FOG) is a common and disabling motor feature of Parkinson’s disease (PD). We developed a novel foot movement analysis device incorporating five light-emitting diodes and corresponding pressure sensors to objectively quantify cue-guided lower-limb movements.,Methods,We enrolled 33 patients with PD, including 16 without FOG (nPD) and 17 with FOG (fPD), alongside 16 age-matched neurologically healthy controls (NL). Participants moved the dominant foot to the pressure sensor corresponding to a light cue, and the latency between the task-specific cue and sensor activation was recorded as the reaction time (RT). Three paradigms were tested: a visually guided mode (task 1), a memory-guided mode (task 2), and a rhythm-guided mode (task 3).,Results,RT did not differ significantly among the three groups in task 1. In task 2, RT was significantly longer in the fPD group than in the nPD and NL groups. The proportion of trials with RT > 2 s correlated with the freezing-related Unified Parkinson’s Disease Rating Scale Part II item 14 score. In task 3, RT did not differ significantly among the groups.,Conclusion,The developed device might objectively quantify cue-guided lower-limb responses in PD and provide a quantitative adjunct to clinical assessment of FOG-related impairment.

Inclusion body myositis is a progressive muscle disease characterized by weakness, specifically in the flexor digitorum profundus and quadriceps muscles, a

A tremor is a significant symptom of Parkinson’s disease, but it can also be a characteristic of essential tremor, thereby hampering even specialists’ ability to differentiate between the two. This study proposes a system that leverages a single RGB camera to evaluate tremor severity and support the differential diagnosis of Parkinson’s disease and essential tremor. The system captures motor symptoms, performs time–frequency analysis using wavelet transforms, and classifies severity and disease using linear classification models. The results showed an accuracy rate of 0.56 for disease classification and 0.50 for severity classification (with an acceptable accuracy rate of 0.96). The analysis indicated that there was a low level of correlation between disease and each feature and a moderate correlation (about 0.6) between severity and each feature. Based on these results, this study recommends classifying severity with a linear model and disease with a nonlinear model to obtain improved accuracy.

Objective: To study the presence of liver‐expressed antimicrobial peptide 2 (LEAP2) in human cerebrospinal fluid (CSF) and to measure its concentrations in neurological disorders.Materials & Methods: We identified the presence of LEAP2 in human CSF by chromatographic analysis and a LEAP2‐specific enzyme immunoassay. We measured LEAP2 concentrations in the CSF of 35 patients with neurological disorders.Results: CSF LEAP2 concentrations in the bacterial meningitis group (mean ± SD, 9.32 ± 3.76 ng/ml) were significantly higher (p < .05) than those in the other four groups (psychosomatic disorder, 0.56 ± 0.15 ng/ml; peripheral autoimmune disease, 1.00 ± 0.60 ng/ml; multiple sclerosis, 0.62 ± 0.30 ng/ml; aseptic meningitis, 1.59 ± 0.69 ng/ml).Conclusions: This is the first study to identify the presence of human LEAP2 in the CSF. Levels of LEAP2 were increased in the CSF of patients with bacterial meningitis. LEAP2 may have potential as a biomarker for bacterial meningitis.

In this paper, we introduce a simple method based on image analysis and deep learning that can be used in the objective assessment and measurement of tremors. A tremor is a neurological disorder that causes involuntary and rhythmic movements in a human body part or parts. There are many types of tremors, depending on their amplitude and frequency type. Appropriate treatment is only possible when there is an accurate diagnosis. Thus, a need exists for a technique to analyze tremors. In this paper, we propose a hybrid approach using imaging technology and machine learning techniques for quantification and extraction of the parameters associated with tremors. These extracted parameters are used to classify the tremor for subsequent identification of the disease. In particular, we focus on essential tremor and cerebellar disorders by monitoring the finger–nose–finger test. First of all, test results obtained from both patients and healthy individuals are analyzed using image processing techniques. Next, data were grouped in order to determine classes of typical responses. A machine learning method using a support vector machine is used to perform an unsupervised clustering. Experimental results showed the highest internal evaluation for distribution into three clusters, which could be used to differentiate the responses of healthy subjects, patients with essential tremor and patients with cerebellar disorders.

A 69-year-old man who had been bedridden in nursing home because of a 5-year history of progressive supranuclear palsy (PSP) was admitted due to aspiration pneumonia. Besides neck dystonia in extension, he showed “alternating flexed–extended posturing”, in which the arm was flexed on one side and extended on the other. Magnetic resonance imaging of the brain revealed global cerebral atrophy that predominantly affected the cortex and midbrain. The mechanisms of complex posturing in late-stage PSP may sometimes be related to decortication and decerebration as well as dystonia, and “alternating flexed–extended posturing” might be one of the phenotypes of pathological progression in PSP.

Aims: Polypharmacy is well known to affect cognitive function in community-dwelling older adults. However, the effect of polypharmacy on cognitive function in patients with newly diagnosed Parkinson’s disease remains unknown. Here, we evaluated the association between polypharmacy and cognitive function in patients with newly diagnosed Parkinson’s disease. Methods: This cross-sectional study enrolled 131 consecutive hospitalized patients with newly diagnosed Parkinson’s disease. Cognitive function was evaluated with the Mini-Mental State Examination and analyzed between groups of patients with or without polypharmacy. Comparisons were adjusted for confounders by performing inverse probability weighting with propensity scores. Results: After inverse probability weighting, patients in the polypharmacy group had a significantly lower Mini-Mental State Examination score than patients in the nonpolypharmacy group (26.2 vs. 27.7, p = 0.001). Conclusion: Polypharmacy was associated with cognitive decline in patients with newly diagnosed Parkinson’s disease. This finding suggests that medication reduction might serve as a promising intervention to prevent the development of dementia in patients with early Parkinson’s disease. Further prospective studies are needed to determine whether medication reduction improves cognitive function in patients with newly diagnosed Parkinson’s disease.

Arsenic (As) contamination affects hundreds of millions of people globally. Although the number of patients with chronic As exposure is large, the symptoms and long-term clinical courses of the patients remain unclear. In addition to reviewing the literature on As contamination and toxicity, we provide useful clinical information on medical care for As-exposed patients. Further, As metabolite pathways, toxicity, speculated toxicity mechanisms, and clinical neurological symptoms are documented. Several mechanisms that seem to play key roles in As-induced neurotoxicity, including oxidative stress, apoptosis, thiamine deficiency, and decreased acetyl cholinesterase activity, are described. The observed neurotoxicity predominantly affects peripheral nerves in sensory fibers, with a lesser effect on motor fibers. A sural nerve biopsy showed the axonal degeneration of peripheral nerves mainly in small myelinated and unmyelinated fibers. Exposure to high concentrations of As causes severe central nervous system impairment in infants, but no or minimal impairment in adults. The exposure dose–response relationship was observed in various organs including neurological systems. The symptoms caused by heavy metal pollution (including As) are often nonspecific. Therefore, in order to recognize patients experiencing health problems caused by As, a multifaceted approach is needed, including not only clinicians, but also specialists from multiple fields.

More than 140 million people drink arsenic-contaminated groundwater. It is unknown how much arsenic exposure is necessary to cause neurological impairment. Here, we evaluate the relationship between neurological impairments and the arsenic concentration in drinking water (ACDW). A cross-sectional study design was employed. We performed medical examinations of 1867 residents in seven villages in the Thabaung township in Myanmar. Medical examinations consisted of interviews regarding subjective neurological symptoms and objective neurological examinations of sensory disturbances. For subjective neurological symptoms, we ascertained the presence or absence of defects in smell, vision, taste, and hearing; the feeling of weakness; and chronic numbness or pain. For objective sensory disturbances, we examined defects in pain sensation, vibration sensation, and two-point discrimination. We analyzed the relationship between the subjective symptoms, objective sensory disturbances, and ACDW. Residents with ACDW ≥ 10 parts per billion (ppb) had experienced a “feeling of weakness” and “chronic numbness or pain” significantly more often than those with ACDW < 10 ppb. Residents with ACDW ≥ 50 ppb had three types of sensory disturbances significantly more often than those with ACDW < 50 ppb. In children, there was no significant association between symptoms or signs and ACDW. Subjective symptoms, probably due to peripheral neuropathy, occurred at very low ACDW (around 10 ppb). Objective peripheral nerve disturbances of both small and large fibers occurred at low ACDW (> 50 ppb). These data suggest a threshold for the occurrence of peripheral neuropathy due to arsenic exposure, and indicate that the arsenic concentration in drinking water should be less than 10 ppb to ensure human health.