[Mechanisms Underlying the Propagation of α-Synuclein Seeds Derived from the Blood of Patients with α-Synucleinopathies].

The aggregation of α-synuclein (α-syn), associated with Parkinson's disease (PD) extends from the peripheral autonomic nervous system to the cerebral cortex, indicating a neural circuit-based mechanism of spread. However, recent studies, have proposed alternative propagation routes beyond neural pathways, including transmission via bodily fluids, such as the blood. This notion expands our understanding of PD progression, underscoring the complexity of α-syn spread and its implications in disease management and therapeutic strategies.

Safinamide as adjunctive therapy to levodopa monotherapy for patients with Parkinson's disease with wearing-off: The Japanese observational J-SILVER study.

BACKGROUND: Safinamide is an effective adjunctive therapy for wearing-off in Parkinson's disease (PD); however, evidence is lacking in older patients and those in the early stages of wearing-off. This study evaluated the efficacy and safety of safinamide as adjunctive therapy in patients with PD treated with levodopa monotherapy in clinical practice. METHODS: This multicentre, open-label observational study was conducted at five sites in Japan. Patients diagnosed with PD and wearing-off initiated safinamide as adjunctive therapy with levodopa monotherapy. Efficacy endpoints were mean changes in Movement Disorder Society-Unified Parkinson's Disease Rating Scale (MDS-UPDRS) Part I, III, and IV scores; daily ON-time without dyskinesia using 24-h patient symptom diaries; and 39-item Parkinson's Disease Questionnaire (PDQ-39) scores at 18 weeks of treatment. RESULTS: In total, 24 patients initiated safinamide (66.7% were aged ≥75 years); the mean duration of wearing-off was 1.2 years. MDS-UPDRS Part III total score, Part IV total score, and PDQ-39 summary index decreased significantly from baseline (mean change -7.0 [p = 0.012], -2.4 [p = 0.007] and - 5.3 [p = 0.012], respectively). There was a non-statistically significant increase of 1.55 h in mean daily ON-time without dyskinesia. Numerical Rating Scale total score for pain (p = 0.015), and scores for OFF-period pain (p = 0.012) and nocturnal pain (p = 0.021) subdomains were significantly improved in the subgroup with pain. Most reported adverse events were classified as mild. CONCLUSION: Safinamide improved motor and non-motor symptoms and quality of life-related measures in older patients with PD in the early stages of wearing-off without new safety concerns. STUDY REGISTRATION: University Hospital Medical Information Network in Japan; study ID: UMIN000044341.

α-Synuclein: A Promising Biomarker for Parkinson's Disease and Related Disorders.

Mutations in the SNCA gene, which encodes α-synuclein (α-syn), play a key role in the development of genetic Parkinson's disease (PD). α-Syn is a major component of Lewy bodies in PD and glial cytoplasmic inclusions in multiple system atrophy (MSA). Rapid eye movement sleep behavior disorder patients often progress to PD, dementia with Lewy bodies, or MSA, which are collectively known as α-synucleinopathies. The loss of dopaminergic neurons with Lewy bodies precedes motor dysfunction in these diseases, but the mechanisms of neurodegeneration due to α-syn aggregation are poorly understood. Monitoring α-syn aggregation in vivo could serve as a diagnostic biomarker and help elucidate pathogenesis, necessitating a simple and accurate detection method. Seed amplification assays (SAAs), such as real-time quaking-induced conversion and protein misfolding cyclic amplification, are used to detect small amounts of abnormally structured α-syn protofibrils, which are central to aggregation. These methods are promising for the early diagnosis of α-synucleinopathy. Differences in α-syn filament structures between α-synucleinopathies, as observed through transmission electron microscopy and cryo-electron microscopy, suggest their role in the pathogenesis of neurodegeneration. SAAs may differentiate between subtypes of α-synucleinopathy and other diseases. Efforts are also being made to identify α-syn from blood using various methods. This review introduces body fluid α-syn biomarkers based on pathogenic α-syn seeds, which are expected to redefine α-synucleinopathy diagnosis and staging, improving clinical research accuracy and facilitating biomarker development.

Pathogenesis of Parkinson's disease: from hints from monogenic familial PD to biomarkers.

Twenty-five years have passed since the causative gene for familial Parkinson's disease (PD), Parkin (now PRKN), was identified in 1998; PRKN is the most common causative gene in young-onset PD. Parkin encodes a ubiquitin-protein ligase, and Parkin is involved in mitophagy, a type of macroautophagy, in concert with PTEN-induced kinase 1 (PINK1). Both gene products are also involved in mitochondrial quality control. Among the many genetic PD-causing genes discovered, discovering PRKN as a cause of juvenile-onset PD has significantly impacted other neurodegenerative disorders. This is because the involvement of proteolytic systems has been suggested as a common mechanism in neurodegenerative diseases in which inclusion body formation is observed. The discovery of the participation of PRKN in PD has brought attention to the involvement of the proteolytic system in neurodegenerative diseases. Our research group has successfully isolated and identified CHCHD2, which is involved in the mitochondrial electron transfer system, and prosaposin (PSAP), which is involved in the lysosomal system, in this Parkin mechanism. Hereditary PD is undoubtedly an essential clue to solitary PD, and at least 25 or so genes and loci have been reported so far. This number of genes indicates that PD is a very diverse group of diseases. Currently, the diagnosis of PD is based on clinical symptoms and imaging studies. Although highly accurate diagnostic criteria have been published, early diagnosis is becoming increasingly important in treatment strategies for neurodegenerative diseases. Here, we also describe biomarkers that our group is working on.

Novel characteristics of the temporal transition to maximum tongue pressure in Parkinson's disease: A pilot study.

Introduction: The reason why maximum tongue pressure (MTP) decreases in patients with Parkinson's disease (PD) remains unclear. Repeated measurements of isometric force and MTP may be useful for analyzing muscle wasting and force generation. The purpose of this pilot study was to evaluate the clinical characteristics and temporal transition of MTP in PD and normal control (NC) groups. Methods: There were 18 participants in this study: 10 with PD and 8 NCs. The MTP was measured 20 times at regular intervals. The area under the curve of MTP temporal transitions, time to reach MTP, and total transition time of the tongue pressure (time to return to baseline) were compared between the groups. Results: MTP decreased from baseline in PD subjects. Unlike NCs, PD subjects showed diverse and inconsistent temporal transitions. The decrease in MTP and delays in time to reach MTP and time to return to baseline were significantly greater in PD subjects (p < 0.05), while there was no group difference in area under the curve values. According to repeated-measures ANOVA, MTP was not different over time between PD subjects and NCs. Conclusion: In this study, muscle fatigue did not affect the decrease in MTP seen in PD subjects, or the diversity and inconsistency of the temporal transition in MTP in that group. These findings indicate that the motor control needed for the repeated, identical movements associated with MTP generation may be impaired in PD patients.

Free water in gray matter linked to gut microbiota changes with decreased butyrate producers in Alzheimer's disease and mild cognitive impairment.

Neuroinflammation contributes to the pathology and progression of Alzheimer's disease (AD), and it can be observed even with mild cognitive impairment (MCI), a prodromal phase of AD. Free water (FW) imaging estimates the extracellular water content and has been used to study neuroinflammation across several neurological diseases including AD. Recently, the role of gut microbiota has been implicated in the pathogenesis of AD. The relationship between FW imaging and gut microbiota was examined in patients with AD and MCI. Fifty-six participants underwent neuropsychological assessments, FW imaging, and gut microbiota analysis targeting the bacterial 16S rRNA gene. They were categorized into the cognitively normal control (NC) (n = 19), MCI (n = 19), and AD (n = 18) groups according to the neuropsychological assessments. The correlations of FW values, neuropsychological assessment scores, and the relative abundance of gut microbiota were analyzed. FW was higher in several white matter tracts and in gray matter regions, predominantly the frontal, temporal, limbic and paralimbic regions in the AD/MCI group than in the NC group. In the AD/MCI group, higher FW values in the temporal (superior temporal and temporal pole), limbic and paralimbic (insula, hippocampus and amygdala) regions were the most associated with worse neuropsychological assessment scores. In the AD/MCI group, FW values in these regions were negatively correlated with the relative abundances of butyrate-producing genera Anaerostipes, Lachnospiraceae UCG-004, and [Ruminococcus] gnavus group, which showed a significant decreasing trend in the order of the NC, MCI, and AD groups. The present study showed that increased FW in the gray matter regions related to cognitive impairment was associated with low abundances of butyrate producers in the AD/MCI group. These findings suggest an association between neuroinflammation and decreased levels of the short-chain fatty acid butyrate that is one of the major gut microbial metabolites having a potentially beneficial role in brain homeostasis.

Extracellular vesicles contain filamentous alpha-synuclein and facilitate the propagation of Parkinson's pathology.

Parkinson's disease (PD) is characterized by the pathological deposition of a-synuclein (a-syn) inclusions, known as Lewy bodies/neurites. Emerging evidence suggests that extracellular vesicles (EVs) play a role in facilitating the spreading of Lewy pathology between the peripheral nervous system and the central nervous system. We analyzed serum EVs obtained from patients with PD (n = 142), multiple system atrophy (MSA) (n = 18), progressive supranuclear palsy (PSP) (n = 28), rapid eye movement sleep behavior disorder (n = 31), and controls (n = 105). While we observed a significant reduction in the number of EVs in PD compared to controls (p = 0.006), we also noted a substantial increase in filamentous α-synuclein within EVs in PD compared to controls (p < 0.0001), MSA (0.012), and PSP (p = 0.03). Further analysis unveiled the role of EVs in facilitating the transmission of filamentous α-synuclein between neurons and from peripheral blood to the CNS. These findings highlight the potential utility of serum α-synuclein filaments within EVs as diagnostic markers for synucleinopathies and underscore the significance of EVs in promoting the dissemination of filamentous α-synuclein throughout the entire body.

Efficacy and Safety of Elobixibat in Parkinson's Disease with Chronic Constipation: CONST-PD Study.

BACKGROUND: Chronic constipation is a common digestive complication of Parkinson's disease (PD). OBJECTIVES: To verify the usefulness of elobixibat, an ileal bile acid transporter inhibitor, for chronic constipation in PD. METHODS: This double-blind, placebo-controlled study consisted of a 2-week observation/washout period and a 4-week treatment period. All patients received a Bowel Movement Diary at Week -2 and were allocated to elobixibat (10 mg) or placebo at Week 0. Patients visited at Weeks 2 and 4 to report daily spontaneous bowel movements (SBM), stool form, drug use, quality of life (QOL), and safety. Changes in these parameters were assessed. RESULTS: The study included 38 patients in the elobixibat group and 39 in the placebo group, and 37 each completed the study. SBM frequency/week (mean ± standard deviation) increased significantly from 4.2 ± 2.6 at baseline to 5.9 ± 3.2 at Week 4 in the elobixibat group (P = 0.0079), but not in the placebo group (4.5 ± 2.7 to 5.3 ± 3.5; P = 0.0889). On analysis of covariance, the between-group difference in frequency changes at Week 4 (primary endpoint) was not significant after adjustment by baseline and sex (point estimate = 0.8; 95% confidence interval = -0.57 to 2.09, P = 0.2601), although a significant difference (P = 0.0011) was evidenced at Week 1 by a similar analysis. Stool form and scores of satisfaction and stigma were improved by elobixibat. Adverse events were as previously reported. CONCLUSIONS: Elobixibat improved the SBM frequency, though the defined primary endpoint was not evidenced. QOL parameters (stool consistency and treatment satisfaction) were also improved. Elobixibat may have therapeutic benefits in PD patients suffering from chronic constipation. TRIAL REGISTRATION INFORMATION: Trial Registration Number: JPRN-jRCTs031200172 (submitted: October 26, 2020; first patient enrolment: December 23, 2020; https://jrct.niph.go.jp/en-latest-detail/jRCTs031200172).

Impact of Istradefylline on Levodopa Dose Escalation in Parkinson's Disease: ISTRA ADJUST PD Study, a Multicenter, Open-Label, Randomized, Parallel-Group Controlled Study.

INTRODUCTION: A higher levodopa dose is a risk factor for motor complications in Parkinson's disease (PD). Istradefylline (IST) is used as adjunctive treatment to levodopa in PD patients with off episodes, but its impact on levodopa dose titration remains unclear. The objective of this study was to investigate the effect of IST on levodopa dose escalation in PD patients with wearing-off. METHODS: This was a multicenter, open-label, randomized, parallel-group controlled study (ISTRA ADJUST PD) in which PD patients experiencing wearing-off (n = 114) who were receiving levodopa 300-400 mg/day were randomized to receive IST or no IST (control). Levodopa dose was escalated according to clinical severity. The primary endpoint was cumulative additional levodopa dose, and secondary endpoints were changes in symptom rating scales, motor activity determined by a wearable device, and safety outcomes. RESULTS: The cumulative additional levodopa dose throughout 37 weeks and dose increase over 36 weeks were significantly lower in the IST group than in the control group (both p < 0.0001). The Movement Disorder Society Unified Parkinson's Disease Rating Scale Part I and device-evaluated motor activities improved significantly from baseline to 36 weeks in the IST group only (all p < 0.05). Other secondary endpoints were comparable between the groups. Adverse drug reactions (ADRs) occurred in 28.8% and 13.2% of patients in the IST and control groups, respectively, with no serious ADRs in either group. CONCLUSION: IST treatment reduced levodopa dose escalation in PD patients, resulting in less cumulative levodopa use. Adjunctive IST may improve motor function more objectively than increased levodopa dose in patients with PD. TRIAL REGISTRATION: Japan Registry of Clinical Trials: jRCTs031180248.

Free-water diffusion magnetic resonance imaging under selegiline treatment in Parkinson's disease.

INTRODUCTION: Monoamine oxidase type B inhibitors, including selegiline, are established as anti-Parkinsonian Drugs. Inhibition of monoamine oxidase type B enzymes might suppress the inflammation because of inhibition to generate reactive oxygen species. However, its effect on brain microstructure remains unclear. The aim of this study is to elucidate white matter and substantia nigra (SN) microstructural differences between Patients with Parkinson's disease with and without selegiline treatment by two independently recruited cohorts. METHODS: Diffusion tensor imaging and free water imaging indices of WM and SN were compared among 22/15 Patients with Parkinson's disease with selegiline (PDselegiline(+)), 33/23 Patients with Parkinson's disease without selegiline (PDselegiline(-)), and 25/20 controls, in the first/second cohorts. Two cohorts were analyzed with different MRI protocols. RESULTS: Diffusion tensor imaging and free-water indices of major white matter tracts were significantly differed between the PDselegiline(-) and controls in both cohorts, although not between the PDselegiline(+) and controls except for restricted areas. Compared with the PDselegiline(+), free-water was significantly higher in the PDselegiline(-) in the inferior fronto-occipital fasciculus, superior longitudinal fasciculus, and superior and posterior corona radiata (first cohort) and the forceps major and splenium of the corpus callosum (second cohort). There were no significant differences in free-water of anterior or posterior substantia nigra between PDselegiline(+) and PDselegiline(-). CONCLUSIONS: Selegiline treatment might reduce the white matter microstructural abnormalities detected by free-water imaging in Parkinson's disease.

The Role of Immune Dysfunction in Parkinson's Disease Development.

Recent research has unveiled intriguing insights suggesting that the body's immune system may be implicated in Parkinson's disease (PD) development. Studies have observed disparities in pro-inflammatory and anti-inflammatory markers between PD patients and healthy individuals. This finding underscores the potential influence of immune system dysfunction in the genesis of this condition. A dysfunctional immune system can serve as a primary catalyst for systemic inflammation in the body, which may contribute to the emergence of various brain disorders. The identification of several genes associated with PD, as well as their connection to neuroinflammation, raises the likelihood of disease susceptibility. Moreover, advancing age and mitochondrial dysfunction can weaken the immune system, potentially implicating them in the onset of the disease, particularly among older individuals. Compromised integrity of the blood-brain barrier could facilitate the immune system's access to brain tissue. This exposure may lead to encounters with native antigens or infections, potentially triggering an autoimmune response. Furthermore, there is mounting evidence supporting the notion that gut dysbiosis might represent an initial trigger for brain inflammation, ultimately promoting neurodegeneration. In this comprehensive review, we will delve into the numerous hypotheses surrounding the role of both innate and adaptive immunity in PD.

Midbrain atrophy in pathologically diagnosed Lewy body disease and clinically diagnosed Parkinson's disease.

OBJECTIVE: Midbrain atrophy is considered specific to progressive supranuclear palsy (PSP) compared with Parkinson's disease (PD). We aimed to determine how often midbrain atrophy is observed in pathologically diagnosed Lewy body disease (LBD) and clinically diagnosed PD and the robustness of midbrain atrophy assessed by the One-Line Method previously developed for the diagnosis of PSP. METHODS: We studied two separate cohorts with MRI: the first pathologically diagnosed cohort consisted of patients with LBD (n = 13), PSP (n = 6), multiple system atrophy (MSA, n = 7), and corticobasal degeneration (CBD, n = 2); the second cohort consisted of patients with PD (n = 122). Midbrain length was measured using the One-Line Method and FreeSurfer estimated volumes of the subcortical nuclei. RESULTS: The area under the curve of midbrain length differentiating PSP from LBD, MSA, and CBD in a pathologically diagnosed cohort was 0.91. Midbrain length with cut-off values of 10.5 mm and 9.5 mm had a sensitivity of 100% and 67% and a specificity of 68% and 96%, respectively. In the first cohort, 7.7% and 23.0% of patients with LBD showed midbrain lengths <9.5 mm and 10.5 mm, respectively, and in the second cohort, 4.9% and 19.7% showed midbrain lengths <9.5 mm and 10.5 mm, respectively. INTERPRETATION: Midbrain length measured using the One-Line Method is helpful in the diagnosis of PSP. Some cases of pathologically diagnosed LBD and clinically diagnosed PD present with midbrain atrophy.

Fiber-Specific White Matter Alterations in Parkinson's Disease Patients with GBA Gene Mutations.

BACKGROUND: Patients with Parkinson's disease (PD) carrying GBA gene mutations (GBA-PD) have a more aggressive disease course than those with idiopathic PD (iPD). OBJECTIVE: The objective of this study was to investigate fiber-specific white matter (WM) differences in nonmedicated patients with early-stage GBA-PD and iPD using fixel-based analysis, a novel technique to assess tract-specific WM microstructural and macrostructural features comprehensively. METHODS: Fixel-based metrics, including microstructural fiber density (FD), macrostructural fiber-bundle cross section (FC), and a combination of FD and FC (FDC), were compared among 30 healthy control subjects, 16 patients with GBA-PD, and 35 patients with iPD. Associations between FDC and clinical evaluations were also explored using multiple linear regression analyses. RESULTS: Patients with GBA-PD showed significantly lower FD in the fornix and superior longitudinal fasciculus than healthy control subjects, and lower FC in the corticospinal tract (CST) and lower FDC in the CST, middle cerebellar peduncle, and striatal-thalamo-cortical pathways than patients with iPD. Contrarily, patients with iPD showed significantly higher FC and FDC in the CST and striatal-thalamo-cortical pathways than healthy control subjects. In addition, lower FDC in patients with GBA-PD was associated with reduced glucocerebrosidase enzyme activity, lower cerebrospinal fluid total α-synuclein levels, lower Montreal Cognitive Assessment scores, lower striatal binding ratio, and higher Unified Parkinson's Disease Rating Scale Part III scores. CONCLUSIONS: We report reduced fiber-specific WM density and bundle cross-sectional size in patients with GBA-PD, suggesting neurodegeneration linked to glucocerebrosidase deficiency, α-synuclein accumulation, and poorer cognition and motor functions. Conversely, patients with iPD showed increased fiber bundle size, likely because of WM reorganization. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

A Case of Tardive Dystonia with Task Specificity Confined to the Lower Extremities only during Walking.

Background: Task-specific dystonia (TSD) confined to the lower extremities (LE) is relatively rare. This report describes dystonia confined to the LE only during forward walking. This case required careful neurological and diagnostic assessment because the patient was taking several neuropsychiatric drugs that cause symptomatic dystonia, such as aripiprazole (ARP). Case: A 53-year-old man visited our university hospital with a complaint of abnormalities in the LE that appeared only during walking. Neurological examinations other than walking were normal. Brain magnetic resonance imaging revealed meningioma in the right sphenoid ridge. The patient had been treated for depression with neuropsychiatric medications for a long time, and his abnormal gait appeared about 2 years after additional administration of ARP. After the meningioma was removed, his symptoms remained. Surface electromyography showed dystonia in both LE during forward walking, although his abnormal gait appeared to be accompanied by spasticity. The patient was tentatively diagnosed with tardive dystonia (TD). Although dystonia did not disappear clinically, it was alleviated after discontinuing ARP. Administration of trihexyphenidyl hydrochloride and concomitant rehabilitation improved his dystonia until return to work, but some residual gait abnormalities remained. Discussion: We report an unusual case of TD with task specificity confined to the LE. The TD was induced by the administration of ARP in combination with multiple psychotropic medications. Careful consideration was required for clinical diagnosis, rehabilitation, and assessment of its relevance to TSD.

Propagative α-synuclein seeds as serum biomarkers for synucleinopathies.

Abnormal α-synuclein aggregation is a key pathological feature of a group of neurodegenerative diseases known as synucleinopathies, which include Parkinson's disease (PD), dementia with Lewy bodies and multiple system atrophy (MSA). The pathogenic ß-sheet seed conformation of α-synuclein is found in various tissues, suggesting potential as a biomarker, but few studies have been able to reliably detect these seeds in serum samples. In this study, we developed a modified assay system, called immunoprecipitation-based real-time quaking-induced conversion (IP/RT-QuIC), which enables the detection of pathogenic α-synuclein seeds in the serum of individuals with synucleinopathies. In our internal first and second cohorts, IP/RT-QuIC showed high diagnostic performance for differentiating PD versus controls (area under the curve (AUC): 0.96 (95% confidence interval (CI) 0.95-0.99)/AUC: 0.93 (95% CI 0.84-1.00)) and MSA versus controls (AUC: 0.64 (95% CI 0.49-0.79)/AUC: 0.73 (95% CI 0.49-0.98)). IP/RT-QuIC also showed high diagnostic performance in differentiating individuals with PD (AUC: 0.86 (95% CI 0.74-0.99)) and MSA (AUC: 0.80 (95% CI 0.65-0.97)) from controls in a blinded external cohort. Notably, amplified seeds maintained disease-specific properties, allowing the differentiation of samples from individuals with PD versus MSA. In summary, here we present a novel platform that may allow the detection of individuals with synucleinopathies using serum samples.

Case report: Saccadic ping-pong gaze in progressive supranuclear palsy with predominant postural instability.

We report a 63-year-old female patient with progressive supranuclear palsy (PSP). She presented predominant postural instability and "saccadic ping-pong gaze" (SPPG). She had unprovoked falls recurrently within a year from the onset of gait disturbance. She tended to fall backward with eye closure but had no freezing of gait on examination. She showed no signs of nuchal dystonia, limb tremor, rigidity, spasticity, or ataxia. The dopaminergic response was negative. On the initial examination, her vertical eye movements were normal, but frequent macro square wave jerks and SPPG were observed. SPPG consisted of short-cycle, horizontal conjugate irregular pendular oscillations of the eye position from the midpoint with superimposed small saccades. SPPG was observed usually in the dark, not in the daylight, and with eye closure by using electrooculogram and infrared charge-coupled device imaging. One and a half years after the first examination, she was diagnosed as probable PSP with vertical supranuclear gaze palsy. SPPG was first described in patients who are unconscious by Johkura in 1998 as a "saccadic" variant of "ping-pong gaze (PPG)." PPG, short-cycle periodic alternating gaze, has been described in comatose patients since 1967. On the other hand, abnormal eye movement, which looks the same as SPPG in coma, has been described in conscious patients with PSP or spinocerebellar degeneration (SCD) in Japanese literature since 1975. However, it has been called "transient alternating saccades (TAS)." Nowadays, we believe it is more appropriate to call this abnormal eye movement "SPPG" instead of TAS. Here, we propose that PSP, a neuro-degenerative disease, should be added as one of the etiologies of SPPG. We discuss the differences between PPG/SPPG in coma and SPPG in PSP and the possible pathophysiological mechanism of SPPG in relation to cerebellar oculomotor dysfunctions.

Analytical and clinical validity of wearable, multi-sensor technology for assessment of motor function in patients with Parkinson's disease in Japan.

Continuous, objective monitoring of motor signs and symptoms may help improve tracking of disease progression and treatment response in Parkinson's disease (PD). This study assessed the analytical and clinical validity of multi-sensor smartwatch measurements in hospitalized and home-based settings (96 patients with PD; mean wear time 19 h/day) using a twice-daily virtual motor examination (VME) at times representing medication OFF/ON states. Digital measurement performance was better during inpatient clinical assessments for composite V-scores than single-sensor-derived features for bradykinesia (Spearman |r|= 0.63, reliability = 0.72), tremor (|r|= 0.41, reliability = 0.65), and overall motor features (|r|= 0.70, reliability = 0.67). Composite levodopa effect sizes during hospitalization were 0.51-1.44 for clinical assessments and 0.56-1.37 for VMEs. Reliability of digital measurements during home-based VMEs was 0.62-0.80 for scores derived from weekly averages and 0.24-0.66 for daily measurements. These results show that unsupervised digital measurements of motor features with wrist-worn sensors are sensitive to medication state and are reliable in naturalistic settings.Trial Registration: Japan Pharmaceutical Information Center Clinical Trials Information (JAPIC-CTI): JapicCTI-194825; Registered June 25, 2019.

A Narrative Review of Current Status and Future Perspective of Telemedicine for Parkinson's Disease, Dementia, and Intractable Neurological Diseases in Japan.

The coronavirus disease 2019 pandemic has uncovered several inherent problems in society. While the demand for telemedicine surged worldwide and some countries responded flexibly, in Japan, most telemedicine services were limited to telephone consultations, and full-fledged telemedicine did not become widespread. In addition, the digitalization process in both medicine and wider society lags behind some other nations. It is necessary to accelerate digital transformation in healthcare to build a sustainable society that is resilient to crises, such as new pandemics. In particular, as Japan is facing an issue of super-aged society, a sustainable care model for people with Parkinson's disease, dementia, and intractable neurological diseases should be established. Many neurodegenerative and intractable neurological diseases are progressive; as the disease progresses, patients could become difficult to visit specialists. Although online medical care has many advantages, it does not provide the same quality of information as face-to-face consultations. However, new technology can overcome the limitations of online medical care. As an evolutionary direction for telemedicine, three-dimensional telemedicine technologies are being developed, which enable online medical treatment to be delivered as if the patient was sharing the same space. Telemonitoring can enable the objective and continuous evaluation of patient information at home through the use of motion capture, wearable devices, and other devices. The advancement of digital transformation in medical care should be a game-changer in accumulating big data and analyzing it using artificial intelligence.

Factor analysis for construct validity of a trunk impairment scale in Parkinson's disease: a cross-sectional study.

Objectives: To investigate the construct validity of the Trunk Impairment Scale (TIS), which was developed to assess trunk impairment in patients with stroke, in patients with Parkinson's disease (PD). Design: This retrospective, cross-sectional study enrolled consecutive PD inpatients. Correlation analysis was performed to clarify whether the TIS assessment was related to other balance functions, lower extremity muscle strength, or walking ability. Factor analysis was performed to see how the background factors of TIS differ from balance function, lower limb muscle strength, and walking ability. Results: Examining the data of 471 patients with PD, there were relationships between TIS and the Mini-Balance Evaluation Systems Test (r = 0.67), Barthel Index (r = 0.57), general lower limb extension torque (r = 0.51), two-minute walk test (r = 0.54), Hoehn and Yahr stage (r = -0.61), and Movement Disorder Society Unified Parkinson's Disease Rating Scale part III total points (r = -0.59). Factor analysis showed that TIS items were divided into three factors (an abdominal muscles and righting reflex component; a perception and verticality component; and a rotational component), differing from other scales that included clinical assessment items. Conclusion: The TIS can be useful for assessing the underlying trunk impairment as a basis for activities of daily living, gait function, and balance ability in patients with PD.