Feasibility of differentiating gait in Parkinson's disease and spinocerebellar degeneration using a pose estimation algorithm in two-dimensional video.

BACKGROUND: Although pose estimation algorithms have been used to analyze videos of patients with Parkinson's disease (PD) to assess symptoms, their feasibility for differentiating PD from other neurological disorders that cause gait disturbances has not been evaluated yet. We aimed to determine whether it was possible to differentiate between PD and spinocerebellar degeneration (SCD) by analyzing video recordings of patient gait using a pose estimation algorithm. METHODS: We videotaped 82 patients with PD and 61 patients with SCD performing the timed up-and-go test. A pose estimation algorithm was used to extract the coordinates of 25 key points of the participants from these videos. A transformer-based deep neural network (DNN) model was trained to predict PD or SCD using the extracted coordinate data. We employed a leave-one-participant-out cross-validation method to evaluate the predictive performance of the trained model using accuracy, sensitivity, and specificity. As there were significant differences in age, weight, and body mass index between the PD and SCD groups, propensity score matching was used to perform the same experiment in a population that did not differ in these clinical characteristics. RESULTS: The accuracy, sensitivity, and specificity of the trained model were 0.86, 0.94, and 0.75 for all participants and 0.83, 0.88, and 0.78 for the participants extracted by propensity score matching. CONCLUSION: The differentiation of PD and SCD using key point coordinates extracted from gait videos and the DNN model was feasible and could be used as a collaborative tool in clinical practice and telemedicine.

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.

Differentiation of speech in Parkinson's disease and spinocerebellar degeneration using deep neural networks.

INTRODUCTION: Assessing dysarthria features in patients with neurodegenerative diseases helps diagnose underlying pathologies. Although deep neural network (DNN) techniques have been widely adopted in various audio processing tasks, few studies have tested whether DNNs can help differentiate neurodegenerative diseases using patients' speech data. This study evaluated whether a DNN model using a transformer architecture could differentiate patients with Parkinson's disease (PD) from patients with spinocerebellar degeneration (SCD) using speech data. METHODS: Speech data were obtained from 251 and 101 patients with PD and SCD, respectively, while they read a passage. We fine-tuned a pre-trained DNN model using log-mel spectrograms generated from speech data. The DNN model was trained to predict whether the input spectrogram was generated from patients with PD or SCD. We used fivefold cross-validation to evaluate the predictive performance using the area under the receiver operating characteristic curve (AUC) and accuracy, sensitivity, and specificity. RESULTS: Average ± standard deviation of the AUC, accuracy, sensitivity, and specificity of the trained model for the fivefold cross-validation were 0.93 ± 0.04, 0.87 ± 0.03, 0.83 ± 0.05, and 0.89 ± 0.05, respectively. CONCLUSION: The DNN model can differentiate speech data of patients with PD from that of patients with SCD with relatively high accuracy and AUC. The proposed method can be used as a non-invasive, easy-to-perform screening method to differentiate PD from SCD using patient speech and is expected to be applied to telemedicine.

Multiple system atrophy in Hokkaido, Japan: a prospective registry study of natural history and symptom assessment scales followed for 5 years.

OBJECTIVES: Multiple system atrophy (MSA) is a refractory neurodegenerative disease, but novel treatments are anticipated. An accurate natural history of MSA is important for clinical trials, but is insufficient. This regional registry was launched to complement clinical information on MSA. SETTING: Patient recruitment started in November 2014 and is ongoing at the time of submission. The number of participating facilities was 66. Postal surveys were sent to medical facilities and patients with MSA in Hokkaido, Japan. PARTICIPANTS: After obtaining written consent from 196 participants, 184 overview surveys and 115 detailed surveys were conducted. PRIMARY AND SECONDARY OUTCOME MEASURES: An overview survey evaluated conformity to diagnostic criteria and a detailed survey implemented an annual assessment based on the Unified Multiple System Atrophy Rating Scale (UMSARS). RESULTS: At the time of registration, 58.2% of patients were diagnosed with cerebellar symptoms predominant type MSA (MSA-C) and 29.9% were diagnosed with parkinsonism predominant type MSA (MSA-P). UMSARS Part Ⅳ score of 4 or 5 accounted for 53.8% of participants. The higher the UMSARS Part Ⅳ score, the higher the proportion of MSA-P. At baseline, levodopa was used by 69 patients (37.5%) and the average levodopa dose was 406.7 mg/day. The frequency of levodopa use increased over time. Eleven cases changed from MSA-C to MSA-P during the study, but the opposite was not observed. Information about survival and causes of death was collected on 54 cases. Half of deaths were respiratory-related. Sudden death was recorded even in the group with UMSARS Part Ⅳ score of 1. CONCLUSIONS: This study is the first large-scale prospective MSA cohort study in Asia. MSA-C was dominant, but the use of antiparkinsonian drugs increased over the study period. Changes from MSA-C to MSA-P occurred, but not vice versa.

Executive dysfunction in patients with spinocerebellar ataxia type 3.

The aim of this study was to assess the cognitive functions of patients with spinocerebellar ataxia type 3(SCA3). We examined 15 patients with genetically confirmed SCA3 and 15 healthy control subjects matched for age, years of education, and intellectual ability. We administered verbal memory (word recall and word recognition) and executive function tasks (word fluency test, forward and backward digit and visual span tests, Kana Pick-out Test, Trail Making Test, and conflicting instructions and a Go/NoGo task from the Frontal Assessment Battery). We found that patients with SCA3 had significantly lower scores than the healthy control subjects on the word recall, semantic, and letter fluency, and backward digit span tests, while word recognition was well preserved. The other executive function tests showed preserved functions in the SCA3 group, indicating that visual working memory, and attention and inhibition control were not affected. The patients with SCA3 showed impaired word recall and intact word recognition, and accordingly, episodic memory encoding and storage processes in short-term memory were preserved. In category and letter-fluency tests, impairment was attributable to word-retrieval from semantic memory. Impaired verbal working memory may be involved in the retrieval of verbal information from phonological storage by means of continuous subvocal rehearsal, rather than a deficit in initial phonological encoding. Essential executive dysfunction in patients with SCA3 may be due to damage in the cerebellar cortex-ventral dentate nucleus-thalamus-prefrontal cortex circuits, which are involved in strategic retrieval of verbal information from different modes of memory storage.

Cognitive dysfunction in patients with spinocerebellar ataxia type 6.

The aim of this study was to assess the cognitive functions of patients with spinocerebellar ataxia type 6 (SCA6). We examined 13 patients with genetically confirmed SCA6 and 13 healthy control subjects matched for age, years of education, global cognitive status, and intellectual ability. We administered verbal memory (word recall and word recognition), executive function (digit span, category and letter fluency, Frontal Assessment Battery, and Trail Making Test-A and B), and visuospatial construction (figure copying) tests. We found that the patients with SCA6 had significantly lower scores on the demanding word recall and letter fluency tests compared to the control subjects, while word recognition was well preserved in the patients with SCA6. The other executive functions tested, as well as visuospatial construction, were preserved in the SCA6 group. However, although memory encoding and storage processes were preserved, the retrieval of memorized information concerning frontal function might be selectively affected in patients with SCA6 compared to in control subjects. The impaired word recall and letter fluency noted in patients with SCA6 were interpreted as being related to a word-retrieval disability. Such dysfunctions may be attributed to damage in the frontal-cerebellum circuit owing to SCA6.

Comparison of Different Symptom Assessment Scales for Multiple System Atrophy.

To identify the most sensitive scale for use in clinical trials on multiple system atrophy (MSA), a short and sensitive scale is needed for MSA clinical trials. Potential candidates are the Unified MSA Rating Scale (UMSARS), Scale for the Assessment and Rating of Ataxia (SARA), Berg Balance Scale (BBS), MSA Health-Related Quality of Life scale (MSA-QoL), and Scales for Outcomes in Parkinson's Disease-Autonomic questionnaire (SCOPA-AUT). We enrolled patients with MSA from eight hospitals in Hokkaido, Japan. Board-certified neurologists assessed each patient at 6-month intervals and scored them on the UMSARS, SARA, BBS, MSA-QoL, and SCOPA-AUT. Score changes were evaluated using the standardized response mean (SRM). The correlation between disease duration and each score was examined. The first evaluation was conducted on 85 patients (60 patients with MSA cerebellar ataxia dominant subtype [MSA-C] and 25 patients with MSA Parkinsonism-dominant subtype [MSA-P]). Sixty-nine patients were examined after 6 months and 63 patients after 12 months. The UMSARS Part 4 had the largest SRM after 6 months and the SARA after 12 months. SRMs for MSA-P, the shorter duration group, and the early-onset group were larger than were those for MSA-C, the longer duration group, and the late-onset group. SRMs for items regarding skilled hand activities, walking, and standing were relatively large. Our study indicates that the UMSARS (parts 2 and 4), SARA, and BBS are sensitive scales for evaluating MSA progression over 12 months. Items with large SRMs effectively evaluated short-term changes.

Low-titer anti-GAD-antibody-positive cerebellar ataxia.

The majority of cases of anti-glutamic acid decarboxylase (GAD)-antibody-positive cerebellar ataxia are reported to have high levels of anti-GAD antibody, and the diagnostic value of low titers of anti-GAD antibody in a patient with cerebellar ataxia is still unknown. The purpose of this study was to verify the characteristics of low-titer-anti-GAD-antibody-positive cerebellar ataxia patients and the diagnostic value of low titers of anti-GAD antibody in patients with cerebellar ataxia. The subjects were six patients positive for low-titer GAD antibody (<100 U/mL). We examined them with MRI, including voxel-based morphometry, and with single-photon emission computed tomography and monitored the GAD antibody index in the cerebrospinal fluid. The levels of antineuronal, antigliadin, anti-SS-A, antithyroid antibodies, and of vitamins E, B1, and B12 were determined. Thoracic and abdominal CT scans were performed to exclude a paraneoplastic origin. We treated three patients with immunotherapy. All cases showed cortical cerebellar atrophy. The GAD antibody index in three of the five patients reviewed was >1.0. Two of the six patients were thyroid antibody-positive, and one was both antinuclear- and anti-SS-A antibody-positive. After the administration of immunotherapy to three patients, two showed clear effectiveness, and one, transient effectiveness. Effectiveness was greatest in the two patients with familial occurrence of the disease. In cerebellar ataxia, regardless of family history or isolated illness, it is critical to measure the GAD antibody level, and, even with a low titer level, if the result is positive, immunotherapy should be considered.

Estimation of skeletal muscle energy metabolism in Machado-Joseph disease using (31)P-MR spectroscopy.

The aim of this study was to determine if muscle energy metabolism, as measured by (31)P-magnetic resonance spectroscopy (MRS), is a metabolic marker for the efficacy of treatment of Machado-Joseph disease (MJD). We obtained (31)P-MRS in the calf muscle of 8 male patients with MJD and 11 healthy men before, during, and after a 4 minute plantar flexion exercise in a supine position. The data showed that there was a significant difference between the groups in terms of the PCr/(Pi + PCr) ratio at rest (P = 0.03) and the maximum rate of mitochondrial ATP production (V(max)) (P < 0.01). In addition, V(max) was inversely correlated with the scale for the assessment and rating of ataxia score (r = -0.34, P = 0.04). The MJD group also showed a reduction in V(max) over the course of 2 years (P < 0.05). These data suggest that this noninvasive measurement of muscle energy metabolism may represent a surrogate marker for MJD.

Difference in the effects of tandospirone on ataxia in various types of spinocerebellar degeneration: an open-label study.

The aim of this study was to investigate the effects of tandospirone on ataxia in various types of spinocerebellar degeneration (SCD). Fifteen milligram per day of tandospirone was administered to 39 patients with SCD (spinocerebellar atrophy (SCA) 1, five patients; SCA2, six patients; Machado-Joseph disease (MJD), 14 patient; SCA6, five patients; multiple system atrophy-cerebellar type (MSA-C), seven patients; and multiple system atrophy-Parkinson type (MSA-P), two patients). All patients were assessed before and 4 weeks after administration of the drug using the international cooperative ataxia rating scale total score (ARS), total length traveled (TLT) of body stabilometry, and a self-rating depression scale. Statistically, ARS showed a significant difference in MJD (p = 0.005) and SCA6 (p = 0.043). TLT also showed a significant difference in MJD (p = 0.002) and SCA6 (p = 0.043). Eight of 39 patients (SCA1, 1/5; SCA2, 0/6; MJD, 4/14; SCA6, 3/5; MSA-C, 0/7; and MSA-P, 0/2) showed more than a five point reduction in ARS, and 13 of 39 patients (SCA1, 0/5; SCA2, 1/6; MJD, 8/14; SCA6, 4/5; MSA-C, 0/7; and MSA-P, 0/2) showed a reduction of TLT. Our data indicate that the effects of tandospirone on ataxia are different between types of SCD. Therefore, tandospirone is useful for cerebellar ataxia in patients with MJD and SCA6.

Associations between multiple system atrophy and polymorphisms of SLC1A4, SQSTM1, and EIF4EBP1 genes.

Multiple system atrophy (MSA) is an adult-onset sporadic neurodegenerative disease. Although the etiology of MSA remains obscure, recent studies suggest that oxidative stress is associated with the pathogenesis of MSA. The aim of this study was to evaluate genetic associations between the candidate genes involved in oxidative stress and MSA in a case-control study. We examined 119 Japanese patients with MSA and 123 controls, and genotyped single-nucleotide polymorphisms (SNPs) of the following eight genes: CCAAT/enhancer-binding protein homologous protein, activating transcription factor 3, CCAAT/enhancer-binding protein-beta, sequestosome 1 (SQSTM1), cysteinyl-tRNA synthetase, solute carrier family 1A4 (SLC1A4), activating transcription factor 4, and eukaryotic translation initiation factor 4E-binding protein 1 (EIF4EBP1). SLC1A4 SNP +28833 (V398I, rs759458, genotype: Pc = 0.0186, allele: Pc = 0.0303, Pc: P-value with Bonferroni correction), two major haplotypes of SLC1A4 "T-C-C-G" and "T-C-T-A" (Pc = 0.0261 and 0.000768), two-SNP haplotypes of SQSTM1 "C-T" and "A-T" (Pc = 0.0136 and 0.0369), and the most common haplotype of EIF4EBP1 "C-T-G-C" (Pc = 0.0480) showed significant associations. This study revealed genetic associations of SLC1A4, SQSTM1, and EIF4EBP1 with MSA. These results may lend genetic support to the hypothesis that oxidative stress is associated with the pathogenesis of MSA.

Dropped head sign as the only symptom of myasthenia gravis.

Neck extensor muscle weakness and the dropped head sign are associated with various neuromuscular disorders. However, these symptoms are comparatively rare in myasthenia gravis (MG). We report a MG case that presented with dropped head sign as the main symptom. A 55-year-old man developed subacute weakness of the neck extensor muscle and presented with dropped head. We established a diagnosis of MG based on the results of an edrophonium test and a voluntary single fiber electromyogram (vSFEMG), and a high serum antiacetylcholine receptor antibody level. This patient was treated with pyridostigmine and his neurological symptoms improved. There are reported cases of dropped head sign as the first symptom of MG, however, in those cases, other muscles showed weakness during the first few months after onset. In the present case, throughout the clinical course no other symptoms outside of dropped head sign were seen.

MSA-C is the predominant clinical phenotype of MSA in Japan: analysis of 142 patients with probable MSA.

We investigated the clinical features and mode of disease progression in 142 patients with probable multiple system atrophy (MSA) according to the Consensus Criteria. The subjects included 84 men and 58 women with a mean age at onset of 58.2+/-7.1 years (range: 38-79 years). Cerebellar signs were detected in 87.3% of these patients at the time of initial examination, and were found in 95.1% of them at latest follow-up. MSA-C was diagnosed in 83.8% of the patients at their first examination. Parkinsonism was initially detected in 28.9% of the patients, increasing to 51.4% at the latest follow-up. Among all of the subjects, only 16.2% were classified as having MSA-P on initial examination. At the latest follow-up, parkinsonian features had become predominant over cerebellar features in 24.6% of the 65 patients with MSA-C who were followed for more than 3 years. Although parkinsonism usually masked the signs of cerebellar involvement in MSA-C patients, none of the patients with MSA-P at an early stage showed predominance of cerebellar features at the latest follow-up. Parkinsonism is the predominant feature of MSA among Western patients, even at an early stage, but this study showed that cerebellar deficits are the main feature in Japanese patients. This difference of disease manifestations between ethnic groups suggests that genetic factors may influence the clinical phenotype of MSA.

Four mutations of the spastin gene in Japanese families with spastic paraplegia.

Hereditary spastic paraplegia (HSP) is a group of genetically heterogeneous neurodegenerative disorders characterized by slowly progressive spasticity and weakness of the lower limbs. HSP is caused by failure of development or selective degeneration of the corticospinal tracts, which contain the longest axons in humans. The most common form of HSP is caused by mutations of the spastin gene (SPAST), located on chromosome 2p21-p22, which encodes spastin, one of the ATPases associated with diverse cellular activities (AAA). In this study, we detected four causative mutations of SPAST among 14 unrelated patients with spastic paraplegia. Two missense mutations (1447A-->G, 1207C-->G) and two deletion mutations (1465delT, 1475-1476delAA) were located in the AAA cassette region. Three of these four mutations were novel. Previous reports and our results suggest that the frequency of SPAST mutations is higher among Japanese patients with autosomal dominant HSP, although SPAST mutations are also observed in patients with sporadic spastic paraplegia.

Heredity in multiple system atrophy.

We investigated the family histories of 157 Japanese patients with probable or possible multiple system atrophy (MSA). A family history of neurodegenerative disorders was only detected in three MSA patients (1.9%). We evaluated these patients by careful neurological examination, neuroimaging studies, and genetic studies to exclude hereditary spinocerebellar ataxia with a similar clinical phenotype to MSA. The results indicated that one of them had a family history of MSA. Although the familial presence of neurodegenerative disorders is rare in MSA patients, the existence of such cases suggests that MSA may have a genetic background.

Treatment of cerebellar ataxia with 5-HT1A agonist.

Effective, pharmacologic approaches to the treatment of cerebellar ataxia are lacking or inadequate. We recently reported preliminary evidence that tandospirone citrate (tandospirone), a 5-HT1A agonist, improved cerebellar ataxia in patients with Machado-Joseph disease (MJD). In the course of that study, we found that such treatment also alleviated the pain associated with cold sensations in the legs, insomnia, anorexia, and depression, all of which are thought to be mediated through activation of the 5-HT1A receptor. In this paper, we reviewed the few published clinical trials that involved the use of 5-HT1A receptor agonists for the treatment of cerebellar ataxia, and discussed the current theories regarding their mechanism of action. Cortical cerebellar atrophy (CCA) was reported, in a double-blind study, to be amenable to treatment with tandospirone. Other types of spinocerebellar degeneration (SCD) i.e., olivopontocerebellar atrophy (OPCA) and Machado-Joseph disease (MJD) have also been reported to respond to the drug, but these have been small studies. Responsive patients exhibited only mild ataxia. The doses of 5-HT1A agonists that have been used successfully ranged from 12.5 mg/day to 60 mg/day (or 1 mg/kg), and were well tolerated by most patients.

Effects of tandospirone on "5-HT1A receptor-associated symptoms" in patients with Machado-Josephe disease: an open-label study.

BACKGROUND: We investigated the frequencies of the symptoms such as "ataxia, depression, insomnia, anorexia, and pain," that have been reported to be associated with 5-HT1A receptor, and the effect of tandospirone citrate (tandospirone: 5-HT1A agonist) in patients with Machado-Joseph disease (MJD). METHODS: Ten MJD patients received tandospirone (15-30 mg/d) for seven weeks. During that time, they were evaluated weekly using the Ataxia Rating Scale (ARS) and Total Length Traveled (TLT) by Stabilimetry tests, the Self-rating Depression Scale (SDS), which in addition to evaluating their level of depression, also evaluated their degree of insomnia and anorexia, and a pain questionnaire. RESULTS: Before tandospirone therapy, all patients displayed cerebellar ataxia, while insomnia, and leg pain was observed in 7 patients, depression in 6 patients, and anorexia was observed in 2 patients. In response to treatment, 7 of the 10 patients who were ataxic showed a reduction in their ARS, while 3 of 6 patients showed a reduction in their SDS, and 5 of 7 patients showed an alleviation of their insomnia and leg pain. Both of the affected patients showed a marked improvement in their anorexia. A stabilimetry test could be performed in 7 patients, 5 of whom showed a reduction in TLT. CONCLUSIONS: Our data indicate that the patients with MJD are prone to manifest 5-HT1A receptor-associated symptoms, and tandospirone is a useful drug for these symptoms in patients with MJD, though a double-blind study is needed.