An autopsy case of progressive supranuclear palsy with severe corticospinal tract degeneration.

We report an autopsy case of a 70-year-old man who was clinically diagnosed with atypical progressive supranuclear palsy (PSP). He initially presented with gait ataxia and then showed vertical gaze palsy, rigidity, akinesia, dysphagia, and mild cognitive impairment, followed by prominent upper motor signs later in the course of the disease. Cranial magnetic resonance imaging revealed tegmental atrophy of the midbrain. Autopsy revealed severe neuronal loss and gliosis in the motor cortex and corticospinal degeneration and mild to moderate neuronal loss and gliosis in the basal ganglia, substantia nigra, midbrain, and pons. Tufted astrocytes were primarily found in the motor cortex and basal ganglia. Globose-type neurofibrillary tangles were observed in the locus coeruleus and nucleus olivaris inferior. In the cerebellar cortex, mild Purkinje cell loss and scattered axonal torpedoes were observed with tau-positive Purkinje cells. The dentate nucleus displayed severe neuronal loss and gliosis. The present case showed characteristics of both PSP with prominent cerebellar ataxia (PSP-C) and PSP-primary lateral sclerosis (PSP-PLS).

The current status of medical care for myotonic dystrophy type 1 in the national registry of Japan.

INTRODUCTION/AIMS: Myotonic dystrophy (DM) is a systemic disease with multiple organ complications, making the standardization of medical care a challenge. We analyzed data from Japan's national registry to clarify the current treatment patterns and demographic features of Japanese DM patients. METHODS: Using the Japanese National Registry of Muscular Dystrophy (Remudy), we analyzed medical care practice for the multisystemic issues associated with adult DM type 1 patients, excluding congenital DM. RESULTS: We included 809 patients with a median age of 44.2 years. Among these patients, 15.8% used ventilators; 31.7% met the index considered at risk for sudden death due to cardiac conduction defects (PR interval over 240 milliseconds or QRS duration over 120 milliseconds) and 2.8% had implanted cardiac devices. Medication for heart failure was prescribed to 9.6% of patients. Overall, 21.2% of patients had abnormal glucose metabolism, of whom 42.9% were treated with oral medications. Among the oral medications, dipeptidyl peptidase-4 inhibitors were the most common. Cancers were observed in 3.7% of the patients, and endometrial and breast cancers were dominant. Mexiletine was prescribed for myotonia in 1.9% of the patients, and only 1% of the patients received medication for daytime sleepiness. DISCUSSION: This study shows difference in treatment patterns for DM1 in Japan compared with other countries, such as lower rates of use of implantable cardiac devices and higher rates of ventilator use. These data may be useful in discussions aimed at standardizing medical care for patients with DM.

Safety and immunogenicity of mRNA COVID-19 vaccine in inpatients with muscular dystrophy.

INTRODUCTION/AIMS: Due to muscular weakness and cardiopulmonary dysfunction, patients with muscular dystrophy (MD) have an increased risk of serious complications from coronavirus disease-2019 (COVID-19). Although vaccination is recommended, COVID-19 vaccination safety and immunogenicity in these patients are unknown. We investigated reaction frequency, post-vaccine antibody titers after two mRNA COVID-19 vaccine doses, and clinical predictors of antibody response among patients with MD. METHODS: We recruited 171 inpatients with MD receiving two BNT162b2 mRNA COVID-19 vaccine doses from seven hospitals. Blood samples were obtained from 53 inpatients before the first dose and 28 to 30 days after the second dose, and antibody titers were measured. RESULTS: Overall, 104 (60.8%) and 115 (67.6%) patients had side effects after the first and second doses, respectively. These were generally mild and self-limited. Multiple logistic regression analysis showed that a bedridden state was associated with reduced side effects (odds ratio [OR] = 0.29; 95% confidence interval [CI], 0.12 to 0.71). The antibody titers of all participants changed from negative to positive after two vaccine doses. The geometric mean titer (GMT) of the inpatients was 239 (95% CI, 159.3 to 358.7). Older age (relative risk [RR] = 0.97; 95% CI, 0.95 to 0.99) and bedridden state (RR = 0.27; 95% CI, 0.14 to 0.51) were associated with a lower antibody titer. Patients with myotonic dystrophy type 1 (DM1) had a lower GMT than patients with other MDs (RR = 0.42; 95% CI, 0.21 to 0.85). DISCUSSION: COVID-19 vaccination is safe and immunogenic in inpatients with MD. Patients with DM1 appear to have a poorer COVID-19 antibody response than those with other MDs.

Biallelic Mutations in MYPN, Encoding Myopalladin, Are Associated with Childhood-Onset, Slowly Progressive Nemaline Myopathy.

Nemaline myopathy (NM) is a common form of congenital nondystrophic skeletal muscle disease characterized by muscular weakness of proximal dominance, hypotonia, and respiratory insufficiency but typically not cardiac dysfunction. Wide variation in severity has been reported. Intranuclear rod myopathy is a subtype of NM in which rod-like bodies are seen in the nucleus, and it often manifests as a severe phenotype. Although ten mutant genes are currently known to be associated with NM, only ACTA1 is associated with intranuclear rod myopathy. In addition, the genetic cause remains unclear in approximately 25%-30% of individuals with NM. We performed whole-exome sequencing on individuals with histologically confirmed but genetically unsolved NM. Our study included individuals with milder, later-onset NM and identified biallelic loss-of-function mutations in myopalladin (MYPN) in four families. Encoded MYPN is a sarcomeric protein exclusively localized in striated muscle in humans. Individuals with identified MYPN mutations in all four of these families have relatively mild, childhood- to adult-onset NM with slowly progressive muscle weakness. Walking difficulties were recognized around their forties. Decreased respiratory function, cardiac involvement, and intranuclear rods in biopsied muscle were observed in two individuals. MYPN was localized at the Z-line in control skeletal muscles but was absent from affected individuals. Homozygous knockin mice with a nonsense mutation in Mypn showed Z-streaming and nemaline-like bodies adjacent to a disorganized Z-line on electron microscopy, recapitulating the disease. Our results suggest that MYPN screening should be considered in individuals with mild NM, especially when cardiac problems or intranuclear rods are present.

Immunohistochemical localization of spatacsin in α-synucleinopathies.

Spatacsin (SPG11) is a major mutated gene in autosomal recessive spastic paraplegia with thin corpus callosum (ARHSP-TCC) and is responsible for juvenile Parkinsonism. To elucidate the role of spatacsin in the pathogenesis of α-synucleinopathies, an immunohistochemical investigation was performed on the brain of patients with Parkinson's disease (PD), dementia with Lewy bodies (DLB) and multiple system atrophy (MSA) using anti-spatacsin antibody. In PD, Lewy bodies (LBs) in the brain stem were positive for spatacsin. These LBs showed intense staining in their peripheral portions and occasionally in the central cores. Lewy neurites were also spatacsin-positive. In DLB, cortical LBs were immunolabeled by spatacsin. In MSA, glial cytoplasmic inclusions (GCI) and a small fraction of neuronal cytoplasmic inclusions (NCI) were positive for spatacsin. The widespread accumulation of spatacsin observed in pathologic α-synuclein-containing inclusions suggests that spatacsin may be involved in the pathogenesis of α-synucleinopathies.

Loss-of-function polymorphisms in NQO1 are not associated with the development of subacute myelo-optico-neuropathy.

BACKGROUND: Subacute myelo-optico-neuropathy (SMON) is a neurological disorder associated with the administration of clioquinol, particularly at very high doses. Although clioquinol has been used worldwide, there was an outbreak of SMON in the 1950s-1970s in which the majority of cases were in Japan, prompting speculation that the unique genetic background of the Japanese population may have contributed to the development of SMON. Recently, a possible association between loss-of-function polymorphisms in NQO1 and the development of SMON has been reported. In this study, we analyzed the relationship between NQO1 polymorphisms and SMON in Japan. METHODS: We analyzed 125 Japanese patients with SMON. NQO1 loss-of-function polymorphisms (rs1800566, rs10517, rs689452, and rs689456) were evaluated. The allele frequency distribution of each polymorphism was compared between the patients and the healthy Japanese individuals (Human Genomic Variation Database and Integrative Japanese Genome Variation Database), as well as our in-house healthy controls. RESULTS: The frequencies of the loss-of-function NQO1 alleles in patients with SMON and the normal control group did not differ significantly. CONCLUSION: We conclude that known NQO1 polymorphisms are not associated with the development of SMON.

The Association Between Physical Activity/Heart Rate Variability Data Obtained Using a Wearable Device and Timed Motor Functional Tests in Patients with Duchenne Muscular Dystrophy: A Pilot Study.

Background: Duchenne muscular dystrophy (DMD) is a devastating X-linked muscle disease. Clinical evaluation of DMD uses patient-intensive motor function tests, and the recent development of wearable devices allows the collection of a variety of biometric information, including physical activity. Objective: In this study, we examined differences in physical activity and heart rate variability (HRV) between patients with DMD and healthy subjects using a wearable device, and investigated any association between these parameters and motor function in patients with DMD. Methods: Participants were 7 patients with DMD and 8 healthy males, whose physical activity and HRV were provided by a wearable device. These data were used to investigate the relationship between both physical activity and HRV parameters and timed motor functional tests [Time to stand from supine, 10-meter walking time (10MWT), North Star Ambulatory Assessment (NSAA), and 6-minute walking test (6MWT)] in patients with DMD. Results: Results of 24-hours physical activity, fat burning, total number of steps and active distance, average step rate, average exercise intensity during walking, exercise, degree of forward lean during walking, maximum heart rate, normalized low frequency power (LF norm), and maximum exercise intensity in patients with DMD were lower than those in control subjects. Physical activity and HRV parameters did not correlate with the time to stand from supine. The 10MWT positively correlated with average heart rate, while NSAA negatively correlated with average heart rate, total frequency power (TF), and very low frequency power (VLF) during arousal. The 6MWT negatively correlated with ratio LF/high frequency power (HF). CONCLUSIONS: Physical activity and HRV indices that differ from those of normal children and that correlate with motor function assessment may serve as digital biomarkers.

Facioscapulohumeral muscular dystrophy Health Index: Japanese translation and validation study.

PURPOSE: The Facioscapulohumeral Muscular Dystrophy Health Index (FSHD-HI) is a patient-reported outcome measure developed for patients with FSHD. This study aimed to translate the FSHD-HI into Japanese (FSHD-HI-J), evaluate cultural adaptation, and examine its psychometric properties. MATERIALS AND METHODS: We created two forward translations, integrated them into a single Japanese version, and evaluated the back-translated version of the FSHD-HI. After finalizing the translation and cultural adaptation, we conducted a survey of 66 patients with FSHD to examine the reliability and validity of the FSHD-HI-J. For psychometric evaluations, we used Cronbach's alpha to assess internal consistency, the intraclass correlation coefficient (ICC) for test-retest reliability, and assessed validity based on the associations between FSHD-HI-J, clinical variables, and quality of life measures. RESULTS: The FSHD-HI-J was found to be clinically relevant, indicating high internal consistency and test-retest reliability (ICC = 0.92 [95% confidence interval: 0.86-0.95] for the total score), as well as significant associations with clinical variables (D4Z4 repeats and functional impairment) and other quality of life measures (|rho| = 0.25-0.73). CONCLUSIONS: The FSHD-HI-J is a valid and reliable patient-reported outcome measure for Japanese patients with FSHD. This validated, disease-specific patient-reported outcome is essential for future clinical practice and clinical trials.

Facioscapulohumeral muscular dystrophy (FSHD) affects not only a patient's physical abilities but also their social activities, participation, and overall quality of life.The FSHD-Health Index (FSHD-HI) is an instrument developed as a disease-specific patient-reported outcome measure to evaluate the burden experienced by patients.The Japanese version of the FSHD-HI has been established as a reliable and validated measure for Japanese-speaking patients with FSHD.The Japanese version of the FSHD-HI can serve as a useful instrument for evaluating the effectiveness of interventions in future trials.

Clinical features and a mutation with late onset of limb girdle muscular dystrophy 2B.

OBJECTIVE AND METHODS: Dysferlin encoded by DYSF deficiency leads to two main phenotypes, limb girdle muscular dystrophy (LGMD) 2B and Miyoshi myopathy. To reveal in detail the mutational and clinical features of LGMD2B in Japan, we observed 40 Japanese patients in 36 families with LGMD2B in whom dysferlin mutations were confirmed. RESULTS AND CONCLUSIONS: Three mutations (c.1566C>G, c.2997G>T and c.4497delT) were relatively more prevalent. The c.2997G>T mutation was associated with late onset, proximal dominant forms of dysferlinopathy, a high probability that muscle weakness started in an upper limb and lower serum creatine kinase (CK) levels. The clinical features of LGMD2B are as follows: (1) onset in the late teens or early adulthood, except patients homozygous for the c.2997G>T mutation; (2) lower limb weakness at onset; (3) distal change of lower limbs on muscle CT at an early stage; (4) impairment of lumbar erector spinal muscles on muscle CT at an early stage; (5) predominant involvement of proximal upper limbs; (6) preservation of function of the hands at late stage; (7) preservation of strength in neck muscles at late stage; (8) lack of facial weakness or dysphagia; (9) avoidance of scoliosis; (10) hyper-Ckaemia; (11) preservation of cardiac function; and (12) a tendency for respiratory function to decline with disease duration. It is important that the late onset phenotype is found with prevalent mutations.