Altered Functional Connectivity during Mild Transient Respiratory Impairment Induced by a Resistive Load.

Background: Previous neuroimaging studies have identified brain regions related to respiratory motor control and perception. However, little is known about the resting-state functional connectivity (FC) associated with respiratory impairment. We aimed to determine the FC involved in mild respiratory impairment without altering transcutaneous oxygen saturation. Methods: We obtained resting-state functional magnetic resonance imaging data from 36 healthy volunteers during normal respiration and mild respiratory impairment induced by resistive load (effort breathing). ROI-to-ROI and seed-to-voxel analyses were performed using Statistical Parametric Mapping 12 and the CONN toolbox. Results: Compared to normal respiration, effort breathing activated FCs within and between the sensory perceptual area (postcentral gyrus, anterior insular cortex (AInsula), and anterior cingulate cortex) and visual cortex (the visual occipital, occipital pole (OP), and occipital fusiform gyrus). Graph theoretical analysis showed strong centrality in the visual cortex. A significant positive correlation was observed between the dyspnoea score (modified Borg scale) and FC between the left AInsula and right OP. Conclusions: These results suggested that the FCs within the respiratory sensory area via the network hub may be neural mechanisms underlying effort breathing and modified Borg scale scores. These findings may provide new insights into the visual networks that contribute to mild respiratory impairments.

Association of Myelin Oligodendrocyte Glycoprotein Antibody-associated Disease with Coronavirus Disease 2019 Vaccination and Infection: A Case Report of Cortical Encephalitis and Transverse Myelitis Relapse.

We herein report a case of myelin oligodendrocyte glycoprotein (MOG) antibody-associated disease (MOGAD) that occurred following coronavirus disease 2019 (COVID-19) vaccination and its subsequent relapse after COVID-19 infection. A 34-year-old woman developed cortical encephalitis in the right temporoparietal lobe one week after receiving the mRNA-1273 vaccine. The cerebrospinal fluid was positive for anti-MOG antibody. Her symptoms gradually improved after three courses of intravenous methylprednisolone therapy. Six months later, she experienced a relapse of transverse myelitis following COVID-19 infection. Despite treatment with plasma exchange, the patient remained paralyzed in both lower limbs. We herein review the relationship between MOGAD and COVID-19 vaccination/infection.

Hereditary Neuralgic Amyotrophy with a Lesion Distal to the Brachial Plexus on Magnetic Resonance Imaging.

A 35-year-old woman first experienced left upper limb weakness at 17 years old, after which it repeatedly recurred and then remitted. She was diagnosed with carpal tunnel syndrome with median nerve hyperintensity by magnetic resonance imaging (MRI). Surgical treatment was ineffective. We suspected hereditary neuralgic amyotrophy because of enlargement distal to the brachial plexus on MRI and administered steroid therapy, after which the weakness improved. Genetic testing revealed a point mutation in SEPT9. Because lesions outside the brachial plexus can be seen in hereditary neuralgic amyotrophy, the diagnosis should be based on typical characteristics and the family history.

Anti-glycine receptor antibody-positive progressive encephalomyelitis with rigidity and myoclonus initially presenting with one-sided stiff face: A case report.

Background: Progressive encephalomyelitis with rigidity and myoclonus (PERM) is a subtype of stiff-person syndrome, a rare cerebrospinal disease that causes brainstem symptoms, myoclonus, muscle rigidity, and hyperekplexia. Case presentation: A 71-year-old man experienced left-sided stiff face, and was subsequently admitted to our hospital because of the appearance of left-dominant lower limb myoclonus. Muscle rigidity followed 3 days later. Magnetic resonance imaging revealed no abnormality. An electrophysiological examination showed a toughness of the antagonistic muscle following evocation of the Achilles tendon reflex, and a tonic phenomenon affecting the left facial muscles during the blink reflex. The patient's serum was positive for anti-glycine receptor (anti-GlyR) antibody, suggesting PERM. The patient was administered steroids, immunoglobulin therapy, and immunosuppressive drugs. He gradually improved after these therapies and became able to walk using a walker. Conclusions: We conclude that this was a rare case of anti-GlyR antibody-positive PERM with unilateral brainstem symptoms, myoclonus, and muscle rigidity.

[A case of localized fasciitis with ulcerative colitis].

A 36-year-old man with ulcerative colitis presented with bloody stools at the beginning of October 2020. His condition had been stable without treatment since diagnosis 4 years prior. He was administered 4,000 mg of salazosulfapyridine orally and the bloody stools resolved. Fifteen days after treatment, he was admitted to our hospital with swelling and pain in his right lower leg. Laboratory results revealed an elevated erythrocyte sedimentation rate (43 mm/hr) and mildly elevated C-reactive protein levels (4.08 mg/dl). His D-dimer level was also elevated at 7.6 µg/ml. MRI using fat saturated T2-weighted imaging demonstrated marked hyperintensity in the fascia of the lower leg flexor and blood vessels of interstitial. In gadolinium-enhanced T1-weighted images, the deep veins were found to be dilated and the vein walls and their surrounding areas strongly contrasted, suggestive of localized fasciitis. No abnormalities were found on biopsy of his right gastrocnemius muscle on the 5th day after admission. Two days after the muscle biopsy, the patient began experiencing swelling and pain in his left lower leg. The high intensity lesions in his right leg were reduced on MRI performed the same day, but that of the fascia between the left gastrocnemius and soleus muscles was noted. We administered 60 mg (1.0 mg/kg/day) of prednisolone orally on day 9 and the pain and swelling in both legs promptly resolved. The prednisolone was tapered to 5 mg/day and as of the time of writing, resolution of pain and swelling has been maintained. Gastrocnemius myalgia syndrome, which causes pain and localized fasciitis, is often reported as a complication of Crohn's disease but is rare in conjunction with ulcerative colitis. It is important that clinicians are aware of this syndrome so it can be recognized early and successfully treated.

Transactivation response DNA-binding protein of 43 kDa proteinopathy and lysosomal abnormalities in spastic paraplegia type 11.

Spastic paraplegia type 11 (SPG11) is the most common autosomal recessive hereditary spastic paraplegia with thinning of the corpus callosum. Spatacsin, a protein encoded by the SPG11 gene, is associated with autophagy. SPG11 patients show spastic paraplegia, intellectual disability, dementia, and parkinsonism. A previous neuropathological analysis of SPG11 cases reported neurodegeneration mimicking amyotrophic lateral sclerosis without transactivation response DNA-binding protein of 43 kDa (TDP-43) deposits and unique sequestosome 1 (SQSTM1)-positive neuronal inclusions. We performed a neuropathological examination of two Japanese patients with complicated spastic paraplegia with thinning of the corpus callosum from different families, and one was genetically diagnosed as having SPG11. Both cases showed diffuse atrophy of the brain and spinal cord. Depigmentation of the substantia nigra was also observed. Immunohistochemistry revealed widespread distribution of areas showing TDP-43 aggregation in the central nervous system. The TDP-43 deposits in the thalamus and substantia nigra especially resembled skein-like inclusions. Unique SQSTM1-positive neuronal inclusions, as previously reported, were widespread in the whole central nervous system as well as the dorsal root ganglia. Double-labeling immunofluorescence of the dorsal root ganglia revealed that the unique, large SQSTM1-positive cytoplasmic inclusions of the ganglion cells were labeled with lysosome-associated membrane protein 1 and lysosome-associated membrane protein 2. This is the first report showing TDP-43 pathology in SPG11. The common neuropathological findings of TDP-43-positive inclusions in both the cases imply a causal connection between the TDP-43 proteinopathy and autophagy dysfunction in SPG11.

Expanded polyglutamine impairs normal nuclear distribution of fused in sarcoma and poly (rC)-binding protein 1 in Huntington's disease.

Huntington's disease (HD) is an inherited neurodegenerative disease caused by a polyglutamine repeat expansion in the huntingtin protein. Immunohistochemical studies using the 1C2 antibody for polyglutamine expansion have detected characteristic intranuclear inclusions (INIs) in affected neurons in HD. Further, in vitro and mouse models of HD have shown that the INIs recruit several proteins relating to RNA splicing and translation. In the present study, we immunohistochemically investigated the association of INIs with various heterogeneous nuclear ribonucleoproteins in the cerebral cortex of four autopsy cases of HD. Fused in sarcoma (FUS) was colocalized with 1C2-positive nuclear inclusions in all examined cases. Localization of poly (rC)-binding protein 1 (PCBP1) in 1C2-positive nuclear inclusions was also observed. Double immunofluorescence revealed complete or partial loss of the normal, diffuse nuclear distribution of FUS or PCBP1 in neurons with 1C2-positive nuclear inclusions. This maldistribution of FUS in cortical neurons suggests a severe disturbance of messenger RNA processing, which may be a common pathogenetic mechanism of FUS-related familial amyotrophic lateral sclerosis.

Reversible Conduction Failure in Anti-lactosylceramide-antibody-positive Combined Central and Peripheral Demyelination.

We describe a 60-year-old woman with combined central and peripheral demyelination who presented with obstinate constipation, weakness in the lower limbs, and a bilateral sensory disturbance below her chest followed by girdle sensation in the right region of the abdomen, which was responsive to steroid therapy and plasmapheresis. Serum anti-lactosylceramide antibody was positive without anti-neurofascin 155 antibody or anti-galactocerebroside antibody positivity. Two months later, the patient had a first relapse that was responsive to steroid treatment. A nerve conduction study confirmed reversible conduction failure (RCF) in both episodes. Our case is unique in that she had an RCF episode as well as some similarities to encephalomyeloradiculoneuropathy.

Bilateral cingulate cortices lesions in two autoantibodies directed against MOG (MOG-Ab)-positive patients.

There are no specific radiologic features in MOG-Ab (autoantibodies directed against myelin oligodendrocyte glycoprotein)-associated diseases. We present two MOG-Ab-positive patients with symmetrical lesions in the bilateral cingulate cortex of the frontal and parietal lobes. Those lesions showed hyperperfusion in acute phase and hypoperfusion in chronic phase on brain SPECT. In both patients, steroid therapy was effective in acute phase and for prevention of recurrence. High signal in the bilateral cingulate cortex on MR T2-weighted and FLAIR images might to be one of the unique findings considered MOG-Ab associated diseases.

Spinocerebellar ataxia 27 with a novel nonsense variant (Lys177X) in FGF14.

Spinocerebellar ataxia 27 (SCA27) is an autosomal dominant SCA caused by variants in the fibroblast growth factor 14 (FGF14) gene. We examined a Japanese SCA patient whose deceased father also suffered from SCA. The patient was a 63-year-old male. He graduated from junior high school but received no further education. The predominant complaint was slowly progressive dysarthria and gait disturbance, which appeared at age 47. He showed pathological saccadic dysmetria, saccadic intrusions into smooth pursuit eye movements, dysarthria, and limb and truncal ataxia. His gait was wide-based but he did not require a walking stick. Limb muscle strength was intact. Deep tendon reflexes were normal or slightly reduced. Pathological reflexes were absent. He demonstrated mildly impaired vibration sense in the lower limbs. There was no urinary dysfunction. Brain MRI showed cerebellar atrophy without brainstem involvement. We first confirmed the absence of repeat expansion in genes known to be responsible for SCAs 1-3, 6-8, 10, 12, 17, 36 and dentatorubral-pallidoluysian atrophy. By exome analysis, we identified a novel heterozygous variant (NM_004115, c.529A>T; Lys177X) in exon 4 of the FGF14 gene. This variant is expected to generate a truncated FGF14 protein lacking the heparin binding sites, those are likely to modify the activity of FGF14. We confirmed the absence of the variant in 502 healthy Japanese individuals by Sanger sequencing. There is no record of the variant in public databases. We conclude that the novel variation in FGF14 is causative for SCA27 in this patient.

MIBG myocardial scintigraphy in progressive supranuclear palsy.

BACKGROUND AND OBJECTIVES: Meta-iodobenzylguanidine (MIBG) myocardial scintigraphy is an effective tool for distinguishing Parkinson's disease (PD) from other diseases accompanied by parkinsonism. Unlike other Parkinsonian diseases, in PD, MIBG accumulation in the heart tends to decrease. However, previous studies have reported that a decrease in MIBG accumulation also occurs in progressive supranuclear palsy (PSP). Thus, we analyzed the relationship between the degree of MIBG accumulation decrease, clinical symptoms, and brainstem atrophy in PSP. METHODS: We retrospectively collected data from patients who underwent MIBG myocardial scintigraphy and compared MIBG indices (heart to mediastinum [H/M] ratio, washout rate) between subjects with PSP and other diseases including PD. In addition, we evaluated the relationship between clinical characteristics, MIBG accumulation, and brainstem atrophy in patients with PSP. RESULTS: Patients with PSP had a significantly lower early H/M ratio compared with multiple system atrophy with predominant parkinsonism (MSA-P) patients, and a control group. In PSP patients there was a correlation between the decrease in delay H/M ratio, atrophy of the pons, and clinical severity as evaluated by Hoehn and Yahr score. CONCLUSION: Unlike in PD, PSP patients exhibited a mild decrease in MIBG accumulation in MIBG myocardial scintigraphy, which may be related to brainstem atrophy.

TDRKH is a candidate gene for an autosomal dominant distal hereditary motor neuropathy.

Distal hereditary motor neuropathies (dHMNs) comprise a group of clinically and genetically heterogeneous inherited lower motor neuron syndromes mainly characterized by a distal-predominant pattern of progressive muscle atrophy, weakness and hyporeflexia, without sensory dysfunction. Although at least 21 causative genes for dHMN have been reported, mutational scanning of these genes often fails to identify the causative variants in dHMN cohorts, suggesting that additional causative genes remain to be identified. We studied a four-generation pedigree of a Japanese family with autosomal dominant dHMN to provide insight into the pathogenetic basis of the disease. Neurological examinations were performed on all six family members enrolled in this study. Whole-exome sequencing (WES) was used to identify the causative gene for dHMN. The clinical features of the patients included muscle weakness with distal extensor dominancy in the lower extremities, accompanied by facial and neck flexor muscle impairment, no sensory involvement, and areflexia. Nerve conduction studies demonstrated axonal changes mainly in the peroneal nerve. WES combined with rigorous filtering revealed three missense variants (NM_001083964: c.851G > A [p.Arg284His] in TDRKH, NM_002858: c.1654G > T [p.Gly552Cys] in ABCD3, NM_001005164: c.898A > T [p.Ile300Phe], in OR52E2). The variant in TDRKH is located in a conserved region of the tudor domain which is also present in the survival of motor neuron (SMN) protein, encoded by the SMN1 gene. Therefore, we concluded the variant in TDRKH is likely to be responsible for dHMN in our pedigree.

Pathogenesis of Lethal Aspiration Pneumonia in Mecp2-null Mouse Model for Rett Syndrome.

Rett syndrome (RTT) is a neurodevelopmental disorder mainly caused by mutations in the gene encoding the transcriptional regulator Methyl-CpG-binding protein 2 (MeCP2), located on the X chromosome. Many RTT patients have breathing abnormalities, such as apnea and breathing irregularity, and respiratory infection is the most common cause of death in these individuals. Previous studies showed that MeCP2 is highly expressed in the lung, but its role in pulmonary function remains unknown. In this study, we found that MeCP2 deficiency affects pulmonary gene expression and structures. We also found that Mecp2-null mice, which also have breathing problems, often exhibit inflammatory lung injury. These injuries occurred in specific sites in the lung lobes. In addition, polarizable foreign materials were identified in the injured lungs of Mecp2-null mice. These results indicated that aspiration might be a cause of inflammatory lung injury in Mecp2-null mice. On the other hand, MeCP2 deficiency affected the expression of several neuromodulator genes in the lower brainstem. Among them, neuropeptide substance P (SP) immunostaining was reduced in Mecp2-null brainstem. These findings suggest that alteration of SP expression in brainstem may be involved in autonomic dysregulation, and may be one of the causes of aspiration in Mecp2-null mice.

A novel missense variant (Gln220Arg) of GNB4 encoding guanine nucleotide-binding protein, subunit beta-4 in a Japanese family with autosomal dominant motor and sensory neuropathy.

Dominant intermediate Charcot-Marie-Tooth disease F (CMTDIF) is an autosomal dominant hereditary form of Charcot-Marie-Tooth disease (CMT) caused by variations in the guanine nucleotide-binding protein, subunit beta-4 gene (GNB4). We examined two Japanese familial cases with CMT. Case 1 was a 49-year-old male whose chief complaint was slowly progressive gait disturbance and limb dysesthesia that appeared at the age of 47. On neurological examination, he showed hyporeflexia or areflexia, distal limb muscle weakness, and distal sensory impairment with lower dominancy. Nerve conduction studies demonstrated demyelinating sensorimotor neuropathy with reduced action potentials in the lower limbs. Case 2 was an 80-year-old man, Case 1's father, who reported difficulty in riding a bicycle at the age of 76. On neurological examination, he showed areflexia in the upper and lower limbs. Distal sensory impairment in the lower limbs was also observed. Nerve conduction studies revealed mainly axonal involvement. Exome sequencing identified a novel heterozygous nonsynonymous variant (NM_021629.3:c.659T > C [p.Gln220Arg]) in GNB4 exon 8, which is known to be responsible for CMT. Sanger sequencing confirmed that both patients are heterozygous for the variation, which causes an amino acid substitution, Gln220Arg, in the highly conserved region of the WD40 domain of GNB4. The frequency of this variant in the Exome Aggregation Consortium Database was 0.000008247, and we confirmed its absence in 502 Japanese control subjects. We conclude that this novel GNB4 variant is causative for CMTDIF in these patients, who represent the first record of the disease in the Japanese population.

Essential Tremor with Aspartic Acidemia.

We describe two cases of typical essential tremor with aspartic acidemia and mildly increased concentrations of plasma glutamic acid. Although this is a preliminary report, we emphasize the possibility of using amino acids, including aspartic acid, as biomarkers for the detection of essential tremor.

Questionnaire survey on recruitment for Japanese Neurology Society.

Many claim that they do not have enough neurologists in Japan, but supply and demand of neurologists remains to be analyzed. To investigate the recruitment for the Japanese Society of Neurology (JSN), the subcommittee of JSN for education performed a questionnaire-based survey in 80 medical universities and 271 board-certified education facilities throughout Japan. The response rate to the questionnaire was 77.5% in medical universities and 42.4% in education facilities. It was shown that each department of neurology in university recruits average 2.2 doctors, while they supposed that more than 4 doctors to be recruited every year. The questionnaire survey included what measures JSN should take in order to promote recruitment for JSN.

A novel frameshift mutation of DDHD1 in a Japanese patient with autosomal recessive spastic paraplegia.

Spastic paraplegia (SPG) type 28 is an autosomal recessive SPG caused by mutations in the DDHD1 gene. We examined a Japanese 54-years-old male patient with autosomal recessive SPG. His parents were consanguineous. He needed a wheelchair for transfer due to spastic paraplegia. There was a history of operations for bilateral hallux valgus, thoracic ossification of the yellow ligament, bilateral carpal tunnel syndrome, bilateral ankle contracture, and lumbar spinal canal stenosis. He noticed gait disturbance at age 14. He used a cane for walking in his 40s. On neurological examination, he showed hyperreflexia, spasticity, and weakness in the lower extremities and bilateral Babinski reflexes. Urinary dysfunctions and impaired vibration sense in the lower limbs were observed. By exome sequencing analysis using Agilent SureSelect and Illumina MiSeq, we identified 17,248 homozygous nucleotide variants in the patient. Through the examination of 48 candidate genes known to be responsible for autosomal recessive SPG, we identified a novel homozygous 4-bp deletion, c.914_917delGTAA, p.Ser305Ilefs*2 in exon2 of the DDHD1 gene encoding phosphatidic acid-preferring phospholipase A1 (PA-PLA1). The mutation is expected to cause a frameshift generating a premature stop codon 3-bp downstream from the deletion. In consequence, the DDHD domain that is known to be critical for PLA1 activity is completely depleted in the mutated DDHD1 protein, predicted to be a functionally null mutation of the DDHD1 gene. By Sanger sequencing, we confirmed that both parents are heterozygous for the mutation. This variation was not detected in 474 Japanese control subjects as well as the data of the 1,000G Project. We conclude that the novel mutation in DDHD1 is the causative variant for the SPG28 patient that is the first record of the disease in Japanese population.

A novel missense mutation of RYR1 in familial idiopathic hyper CK-emia.

Persistent elevation of serum creatine kinase (CK) without any symptoms has been called idiopathic hyper CK-emia (IHCK). We examined a four-generation Japanese pedigree of familial IHCK. The multipoint linkage analysis of the pedigree showed seven clear peaks of logarithm of odds (LOD) scores (>1.4). By the exome sequencing followed by multiple filtering processes, we identified one novel heterozygous nonsynonymous single nucleotide variant (SNV), c.7034G>C, p.S2345T in the ryanodine receptor 1 gene, RYR1 cosegregated with IHCK in the pedigree. Mutation Taster predicted this substitution as "disease causing" (p=0.999). The PolyPhen-2 and PANTHER subPSEC scores for the substitution are 0.911 (possibly damaging) and -3.56 (probably damaging), respectively. We confirmed the absence of the SNV in 511 healthy Japanese individuals excluding the possibility of a normal variant with a very low frequency. Immunohistochemistry and Western blotting of biopsy samples consistently showed the expression level of RYR1 reduced in the patient. In real-time RT-PCR, the mRNA expression level of RYR1 was also significantly reduced in the patient (p=0.009). These results suggest that the novel nonsynonymous SNV contribute to the vulnerability of the RYR1 protein through the dominant negative effect. We conclude that the SNV in the RYR1 gene is one of the responsible genes of IHCK.

[Actual state and problems in neurology training in medical schools].

To investigate the need for pre- and post-graduate education for neurologists, the subcommittee of the Japanese Society of Neurology for education performed a questionnaire-based survey in 80 medical universities throughout Japan. The response rate to the questionnaire was 82.5%. Textbooks for lectures for medical students were used in only 22.7% of those universities. If the Japanese Society of Neurology (JSN) made a standard text, 77.8% of universities would like to use it. Most of the training programs for residents were compatible with the minimum requirements of the JSN. Just 66.7% of those training programs were completed in their own institute, and 77.3% of universities required help from the JSN.

[Actual state and problems in neurology training at hospital].

To evaluate postgraduate neurological education, a questionnaire-based survey regarding junior and senior doctor-in-training and the Board Certification Examination in Neurology was carried out on the training supervisors of 690 insitutes, excluding 80 university hospitals. The institutes included 243 teaching hospitals, 326 semi-teaching hospitals and 121 education-associated institutes authorized by the Japanese Society of Neurology (JSN). The results were obtained from 388 institutes, and the response rate was 56.2%. The percentage of junior doctors-in-training that received training in neurology was 68.6% (the average of 2.1 months during 2 years). More than half of the institutes did not have any teaching programs for junior doctors-in-training who did not train in neurology. In senior doctors-in-training, the number of senior doctors-in-trainings per year per institute was 0.44 and was only able to experience limited types of disorders. Also, many institutes could not achieve training goals by the institutes themselves (56%). The problems were due to lack of teaching staffs and manpower, and there were many requests to the Society regarding training methods. As for the Board Certification Examination in Neurology by the Society, it was revealed that there were small number of candidates per year per institute, and over half of institutes could not sufficiently teach and support them. Most requests to the Society were regarding teaching seminars and hands-on courses, and some institutes asked small group meetings for arts and techniques of neurology to be held the Regional Society. In conclusion, there are problems that cannot be solved by individual institutes alone, and we need procedures for postgraduate training in neurology that is organized by the Regional and JSN working as the central organization.