De novo non-synonymous DPYSL2 (CRMP2) variants in two patients with intellectual disabilities and documentation of functional relevance through zebrafish rescue and cellular transfection experiments.

Collapsin response mediator protein 2 (Crmp2) is an evolutionarily well-conserved tubulin-binding cytosolic protein that plays critical roles in the formation of neural circuitry in model organisms including zebrafish and rodents. No clinical evidence that CRMP2 variants are responsible for monogenic neurogenic disorders in humans presently exists. Here, we describe two patients with de novo non-synonymous variants (S14R and R565C) of CRMP2 and intellectual disability associated with hypoplasia of the corpus callosum. We further performed various functional assays of CRMP2 variants using zebrafish and zebrafish Crmp2 (abbreviated as z-CRMP2 hereafter) and an antisense morpholino oligonucleotide [AMO]-based experimental system in which crmp2-morphant zebrafish exhibit the ectopic positioning of caudal primary (CaP) motor neurons. Whereas the co-injection of wild-type z-CRMP2 mRNA suppressed the ectopic positioning of CaP motor neurons in Crmp2-morphant zebrafish, the co-injection of R566C or S15R, z-CRMP2, which corresponds to R565C and S14R of human CRMP2, failed to rescue the ectopic positioning. Transfection experiments of zebrafish or rat Crmp2 using plasmid vectors in HeLa cells, with or without a proteasome inhibitor, demonstrated that the expression levels of mutant Crmp2 protein encoded by R565C and S14R CRMP2 variants were decreased, presumably because of increased degradation by proteasomes. When we compared CRMP2-tubulin interactions using co-immunoprecipitation and cellular localization studies, the R565C and S14R mutations weakened the interactions. These results collectively suggest that the CRMP2 variants detected in the present study consistently led to the loss-of-function of CRMP2 protein and support the notion that pathogenic variants in CRMP2 can cause intellectual disabilities in humans.

An autopsied case report of spastic paraplegia with thin corpus callosum carrying a novel mutation in the SPG11 gene: widespread degeneration with eosinophilic inclusions.

BACKGROUND: The detailed neuropathological features of patients with autosomal recessive hereditary spastic paraplegia with a thin corpus callosum (TCC) and SPG11 mutations are poorly understood, as only a few autopsies have been reported. Herein, we describe the clinicopathological findings of a patient with this disease who received long-term care at our medical facility. CASE PRESENTATION: A Japanese man exhibited a mild developmental delay in early childhood and intellectual disability, followed by the appearance of a spastic gait by age 13. At the age of 25 years, he became bedridden and needed a ventilator. Genetic analysis revealed a homozygous splice site variant in the SPG11 gene (c. 4162-2A > G) after the provision of genetic counselling and acquisition of informed consent from his parents. He died of pneumonia at the age of 44. His brain weighed 967 g and was characterized by a TCC, and his spinal cord was flattened. Microscopically, degeneration was observed in the posterior spinocerebellar tract, the gracile fasciculus, and the posterior column in addition to the corticospinal tract. Marked neuronal loss and gliosis were observed in the anterior horn, Clarke's column, and hypoglossal and facial nuclei. Various types of neurons, in addition to motor neurons, showed coarse eosinophilic granules that were immunoreactive for p62. The loss of pigmented neurons with gliosis was apparent in both the substantia nigra and locus coeruleus. Lateral geniculate body degeneration was a characteristic feature of this patient. Furthermore, peripheral Lewy body-related α-synucleinopathy and scattered α-synuclein-immunoreactive neurites in the locus coeruleus and reticular formation of the brainstem were observed. CONCLUSIONS: In patients with hereditary spastic paraplegia with SPG11 mutations, a variety of clinical phenotypes develop due to widespread lesions containing p62-immunoreactive neuronal cytoplasmic inclusions. We herein report the lateral geniculate body as another degenerative site related to SPG11-related pathologies that should be studied in future investigations.

Endothelial Microsomal Prostaglandin E Synthetase-1 Upregulates Vascularity and Endothelial Interleukin-1ß in Deteriorative Progression of Experimental Autoimmune Encephalomyelitis.

Microsomal prostaglandin E synthetase-1 (mPGES-1) is an inducible terminal enzyme for the production of prostaglandin E2 (PGE2). In experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis, mPGES-1 is induced in vascular endothelial cells (VECs) around inflammatory foci and facilitates inflammation, demyelination, and paralysis. Therefore, we investigated the role of CD31-positive VECs in mPGES-1-mediated EAE aggravation using immunohistochemical analysis and imaging of wild-type (wt) and mPGES-1-deficient (mPGES-1-/-) mice. We demonstrated that EAE induction facilitated vascularity in inflammatory lesions in the spinal cord, and this was significantly higher in wt mice than in mPGES-1-/- mice. In addition, endothelial interleukin-1ß (IL-1ß) production was significantly higher in wt mice than in mPGES-1-/- mice. Moreover, endothelial PGE2 receptors (E-prostanoid (EP) receptors EP1⁻4) were expressed after EAE induction, and IL-1ß was induced in EP receptor-positive VECs. Furthermore, IL-1 receptor 1 expression on VECs was increased upon EAE induction. Thus, increased vascularity is one mechanism involved in EAE aggravation induced by mPGES-1. Furthermore, mPGES-1 facilitated the autocrine function of VECs upon EP receptor induction and IL-1ß production, modulating mPGES-1 induction in EAE.

Microsomal Prostaglandin E Synthase-1 Facilitates an Intercellular Interaction between CD4⁺ T Cells through IL-1ß Autocrine Function in Experimental Autoimmune Encephalomyelitis.

Microsomal prostaglandin synthetase-1 (mPGES-1) is an inducible terminal enzyme that produces prostaglandin E2 (PGE2). In our previous study, we investigated the role of mPGES-1 in the inflammation and demyelination observed in experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis, using mPGES-1-deficient (mPGES-1-/-) and wild-type (wt) mice. We found that mPGES-1 facilitated inflammation, demyelination, and paralysis and was induced in vascular endothelial cells and macrophages and microglia around inflammatory foci. Here, we investigated the role of interleukin-1ß (IL-1ß) in the intercellular mechanism stimulated by mPGES-1 in EAE spinal cords in the presence of inflammation. We found that the area invaded by CD4-positive (CD4⁺) T cells was extensive, and that PGE2 receptors EP1-4 were more induced in activated CD4⁺ T cells of wt mice than in those of mPGES-1-/- mice. Moreover, IL-1ß and IL-1 receptor 1 (IL-1r1) were produced by 65% and 48% of CD4⁺ T cells in wt mice and by 44% and 27% of CD4⁺ T cells in mPGES-1-/- mice. Furthermore, interleukin-17 (IL-17) was released from the activated CD4⁺ T cells. Therefore, mPGES-1 stimulates an intercellular interaction between CD4⁺ T cells by upregulating the autocrine function of IL-1ß in activated CD4⁺ T cells, which release IL-17 to facilitate axonal and myelin damage in EAE mice.

[Safety and efficacy of surgical closure of the larynx for recurrent aspiration pneumonia in persons with severe motor and intellectual disabilities: a comparative study with tracheoesophageal diversion].

OBJECTIVE: We retrospectively investigated the efficacy and complications of surgical closure of the larynx (SCL) for recurrent aspiration pneumonia in comparison with tracheoesophageal diversion. METHODS: The subjects were persons with severe motor and intellectual disabilities (SMID) who had undergone surgery for recurrent aspiration pneumonia between 1994 and 2011: A 8 SCL patients group and a 16 tracheoesophageal diversion patients group. We investigated two groups the lower respiratory infection incidence, length of hospital stay for the surgery, postoperative complications, and rate of cannula withdrawal, by reviewing medical records. RESULTS: Both the SCL and the tracheoesophageal diversion group showed a reduction in the incidence of infection after surgery, indicating that the efficacy of SCL was equivalent to that of tracheoesophageal diversion in preventing aspiration pneumonea. The SCL group showed a reduction in the length of hospital stay and an increased rate of cannula withdrawal as compared with the tracheoesophageal diversion group. CONCLUSION: The efficacy of SCL was equivalent to that of tracheoesophageal diversion in preventing aspiration for SMID. We consider SLC to have potential for reducing the burden on patients.

Charcot-Marie-Tooth disease type 4C in Japan: report of a case.

INTRODUCTION: The distribution of documented cases of Charcot-Marie-Tooth disease type 4C (CMT4C) is mainly limited to the Mediterranean region. We report the first documented case of CMT4C in East Asia. Furthermore, we estimate the proportion of CMT4C in Japan and compare the same with that in European countries. CASE REPORT: A 72-year-old Japanese woman presented with early-onset motor and sensory neuropathy associated with scoliosis, deformities of the hands and feet, and carpal tunnel syndrome. A genetic screen detected a homozygous p.R529Q mutation in SH3TC2, the causative gene of CMT4C. The SH3TC2 mutation identified here is unique among 426 unrelated Japanese CMT patients, excluding those with CMT1A. CONCLUSIONS: Although CMT4C also occurs in Japan, it is less common than in European countries.

Medical Needs of Adults with Down Syndrome Presenting at a Regional Medical and Rehabilitation Center in Japan.

BACKGROUND: Down syndrome (DS) is the most frequent chromosomal aberration; however, knowledge of associated health issues in adulthood is inadequate. We analyzed health data from Japanese adults with DS. METHODS: We conducted a retrospective chart review of 151 patients with DS who visited the Internal Medicine Outpatient Department of the Tokyo Metropolitan Kita Medical and Rehabilitation Center for the Disabled. RESULTS: Endocrine disorders such as obesity, hyperlipidemia, and hyperuricemia were most common in adulthood (≤40 years) and senescence (>40 years); neurological diseases were more prevalent in senescence. Multimorbidity was noted even patients with DS who were younger than 30 years, and the prevalence increased with age. Only 21 patients (13.9%) with DS visited our hospital with referral letters from pediatricians; 94 patients (62.3%) visited without such referrals from other medical institutions. Patients without a referral letter had a mean of 3.1 comorbidities per patient. Moreover, medical care for some people with DS was interrupted during childhood. CONCLUSIONS: Prevention and detection of comorbidities in patients with DS requires continuous medical care from childhood through adulthood. Recently, DS has been diagnosed by chromosome testing and genetic counseling. Clinical geneticists and genetic counselors can help patients with DS, and their caregivers, to obtain appropriate health care and achieve well-being on their own by seamlessly engaging them throughout childhood and adulthood.

Benefits and Challenges of Pediatric-to-Adult Health Care Transition in Childhood-Onset Neurologic Conditions.

Background and Objectives: Although the importance of pediatric-to-adult health care transition (HCT) has been recognized, individuals with childhood-onset neurologic conditions often encounter challenges during pediatric-to-adult HCT, and HCT benefits for this population remain elusive. We assessed the current HCT situation in individuals with childhood-onset neurologic conditions to develop an improved transition system that incorporates patient perspectives. Methods: This cross-sectional study was conducted at the Tokyo Metropolitan Kita Medical and Rehabilitation Center for the Disabled from November 2020 to December 2020. We targeted adults with childhood-onset neurologic conditions who visited the Department of Internal Medicine and their families. Questionnaires provided to 127 patients asked them about their experiences with pediatric-to-adult HCT (i.e., educational opportunities regarding HCT during pediatric visits, difficulties in transition, and the merits/demerits of adult practice) and their families' perspectives regarding pediatric-to-adult HCT. We also reviewed the patients' medical records to examine the severity of their disabilities. Results: Responses were collected from 111 patients (response rate: 87%). Most patients had both severe physical and intellectual disabilities, and approximately half had a physical disability level of Gross Motor Function Classification System V and a profound intellectual disability. Half of the respondents were not transitioned through pediatric-to-adult HCT by their pediatricians, and they visited adult departments by themselves without a formal referral process. They experienced difficulties during HCT, such as a lack of knowledge regarding adult health care providers and consultants. However, those who underwent HCT benefited from it in terms of their health, experience, and service use, such as age- and condition-appropriate care, seeing adult specialists, and the introduction of adult services. They also addressed challenges in managing appointments and having adult doctors understand their medical history. Nonetheless, they were not informed about diseases and medical and welfare resources for adulthood during pediatric visits and desired to discuss future plans with pediatricians. Discussion: Systems that provide sufficient pediatric-to-adult HCT for individuals with childhood-onset neurologic conditions are required. Lifelong education for patients and families, training for pediatricians on HCT and neurologists on childhood-onset conditions and disabilities, and clinical practice and human resources that support patients and families are warranted.

[Effect of laryngeal closure on recurrent aspiration pneumonia in patients with neurodegenerative disease].

Three patients with neurodegenerative diseases who had developed repeated aspiration pneumonia underwent laryngeal closure, a surgical procedure at the larynx to prevent aspiration. None of these patients have developed aspiration pneumonia since the procedure. One patient needed endoscopic suction and cough assist machine to clear thick sputum, because tracheostomy bypassed the upper airway and so prevented moisturization of inhaled air. While two patients achieved freedom from tracheal cannulation, one needed continued cannulation because of narrowing of the stoma due to improvements in the nutritional condition. One patient was able to resume oral intake. Although the right timing to perform the procedure and optimal care along with long-term observation are important, laryngeal closure is an effective option for patients with neurodegenerative diseases to prevent recurrent aspiration pneumonia.

[Investigation of transition from pediatric to adult health care for patients with special health-care needs for neurological disease dating from childhood].

We investigated the patients followed in our hospital's adult neurology department to evaluate issues during the transition from pediatric to adult health care for patients with special health-care needs for neurological diseases. There has been an increase in the number of transition patients, and they were often recommended for the transition by pediatricians. Many patients had complications such as epilepsy, and there were also patients with an intractable disease. Therefore, patients undergoing this transition need neurologists. The transition requires a long time, and there is a difference in the medical administrative fees between pediatric and adult health care. The Japanese Society of Neurology and related societies need to take measures to improve these health-care transitions.

High frequency of beta-propeller protein-associated neurodegeneration (BPAN) among patients with intellectual disability and young-onset parkinsonism.

Neurodegeneration with brain iron accumulation (NBIA) is a genetically heterogeneous disorder, characterized by the accumulation of iron in regions such as the basal ganglia. We enrolled 28 patients with childhood intellectual disability and young-onset parkinsonism (≤40 years at onset) and 4 patients with infantile neuroaxonal dystrophy. All had been clinically diagnosed, and the prevalence of genetic mutations linked to NBIA (PANK2 [exons 1-7], PLA2G6 [exons 2-17], C19orf12 [exons 1-3], WDR45 [exons 2-11], COASY [exons 1-9], FA2H [exons 1-7], and RAB39B [exons 1, 2]) was evaluated. We detected 7 female patients (25.0%, 7 of 28) with de novo heterozygote WDR45 mutations, which are known to be pathogenic for beta-propeller protein-associated neurodegeneration. All 7 patients had common clinical features. Pathogenic mutations in other NBIA genes were not found. We also screened 98 patients with early-onset parkinsonism without intellectual disability and 110 normal controls of Japanese origin for WDR45 mutations. None had WDR45 mutations. Our data suggest a high frequency of beta-propeller protein-associated neurodegeneration mutations in the Japanese population.

Traveled distance is a sensitive and accurate marker of motor dysfunction in a mouse model of multiple sclerosis.

Multiple sclerosis (MS) is a common central nervous system disease associated with progressive physical impairment. To study the mechanisms of the disease, we used experimental autoimmune encephalomyelitis (EAE), an animal model of MS. EAE is induced by myelin oligodendrocyte glycoprotein35-55 peptide, and the severity of paralysis in the disease is generally measured using the EAE score. Here, we compared EAE scores and traveled distance using the open-field test for an assessment of EAE progression. EAE scores were obtained with a 6-step observational scoring system for paralysis, and the traveled distance was obtained by automatic trajectory analysis of natural exploratory behaviors detected by a computer. The traveled distance of the EAE mice started to decrease significantly at day 7 of the EAE process, when the EAE score still did not reflect a change. Moreover, in the relationship between the traveled distance and paralysis as measured by the EAE score after day 14, there was a high coefficient of determination between the distance and the score. The results suggest that traveled distance is a sensitive marker of motor dysfunction in the early phases of EAE progression and that it reflects the degree of motor dysfunction after the onset of paralysis in EAE.

Microsomal prostaglandin E synthase-1 aggravates inflammation and demyelination in a mouse model of multiple sclerosis.

Microsomal prostaglandin synthetase-1 (mPGES-1) is an inducible terminal enzyme required for prostaglandin E(2) (PGE(2)) biosynthesis. In this study, we examined the role of mPGES-1 in the inflammation and demyelination observed in experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis (MS). We induced EAE with myelin oligodendrocyte glycoprotein(35-55) peptide in mPGES-1-deficient (mPGES-1(-/-)) and wild-type (WT) mice. First, we examined the histopathology in the early and late phases of EAE progression. Next, we measured the concentration of PGE(2) in the spinal cord and investigated the expression of mPGES-1 using immunohistochemistry. In addition, we examined the progression of the severity of EAE using an EAE score to investigate a correlation between pathological features and paralysis. In this paper, we demonstrate that WT mice showed extensive inflammation and demyelination, whereas mPGES-1(-/-) mice exhibited significantly smaller and more localized changes in the perivascular area. The mPGES-1 protein was induced in vascular endothelial cells and microglia around inflammatory foci, and PGE(2) production was increased in WT mice but not mPGES-1(-/-) mice. Furthermore, mPGES-1(-/-) mice showed a significant reduction in the maximum EAE score and improved locomotor activity. These results suggest that central PGE(2) derived from non-neuronal mPGES-1 aggravates the disruption of the vessel structure, leading to the spread of inflammation and local demyelination in the spinal cord, which corresponds to the symptoms of EAE. The inhibition of mPGES-1 may be useful for the treatment of human MS.