In Japan, there are no nationwide guidelines for presymptomatic testing for hereditary neuromuscular diseases. Although each institution has been dealing with this situation by using their own procedures to date, it is necessary to develop a standardized guidelines based on the Japanese medical system, because the development of disease-modifying therapies has progressed, and we are entering an era in which early diagnosis and early treatment are necessary. The guidelines presented here were devised by the Committee on Medical Genetics of the Japan Neurological Society. During their development, Delphi surveys were conducted among individuals with extensive experience in presymptomatic testing throughout Japan, with 42 experts participating in all three surveys, and a consensus-building process was undertaken. Finally, the guidelines consist of 45 recommendations for performing presymptomatic testing for adult-onset inherited neurological and muscular diseases.

A 78-years-old man was treated for asthma and pansinusitis for >5 years, and mepolizumab was initiated two years previously. Two months after the cessation of mepolizumab treatment, the asthma symptoms worsened and acute progressive muscle weakness and sensory disturbance developed. On day 8 after the onset of weakness and hypoesthesia, the patient presented with complete flaccid tetraplegia and diffuse hypoesthesia of all extremities, without paresthesia or pain, and was admitted to our hospital. Blood tests revealed eosinophilia without anti-neutrophil cytoplasmic antibody elevation. Nerve conduction studies revealed severe axonal polyneuropathy and multifocal absent F-waves. Cerebrospinal fluid was normal. Eosinophilic granulomatosis with polyangiitis (EGPA) and Guillain–Barré syndrome (GBS) were suspected, and high-dose methylprednisolone was administered, followed by oral prednisolone. Eosinophils rapidly disappeared; however, the neurological symptoms did not improve. On day 16, sural nerve biopsy revealed myelinated fiber loss in most of the fibers in every nerve bundle regardless of fiber size, while eosinophilic infiltration in the epineurium and findings suggestive of necrotizing vasculitis were not observed. The results did not fulfill the pathological criteria for EGPA but supported the changes in vasculitis; hence, EGPA was diagnosed. Intravenous immunoglobulin, azathioprine, and rituximab were administered, and the prednisolone dose was gradually reduced to 10 ‍mg/d. The eosinophil count increased to 50/μl without pneumonia recurrence or worsening asthma. Neuropathy in the upper limbs gradually improved over two years, whereas that in the lower limbs did not change. This is the first reported case of sequential exacerbation of asthma and onset of EGPA after mepolizumab discontinuation. Among patients with asthma, the cessation of mepolizumab treatment may lead to the development of EGPA with an atypical clinical course, such as rapidly progressive severe neuropathy mimicking GBS.

This study investigated two cases. Case 1 involves a 53-year-old man who suffered from sleep apnea syndrome at age 48. Moreover, he was involved in a rear-end collision while driving and was admitted to the hospital at age. He exhibited impaired consciousness, postural tremors, and bradykinesia in the upper extremities. Subsequently, he was managed on a ventilator due to unexplained alveolar hypoventilation. Case 2 is his younger sister, a 46-year-old woman, who was being treated for depression and began to show signs of parkinsonism around age 43. The metaiodobenzylguanidine (MIBG) myocardial scintigraphy results were normal in both cases. Given that their father was also managed on a ventilator due to unexplained alveolar hypoventilation, exome analyses were performed. Both were found to have a previously reported heterozygous mutation (p.Y78C) in the DCTN1 gene and were diagnosed with Perry disease. Although MIBG myocardial scintigraphy is a useful test for diagnosing Perry disease, it is important to note that there are cases where it may yield normal results.

An 86-year-old male patient developed paresthesia in both hands, and six months later, pancytopenia was noted. He was diagnosed with myelodysplastic syndrome following bone marrow aspiration. Despite high serum vitamin B12 level, elevated level of serum homocysteine, positive anti-intrinsic factor antibody, and T₂-weighted hyperintense lesions on spinal cord MRI led to a diagnosis of subacute combined degeneration of the spinal cord. Treatment with intramuscular mecobalamin injections improved the pancytopenia and resolved the MRI lesions. The pancytopenia in this patient was considered to be caused by pernicious anemia. The presence of anti-intrinsic factor antibody can cause falsely normal or elevated serum vitamin B12 levels. When patients with pancytopenia report numbness, even without a decrease in serum vitamin B12 levels, pernicious anemia and subacute combined degeneration of the spinal cord should be suspected, and measurements of serum homocysteine and anti-intrinsic factor antibodies should be considered.

In an 81-year-old man, brain diffusion-weighted MRI revealed punctate high-intensity lesions in the bilateral frontal cortex. Three months later, these lesions had extended into the cerebral cortices. Six months after the original MRI, the patient developed cognitive decline. Clinically, he appeared to have Creutzfeldt–Jakob disease (CJD) based on brain MRI and cerebrospinal fluid examination findings. We identified a compound heterozygous mutation (V180I/M232R) in PRNP and diagnosed him with genetic CJD. This case of CJD with a compound heterozygous PRNP mutation had a relatively old onset, slowly progressive course, and low frequency of periodic synchronous discharges. Additionally, we detected CJD-associated brain MRI abnormalities before symptom onset. Reports of presymptomatic CJD such as the present case are important for the development of new therapeutic agents for CJD.

A 49-year-old female presented with the primary complaint of hand tremors. Neurological examination on admission revealed signs of cognitive impairment, bulbar palsy, dystonia, cerebellar ataxia, and pyramidal tract disease. T₂-weighted brain MRI revealed hyperintense signals in the subcortical white matter, basal ganglia, and cerebellar dentate nucleus, with no atrophy of the brainstem or corpus callosum. Urinary organic acid analysis revealed elevated 2-hydroxyglutaric acid levels. Although the optical isomers could not be distinguished, L-2-hydroxyglutaric aciduria was diagnosed based on the disease course, symptoms, and characteristic MRI findings. The patient was started on riboflavin-enriched compounds and levocarnitine, resulting in an improvement in the Scale for the Assessment and Rating of Ataxia (SARA) score from 21 to 15 after six months. The case suggests that symptoms in adult patients who have not been treated for a long time can be improved by appropriate diagnosis based on neurological presentation, characteristic MRI findings, and intervention.

The patient was a 33-year-old woman with no family history of a similar disorder. At one year of age, she exhibited scoliosis and respiratory failure, necessitating a tracheostomy performed at 5 years of age (1990s). During that time, the patient was provisionally diagnosed with “non-Fukuyama congenital muscular dystrophy” via muscle biopsy. Difficulties in independent walking and standing emerged by 14 years of age, progressing to significant mobility challenges by 21 years of age. The patient was referred to our department at 33 years of age for the transition to adult care. The examination revealed predominant trunk muscle weakness, persistent scoliosis, restricted neck and trunk mobility, significant restrictive ventilatory impairment, and mild intellectual developmental delay. Reanalysis of the muscle biopsy pathology was conducted, and genetic testing identified a known homozygous mutation, c.1574T>G (p.M525R), in the SELENON (SEPN1) gene, leading to a diagnosis of SELENON-related myopathy. The pediatric-to-adult healthcare transition can provide a valuable opportunity for the reassessment of diagnoses and disabilities.

The patient was a 21-year-old female. She had frequently had status seizures when she had a fever or while taking a bath since she was 6 months old. At 1 year and 8 months old, she developed epilepsy. She was treated with multiple antiepileptic drugs, but her condition was intractable. At the age of 3, the patient suffered from acute encephalopathy, which was complicated by severe psychomotor developmental retardation. Tonic seizures continued to occur on a daily basis even after school age, but they did not worsen even during periods of fever, and the patient was not hospitalized until the age of 8. At the age of 19, the diagnosis was revised and Dravet syndrome was diagnosed. Lamotrigine, which had been taken at the time of diagnosis, was discontinued and stiripentol was administered, but the seizure frequency worsened. Because of the pathology of Dravet syndrome in adults may differ from that in children, care must be taken when selecting antiepileptic drugs.

Figures are essential components of case reports, often conveying information more effectively than the text. Common figure types include images, pathology slides, photographs, schematic drawings, and clinical courses. Each figure type should follow four design principles: alignment, repetition, proximity, and contrast. Precise “alignment” of elements and “repetition” with font usage are crucial for improving clarity. Employing “contrast,” such as arrows to highlight specific areas, can also significantly improve visual impact. Additionally, enlarged views or detailed schematics can be beneficial in certain cases. Creating figures early in the process can boost your motivation to write case reports. The enjoyment of writing case reports lies in discovering the key learning points of the case and summarising them. Additionally, creating figures for your case can be enjoyable.