Benign adult familial myoclonus epilepsy (BAFME) is an autosomal dominantly inherited disease characterized by infrequent seizures and tremorous myoclonus. The disease is also called familial adult myoclonic epilepsy (FAME) or familial cortical myoclonic tremor with epilepsy (FCMTE). Although the causes of BAFME had been unknown for a long, we identified TTTCA and TTTTA repeat expansions in intron 4 of SAMD12 as a cause of BAFME type 1. We also found TTTCA and TTTTA repeat expansions in TNRC6A and RAPGEF2 also cause the disease (BAFME types 6 and 7, respectively), thus proposing a concept of repeat motif–phenotype correlation. After that, TTTCA and TTTTA repeat expansions in STARD7, MARCHF6, YEATS2, and RAI1 have been identified as causes of BAFME types 2, 3, 4, and 8. The findings further supported the concept. The involvement of RNA-mediated toxicity, particularly of UUUCA repeats, is assumed to be the pathomechanism of this disease. The next step will be understanding the molecular pathomechanism of BAFME and identifying molecular targets of more efficient therapeutic approaches.

The Special Committee on Measures for Transition from Pediatric to Adult Health Care surveyed approximately 9,000 members of the Japanese Society of Neurology regarding transitional care. Only 744 responses were returned, less than 10% of the total number of members contacted. More than half answered that they generally provide treatment for adult patients with a childhood-onset disease, with many noting as reasons that the related diseases and ages in such cases are targeted by neurology specialists, and that other adult medical departments are not equipped to treat them. As for reasons given for not treating such patients, lack of knowledge related to developmental disorders, lack of support system, and difficulties with communication were noted. There were no noticeable differences in the responses of providing treatment for adult patients with a childhood-onset disease in association with the affiliated regional association or branch. These results indicate that resolution of issues related to neurologist unfamiliarity with pediatric neurological disorders and lack of relevant information are important issues to be addressed for establishment of a smooth medical care transition.

A 54-years-old Japanese man visited local hospital with six-month history of progressive numbness and muscle weakness in his lower limbs. He was diagnosed with POEMS syndrome based on positive serum M-protein, elevated serum VEGF, and splenomegaly. MRI showed multiple cerebral infarcts in the watershed area, and MRA showed complete vascular occlusion of the right internal carotid artery and severe vascular stenosis of the left common carotid artery, suggesting hemodynamic cerebral infarction. He was referred to our department and treated with three courses of Daratumumab-Bortezomib-Dexamethasone (DBd) therapy. After normalization of VEGF was confirmed, right superficial temporal artery-middle cerebral bypass surgery was performed. He has been kept in good condition with improved muscle strength and walking ability, and normalized VEGF level under the maintenance Daratumumab-Lenalidomide-Dexamethasone (DLd) therapy. Because POEMS syndrome-associated vasculopathy can develop even in the very early stage of the disease, intensive evaluation of craniocervical vessels before treatment initiation is very important for treatment selection and risk assessment.

We report a 54-year-old woman previously healthy who developed acute fever, headache, and impaired consciousness. We administered corticosteroid therapy as autoimmune mediated meningoencephalitis, which improved her symptoms and reduced cerebrospinal IL-6 level, but her cognitive impairment persisted. Contrast-enhanced MRI showed diffuse meningeal enhancement lesion, which led us to the possibility of leptomeningeal amyloidosis (LA). We performed transthyretin gene analysis identified heterozygosity for the c.265T>C, p.Y89H (Y69H) variant, which is known as one of the causative mutations of familial LA. Given the responsiveness to steroid treatment, it is possible that the inflammatory pathology related to amyloid deposition in leptomeninges with encephalitis-like symptoms contributed to the prolonged duration of symptoms lasting from hours to days.

A 23-year-old female student was admitted to a local hospital because of consciousness disturbance caused by diabetic ketoacidosis on the 4th day after COVID-19 infection. She was subsequently transferred to our hospital, having developed respiratory failure, acute renal failure and DIC. Although intensive treatment improved her condition, she remained hypoactive. Brain MRI revealed multiple microbleeds (MBs) spreading to the subcortical white matter, internal capsule, splenium of the corpus callosum and brainstem. The WAIS-IV score suggested general attention deficit disorder and mild impairment of working memory and processing speed. These symptoms disappeared with time, and she was able to return to her studies without any after-effects. COVID-19 tends to cause thrombosis and MBs in the brain due to vascular endothelial damage. Although the reason for the specific localization of these MBs remains unclear, differences in regional vulnerability to cytokines may have been partly responsible.

We present a case of a 66-year-old man who initially presented with spinal cord lesions and was ultimately diagnosed with intravascular large B-cell lymphoma (IVLBCL) by autopsy after two inconclusive random skin biopsies (RSB). Prior steroid use may have contributed to the reduced diagnostic sensitivity of the skin biopsies. Given that brain and spinal cord biopsies are highly invasive, if IVLBCL of the central nervous system is strongly suspected for such reasons as elevated IL-10 in the cerebrospinal fluid, positron emission tomography (PET) may help identify non-neural or non-nervous organ lesions as the target of subsequent biopsies, potentially allowing the definite histological diagnosis when RSB are inconclusive.

A woman in her 50s. Since October of X−1, she had been suffering from lower back and occipital pain. Despite undergoing medical evaluations at multiple hospitals, no discernible abnormalities were identified. As her symptoms worsened, she presented to our department in January of X, reporting severe pain in the left occipital to posterior neck that increased with both neck flexion and extension. A neurological examination revealed a left-sided deviation of the tongue (left hypoglossal nerve paralysis). A head MRI revealed signal abnormalities in the left occipital condyle and multiple nodules with contrast effects in the brain parenchyma. A computed tomography (CT) scan revealed a mass in the left lung, multiple intrahepatic masses, and bone destruction in the spine and left occipital condyle. In light of these findings, a diagnosis of lung cancer with metastasis to multiple organs and occipital condyle syndrome due to metastasis to the left occipital condyle was suspected. Subsequent cytological analysis of bronchoalveolar lavage fluid and liver biopsy substantiated the diagnosis of adenocaricinoma. The subsequent administration of osimertinib, an epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor, led to a reduction in the size of the tumor, as well as improvements in the hypoglossal nerve palsy and occipital pain. It is imperative to note that occipital condyle syndrome signifies the metastasis of a malignancy to the base of the skull, necessitating meticulous observation and management.

This patient was a 78-year-old woman. In year X−23, she presented with gait disturbance and sensory impairment below the chest level and was diagnosed with and treated for acute transverse myelitis. The neurological symptoms recurred in year X−22, and she was treated under suspicion of opticospinal multiple sclerosis (OSMS). Subsequently, she did not experience a relapse of neurological symptoms; however, she developed left facial paralysis, abnormal sensations in both upper limbs, and muscle weakness in the left lower limb in year X. MRI revealed lesions extending from the medulla oblongata to the C6 level, and serum testing was positive for anti-AQP4 antibodies, leading to a diagnosis of neuromyelitis optica spectrum disorder. This case was considered clinically significant as an example of neuromyelitis optica spectrum disorder recurrence after a long period.

Case Male in his 40s. Due to end-stage renal failure, a living donor kidney transplantation was performed in September 2019 from his mother, who was positive for anti-HTLV-1 antibodies, to this case, who was negative for anti-HTLV-1. He was admitted in September 2021 due to progressive lower limb muscle weakness since March 2021. The patient was unable to stand or walk due to spastic paraplegia. Spinal cord MRI T₂-weighted image showed continuous high signal and myelopathy from the cervical to thoracic spinal cord. Serum and spinal fluid anti-HTLV-1 antibodies were positive. The diagnosis of rapidly progressive HTLV-1-associated myelopathy (HAM) was made, which was problematic because kidney transplantation from an HTLV-1-positive donor to a negative recipient was performed in this case, even though it had already been noted that living donor-negative recipients are at high risk of developing HAM.