Hereditary spastic paraplegia and extensive leukoencephalopathy: a case report of a unique phenotype associated with a GJB1/Cx32 p.Pro174Ser variant.

Background: Pathogenic variants in Gap junction protein beta 1 (GJB1), which encodes Connexin 32, are known to cause X-linked Charcot-Marie-Tooth disease (CMTX), the second most common form of CMT. CMTX presents with the following five central nervous systems (CNS) phenotypes: subclinical electrophysiological abnormalities, mild fixed abnormalities on neurological examination and/or imaging, transient CNS dysfunction, cognitive impairment, and persistent CNS manifestations.

Case Presentation: A 40-year-old Japanese male showed CNS symptoms, including nystagmus, prominent spastic paraplegia, and mild cerebellar ataxia, accompanied by subclinical peripheral neuropathy.

The speed of completion of the decremental responses on repetitive nerve stimulation.

Objective: It is generally believed that the decremental response in repetitive nerve stimulation (RNS) stabilizes at the fourth or fifth response. We have a preliminary impression that the decremental response approaches a plateau earlier in proximal muscles than in distal muscles. We investigated the speed of the completion of the decremental response in different muscles.

RNA Foci in Two bi-Allelic RFC1 Expansion Carriers.

Cerebellar ataxia, neuropathy, vestibular areflexia syndrome (CANVAS) is a late-onset, autosomal recessive neurodegenerative disorder caused by biallelic AAGGG/ACAGG repeat expansion (AAGGG-exp/ACAGG-exp) in RFC1. The recent identification of patients with CANVAS exhibiting compound heterozygosity for AAGGG-exp and truncating variants supports the loss-of-function of RFC1 in CANVAS patients. We investigated the pathological changes in 2 autopsied patients with CANVAS harboring biallelic ACAGG-exp and AAGGG-exp.

Long-read sequencing revealing intragenic deletions in exome-negative spastic paraplegias.

Hereditary spastic paraplegias (HSPs) are a heterogeneous group of neurodegenerative disorders characterized by progressive spasticity and weakness in the lower extremities. To date, a total of 88 types of SPG are known. To diagnose HSP, multiple technologies, including microarray, direct sequencing, multiplex ligation-dependent probe amplification, and short-read next-generation sequencing, are often chosen based on the frequency of HSP subtypes.

Reduced likelihood of the Poggendorff illusion in cerebellar strokes: a clinical and neuroimaging study.

This study aimed to test our hypothesis that the cerebellum plays an important role in the generation of the optical-geometric illusion known as the Poggendorff illusion, the mechanism of which has been explained by accumulated experience with natural scene geometry. A total of 79 participants, comprising 28 patients with isolated cerebellar stroke, 27 patients with isolated cerebral stroke and 24 healthy controls, performed Poggendorff illusion tasks and 2 different control tasks. We also investigated core brain regions underpinning changes in the experience of the illusion effect using multivariate lesion-symptom mapping.

[Motor Neuron Involvement in RFC1 CANVAS/Spectrum Disorders].

Cerebellar ataxia with neuropathy and vestibular areflexia syndrome (CANVAS) is characterized by the triad of cerebellar ataxia, bilateral vestibular impairment, and sensory neuropathy. The responsible anatomical region for the sensory disturbance in CANVAS is reportedly the dorsal root ganglion, which suggests neuronopathy rather than neuropathy as the pathomechanism of this peripheral nervous system disorder. Early on, motor neuron involvement was considered rare in CANVAS.

Periodic paralysis due to cumulative effects of rare variants in SCN4A with small functional alterations.

Introduction/aims: Mutations in the SCN4A gene encoding a voltage-gated sodium channel (Nav1.4) cause hyperkalemic periodic paralysis (HyperPP) and hypokalemic periodic paralysis (HypoPP). Typically, both HyperPP and HypoPP are considered as monogenic disorders caused by a missense mutation with a large functional effect.

Repeat conformation heterogeneity in cerebellar ataxia, neuropathy, vestibular areflexia syndrome.

Cerebellar ataxia, neuropathy, vestibular areflexia syndrome (CANVAS) is a late-onset, slow-progressing multisystem neurodegenerative disorder. Biallelic AAGGG repeat expansion in RFC1 has been identified as causative of this disease, and repeat conformation heterogeneity (ACAGG repeat) was also recently implied. To molecularly characterize this disease in Japanese patients with adult-onset ataxia, we accumulated and screened 212 candidate families by an integrated approach consisting of flanking PCR, repeat-primed PCR, Southern blotting and long-read sequencing using Sequel II, GridION or PromethION.

Sensory Ataxic Guillain-Barré Syndrome with Dysgeusia after mRNA COVID-19 Vaccination.

Guillain-Barré syndrome (GBS) has occasionally occurred in people who have received coronavirus disease 2019 (COVID-19) vaccines. Dysgeusia is rare symptom of GBS. We herein report a rare case of sensory ataxic GBS with dysgeusia just after the second dose of the Pfizer-BioNTech COVID-19 vaccine.

Ultrasonographic evaluation reveals thinning of cervical nerve roots and peripheral nerves in spinal and bulbar muscular atrophy.

Background: Ultrasonography (US) is a noninvasive and patient-friendly tool for the evaluation of peripheral nerves. In motor neuron diseases, amyotrophic lateral sclerosis (ALS) has been reported to show the atrophy of peripheral nerves on US. However, the US findings are still unclear in spinal and bulbar muscular atrophy (SBMA), an adult-onset lower motor neuron disease caused by an abnormal CAG repeat expansion in the androgen receptor gene.

Case Report: Takotsubo Cardiomyopathy in Bickerstaff Brainstem Encephalitis Triggered by COVID-19.

Takotsubo cardiomyopathy (TCM) is a stress-induced cardiomyopathy triggered by critical illness including severe neurological disorders. However, an association between TCM and Bickerstaff brainstem encephalitis (BBE) has rarely been described. During the current coronavirus disease 2019 (COVID-19) pandemic, growing evidence indicates that COVID-19 often leads to various neurological disorders, but there are few reports of an association between COVID-19 and BBE.

Therapeutic efficacy of heparin and direct factor Xa inhibitors in cancer-associated cryptogenic ischemic stroke with venous thromboembolism.

Background: Anticoagulation therapy, especially using heparin or recently developed oral direct factor Xa inhibitors (DiXals), is recommended as first-line treatment for cancer-related venous thromboembolism (VTE). However, the preventive efficacy of these anticoagulants for cancer-associated ischemic stroke is still unknown. We retrospectively investigated the efficacy of subcutaneous unfractionated heparin (UFH) and DiXals for preventing the recurrence of cancer-associated cryptogenic ischemic stroke with VTE.

Hepatitis B Virus-related Vasculitic Neuropathy in an Inactive Virus Carrier Treated with Intravenous Immunoglobulin.

We herein report a 33-year-old woman who was an asymptomatic hepatitis B virus (HBV) carrier and presented with distal muscle weakness in the legs and asymmetrical paresthesia in the distal extremities. A nerve biopsy specimen revealed fibrinoid necrosis associated with inflammatory infiltration in the perineural space, and deposition of hepatitis B core antigen and C4d complement was detected in the vascular endothelial cells as well as around the vessels. She was diagnosed with HBV-related vasculitic neuropathy and treated with intravenous immunoglobulin (IVIG).

A new method to define cutoff values in nerve conduction studies for carpal tunnel syndrome considering the presence of false-positive cases.

Background: Nerve conduction studies (NCS) are useful tools for diagnosing carpal tunnel syndrome (CTS). Establishing the normal values is the first step required for utilizing NCS for diagnosis. Previous epidemiological studies demonstrated the presence of fairly large number of false-positive subjects regarding NCS among control population, which has not been properly considered in past studies.

Interaction of cathodal and anodal stimulations in nerve conduction studies.

Introduction: In this work we investigated the interaction of cathodal and anodal stimulations in nerve conduction studies (NCSs).

Methods: Subjects assessed consisted of 10 healthy volunteers. The ulnar nerve was stimulated at the wrist using 2 bipolar surface electrodes, simulating ordinary NCSs.

Fasciculation potentials and decremental responses in amyotrophic lateral sclerosis.

Objective: The positive correlation between fasciculation potentials (FPs) and decremental responses in repetitive nerve stimulation test (RNS) in amyotrophic lateral sclerosis (ALS) patients has been described based on only one past study. We revisited this issue.

Methods: Subjects consisted of 30 prospectively-enrolled ALS patients on whom both needle EMG and RNS were conducted in the same trapezius muscle.

Utility of repetitive nerve stimulation test for ALS diagnosis.

Objective: Decremental responses in the repetitive nerve stimulation (RNS) test in amyotrophic lateral sclerosis (ALS) patients have been reported, although their possible diagnostic role has received little investigation. We investigated their diagnostic role in differentiation between ALS and cervical spondylotic amyotrophy (CSA), an important ALS mimic especially in Japan.

Methods: Patients were prospectively enrolled and the diagnosis was confirmed by follow-up.

Late Seizures after Stroke in Clinical Practice: The Prevalence of Non-convulsive Seizures.

Objective The prevalence of the non-convulsive type of late seizure after stroke is unknown. The aim of the present study was to clarify the characteristics of late seizure in clinical practice, mainly focusing on the prevalence of non-convulsive seizure. Methods A total of 178 consecutive patients who were admitted and diagnosed with late seizure after stroke were retrospectively enrolled, and the data of 127 patients for whom the complete seizure was observed by a bystander were analyzed.

Investigation of anodal stimulation and its implications for F-wave examinations.

Introduction: Recent studies have shown that stimulation occurs at the anode of stimulating electrodes instead of anodal block. This phenomenon may be a pitfall in F-wave examinations.

Methods: Subjects included 10 healthy volunteers.

Primary aldosteronism in patients with acute stroke: prevalence and diagnosis during initial hospitalization.

Background: Hypertension is the prime risk factor for stroke, and primary aldosteronism (PA) is the most common cause of secondary hypertension. The prevalence of PA in stroke patients has never been reported. The aim of this study was to elucidate the prevalence of PA.

[Aseptic meningitis in a patient with cerebrospinal fluid anti-agalactosyl IgG antibody-positive preclinical rheumatoid arthritis: a case report].

A 69-year-old woman presented with non-fluent aphasia, ideomotor apraxia, right hemiparesis and convulsion. Her medical history was unremarkable, and she had not suffered from arthritis. DWI and FLAIR image of brain MRI showed hyperintensities in the subarachnoid space along the left frontal and both parietal lobes, and these lesions were associated with gadolinium enhancement.

High-resolution magnetic resonance imaging findings of basilar artery plaque in a patient with branch atheromatous disease: a case report.

Introduction: Intracranial branch atheromatous disease is a type of ischemic stroke that is caused by narrowing or occlusion of the orifice of the penetrating artery by atheromatous plaque. Pontine branch atheromatous disease is usually diagnosed using indirect findings such as the extension of a lesion to the basal surface of the pons because of the difficulty of demonstrating plaque in the basilar artery.

Case Presentation: A 72-year-old Japanese man developed sudden dysarthria and left hemiparesis, and his symptoms deteriorated thereafter.

Isolated index finger palsy due to cortical infarction.

The case of an 86-year-old man presenting with isolated left index finger palsy caused by infarction on the lateral side of the right precentral knob is presented. Embolization from aortic atheroma was considered the cause of infarction. Cases with selective palsy of a particular group of fingers without sensory deficits due to cortical infarction of the precentral knob have been reported by several authors, and predominant weakness of radial-side fingers is known to be usually caused by laterally located infarction of the precentral knob.