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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. However, a few cases with atypical periodic paralysis phenotype have been caused by multiple mutations in ion-channel genes expressed in skeletal muscles. In this study we investigated the underlying pathogenic mechanisms in such cases.We clinically assessed two families: proband 1 with HyperPP and proband 2 with atypical periodic paralysis with hypokalemia. Genetic analyses were performed by next-generation sequencing and conventional Sanger sequencing, followed by electrophysiological analyses of the mutant Nav1.4 channels expressed in human embryonic kidney 293T (HEK293T) cells using the whole-cell patch-clamp technique.In proband 1, K880del was identified in the SCN4A gene. In proband 2, K880del and a novel mutation, R1639H, were identified in the same allele of the SCN4A gene. Functional analyses revealed that the K880del in SCN4A has a weak functional effect on hNav1.4, increasing the excitability of the sarcolemma, which could represent a potential pathogenic factor. Although R1639H alone did not reveal functional changes strong enough to be pathogenic, Nav1.4 with both K880del and R1639H showed enhanced activation compared with K880del alone, indicating that R1639H may modify the hNav1.4 channel function.A cumulative effect of variants with small functional alterations may be considered as the underpinning oligogenic pathogenic mechanisms for the unusual phenotype of periodic paralysis.

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. Our results indicate that patients with isolated cerebellar stroke were significantly less likely to experience the Poggendorff illusion effect than patients with isolated cerebral stroke or healthy controls (74.6, 90.5 and 89.8%, respectively; F(2,76) = 6.675, P = 0.002). However, there were no inter-group differences in the control tasks. Lesion-symptom mapping analysis revealed that the brain lesions associated with the reduced frequency of the Poggendorff illusion effect were mainly centred on the right posteromedial cerebellar region, including the right lobules VI, VII, VIII, IX and Crus II. Our findings demonstrated, for the first time, that patients with cerebellar damage were significantly less likely to experience the Poggendorff illusion effect and that right posteromedial cerebellar lesions played an important role in this effect. These results provide new insight into alterations of a geometric illusion effect in patients with cerebellar disorders and pave the way for future clinical use of the illusion task to detect cerebellar abnormalities.

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. We identified 16 patients from 11 families, of whom seven had ACAGG expansions [(ACAGG)exp/(ACAGG)exp] (ACAGG homozygotes), two had ACAGG and AAGGG expansions [(ACAGG)exp/(AAGGG)exp] (ACAGG/AAGGG compound heterozygotes) and seven had AAGGG expansions [(AAGGG)exp/(AAGGG)exp] (AAGGG homozygotes). The overall detection rate was 5.2% (11/212 families including one family having two expansion genotypes). Long-read sequencers revealed the entire sequence of both AAGGG and ACAGG repeat expansions at the nucleotide level of resolution. Clinical assessment and neuropathology results suggested that patients with ACAGG expansions have similar clinical features to previously reported patients with homozygous AAGGG expansions, although motor neuron involvement was more notable in patients with ACAGG expansions (even if one allele was involved). Furthermore, a later age of onset and slower clinical progression were implied in patients with ACAGG/AAGGG compound heterozygous expansions compared with either ACAGG or AAGGG homozygotes in our very limited cohort. Our study clearly shows the occurrence of repeat conformation heterogeneity, with possible different impacts on the affected nervous systems. The difference in disease onset and progression between compound heterozygotes and homozygotes might also be suspected but with very limited certainty due to the small sample number of cases in our study. Studies of additional patients are needed to confirm this.

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. The etiology of CANVAS includes the homozygous pentanucleotide repeat expansion within the RFC1 gene, resulting in diverse phenotypes and motor deficits such as brisk reflex, extensor plantar responses, or spasticity of the upper motor neurons and muscle wasting, weakness, cramp, or fasciculation of the lower motor neurons. CANVAS patients with AAGGG repeat expansions may show motor neuron involvement, with considerable variation in the reported frequencies. In contrast, although some patients with ACAGG repeat expansions also show motor neuron involvement, its frequency remains elusive.

Highlights • We determined C5/C6/C7 myotomes from patients with MRI-confirmed single-root radiculopathy. • The brachioradialis was mainly innervated by C5. • C6 muscles were the pronator teres and extensor carpi radialis brevis., Objective There are many myotome charts in the literature, but few studies have presented actual data to support their identification. We aimed to determine C5/C6/C7 myotomes based on clinical and EMG data of patients with cervical spondylotic radiculopathy (CSR) having a single-root lesion confirmed by MRI. Methods Medical Research Council (MRC) scores and EMG findings were retrospectively reviewed for patients enrolled from our EMG database. Results Enrolled were 25 patients (10 C5, 6 C6, and 9 C7 CSR). In C5 CSR, weakness or denervation potentials in EMG, or both, were observed in the deltoid (Del) and infraspinatus (Isp) muscles for all patients, and in the biceps brachii (BB) and brachioradialis (BR) muscles for 9/10 and 8/9 patients, respectively. In C6 CSR, weakness of the wrist extensor and/or denervation of the extensor carpi radialis longus (ECRL)/extensor carpi radialis brevis (ECRB), and those of the pronator teres (PT) were observed for all patients. Weakness was not observed for any other muscle in C6 CSR. Denervation potentials of ECRL were found in 5/8 and 3/5 patients with C5 and C6 CSR, respectively, whereas those of ECRB were found in 1/5, 6/6, and 2/5 patients with C5, C6 and C7 CSR, respectively. In C7 CSR, weakness/denervation of the triceps brachii (TB) and denervation potentials of the flexor carpi radialis (FCR) were observed for all patients. Denervation potentials in PT and weakness/denervation of the extensor digitorum (ED) were observed in 2/9 and 4/9 patients, respectively. Conclusion Suggested dominant myotomes are: C5 for the Del, Isp, BB, and BR, C5/6 for the ECRL, C6 > C7 for the ECRB and PT, and C7 for the TB and FCR. Significance The current study identified dominant myotomes that differ from the existing literature.

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. Although autoantibodies against glycolipids were not detected, immunotherapy with intravenous immunoglobulin and methylprednisolone pulse therapy effectively ameliorated the symptoms. Our report suggests that the COVID-19 vaccine may induce various clinical subtypes of GBS, including a rare variant with sensory ataxia and dysgeusia.

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). Her symptoms completely subsided after eight weeks. Vasculitic neuropathy rarely develops in the chronic inactive stages of HBV infection. This is the first report of an HBV-inactive carrier with vasculitic neuropathy successfully treated with IVIG.

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.We prospectively recruited and evaluated 11 patients with genetically confirmed SBMA and 9 patients with ALS diagnosed according to the revised El Escorial ALS criteria or the Awaji electrodiagnostic criteria. The C5-C7 cervical nerve roots and the median and ulnar nerves were evaluated ultrasonographically.The cross-sectional areas (CSAs) of the C6 and C7 nerve roots, the median nerve in the upper arm and forearm, and the ulnar nerve in the upper arm were smaller in patients with SBMA than those in patients with ALS (p 0.05), whereas the CSAs of the C5 nerve root and the ulnar nerve in the forearm were not smaller.US showed that the peripheral nerves in patients with SBMA were thinner than those in patients with ALS despite similar degrees of weakness and motor neuron loss. Possible causes include additional sensory nerve involvement and longer disease duration in patients with SBMA than those in patients with ALS.

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. We were able to independently change the stimulus current value at the distal cathode and the proximal anode. Results The anodal stimulation became more difficult to elicit as the stimulus current at the cathode was increased, whereas the cathodal stimulation became more likely to occur as the stimulus current at the anode was increased. Discussion During bipolar stimulation, the cathodal stimulation suppresses the anodal stimulation, whereas the anodal stimulation assists the cathodal stimulation. This explains the common observation in NCSs that the cathodal stimulation becomes difficult to elicit when the anode is moved away from the nerve. Muscle Nerve 59:713-716, 2019.

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., We retrospectively studied consecutive patients with cancer-associated cryptogenic ischemic stroke and comorbid VTE who received subcutaneous UFH or oral DiXaIs at 9 hospitals., Fifty-three patients (24 treated with UFH and 29 treated with DiXaIs) were enrolled. Of these, 47 demonstrated systemic metastasis (cancer stage IV). During 30-day follow-up after initiation of anticoagulation therapy, recurrent ischemic stroke was observed in only 1 patient (4%) in the UFH group and in 9 patients (31%) in the DiXal group. The incidence of major bleeding complications was similar between the 2 groups (4% and 10%, respectively). The cumulative risk of ischemic stroke recurrence within 30days was lower with UFH than with DiXals (competing risk analysis, p=0.008). In the DiXal group, patients who experienced recurrence showed significantly higher D-dimer levels than those without recurrence., In patients with cancer-associated cryptogenic ischemic stroke and comorbid VTE, UFH demonstrated a lower rate of recurrent ischemic stroke than DiXaIs, and there were no differences in bleeding risk between the 2 treatments. D-dimer levels at stroke onset increased the risk of recurrence in the DiXal group but not in the UFH group.

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. RNS was performed on the abductor pollicis brevis (APB), upper trapezius (trapezius) and deltoid muscles. Results Enrolled subjects consisted of 53 ALS and 37 CSA patients. Abnormal decremental responses (>5%) were observed in 32%, 51% and 75% of ALS patients and 3%, 0% and 20% of CSA patients for the APB, trapezius and deltoid muscles, respectively. The sensitivity for 23 ALS patients with upper-limb onset was 78% for the trapezius and 100% for the deltoid muscles. Conclusions An abnormal decremental response in the trapezius muscle was 100% specific to ALS in comparison with CSA: abnormal decrement in this muscle would strongly suggest ALS. No decrement in the deltoid muscle might exclude ALS in patients having symptoms with upper-limb onset. Significance RNS is useful in differentiation between ALS and CSA.

Introduction: Recent studies have shown that stimulation occurs at the anode of stimulating electrodes instead of anodal block. This phenomenon may become a pitfall in F-wave examinations. Methods: Subjects were 10 healthy volunteers. Their ulnar nerve was stimulated at the wrist with the cathode placed distally. Antidromic impulses were evaluated using the mixed nerve action potential (MNAP) at the elbow. Results: Anodal stimulation occurred for both sensory and motor fibers at 22 mm proximal to the anode on average, which may theoretically shorten the F-wave latency by about 0.8 ms. Displacement of the anode away from the nerve made anodal stimulation less likely. In contrast, displacement of the cathode away from the nerve lowered the threshold for anodal stimulation, a newly-found interaction between cathode and anode. Conclusions: We describe detailed features of anodal stimulation, and its potential influence on F-wave examinations is discussed. This article is protected by copyright. All rights reserved.

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. This study proposed a new method to address this issue. Non-diabetic 144 CTS patients were retrospectively enrolled using clinically defined inclusion criteria. Controls consisted of 73 age-matched volunteers without hand symptoms. Six NCS parameters were evaluated including peak-latency difference by the thumb method (thumbdif) and that by the ring-finger method (ringdif). The Youden index of the receiver operator characteristic curve was used both to judge the sensitivity of a parameter and to identify false-positive cases that were thought to have subclinical median neuropathy at the wrist. The linear function of six parameters was constructed, and the coefficient for each parameter was variously changed. When the Youden index took on the maximum value, seven control subjects (10%) were identified as false-positive and were excluded from the calculation of normal values. The most sensitive parameter before exclusion was thumbdif, whereas ringdif became the most sensitive after exclusion. The cut-off value for ringdif was 1.15 ms before exclusion, but was 0.37 ms after exclusion. This method can be widely applied to solve the statistical problem when the gold standard is lacking, and the outside reference standard is not completely reliable.

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. Fasciculation potentials (FPs) were identified off-line from the restored 3-min signal. Firing rate of FPs (FR-FP) per minute was calculated from the total count of FPs of different origins. Correlations between FR-FP, decremental percentage (Decr%) and the amplitude of the initial compound muscle action potential (CMAPamp) in RNS were investigated. Results There was no correlation between FR-FP and Decr% (r = 0.03) or between FR-FP and CMAPamp (r = 0.04). A significant negative correlation was observed between CMAPamp and Decr% (r = −0.56, P Conclusion FPs are not correlated with the decremental response in RNS. Significance The underlying mechanism for FPs and decremental responses in ALS must be different and unrelated to each other.

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. Clinical information was obtained from the medical records and nursing notes. Results A non-convulsive seizure was observed in 37 patients (29%). A focal seizure and its secondary generalization accounted for 79% of the seizure types. Status epilepticus was observed in 60 patients (47%), including 11 patients (9%) without convulsion. The patients with non-convulsive seizures were significantly younger than those with convulsive seizures, but there were no other significant differences between the two groups with respect to sex, classification or the lesion of stroke. Conclusion There was a high rate of non-convulsive seizures in patients with late seizure after stroke. A non-convulsive seizure may be caused by any type or location of preceding stroke. More attention is needed in the differential diagnosis of neurological deterioration after stroke.

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.Subjects included 10 healthy volunteers. Their ulnar nerve was stimulated at the wrist with the cathode placed distally. Antidromic impulses were evaluated using mixed nerve action potential (MNAP) at the elbow.Anodal stimulation occurred for both sensory and motor fibers at 22 mm proximal to the anode, on average, which may theoretically shorten the F-wave latency by about 0.8 ms. Displacement of the anode away from the nerve made anodal stimulation less likely. In contrast, displacement of the cathode away from the nerve lowered the threshold for anodal stimulation, a newly found interaction between cathode and anode.In this work we identified detailed features of anodal stimulation and potential influence on F-wave examinations. Muscle Nerve 56: 51-56, 2017.

Introduction In nerve conduction studies (NCS), it has long been believed that the phenomenon of anodal block occurs under the anode during bipolar stimulation. However, recent studies demonstrated that anodal block hardly occurs, whereas anodal stimulation actually occurs instead, i.e. the action potential is generated from the anode itself. During our previous investigation on anodal stimulation, we unexpectedly discovered a phenomenon that the anodal stimulation was easy to occur when the cathode was placed away from the nerve trunk. Furthermore, careful observation in ordinary NCS reveals that the cathodal stimulation becomes difficult to elicit when the anode is moved away from the nerve during the effort to make the baseline flat. These findings suggest that the cathodal stimulation and anodal stimulation may interact with each other. In this study, we aimed to investigate the interaction of cathodal and anodal stimulations. Methods Subjects were 7 healthy volunteers. The ulnar nerve was stimulated at the wrist using two bipolar surface electrodes. Both stimulating electrodes were placed perpendicular to the nerve course. The cathode of one electrode was placed distally, whereas the anode of the other electrode was placed proximally separated by the inter-electrode distance of 23 mm. In this way, we reproduced the setting of ordinary NCS. Furthermore, we were able to change the stimulus intensity at cathode and anode independently. The ascending volley from the anode was evaluated by the antidromic mixed nerve action potential (MNAP) at the elbow, and the descending volley from the cathode was evaluated by the compound muscle action potential (CMAP) from the abductor digiti minimi muscle. In this study, we performed two experiments. In Experiment 1, we variously changed the stimulus intensity at the cathode, and investigated how the current required for the anodal stimulation changes. In Experiment 2, we variously changed the stimulus intensity at the anode, and investigated how the current required for the cathodal stimulation changes. Results In Experiment 1, when the stimulus intensity at the distal cathode was set at 0, 5, 10, 15, and 20 mA, the threshold of MNAP by anodal stimulation was 8.8 ± 2.0, 10.2 ± 1.8, 11.5 ± 2.3, 12.6 ± 2.8, and 13.6 ± 3.0 mA, respectively. In Experiment 2, when the stimulus intensity at the proximal anode was set at 0, 2, 4, 6, and 8 mA, the threshold of CMAP by cathodal stimulation was 2.9 ± 0.3, 2.8 ± 0.3, 2.6 ± 0.3, 2.5 ± 0.3, and 2.3 ± 0.3 mA, respectively. Conclusion During bipolar stimulation, the cathodal stimulation suppresses the anodal stimulation, whereas the anodal stimulation assists the cathodal stimulation. As a mechanism of such inter-electrode interaction, we postulated that the hyperpolarized zone formed around the depolarized cathode suppresses the anodal stimulation, whereas the depolarized zone formed around the hyperpolarized anode assists the cathodal stimulation.

Many myotomal charts have been published, although there is considerable discordance among them. We aimed to determine C5, C6, and C7 myotomes of upper limb muscles. We retrospectively reviewed the patients with MRI-confirmed isolated C5, C6, or C7 cervical spondylotic radiculopathy (CSR). Twenty-four CSR patients (7 C5, 7 C6, and 10 C7 CSR) were enrolled. Muscle weaknesses were found in 7/7 deltoid, 7/7 infraspinatus, 6/7 biceps brachii (BB), and 5/6 brachioradialis among C5 CSR cases, in 4/4 pronator teres (PT) and 5/7 wrist extensor among C6 cases, and in 5/10 triceps brachii among C7 cases. Denervation potentials on needle EMG were found in 0/5 C5, 6/7 C6, and 1/4 C7 cases at PT, in 0/2 C5 and 4/7 C6 cases at extensor carpi radialis brevis (ECRB), in 2/4 C5 and 2/5 C6 cases at extensor carpi radialis longus (ECRL), and in 1/4 C6 and 5/8 C7 cases at flexor carpi radialis (FCR). Main innervation of deltoid, infraspinatus, and BB by C5, and that of triceps by C7 coincide with most previous literature. Among muscles in which controversy remains regarding myotome, brachioradialis is mainly innervated by C5 root, ECRL by C5/C6, ECRB and PT by C6, and FCR by C7.

It is widely believed that sensory conduction study (SCS) is more sensitive than motor conduction study (MCS) in carpal tunnel syndrome (CTS). However, the sensitivity depends not only on the vulnerability of each branch of the median nerve, but on measurement errors and cut-off values. In this study, we aimed to clarify the true vulnerability of each branch in CTS. Subjects consisted of 144 CTS patients and 66 controls. The impairment of a branch was defined as the prolongation of onset latency. Following 6 parameters were evaluated; DMLAp from routine MCS, DMLLp from second lumbrical (2L)-interossei method, DSLIap and DSLIop from antidromic and orthodromic SCS at index-finger, DSLRp from ring-finger method, and DSLTp from thumb method. The mean values for patients were 1.57 ms, 1.12 ms, 1.03 ms, 1.08 ms, 1.63 ms, and 1.09 ms, respectively. The most severely impaired branch was the ring-finger sensory branch, which was narrowly followed by the motor branch to APB. The sensory branch to thumb was relatively preserved, comparable to the sensory branch to index-finger and even the motor branch to 2L. The vulnerabilities of the branches of median nerve in CTS are not sensory predominant but specific to the respective branches.

We report a 50-year-old woman with an unremarkable birth and developmental history, and with no family history of neurological disorders. The patient had a 6-year history of progressive cervical dystonia, oral dyskinesia, and hyperreflexia. She was initially considered to have spastic paraparesis of unknown cause. Because brain MRI showed mild atrophy of the cerebellar vermis, genetic analysis for spinocerebellar ataxia types 1, 2, 3, 6, 7, 8, 12, and 17, and dentatorubral-pallidoluysian atrophy was performed. The results revealed an abnormal expansion of CAG repeats (38 repeats) in one allele of ATXN2, and the patient was diagnosed with spinocerebellar ataxia type 2 (SCA2). She had no major clinical features of SCA2 such as cerebellar ataxia, slow saccade, or hyporeflexia. Recent reports have shown the CAG repeat expansion in ATXN2 to be detected in patients with familial L-dopa-responsive parkinsonism. The present case suggests that CAG repeat expansion in ATXN2 may be detected in some patients with spastic paraparesis, and that wide variations of clinical manifestations exist in SCA2.

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. The levels of serum anti-cyclic citrullinated peptide antibody, anti-agalactosyl IgG antibody and matrix metalloproteinase-3 were elevated. The results of blood cultures were negative. Cerebrospinal fluid (CSF) analysis revealed monocytic pleocytosis and negative findings for infection or malignancy. The level of anti-agalactosyl IgG antibody in CSF was elevated. The antibody index (AI) of anti-agalactosyl IgG antibody (the ratio between the CSF/serum quotient for IgG antibodies, and the CSF/serum quotient for total IgG; normal value of AI < 1.3) showed considerably high value of 8.4, indicating the intrathecal-specific antibody synthesis. As a result, the pathogenesis of her disease was consistent with rheumatoid meningitis despite lack of arthritis. After intravenous administration of methylprednisolone, her symptoms, the level of anti-agalactosyl IgG antibody in CSF, and the MRI findings were ameliorated. Anti-agalactosyl IgG antibody in the CSF was a helpful biomarker in diagnosis and assessment of the severity of rheumatoid meningitis.

A 65-year-old man developed progressive worsening of right-sided limb-kinetic apraxia and extrapyramidal dysfunction. His left internal carotid artery was found to be occluded, and there was general atrophy and severely decreased cerebral blood flow in the left hemisphere. He had experienced an acute infarction in the left watershed area before superficial temporal artery to middle cerebral artery bypass surgery. After surgery, the cerebral blood flow in the left hemisphere was remarkably improved. Unilateral internal carotid artery occlusion may result in clinical manifestations similar to corticobasal degeneration.

Vitamin B12 deficiency mainly affects the dorsal column. In this study, we investigated which part of the sensory pathway is affected in vitamin B12 deficiency using NCS and SEPs. We retrospectively reviewed EMG database of Teikyo University and Mitsui Memorial Hospital from 2008 to 2016, and enrolled patients who presented with sensory symptoms and/or gait disturbance, and whose serum B12 level was below 170 ng/ml. Enrolled were 17 patients. Spinal MRI demonstrated abnormalities in 4/17. NCS was abnormal in 3/15 patients for the sural nerve and in 5/12 patients for the median nerve. When NCS and peripheral segments of the SEPs were combined, conduction delay was detected in 12/15 patients for the lower limb and 8/13 patients for the upper limb. Delay of the central conduction was rarer, 3/15 patients in tibial SEPs. N9o to P13/14o segment in median SEPs was abnormal in 4/8 patients, although this is a mixture of the peripheral and central conductions. Vitamin B12 deficiency patients showed abnormalities of the peripheral nerve conduction more frequently than those of the central conduction. SEPs are useful in localizing the lesion along the sensory pathway, not only for CCT but for peripheral conduction.

Measurement of the muscle fiber conduction velocity (MFCV) using direct muscle stimulation has been considered to be useful for the evaluation of critical illness myopathy (CIM), although there are rather few reports on this issue. Subjects consisted of 2 normal volunteers, 4 patients with myositis, and 1 patient with CIM. Stimulation was given to the muscle using a monopolar needle and the muscle fiber action potentials (MFAPs) was recorded using a concentric needle electrode. MFCV was calculated based on the onset latencies of the MFAPs recorded at different intramuscular locations. As results, MFCV was 4–5 m/s in the CIM patient. It was 4.2 and 4.8 m/s on average in control subjects, and was 3.6–4.3 m/s in patients with myositis. The CIM patient presented with markedly prolonged duration of the compound muscle action potential (CMAP). Normal MFCV in the CIM patient may suggest that the prolonged CMAP duration in CIM may not be due to the slowed MFCV, but to other mechanisms. MFCV measurement is a difficult technique, and its diagnostic role is yet to be documented, including for CIM.

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. Among the previous reports, only 1 case involved isolated index finger palsy by an atypical, medially located infarction of the precentral knob in association with a concurrent nonrelated lesion. This is the first reported isolated index finger palsy caused by a single lateral precentral knob infarction.

Background and purpose Arterial spin labeling (ASL) is a non-invasive modality of magnetic resonance imaging (MRI) used to evaluate cerebral perfusion without a contrast agent. The usefulness of ASL for diagnosis in the acute phase of late seizure after stroke was evaluated. Methods Twelve consecutive patients diagnosed with late seizure after stroke were enrolled in this study. MRI including ASL was performed for each patient at the time of the emergency department visit. Eight of the patients underwent electroencephalography (EEG). Results All patients showed hyperperfusion around the stroke lesion on ASL. Only 6 patients showed high signal intensity along the cerebral cortex around the stroke lesion on diffusion-weighted imaging. The patients who underwent EEG showed slow activity, but paroxysmal discharges such as spikes or sharp waves were not observed. Conclusions ASL was able to reveal hyperperfusion and was of great diagnostic value in the peri-ictal phase of late seizure after stroke.

Arterial spin labeling (ASL) is a non-invasive modality of magnetic resonance imaging (MRI) used to evaluate cerebral perfusion without a contrast agent. The usefulness of ASL for diagnosis in the acute phase of late seizure after stroke was evaluated.Twelve consecutive patients diagnosed with late seizure after stroke were enrolled in this study. MRI including ASL was performed for each patient at the time of the emergency department visit. Eight of the patients underwent electroencephalography (EEG).All patients showed hyperperfusion around the stroke lesion on ASL. Only 6 patients showed high signal intensity along the cerebral cortex around the stroke lesion on diffusion-weighted imaging. The patients who underwent EEG showed slow activity, but paroxysmal discharges such as spikes or sharp waves were not observed.ASL was able to reveal hyperperfusion and was of great diagnostic value in the peri-ictal phase of late seizure after stroke.

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. Brain magnetic resonance imaging revealed an acute infarction in the territory of the right paramedian pontine artery extending to the basal surface. Non-contrast-enhanced three-dimensional fast spin-echo T1 imaging with variable flip angles and three-dimensional fast imaging with steady-state acquisition revealed a plaque in the dorsal wall of the basilar artery that spread to the origin of the paramedian pontine artery that branched toward the infarction. Although antithrombotic agents were started, the left hemiparesis got worse and became flaccid on the following day. Conclusions This is the first report to confirm the pathological basis of branch atheromatous disease by three-dimensional images using the new modalities of 3-Tesla magnetic resonance imaging. The use of these techniques will foster better understanding of the clinicopathological mechanisms of branch atheromatous disease.

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. A total of 427 consecutive patients with acute stroke were prospectively enrolled for this study. The screening tests were performed at the initial visit and a week after admission by measuring plasma aldosterone concentration and plasma renin activity. The rapid adrenocorticotropic hormone (ACTH) test was performed as the confirmatory test when both screening tests were positive. The primary endpoint was a final diagnosis of PA. The sensitivity of the dual screening system for the diagnosis of PA was 88.2 %, and PA was finally diagnosed in 4.0 % of acute stroke patients and in 4.9 % of stroke patients with a history of hypertension. Patients with PA were less likely to be male and have diabetes, and they had higher blood pressure at the initial visit, lower potassium concentration, and more intracerebral hemorrhage. The rapid ACTH test was performed safely even in acute stroke patients. The prevalence of PA is not low among acute stroke patients. Efficient screening of PA should be performed particularly for patients with risk factors. UMIN-CTR; UMIN000011021 . Trial registration date: June 23, 2013 (retrospectively registered).