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en: A Case of Anti-NXP2 Antibody-positive Juvenile Dermatomyositis with Characteristic Fascial Thickening on Muscle Ultrasound and Improvement with Immunotherapy

en: Internal Medicine

ja: Internal Medicine


en: Correlation of muscle ultrasound with clinical and pathological findings in idiopathic inflammatory myopathies

en: In idiopathic inflammatory myopathies (IIMs), the change in muscle echogenicity and its histopathological basis are not well understood. We quantitatively measured muscle echogenicity in patients with IIMs and evaluated its correlation with disease activity and histopathological findings. This study involved patients with IIMs who underwent both ultrasonography (US) and muscle biopsy, as well as age- and sex-matched rheumatoid arthritis patients as inflammatory disease controls. On US, axial images of the right biceps brachii and vastus medialis were obtained. Standardized histopathological scoring was used to quantitatively measure each pathological domain. Forty-two patients (17 with inclusion body myositis [IBM] and 25 with IIMs other than IBM) and 25 controls were included. The muscle echo intensity (EI) of patients with IIMs was significantly higher than that of controls. Muscle EI showed significant correlations with creatine kinase (r = 0.66, p < .001) and muscle strength (r = -0.73, p < .0001) in patients with non-IBM IIMs. In patients with IBM, moderate correlation was found between muscle EI and quadriceps muscle strength (r = -0.53, p = .028). Histopathologically, the number of infiltrating CD3+ inflammatory cells correlated with muscle EI in the non-IBM group (r = 0.56, p = .017), but not in the IBM group. Muscle EI may be useful as a surrogate marker of muscle inflammation in non-IBM IIM. Increased muscle EI may be difficult to interpret in patients with long-standing IBM, which has advanced and complex histopathology.

en: Muscle & Nerve

ja: Muscle & Nerve


en: Far-field potential of the compound muscle action potential as a reliable marker in amyotrophic lateral sclerosis

en: Reliable neurophysiological markers in amyotrophic lateral sclerosis (ALS) are of great interest. The compound muscle action potential (CMAP) amplitude has been a conventional marker, although it is greatly influenced by the electrode position. We propose the far-field potential of the CMAP (FFP-CMAP) as a new neurophysiological marker in ALS. Patients with ALS and age-matched healthy controls were enrolled. We used a proximal reference (pref) in addition to the conventional distal reference (dref). Routine CMAP was recorded from the belly-dref lead and FFP-CMAP from the dref-pref lead for the ulnar and tibial nerves. Multiple point stimulation motor unit number estimation (MUNE) was also examined in the ulnar nerve. Inter-rater reproducibility was evaluated by two examiners, and some patients were followed up every 3 mo for 1 y. We tested 17 patients with ALS and 10 controls. The amplitudes of routine CMAP and FFP-CMAP in the ulnar and tibial nerves, and hypothenar MUNE value in the ulnar nerve were significantly decreased in ALS compared to controls. Ulnar FFP-CMAP achieved the highest inter-rater intraclass correlation coefficient (ICC) value (0.942) when compared with routine CMAP (0.880) and MUNE (0.839). The tibial FFP-CMAP had a higher ICC value (0.986) than the routine CMAP (0.697). In this way, the FFP-CMAP showed high inter-rater reproducibility because its shape was not much influenced by the electrode position. During 1-y follow-up, decline of CMAP, FFP, and MUNE showed significant correlations with the Amyotrophic Lateral Sclerosis Functional Rating Scale - Revised (ALSFRS-R). The FFP-CMAP shows promise as a reliable marker for ALS.


en: A case of anti-NT5c1A antibody-seropositive inclusion body myositis associated with severe dysphagia and prominent forearm weakness

en: Neurology and Clinical Neuroscience

ja: Neurology and Clinical Neuroscience


en: Application of ultrasound in a case of eosinophilic fasciitis mimicking stiff-person syndrome

en: Eosinophilic fasciitis (EF) is a rare disorder characterized by muscle stiffness mimicking other neuromuscular diseases. The diagnosis of EF is made on the basis of typical skin lesions. We report a case of a 36-year-old male patient with suspected stiff-person syndrome (SPS), who presented with progressive limb muscle stiffness and limited mobility of both wrists without obvious skin changes. Ultrasound revealed fascial thickening of bilateral upper and lower limb muscles and enlargement of hypoechoic tissues around the flexor digitorum tendons of the wrist. Skin and fascia biopsy confirmed the diagnosis of EF. Prednisolone therapy resulted in the improvement of muscle stiffness and tightness. Our findings suggest the need to consider connective tissue diseases such as EF in a patient with atypical features of SPS. Ultrasound is helpful for visualizing the causes of muscle stiffness and joint contractures in EF patients.

en: Neuromuscular Disorders

ja: Neuromuscular Disorders


en: Early diagnosis of amyotrophic lateral sclerosis based on fasciculations in muscle ultrasonography: A machine learning approach.

en: Fasciculation detected in relevant muscles on MUS can contribute to the diagnosis of ALS from the early stage.

ja: We investigated 100 patients with ALS, including 50 with early-stage ALS within 9 months from onset, and 100 without ALS. Fifteen muscles were bilaterally observed for 10 s each and the presence of fasciculations was recorded. Hierarchical clustering and nominal logistic regression, neural network, or ensemble learning were applied to the training cohort comprising the early-stage ALS to develop MUS-based diagnostic models, and they were tested in the validation cohort comprising the later-stage ALS.

en: Clinical Neurophysiology

ja: Clinical Neurophysiology


en: Seizure types associated with negative arterial spin labeling and positive diffusion-weighted imaging on peri-ictal magnetic resonance imaging

en: Arterial spin labeling (ASL) and diffusion-weighted imaging (DWI) are useful for assessing hyperperfusion and cytotoxic edema, respectively, caused by acute seizures. This study investigated the clinical characteristics associated with normal ASL findings and DWI abnormalities in patients with acute seizures. Overall, 41 patients with ASL and DWI images that were obtained within 48 h of focal onset seizure diagnosis, due to epilepsy or acute symptomatic seizures, were divided into groups based on initial ASL findings (ASL-negative vs. ASL-positive), and DWI abnormalities (DWI-negative vs. DWI-positive). The diagnosis was made based on seizure semiology, electroencephalography, and conventional imaging modalities. ASL and DWI abnormalities were based on visual assessment. Of the 41 patients, eight (19.5%) displayed normal ASL findings. The proportion of patients with focal aware seizures (FAS) was significantly higher among ASL-negative patients (62.5%) than that in ASL-positive patients (15.2%); the proportion of patients with focal impaired awareness seizures (FIAS) was significantly lower among ASL-negative patients (12.5%) than that among ASL-positive patients (57.6%). Hyperintensity findings on DWI were observed in 12 patients (29.3%, DWI-positive). The proportion of patients with FIAS was significantly higher among DWI-positive patients (75.0%) than that among DWI-negative patients (37.9%). Multivariate analysis revealed that FAS and FIAS were associated with normal ASL findings (odds ratio [OR]: 21.37, P = 0.010) and DWI abnormalities (OR = 6.11, P = 0.028). A diagnosis of seizures should not be excluded based on normal ASL findings, especially in patients with FAS. FIAS may be a risk factor for neuronal damage caused by seizure activity.

en: Journal of the Neurological Sciences

ja: Journal of the Neurological Sciences


en: 血管炎性ニューロパチー様の臨床像で発症した抗Hu抗体陽性脳脊髄炎の1例

ja: 血管炎性ニューロパチー様の臨床像で発症した抗Hu抗体陽性脳脊髄炎の1例

en: Peripheral Nerve

ja: Peripheral Nerve


en: Utility of phrenic nerve ultrasound in amyotrophic lateral sclerosis

en: Acta Neurologica Belgica

ja: Acta Neurologica Belgica


en: 神経超音波を用いた症状誘発肢位での動的評価が診断の一助となった真の神経原性胸部出口症候群の1例

en: Japanese Journal of Clinical Neurophysiology

ja: 臨床神経生理学


en: A case of led to diagnosis of malignancy by brachial plexus ultrasonography

ja: 腕神経叢エコー検査が契機となって悪性腫瘍が診断できた1例

en: A 72-year-old man admitted to our hospital due to severe pain and drop hand in the left arm. MRI and CT of the head and neck at an outside hospital showed no abnormality. Neurological findings revealed distal weakness in the left upper extremity, vague pain between the radial aspect of the left hand and the middle of the digits 1-3, as well as brisk reflexes in the left extremities. Small masses were palpable in the posterior neck, the lower jaw, and the left neck. Clinically, left radial neuropathy and cervical radiculopathy were suspected. We performed ultrasound of the nerve roots, brachial plexus, and the radial nerve. There was a mass compressing the left brachial plexus from the caudolateral direction. Additionally, nerve swelling in the left arm was identified. Skin biopsy over the mass suggested metastatic adenocarcinoma. Chest CT scan showed a mass in the upper right lobe suggestive of a lung cancer. We concluded that the pain was due to radial neuropathy and upper and middle trunk disturbance of the left brachial plexopathy, of which neuromuscular ultrasound was useful in diagnosis.

en: Neurosonology

ja: 神経超音波医学


en: PMP22-related disease: A novel splice site acceptor variant and intrafamilial phenotype variability.

en: PMP22 is the most frequent mutated gene in Charcot-Marie-Tooth disease (CMT) type 1A. Another phenotype, hereditary neuropathy with pressure palsies (HNPP), could be caused by PMP22 mutations. PMP22 encodes a peripheral myelin protein with molecular weight 22-kDa. Various pathomechanisms have been postulated in PMP22-related disease, including dysfunction due to missense mutations, and alteration of a gene dose due to duplication/deletion mutations. We identified a novel PMP22 splice site acceptor variant, c.179-1G>A, in a patient with adult-onset chronic generalized polyneuropathy and two asymptomatic family members. Pathophysiological features of the members mainly overlapped with those reported in HNPP, but broad intrafamilial clinical variations were observed. PMP22 transcripts lacking of exon 4 were produced by the variant, presumably leading to in-frame deletion of 47 amino acids. The variant was also shown to exert effect on dosage of PMP22 mRNA. The complex molecular pathology would lead to the unique clinical and pathophysiological conditions.