Compound muscle action potential of whole-forearm flexors: A clinical biomarker for inclusion body myositis.

Objective: This study aimed to investigate the potential of whole-forearm flexor muscle (WFFM) compound muscle action potential (CMAP) as a quantitative biomarker for inclusion body myositis (IBM) pathology. Methods: We prospectively enrolled 14 consecutive patients (10 men and 4 women) diagnosed with IBM based on muscle biopsies. We evaluated the baseline-to-peak amplitude of the WFFM CMAP and other quantitative parameters, including grip and pinch strength, Inclusion Body Myositis Functional Rating Scale (IBMFRS) score, and other routine muscle CMAP amplitudes. Results: The WFFM CMAP was strongly correlated with disease duration and the IBMFRS score. The WFFM CMAP on the more affected side was lower than that on the less affected side. Furthermore, grip power was strongly correlated with the WFFM CMAP, whereas lateral pinch strength was strongly correlated with the WFFM and first dorsal interosseous CMAPs. The 3-point pinch strength was also correlated with the WFFM CMAP. Conclusions: This study demonstrates that the WFFM CMAP may serve as a biomarker of severity in IBM. Significance: Identification of this biomarker can support drug development, diagnosis, prognosis, and treatment options for patients with IBM.

Protocol for high-quality single-cell RNA-seq from tissue sections with DRaqL.

Single-cell RNA sequencing (scRNA-seq) combined with laser capture microdissection (LCM) offers a versatile framework for comprehensive transcriptomics from tissue sections. Here, we present a detailed protocol for DRaqL (direct RNA recovery and quenching for LCM) in combination with Smart-seq2 (DRaqL-Smart-seq2), which enables high-quality RNA sequencing for single cells obtained from alcohol-fixed murine ovarian sections. Additionally, we provide an optional procedure for scRNA-seq from formalin-fixed sections (DRaqL-Protease-Smart-seq2). We outline key steps for cell lysis, cDNA amplification, and sequencing library preparation. For complete details on the use and execution of this protocol, please refer to Ikeda et al.1.

Mitral Valve Replacement for Enlarged Libman-Sacks Endocarditis in a Patient with Persistent Primary Antiphospholipid Syndrome and Recurrent Stroke: A Case Report.

BACKGROUND Anticardiolipin antibodies in patients with Libman-Sacks endocarditis (LS) are indicative of comorbid antiphospholipid syndrome (APS) and can result in cerebral infarctions. We describe a case of LS and primary APS with recurrent cerebral infarctions despite anticoagulation treatment. The patient underwent surgery for enlarged LS vegetation with high titers of antiphospholipid antibodies. CASE REPORT A 41-year-old Japanese man was admitted to hospital for small cerebral infarction recurrence in a left parietal lesion. At age 35, the patient had suffered multiple cerebral infarctions. He was found to have high serum titers of all 3 antiphospholipid antibodies. Transesophageal echocardiography (TEE) findings were normal. Differential diagnosis ruled out other autoimmune diseases and a clinical diagnosis of primary APS was made. Warfarin anticoagulation was started. When cerebral infarction recurred 6 years after the first episode, serum titers of antiphospholipid antibodies remained high, and TEE showed a 7×8 mm area of mitral vegetation. A TEE results from his first admission revealed a 5×6 mm area of mitral vegetation, which was believed to be related to the current vegetation. As anticoagulation produced no improvement, the mitral valve was replaced with a mechanical valve. Examination of the excised vegetation found it to be consistent with LS. The patient made good progress within 3 years after surgery. CONCLUSIONS LS size can increase despite anticoagulation in cases with high titers of all 3 antiphospholipid antibodies and cerebral infarction. Such patients require ongoing TEE follow-up and surgical treatment should be considered.

Electromyography varies by stage in inclusion body myositis.

Introduction: Inclusion body myositis (IBM) is a chronic inflammatory muscle disease that is characterized by mixed myogenic and neurogenic electromyography (EMG) findings. We investigated the association between EMG findings and the IBM stage. Methods: We included consecutive patients diagnosed with IBM based on muscle biopsy and had needle EMG performed within 1 month of biopsy. Motor unit potential waveform (MUP) in EMG and pathological findings were compared between patients in early and late phases. Results: In total, 30 patients with biopsy-confirmed IBM and 254 muscles were included. The rate of abnormal discharge did not differ according to disease stage. There was a difference in the frequency of occurrence between myogenic suggestive MUP and neurogenic of biceps and flexor digitorum profundus in the late phase. Abnormal MUP was observed even in muscles without muscle weakness, and myogenic changes were predominant in biceps and gastrocnemius with muscle weakness. The biopsy findings on the contralateral side of the muscle where electromyography was performed revealed a tendency for muscles that exhibited myogenic origin to have more inflammatory cells and RV; however, the difference was not significant. Conclusion: The target muscles for EMG must be selected considering the disease stage as well. In the early stages of IBM, EMG results should be interpreted cautiously, as neurogenic suggestive pattern of MUP might also be exhibited. Contralateral electromyography findings may be helpful in selecting muscles for muscle biopsies, such as biceps and quadriceps.

[A case of the palatal tremor that disappeared during swallowing, thought to be caused by microbleeds of bilateral dentate nucleus].

A 72-year-old female presented with slowly progressive dysphonia, which was a syllable-separated utterance, for three years. She had the rhythmic continues contraction of palatal and uvula muscles during speech with a frequency of about 2 Hz. The videoendoscopy showed that the rhythmic contraction, which synchronized in the nasopharynx and the larynx, did not disappear during vocalization. The swallowing videofluorography showed that the rhythmic contraction disappeared transiently during the swallowing reflex, and there was no aspiration. The MRI revealed olivary pseudohypertrophy and multiple microbleedings including the bilateral dentate nucleus. The degeneration of olivary nucleus secondary to the bilateral asymptomatic dentate nucleus microbleedings within the dentato-rubro-olivary pathway was thought to be a cause of palatal tremor. This is a first report that a dynamic relation between vocalization and swallowing in palatal tremor.

Thoracic Excursion Is a Biomarker for Evaluating Respiratory Function in Amyotrophic Lateral Sclerosis.

Objective: To evaluate the usefulness of thoracic excursion as a biomarker in patients with amyotrophic lateral sclerosis (ALS). Methods: We measured the forced the vital capacity (FVC), thoracic excursion, baseline-to-peak diaphragmatic compound muscle action potential (DCMAP) amplitude, diaphragm thickness at full inspiration (DTfi), Medical Research Council (MRC) sum score for muscle strength, and arterial partial pressures of oxygen and carbon dioxide and administered the Amyotrophic Lateral Sclerosis Functional Rating Scale-Revised (ALSFRS-R) and modified Medical Research Council (mMRC) Dyspnea Scale. The test-retest reliability of thoracic excursion was determined. Results and Conclusions: Thirty-four patients with ALS and 26 age- and sex-matched healthy participants were enrolled. Thoracic excursion measurement had excellent test-retest reliability (intraclass coefficient: 0.974). Thoracic excursion was more strongly correlated with FVC (r = 0.678, p < 0.001) than DCMAP amplitude (r = 0.501, p = 0.003) and DTfi (r = 0.597, p < 0.001). It was also correlated with ALSFRS-R score (r = 0.610, p < 0.001), MRC sum score (r = 0.470, p = 0.005), and mMRC Dyspnea Scale score (r = -0.446, p = 0.008) and was the most sensitive parameter for assessing dyspnea and FVC. Thoracic excursion decreased as FVC declined in the early and late stages, there were no differences in DCMAP amplitude and DTfi between the early and late stages, and ALSFRS-R score and MRC sum score decreased only in the late stage. Thoracic excursion was well correlated with respiratory function and is useful for predicting respiratory and general dysfunction in patients with ALS regardless of stage.