Journal of Clinical Neuromuscular Disease最新文献

Abstract: Hereditary neuropathies are typically associated with an early onset of symptoms, but same types of neuropathies may also manifest late, after the age 50 years. A 62-year-old African American woman presented with a 6-year history of gait unsteadiness and has been using a walker since the age 57 years after an unwitnessed fall. Gradual worsening of walking difficulties was later followed by decreased dexterity. The family history was negative for neuromuscular disorders, including neuropathy. On examination, the patient had both distal and proximal weakness with distal sensory loss to all modalities and hyporeflexia. Charcot Marie Tooth Examination Score was 12. Previous electrodiagnostic testing at the age 60 years showed severe sensorimotor demyelinating polyneuropathy with bilateral severe carpal tunnel syndrome. Genetic testing showed a homozygous pathogenic mutation in SH3TC2 gene (c.2860C>T; p.Arg954*), associated with CMT4C. CMT4C is the most common recessive demyelinating sensorimotor polyneuropathy and overall comprises 0.4%-1.7% of all patients with Charcot-Marie-Tooth disease. It is more common in French Canadians and Spanish Roma and in recent natural history study; only 1 of 56 patients was African American. This report demonstrates sporadic occurrence of CMT4C in other ethnic groups as well.

Objectives: In 2015, a new term "nodopathy" was introduced to represent a group of neuropathy because of autoantibodies at the node of Ranvier and paranodal area. This review was conducted to highlight the electrophysiologic characteristics of acute and chronic nodopathies by the newly introduced term: "nodal conduction block (CB); CB without temporal dispersion or slow nerve conduction velocity" and by introducing a new term: "internodal CB; CB with temporal dispersion or/and slow nerve conduction velocity".

Methods: Through PubMed searches, 23 cases of acute (<4 weeks of neuropathy) nodopathy and 12 cases of chronic (>4 weeks of neuropathy) nodopathy are identified. Two other required inclusion criteria are positive nodal antibody test and detailed nerve conduction data with or without figure. All existing data were analyzed to see whether these cases had nodal or internodal CB.

Results: Among 23 cases of acute nodopathy, 11 had nodal CB, 9 internodal CB, and 3 mixed CB. Thus, nodal CB was observed in 61% of acute nodopathy cases and internodal CB in 52% of acute nodopathy cases. Among 12 cases of chronic nodopathy, all 12 had internodal CB.

Conclusions: Nodal CB is the nerve conduction characteristic of acute nodopathy, but internodal CB does not rule out acute nodopathy. Internodal CB is the nerve conduction characteristic of chronic nodopathy.

Objective: Ultrasound studies in inclusion body myositis (IBM) have reported a characteristic pattern of increased echointensity in the flexor digitorum profundus (FDP) with relative sparing of the flexor carpi ulnaris (FCU). We examined the relationship between echointensity of the FDP and FCU muscles and hand strength or patient-reported outcomes (PROs).

Methods: A total of 15 patients with IBM were recruited. Ultrasound images of the FDP and FCU muscles were obtained by a point-of-care ultrasound and graded using the modified Heckmatt score. Hand grip and neutral pinch strength were measured by dynamometry. PROs were assessed by the IBM Upper Extremity Function Scale.

Results: FDP and/or FCU modified Heckmatt score showed a significant relationship with grip, neutral pinch strength, and PROs.

Conclusions: Point-of-care ultrasound examination of the forearm may serve as an extension of the neuromuscular examination. The semi-qualitative echointensity rating based on modified Heckmatt score seems to correlate well with the objective strength measurement and PROs.

Objectives: Neuromuscular disorders could have respiratory involvement early or late into illness. Rarely, patients may present with a hypercapnic respiratory failure (with minimal motor signs) unmasking an underlying disease. There are hardly any studies which have addressed the spectrum and challenges involved in management of this subset, especially in the real-world scenario.

Methods: A retrospective study comprising consecutive patients hospitalized with hypercapnic respiratory failure as the sole/dominant manifestation. The clinical-electrophysiological spectrum, phrenic conductions, diaphragm thickness, and outcomes were analyzed.

Results: Twenty-seven patients were included, the mean age was 47.29 (SD 15.22) years, and the median duration of respiratory symptoms was 2 months (interquartile range [IQR] 1-4). Orthopnea was present in 23 patients (85.2%) and encephalopathy in 8 patients (29.6%). Phrenic nerve latencies and amplitudes were abnormal in 83.3% and 95.6%, respectively. Abnormal diaphragm thickness was noted in 78.5%. Based on a comprehensive electrophysiological strategy and paraclinical tests, an etiology was established in all. Reversible etiologies were identified in 17 patients (62.9%). These included myasthenia gravis (anti-AChR and MuSK), inflammatory myopathy, riboflavin transporter deficiency neuronopathy, Pompe disease, bilateral phrenic neuritis, and thyrotoxicosis. Respiratory onset motor neuron disease was diagnosed in 8 patients (29.6%). Despite diaphragmatic involvement, a functional respiratory recovery was noted at discharge (45%) and last follow-up (60%). Predictors for good outcomes included female sex, normal nerve conductions, and recent-onset respiratory symptoms.

Discussion: A good functional recovery was noted in most of the patients including respiratory onset motor neuron disease. A systematic algorithmic approach helps in proper triaging, early diagnosis, and treatment. Clinical and electrodiagnostic challenges and observations from a tertiary care referral center are discussed.

Objectives: Small fiber neuropathy (SFN) is a subtype of painful neuropathies defined by dysfunction of the Aδ and unmyelinated C fibers. It presents with both neuropathic pain and dysautonomia symptoms, posing a significant diagnostic and therapeutic challenge. To address this challenge, research has been conducted to identify autoantibodies and define their association with phenotypes.

Methods: Eleven cases of anti-plexin-D1 seropositive SFN were reviewed, along with relevant literature, in attempt to better define anti-plexin-D1 SFN demographics, symptoms, associated medical conditions, and therapeutics.

Results: Anti-plexin-D1 SFN typically presents in female patients, with neuropathic pain, normal skin biopsy findings, and normal nerve conduction studies. Anti-plexin-D1 shows an association with concurrent chronic pain, with almost half of the patients undergoing an interventional procedure.

Conclusions: Anti-plexin-D1 represents a unique subgroup of SFN, defined by distinct demographics, phenotype, biopsy findings, and therapeutic management.

Abstract: Immune checkpoint inhibitors used to treat malignancies may lead to various immune-related adverse events (irAEs) including conditions such as myositis and myasthenia gravis (MG). Here, we describe 2 cases of myositis treated effectively with therapeutic plasma exchange (PLEX). A 64-year-old man with thymic cancer developed leg weakness and dyspnea 1 month after the second dose of nivolumab with moderate weakness in proximal and distal muscles, with elevated creatine kinase levels. Another 77-year-old man with Stage IIIB squamous cell carcinoma of the lung developed progressive proximal muscle weakness and became nonambulatory after cycle 2 of durvalumab with persistently high creatine kinase levels despite prednisone treatment. Electrophysiology revealed irritative myopathy without evidence of neuromuscular junction dysfunction and MG antibody testing was nonrevealing. With PLEX, both patients noticed rapid improvement in strength. PLEX in conjunction with other immunosuppressive agents can result in rapid improvement in irAE-myositis even in patients without associated MG.