Acquired neuromyotonia encompasses a group of inflammatory disorders characterized by symptoms reflecting peripheral nerve hyperexcitability, which may be clinically confused in the early stages with amyotrophic lateral sclerosis. Despite a clear peripheral nerve focus, it remains unclear whether the ectopic activity in acquired neuromyotonia receives a central contribution. To clarify whether cortical hyperexcitability contributes to development of clinical features of acquired neuromyotonia, the present study investigated whether threshold tracking transcranial magnetic stimulation could detect cortical hyperexcitability in acquired neuromyotonia, and whether this technique could differentiate acquired neuromyotonia from amyotrophic lateral sclerosis. Cortical excitability studies were undertaken in 18 patients with acquired neuromyotonia and 104 patients with amyotrophic lateral sclerosis, with results compared to 62 normal controls. Short-interval intracortical inhibition in patients with acquired neuromyotonia was significantly different when compared to patients with amyotrophic lateral sclerosis (averaged short interval intracortical inhibition acquired neuromyotonia 11.3 +/- 1.9%; amyotrophic lateral sclerosis 2.6 +/- 0.9%, P < 0.001). In addition, the motor evoked potential amplitudes (acquired neuromyotonia 21.0 +/- 3.1%; amyotrophic lateral sclerosis 38.1 +/- 2.2%, P < 0.0001), intracortical facilitation (acquired neuromyotonia -0.9 +/- 1.3%; amyotrophic lateral sclerosis -2.3 +/- 0.6%, P < 0.0001), resting motor thresholds (acquired neuromyotonia 62.2 +/- 1.6%; amyotrophic lateral sclerosis 57.2 +/- 0.9%, P < 0.05) and cortical silent period durations (acquired neuromyotonia 212.8 +/- 6.9 ms; amyotrophic lateral sclerosis 181.1 +/- 4.3 ms, P < 0.0001) were significantly different between patients with acquired neuromyotonia and amyotrophic lateral sclerosis. Threshold tracking transcranial magnetic stimulation established corticomotoneuronal integrity in acquired neuromyotonia, arguing against a contribution of central processes to the development of nerve hyperexcitability in acquired neuromyotonia.
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http://dx.doi.org/10.1093/brain/awq188 | DOI Listing |
JFMS Open Rep
December 2024
IVC Evidensia Small Animal Referral Hospital Hart van Brabant, Waalwijk, The Netherlands.
Case Summary: A 16-year-old spayed female domestic shorthair cat with methimazole-treated hyperthyroidism presented with a chronic progressive history of a stiff gait progressing to recumbency. A neurological examination revealed continuous excessive muscle tone with myokymia, which exacerbated with exercise and persisted during general anaesthesia. An electromyographic study revealed myokymic discharges in all tested muscles, as well as complex repetitive discharges, fibrillation potentials and positive sharp waves.
View Article and Find Full Text PDFBreast Cancer Res Treat
December 2024
University of California San Francisco, Box 1710, San Francisco, CA, 94143, USA.
Purpose: We investigated the small-molecule receptor tyrosine kinase-inhibitor of colony-stimulating factor-1 receptor pexidartinib in the stage II/III breast cancer in the I-SPY2 platform trial.
Methods: I-SPY2 is an adaptive platform trial that features multiple arms of experimental agents administered on a background of standard neoadjuvant therapy with paclitaxel and adriamycin/cyclophosphamide, followed by definitive surgery. The adaptive randomization engine preferentially assigns patients based upon cumulative performance of each agent in a given breast cancer subtype based on hormone receptor and HER2 receptor status.
Neuromuscul Disord
November 2024
Consultant Neurosurgeon, Department of Neurosurgery, Devanika Hospital, Ranchi, India.
Neuromyotonia or Isaacs syndrome is a rare neuromuscular disorder secondary to hyperexcitable peripheral nerves which fire continuously causing motor unit activation and manifests clinically as cramps, muscle twitches, or visible muscle contraction associated with impaired muscle relaxation. Clinical suspicion and subsequent diagnostic work-up, including electrophysiology, aid in the diagnosis. However, when contractions are not appreciated clinically, there is a high possibility of misdiagnosis.
View Article and Find Full Text PDFGenes (Basel)
November 2024
Department of Neuroscience, IRCCS Stella Maris Foundation, 56128 Pisa, Italy.
Background: Autosomal recessive inherited pathogenetic variants in the histidine triad nucleotide-binding protein 1 () gene are responsible for an axonal Charcot-Marie-Tooth neuropathy associated with neuromyotonia, a phenomenon resulting from peripheral nerve hyperexcitability that causes a spontaneous muscle activity such as persistent muscle contraction, impaired relaxation and myokymias.
Methods: Herein, we describe two brothers in whom biallelic variants were identified following a multidisciplinary approach.
Results: The younger brother came to our attention for clinical evaluation of moderate intellectual disability, language developmental delay, and some behavioral issues.
J Exp Med
December 2024
Section of Paediatric Infectious Disease, Department of Infectious Disease, Faculty of Medicine, Imperial College London, London, UK.
Multisystem inflammatory syndrome in children (MIS-C) is a rare condition following SARS-CoV-2 infection associated with intestinal manifestations. Genetic predisposition, including inborn errors of the OAS-RNAseL pathway, has been reported. We sequenced 154 MIS-C patients and utilized a novel statistical framework of gene burden analysis, "burdenMC," which identified an enrichment for rare predicted-deleterious variants in BTNL8 (OR = 4.
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