Peripheral nerve hyperexcitability syndrome, Morvan’s syndrome

2013 ◽  
pp. 68-69
Author(s):  
John H. J. Wokke ◽  
Pieter A. van Doorn ◽  
Jessica E. Hoogendijk ◽  
Marianne de Visser
Keyword(s):  
Peripheral Nerve ◽  
Morvan’S Syndrome ◽  
Peripheral Nerve Hyperexcitability

Confusion, Muscle Cramps, and Weight Loss

2018 ◽  
pp. 127-132
Author(s):  
Aaron E. Miller ◽  
Tracy M. DeAngelis ◽  
Michelle Fabian ◽  
Ilana Katz Sand
Keyword(s):  
Weight Loss ◽  
Nervous System ◽  
Neuropathic Pain ◽  
Peripheral Nerve ◽  
Immunosuppressive Agents ◽  
Muscle Cramps ◽  
Morvan’S Syndrome ◽  
Peripheral Nerve Hyperexcitability ◽  
Core Symptoms ◽  
Cerebellar Symptoms

Morvan’s syndrome is a rare autoimmune antibody syndrome causing central, peripheral, and autonomic manifestations. It has been most consistently associated with Caspr2 antibodies, although LGI1 antibodies have also been found in some patients. The Caspr2 protein is located throughout the central and peripheral nervous system. This may account for the diversity of presentations that have been reported in patients with Caspr2 antibodies. The seven core symptoms of Caspr2 antibodies include cognitive dysfunction/seizures, cerebellar symptoms, peripheral nerve hyperexcitability, autonomic dysfunction, insomnia, neuropathic pain, and weight loss. Treatment of Morvan’s syndrome and other Caspr-associated antibody syndromes is largely empirical. Typically, patients are given steroids, intravenous immunoglobulin, and if necessary, other immunosuppressive agents. Prognosis for remission is very good, but relapses may occur.

Peripheral nerve hyperexcitability syndromes

2015 ◽  
Vol 26 (2) ◽  
Author(s):  
Cem Ismail Küçükali ◽  
Murat Kürtüncü ◽  
Halil İbrahim Akçay ◽  
Erdem Tüzün ◽  
Ali Emre Öge
Keyword(s):  
Nervous System ◽  
Peripheral Nerve ◽  
Immune Modulation ◽  
Symptomatic Treatment ◽  
Immune Mediated ◽  
Morvan’S Syndrome ◽  
Peripheral Nerve Hyperexcitability ◽  
The Central Nervous System ◽  
Electrophysiological Findings ◽  
Symptoms And Signs

AbstractPeripheral nerve hyperexcitability (PNH) syndromes can be subclassified as primary and secondary. The main primary PNH syndromes are neuromyotonia, cramp-fasciculation syndrome (CFS), and Morvan’s syndrome, which cause widespread symptoms and signs without the association of an evident peripheral nerve disease. Their major symptoms are muscle twitching and stiffness, which differ only in severity between neuromyotonia and CFS. Cramps, pseudomyotonia, hyperhidrosis, and some other autonomic abnormalities, as well as mild positive sensory phenomena, can be seen in several patients. Symptoms reflecting the involvement of the central nervous system occur in Morvan’s syndrome. Secondary PNH syndromes are generally seen in patients with focal or diffuse diseases affecting the peripheral nervous system. The PNH-related symptoms and signs are generally found incidentally during clinical or electrodiagnostic examinations. The electrophysiological findings that are very useful in the diagnosis of PNH are myokymic and neuromyotonic discharges in needle electromyography along with some additional indicators of increased nerve fiber excitability. Based on clinicopathological and etiological associations, PNH syndromes can also be classified as immune mediated, genetic, and those caused by other miscellaneous factors. There has been an increasing awareness on the role of voltage-gated potassium channel complex autoimmunity in primary PNH pathogenesis. Then again, a long list of toxic compounds and genetic factors has also been implicated in development of PNH. The management of primary PNH syndromes comprises symptomatic treatment with anticonvulsant drugs, immune modulation if necessary, and treatment of possible associated dysimmune and/or malignant conditions.

scholarly journals A Patient with Double-Negative VGKC, Peripheral Nerve Hyperexcitability, and Central Nervous System Symptoms: A Postinfectious Autoimmune Disease

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Birte Eikeland
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Autoimmune Disease ◽  
Peripheral Nerve ◽  
Skin Lesions ◽  
Double Negative ◽  
Pathogenic Potential ◽  
Peripheral Nerve Hyperexcitability ◽  
Systemic Symptoms ◽  
Kinetics Of

Research in the last few years has indicated that most voltage-gated potassium channel- (VGKC-) complex antibodies without leucine-rich glioma-inactivated protein 1 or contactin-associated protein-like 2 antibody specificity lack pathogenic potential and are not clear markers for autoimmune inflammation. Here we report on a patient with double-negative VGKC who developed severe peripheral nerve hyperexcitability, central nervous system symptoms with agitation and insomnia, dysautonomia, and systemic symptoms with weight loss, itch, and skin lesions. The disease started acutely one month after an episode of enteroviral pericarditis and responded well to immunotherapy. The patient is presumed to have developed a postinfectious immunotherapy-responsive autoimmune disease. In the setting of anti-VGKC positivity, it seems likely that anti-VGKC contributed to the pathogenesis of the patient’s symptoms of nerve hyperexcitability and that the disease was caused by an acquired autoimmune effect on the neuronal kinetics of VGKC. It is still unknown whether or not there are unidentified extracellular molecular targets within the VGKC-complex, i.e., a novel surface antigen and a pathogenic antibody that can cause affected individuals to develop a peripheral nerve hyperexcitability syndrome. This case highlights the fact that less well-characterized autoimmune central and peripheral nervous system syndromes may have infectious triggers.

THUR 153 Antibodies against the voltage-gated potassium channel complex

2018 ◽  
Vol 89 (10) ◽  
pp. A18.2-A18
Author(s):  
Joyutpal Das ◽  
Vanisha Chauhan ◽  
Ryan Keh ◽  
Daniel Mills ◽  
Johal Nicholas ◽  
...  
Keyword(s):  
Potassium Channel ◽  
Intravenous Immunoglobulins ◽  
Voltage Gated ◽  
Morvan’S Syndrome ◽  
Classic Phenotype ◽  
Antibody Titres ◽  
Peripheral Nerve Hyperexcitability ◽  
Clinical Phenotyping ◽  
Positive Results ◽  
Autoimmune Encephalopathy

Voltage-gated potassium channel (VGKC) complex antibodies have been associated with a spectrum of presentations including peripheral nerve hyperexcitability (PNH), Morvan’s syndrome, autoimmune encephalopathy, epilepsy and recently psychosis.We retrospectively reviewed the medical records of 70 patients from the Greater Manchester Neuroscience Centre, who had tested positive for VGKC-complex antibodies between 2012 and 2015 to identify the clinical relevance of positive results.The majority were diagnosed with autoimmune encephalopathy(19) followed by epilepsy(14), psychosis(10) and PNH(6). The remaining fifteen had other neurological presentations and six had no primary neurological disorder. 39/70 patients who had antibody titres>400 pM, were diagnosed with autoimmune encephalopathy(19), epilepsy(9), psychosis(4), PNH(3) and other disorders(4). 24/39 patients, who received treatment with one or a combination of corticosteroids, intravenous immunoglobulins, cyclophosphamide, plasma exchange, azathioprine or rituximab, had a diagnosis of autoimmune encephalopathy(18), epilepsy(2), psychosis(2) and malignancy(2). 16/24 were treatment responsive. 3/31 patients with lower titres were also treated, but only one with the classic phenotype (PNH) responded to treatment.The classic phenotype often had a titre >400 pM. PNH may have a titre ≤400 pM. The patients without classic presentations typically had titres≤400 pM. Consistent with previous studies, clinical phenotyping and antibody titre helped to determine the relevance of VGKC-complex antibodies.

scholarly journals Insomnia and Dysautonomia with Contactin-Associated Protein 2 and Leucine-Rich Glioma Inactivated Protein 1 Antibodies: A “Forme Fruste” of Morvan Syndrome?

2019 ◽  
Vol 11 (1) ◽  
pp. 80-86
Author(s):  
Ezgi Bakırcıoğlu-Duman ◽  
Zeynep Acar ◽  
Gülçin Benbir ◽  
Hande Yüceer ◽  
Hürtan Acar ◽  
...  
Keyword(s):  
Peripheral Nerve ◽  
Neuropsychological Assessment ◽  
Executive Dysfunction ◽  
Cognitive Symptoms ◽  
Neurologic Examination ◽  
Cognitive Domains ◽  
Needle Electromyography ◽  
Muscle Twitching ◽  
Peripheral Nerve Hyperexcitability ◽  
History Of

Morvan syndrome (MoS) is typically characterized by neuromyotonia, sleep dysfunction, dysautonomia, and cognitive dysfunction. However, MoS patients with mild peripheral nerve hyperexcitability (PNH) or encephalopathy features have been described. A 46-year-old woman presented with a 2-month history of constipation, hyperhidrosis, and insomnia. Neurologic examination revealed muscle twitching and needle electromyography showed myokymic discharges in all limbs. No clinical or electrophysiological features of neuromyotonia were present. Although the patient denied any cognitive symptoms, neuropsychological assessment revealed executive dysfunction, while other cognitive domains were preserved. Cranial and spinal MRIs were unrevealing and tumor investigation proved negative. Polysomnography examination revealed total insomnia, which was partially reversed upon immune-modulatory therapy. Investigation of a broad panel of antibodies revealed serum leucine-rich glioma inactivated protein 1 and contactin-associated protein 2 antibodies. The features of this case indicate that the presentation of PNH syndromes may show significant variability and that MoS patients may not necessarily exhibit full-scale PNH and encephalopathy symptoms.

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