Neuromyotonia: autoimmune pathogenesis and response to immune modulating therapy

Clinical spectrum of voltage-gated potassium channel autoimmunity

“…Evidence for neoplasm in the other 10 patients (14%) included CT findings of a mass lesion or lymphadenopathy in five (three thoracic, two abdominal), or lung parenchymal abnormalities in two, abnormal whole-body PET in two, and elevated prostate-specific antigen in 1. Neurologic symptoms preceded diagnosis of neoplasia in 18 patients (by a median of 5 months; range, [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19]. In those cases, detection of VGKC autoantibodies (and coexisting autoantibodies in some cases) expedited the tumor diagnosis.…”

“…16 The reported therapeutic benefits of IV immunoglobulin and plasmapheresis are also consistent with a humoral immune pathogenesis. 17,18 Some VGKC autoantibody specificities yield recognizable synaptic immunostaining patterns, 8,19 some of which correspond to different neurologic presentations and VGKC-subtype autoantibody specificities. 20 VGKC autoantibodies also have been identified by radioimmunoprecipitation assay (RIA) utilizing detergent-solubilized brain synaptic membranes complexed with 125 I-labeled ␣-dendrotoxin.…”

Voltage-Gated Potassium Channel Autoimmunity Mimicking Creutzfeldt-Jakob Disease

“…Conditions of most patients improve after early initiation of antibody-depleting immunomodulatory therapies 15. The observations described in this article, made independently at 2 separate institutions, involve 15 patients given an initial diagnosis of CJD but subsequently confirmed to have VGKC autoantibody–associated encephalopathy.…”

Isaacs' syndrome: Clinical and electrophysiological response to gabapentin

“…1,11,15 However, symptomatic treatment appears to be the mainstay, because nearly all patients respond well to treatment with phenytoin or carbamazepine. Gabapentin may be a useful addition for symptomatic treatment of neuromyotonia.…”