title: Peripheral nerve hyperexcitability: a clinical and immunologic study of 38 patients.
abstract: OBJECTIVE
  We studied a case series of peripheral nerve hyperexcitability (PNH) aiming to describe clinical characteristics, immunologic and cancer associations, antibodies against neuronal antigens (voltage-gated potassium channel antibodies [VGKC-Abs] and other), and muscle biopsy findings.
  
  
  METHODS
  Patients presenting with clinical and electrophysiologic signs of PNH were selected. We studied clinical and electrophysiologic features; a panel of non-neuronal organ-specific antibodies, immunofluorescence on rat nervous tissues, and radioimmunoprecipitation for VGKC-Abs; and muscle biopsies.
  
  
  RESULTS
  Thirty-eight patients were included. After the exclusion of 6 cases with axonopathy of known origin, patients were subdivided according to the presence of electrophysiologic findings of motor axonopathy and association with cancer: axonopathic-PNH (group A: 12 patients), isolated nonparaneoplastic PNH (group B: 16 patients), and isolated paraneoplastic PNH (3 with thymoma and myasthenia gravis, 1 with thyroid carcinoma). PNH clinical features were similar in groups A and B. We found an overall high prevalence of clinical autoimmunity (33% of group A and 63% of group B) and systemic non-neuronal autoantibodies (42% of group A and 75% of group B). However, VGKC-Abs were only positive in 2 patients of group B. Ten patients underwent muscle biopsy, which showed inflammatory changes in 2 cases and nonspecific myopathic features in 8.
  
  
  CONCLUSIONS
  PNH is a heterogeneous disorder involving the peripheral nerves in patients with a high propensity for developing autoimmunity. Associated muscle diseases are frequent in the form of myositis, myasthenia gravis, or nonspecific myopathic pathologic findings. VGKC-Abs were uncommon in this series.
authors.affiliation: Department of Neurology, Hospital Universitari La Fe, Avenida de Campanar 21, 46009 Valencia, Spain.
authors.forename: I
authors.initials: I
authors.lastname: Rubio-Agusti
authors.forename: F
authors.initials: F
authors.lastname: Perez-Miralles
authors.forename: T
authors.initials: T
authors.lastname: Sevilla
authors.forename: N
authors.initials: N
authors.lastname: Muelas
authors.forename: M J
authors.initials: MJ
authors.lastname: Chumillas
authors.forename: F
authors.initials: F
authors.lastname: Mayordomo
authors.forename: I
authors.initials: I
authors.lastname: Azorin
authors.forename: E
authors.initials: E
authors.lastname: Carmona
authors.forename: F
authors.initials: F
authors.lastname: Moscardo
authors.forename: J
authors.initials: J
authors.lastname: Palau
authors.forename: L
authors.initials: L
authors.lastname: Jacobson
authors.forename: A
authors.initials: A
authors.lastname: Vincent
authors.forename: J J
authors.initials: JJ
authors.lastname: Vilchez
authors.forename: L
authors.initials: L
authors.lastname: Bataller
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000974:Antibodies, Antinuclear / Q000378:metabolism*; D001706:Biopsy; D004594:Electrophysiology; D005260:Female; D005455:Fluorescent Antibody Technique; D006801:Humans; D007249:Inflammation; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000473:pathology*; D009157:Myasthenia Gravis / Q000276:immunology; D020364:Paraneoplastic Polyneuropathy / Q000276:immunology / Q000503:physiopathology; D010523:Peripheral Nervous System Diseases / Q000276:immunology* / Q000473:pathology / Q000503:physiopathology*; D024642:Potassium Channels, Voltage-Gated / Q000378:metabolism*; D015531:Radioimmunoprecipitation Assay; D012307:Risk Factors; D013945:Thymoma / Q000276:immunology; D013964:Thyroid Neoplasms / Q000276:immunology; D055815:Young Adult
chemical_list: D000974:Antibodies, Antinuclear; D024642:Potassium Channels, Voltage-Gated