title: Autonomic dysfunction in chronic inflammatory demyelinating polyradiculoneuropathy.
abstract: OBJECTIVE
  Autonomic deficits in chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) have not been adequately quantitated. The Composite Autonomic Severity Score (CASS) is a validated instrument for laboratory quantitation of autonomic failure derived from standard autonomic reflex tests. We characterized dysautonomia in CIDP using CASS.
  
  
  METHODS
  Autonomic function was retrospectively analyzed in 47 patients meeting CIDP criteria. CASS ranges from 0 (normal) to 10 (pandysautonomia), reflecting summation of sudomotor (0-3), cardiovagal (0-3), and adrenergic (0-4) subscores. Severity of neurologic deficits was measured with Neuropathy Impairment Score (NIS). Degree of small fiber involvement was assessed with quantitative sensation testing. Thermoregulatory sweat test (TST) was available in 8 patients.
  
  
  RESULTS
  Patients (25 men) were middle-aged (45.0 ± 14.9 years) with longstanding CIDP (3.5 ± 4.3 years) of moderate severity (NIS, 46.5 ± 32.7). Autonomic symptoms were uncommon, mainly gastrointestinal (9/47; 19%) and genitourinary (8/47; 17%). Autonomic deficits (CASS ≥1) were frequent (22/47; 47%) but very mild (CASS, 0.8 ± 0.9; CASS ≤3, all cases). Deficits were predominantly sudomotor (16/47; 34%) and cardiovagal (10/47; 21%) with relative adrenergic sparing (4/47; 9%). TST was abnormal in 5 of 8 patients (anhidrosis range, 2%-59%). Sudomotor impairment was predominantly distal and postganglionic. Somatic deficits (disease duration, severity, small fiber deficits) did not predict presence of autonomic deficits.
  
  
  CONCLUSIONS
  Our data characterize the autonomic involvement in classic CIDP as mild, cholinergic, and predominantly sudomotor mainly as a result of lesions at the distal postganglionic axon. Extensive or severe autonomic involvement (CASS ≥4) in suspected CIDP should raise concern for an alternative diagnosis.
authors.affiliation: Department of Neurology, Mayo Clinic, Rochester, MN, USA.
authors.forename: J J
authors.initials: JJ
authors.lastname: Figueroa
authors.forename: P J B
authors.initials: PJ
authors.lastname: Dyck
authors.forename: R S
authors.initials: RS
authors.lastname: Laughlin
authors.forename: J A
authors.initials: JA
authors.lastname: Mercado
authors.forename: R
authors.initials: R
authors.lastname: Massie
authors.forename: P
authors.initials: P
authors.lastname: Sandroni
authors.forename: P J
authors.initials: PJ
authors.lastname: Dyck
authors.forename: P A
authors.initials: PA
authors.lastname: Low
mesh_terms: D000328:Adult; D001341:Autonomic Nervous System / Q000503:physiopathology*; D001342:Autonomic Nervous System Diseases / Q000503:physiopathology*; D001833:Body Temperature Regulation / Q000502:physiology; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D020277:Polyradiculoneuropathy, Chronic Inflammatory Demyelinating / Q000503:physiopathology*; D012720:Severity of Illness Index; D013546:Sweating / Q000502:physiology