title: Subacute inflammatory demyelinating polyneuropathy.
abstract: OBJECTIVE
  To report the clinical, electrophysiologic, and histologic characteristics of subacute inflammatory demyelinating polyneuropathy (SIDP) and to present the diagnostic criteria of this disease.
  
  
  METHODS
  For a diagnosis of "definite SIDP," there were four mandatory criteria: 1) progressive motor and/or sensory dysfunction consistent with neuropathy in more than one limb with time to nadir between 4 and 8 weeks, 2) electrophysiologic evidence of demyelination in at least two nerves, 3) no other etiology of neuropathy, and 4) no relapse on adequate follow-up. Supportive criteria included high spinal fluid protein level (>55 mg/dL) and inflammatory cells in the nerve biopsy. A diagnosis of "probable SIDP" required progression of demyelinating neuropathy over a 4- to 8-week period.
  
  
  RESULTS
  Sixteen definite SIDP patients were identified among 29 probable SIDP patients. An antecedent infection was found in 38% of cases. The two most common neuropathy types were a symmetric motor-sensory neuropathy and a pure motor neuropathy. Cranial nerve deficits and respiratory failure were rare. Spinal fluid protein was high in 93% of cases. Demyelination was documented by the motor nerve conduction in 88% of cases and by the near-nerve needle sensory nerve conduction in two cases. Almost all patients were treated with prednisone and some with additional immunotherapies. Complete recovery was achieved in 69% of cases and partial recovery in others. Definite SIDP had all the characteristics of CIDP with three exceptions: a higher rate of antecedent infection, no relapse rate, and a high rate of recovery to normal.
  
  
  CONCLUSIONS
  Subacute inflammatory demyelinating polyneuropathy is a definite entity bridging the gap between Guillain-Barré syndrome and chronic inflammatory demyelinating polyneuropathy.
authors.affiliation: Department of Neurology, University of Alabama at Birmingham, and Department of Veterans Affairs Medical Center, 35294, USA. shinjoh@uab.edu
authors.forename: S J
authors.initials: SJ
authors.lastname: Oh
authors.forename: K
authors.initials: K
authors.lastname: Kurokawa
authors.forename: D F
authors.initials: DF
authors.lastname: de Almeida
authors.forename: H F
authors.initials: HF
authors.lastname: Ryan
authors.forename: G C
authors.initials: GC
authors.lastname: Claussen
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001706:Biopsy; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009412:Nerve Fibers / Q000473:pathology; D011129:Polyradiculoneuropathy / Q000175:diagnosis* / Q000473:pathology / Q000628:therapy; D020277:Polyradiculoneuropathy, Chronic Inflammatory Demyelinating / Q000175:diagnosis; D016896:Treatment Outcome