title: Lower motor neuron syndrome due to cauda equina hypertrophy with onion bulbs.
abstract: BACKGROUND
  Hypertrophy of the nerve roots of the cauda equina may occur with both acquired and inherited neuropathies. Although selective nerve root involvement of the sensory roots has been described and termed chronic inflammatory sensory polyradiculoneuropathy (CISP), selective involvement of the proximal motor roots has not been described.
  
  
  METHODS
  Clinical, electrophysiological, MRI, and pathological findings are reported.
  
  
  RESULTS
  Here, we report a patient with cauda equina hypertrophy presenting with a pure lower motor neuron syndrome without clinical or electrophysiological evidence of sensory fiber involvement. Bowel and bladder functions were spared. Nerve root biopsy demonstrated abundant onion bulb formations. The patient experienced improvement in motor function with immunomodulatory treatment.
  
  
  CONCLUSIONS
  We suggest the term chronic immune demyelinating motor polyradiculopathy (CIMP) to describe this particular form of CIDP, thereby expanding the clinical spectrum of CIDP.
authors: Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada.
authors: Erin K
authors: EK
authors: O'Ferrall
authors: Daniel
authors: D
authors: Gendron
authors: Marie-Christine
authors: MC
authors: Guiot
authors: Jeffery
authors: J
authors: Hall
authors: Michael
authors: M
authors: Sinnreich
mesh_terms: D000368:Aged; D002420:Cauda Equina / Q000473:pathology*; D006801:Humans; D006984:Hypertrophy / Q000473:pathology; D007796:Laminectomy; D008279:Magnetic Resonance Imaging; D008297:Male; D016472:Motor Neuron Disease / Q000209:etiology* / Q000473:pathology*; D009046:Motor Neurons / Q000473:pathology / Q000648:ultrastructure; D011128:Polyradiculopathy / Q000150:complications*
keywords: cauda equina hypertrophy; demyelination; lower motor neuron syndrome; neuropathy; onion bulbs