title: Peripheral nerve ultrasound in cerebellar ataxia neuropathy vestibular areflexia syndrome (CANVAS).
abstract: We report preliminary findings of nerve ultrasound in patients with cerebellar ataxia neuropathy vestibular areflexia syndrome (CANVAS) who have sensory impairment due to dorsal root ganglionopathy.
  
  
  
  The ultrasound cross-sectional area (CSA) of median and ulnar nerves of 7 CANVAS patients was compared with 7 age- and gender-matched controls and with the mean CSA of our reference population.
  
  
  
  The nerve CSA of CANVAS patients was significantly smaller than that of controls at all sites (P < 0.01). All but 1 individual measurement of CSA at the mid-forearm level in the CANVAS patients fell outside the normal control range and was >2 standard deviations below the reference mean.
  
  
  
  The small nerves in CANVAS probably reflect nerve thinning from axonal loss secondary to ganglion cell loss. Our data show a role for ultrasound in the diagnosis of CANVAS ganglionopathy. This may also be applicable to ganglionopathy from other causes. Muscle Nerve 56: 160-162, 2017.
authors.affiliation: Department of Neurology and Clinical Neurophysiology, Bay of Plenty District Health Board, Tauranga, 3143, New Zealand.
authors.forename: Luciana
authors.initials: L
authors.lastname: Pelosi
authors.affiliation: Capital and Coast District Health Board, Wellington, New Zealand.
authors.forename: Ruth
authors.initials: R
authors.lastname: Leadbetter
authors.affiliation: Auckland District Health Board, Auckland, New Zealand.
authors.forename: Eoin
authors.initials: E
authors.lastname: Mulroy
authors.affiliation: Department of Neurology and Clinical Neurophysiology, Bay of Plenty District Health Board, Tauranga, 3143, New Zealand.
authors.forename: Andrew M
authors.initials: AM
authors.lastname: Chancellor
authors.affiliation: Capital and Coast District Health Board, Wellington, New Zealand.
authors.forename: Stuart
authors.initials: S
authors.lastname: Mossman
authors.affiliation: Auckland District Health Board, Auckland, New Zealand.
authors.forename: Richard
authors.initials: R
authors.lastname: Roxburgh
mesh_terms: D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D002524:Cerebellar Ataxia / Q000150:complications / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010525:Peripheral Nerves / Q000000981:diagnostic imaging*; D014463:Ultrasonography / Q000379:methods*; D015837:Vestibular Diseases / Q000150:complications / Q000000981:diagnostic imaging*
keywords: CANVAS; cross-sectional area; ganglionopathy; nerve ultrasound; peripheral nerves; sensory neuropathy