title: Progressive polyradiculoneuropathy due to intraneural oxalate deposition in type 1 primary hyperoxaluria.
abstract: BACKGROUND
  A 24-year-old man with primary hyperoxaluria type 1 (PH1) presented with a rapidly progressive axonal and demyelinating sensorimotor polyradiculoneuropathy shortly after the onset of end-stage renal disease. His plasma oxalate level was markedly elevated at 107 µmol/L (normal<1.8 µmol/L).
  
  
  METHODS
  A sural nerve biopsy was performed. Teased fiber and paraffin and epoxy sections were done and morphometric procedures were performed on this sample and on an archived sample from a 22-year-old man as an age- and gender-matched control. Embedded teased fiber electron microscopy was also performed.
  
  
  RESULTS
  The biopsy revealed secondary demyelination and axonal degeneration. Under polarized light, multiple bright hexagonal, rectangular, and starburst inclusions, typical of calcium oxalate monohydrate crystals, were seen.
  
  
  CONCLUSIONS
  The proposed mechanisms of nerve damage include disruption of axonal transport due to crystal deposition, toxic effect of oxalate, or nerve ischemia related to vessel occlusion from oxalate crystal deposition.
authors.affiliation: Peripheral Neuropathy Laboratory, Department of Neurology, Mayo Clinic and Mayo Foundation, 200 First Street SW, Rochester, Minnesota, 55905, USA.
authors.forename: Sarah E
authors.initials: SE
authors.lastname: Berini
authors.forename: Jennifer A
authors.initials: JA
authors.lastname: Tracy
authors.forename: Janean K
authors.initials: JK
authors.lastname: Engelstad
authors.forename: Elizabeth C
authors.initials: EC
authors.lastname: Lorenz
authors.forename: Dawn S
authors.initials: DS
authors.lastname: Milliner
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Dyck
mesh_terms: D002129:Calcium Oxalate / Q000378:metabolism*; D018450:Disease Progression; D006801:Humans; D006960:Hyperoxaluria, Primary / Q000150:complications / Q000175:diagnosis / Q000378:metabolism*; D008297:Male; D011129:Polyradiculoneuropathy / Q000175:diagnosis / Q000209:etiology / Q000378:metabolism*; D013497:Sural Nerve / Q000378:metabolism* / Q000473:pathology; D055815:Young Adult
chemical_list: D002129:Calcium Oxalate
keywords: crystalline neuropathy; nerve pathology; peripheral neuropathy; primary hyperoxaluria type 1; renal failure