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Sensory Disorders: Large Fiber & Ataxic

Toxic
  Vitamin B6
  cis-platinum
  Semi-synthetic penicillins
  Taxol

Deficiency/ Malabsorption
  Vitamin B12
  Vitamin E

Immune
  GALOP Syndrome
  Anti-MAG antibody syndrome
  Miller Fisher Syndrome
  Anti-GD1b antibody syndrome
  Sensory ganglionopathy
    Hu (Paraneoplastic)
    Sjögren's
    Idiopathic

Infection
 Syphilis - Tabes dorsalis
Hereditary
  Recessive
    a-β-lipoproteinemia (Bassen-Kornzweig)
    Ataxia Telangectasia
    Friedreich's Ataxia
    Mitochondrial
    Scoliosis: PIEZO2
  Dominant
    Sensory ataxic neuropathy
    Sensory ataxic neuropathy 2: 16q22
    Sensory ataxia (SNAX1): RNF170; 8p11
    Posterior column ataxia (Biemond)
    Sensory neuropathy + scoliosis (Robinson)
    SCA 4

Also see
  Hereditary
    Ataxic neuropathy + Thermoanalgesia
    Sensory & Autonomic Neuropathies
    Mitochondrial: Sporadic
  More pathology
  Large and Small Axon loss
    Neuropathies
    Ganglionopathies


Loss of large myelinated axons
in peripheral nerve

Posterior column ataxia (Biemond)

  Autosomal Dominant or Single generation

Sensory neuropathy with Scoliosis (Robinson)

  Autosomal Dominant

SCA46: Ataxia, Sensory Neuropathy + Cerebellar 1

  Phospholipase D family, member 3 (PLD3) ; Chromosome 19q13.2; Dominant
  • Epidemiology: 1 Dutch family; 5 patients
  • Genetics
    • Mutation: Missense; Leu308Pro
  • PLD3 protein
    • Catalyze hydrolysis of membrane phospholipids
    • Expression: High in cerebellum
    • Cell localization: Endoplasmic reticulum
  • Clinical
    • Onset age: 35 to 70 years
    • Sensory
      • Large fiber loss
        • Vibration: Reduced or Absent
        • Proprioception: Reduced
        • Distal > Proximal
        • Legs > Arms
      • Ataxia: Gait
      • Small fiber loss: Pain sensation mildly reduced
    • Strength: Normal
    • Reflexes: Reduced or absent in legs
    • Cerebellar
      • Eyes: Square wave jerks; Nystagmus; Saccades slow
      • Dysarthria
    • Course: Slow progression
  • Laboratory
    • Nerve conduction
      • SNAP amplitudes: Reduced or Absent
      • Conduction Velocity: Normal
    • Pathology
      • Myelinated axons: Reduced to 10% of normal
      • No regenerating clusters or onion bulbs
    • Sensory evoked potentials: Often unobtainable or reduced amplitude
    • Brain MRI: Normal or Cereberllar atrophy, mild

Sensory Ataxic Neuropathy 2

  Chromosome 16q22.1; Dominant

Toluidine blue stain

Loss of large myelinated axons with relative preservation of small myelinated axons

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References
1. Brain 1995;118:1557-1563

8/5/2009