What peripheral neuropathies can cause sensory ataxia?

Peripheral Neuropathies That Cause Sensory Ataxia

Sensory ataxia is primarily caused by peripheral neuropathies affecting the proprioceptive pathways, with vitamin B12 deficiency, immune-mediated neuropathies, and toxic/medication-induced neuropathies being the most common etiologies.

Common Causes of Sensory Ataxic Neuropathies

Nutritional/Metabolic Causes

• Vitamin B12 deficiency: Causes impaired proprioception and sensory ataxia due to damage to dorsal columns and peripheral nerves 1
• Vitamin E deficiency: Associated with cerebellar atrophy and sensory ataxia 1
• Copper deficiency: Can mimic B12 deficiency with sensory ataxia 2

Immune-Mediated Causes

• Sensory variants of Guillain-Barré syndrome: Including Miller Fisher syndrome (characterized by ataxia, areflexia, and ophthalmoplegia) 1
• Paraneoplastic sensory neuronopathies: Often associated with anti-Hu antibodies, may herald underlying malignancy 3, 4
• Sjögren's syndrome: Can present with sensory neuronopathy and ataxia before other systemic symptoms appear 4, 5
• Autoimmune sensory ganglionopathies: Including those associated with anti-GD1b ganglioside antibodies 5
• Celiac disease: Can cause sensory neuronopathy with ataxia 4
• Autoimmune hepatitis: Associated with sensory neuronopathy 4

Toxic/Medication-Induced Causes

• Chemotherapeutic agents:
  • Platinum compounds (cisplatin, oxaliplatin): Cause dorsal root ganglion damage 1
  • Taxanes (paclitaxel): Predominantly sensory axonal neuropathy 1
  • Vinca alkaloids: Can cause small fiber neuropathy 1
• Proteasome inhibitors:
  • Bortezomib: Causes predominantly sensory neuropathy with potential proprioceptive involvement 1
• Thalidomide: Causes length-dependent axonal neuropathy affecting proprioception 1
• Metronidazole: Can cause cerebellar toxicity and peripheral neuropathy 1
• Other medications:
  • Phenobarbital, pregabalin, colchicine: Associated with vitamin B12 deficiency which can lead to sensory ataxia 1
  • H2 receptor antagonists: Can contribute to B12 deficiency 1

Inflammatory Bowel Disease-Related

• Peripheral neuropathy in IBD: Can present with sensory ataxia, often related to vitamin deficiencies or immune mechanisms 1

Infectious Causes

• HIV-associated neuropathy: Can present with sensory ataxia 1
• Hepatitis C: Associated with cryoglobulinemic neuropathy 1

Clinical Presentation and Diagnosis

Key Clinical Features

• Balance issues and falls due to impaired proprioception 1
• Sensory loss in a "glove and stocking" distribution 1
• Reduced or absent deep tendon reflexes 1
• Positive Romberg test (worsening with eye closure) 1
• Pain and paresthesias may be present but not always 3
• Symptoms often begin asymmetrically and may affect arms before legs in some forms 3

Diagnostic Approach

• Laboratory testing:

  • Vitamin B12 levels (active B12/holotranscobalamin preferred over total B12) 1
  • Autoimmune panels (ANA, SS-A/SS-B, anti-neuronal antibodies) 4
  • Paraneoplastic antibody panel (anti-Hu, anti-CV2) 4
  • Ganglioside antibodies (especially for Miller Fisher variant) 1, 5

• Electrophysiological studies:

  • Nerve conduction studies typically show reduced sensory nerve action potentials with preserved conduction velocities 1
  • Motor responses may be normal or less affected than sensory responses 1

• Neuroimaging:

  • MRI of the brain and spinal cord to exclude central causes 1
  • MRI cervical and thoracic spine without and with contrast to evaluate for spinal cord atrophy or lesions 1

Management Considerations

• Treatment depends on the underlying cause:

  • Vitamin B12 deficiency: Parenteral B12 supplementation 1
  • Immune-mediated: IVIG, plasmapheresis, or corticosteroids 1
  • Medication-induced: Dose reduction or discontinuation of the offending agent 1

• Prognosis varies by etiology:

  • Nutritional deficiencies may improve with supplementation 2
  • Paraneoplastic and autoimmune causes often have a poorer functional prognosis 3
  • Approximately 25% of patients with idiopathic sensory neuropathies show progressive worsening 3

Important Clinical Pearls

• Sensory ataxia that begins in the arms or presents asymmetrically should raise suspicion for sensory neuronopathy/ganglionopathy rather than length-dependent neuropathy 3, 6
• Pure sensory presentation without motor involvement suggests dorsal root ganglion pathology 6
• Nearly half of all sensory neuropathies remain idiopathic despite thorough investigation 3
• Sensory ataxia may precede other symptoms in systemic autoimmune diseases like Sjögren's syndrome 4, 5
• Vitamin B12 deficiency can occur even with normal total B12 levels, making active B12 testing more reliable 1