[Chronic demyelinating polyneuropathy and B6 hypervitaminosis].

Area of Science:

• Neurology
• Clinical Toxicology
• Nutritional Science

Background:

• Peripheral neuropathy and ataxia can stem from various causes, including immune-mediated conditions.
• Corticosteroid therapy is a common treatment for immune-related neuropathies.
• Diagnostic challenges arise when symptoms are resistant to standard treatments.

Observation:

• A 62-year-old patient presented with sensory neuropathy and ataxia unresponsive to corticosteroids.
• Extensive investigation revealed elevated serum pyridoxine levels.
• The patient had a history of several years of chronic oral vitamin supplementation.

Findings:

• Chronic high intake of oral vitamin B6 (pyridoxine) can lead to toxic polyneuropathy.
• Pyridoxine-induced neuropathy may mimic chronic immune demyelinating polyneuropathy.
• Electrophysiological studies can help differentiate vitamin toxicity from other neuropathic causes.

Implications:

• This case underscores the potential for long-term adverse effects from excessive vitamin supplementation.
• Clinicians should consider vitamin toxicity in patients with unexplained neuropathies, especially with a history of supplement use.
• Awareness of pyridoxine toxicity is crucial for patient safety and effective treatment strategies.