Elevated B6 levels and peripheral neuropathies

Polyneuropathy related to decreased levels of Vitamin B6 are well known. In contrast, the association between elevated levels of pyridoxine and neuropathy is not well described. This study is a retrospective review of patients in our neuromuscular clinic that were found to have elevated B6 levels. Twenty-six patients were found to have elevated serum B6 levels. The mean B6 level was 68.8 ng/ml. Twenty patients (76.9%) reported daily vitamin use. Twenty-one patients (80.8%) reported only sensory complaints. The most common symptoms reported were numbness (96%), burning pain (49.9%), tingling (57.7%), balance difficulties (30.7%), and weakness (7.8%). Nine (out of 26) had an abnormal EMG/NCS. Eight patients had an abnormal quantitative sensory study. We conclude that elevated pyridoxine levels should be considered in the differential diagnosis of any sensory or sensorimotor polyneuropathy.