Echaniz-Laguna Andoni, Mourot-Cottet Rachel, Noel Esther, Chanson Jean-Baptiste
Neurologie, Hopitaux universitaires de Strasbourg, Strasbourg, France.
Medecine Interne, Hopitaux universitaires de Strasbourg, Strasbourg, France.
BMJ Case Rep. 2018 Jun 28;2018:bcr-2018-225059. doi: 10.1136/bcr-2018-225059.
Pyridoxine (vitamin B6) is an essential vitamin playing a crucial role in amino acid metabolism. Pyridoxine is used for isoniazid side-effects prevention, pyridoxine-dependent epilepsy treatment and cystathionine beta-synthase deficiency (homocystinuria) treatment. However, vitamin B6 hypervitaminosis is neurotoxic and may provoke a progressive sensory neuronopathy (sensory ganglionopathy), usually when daily uptake is above 50 mg. We describe the case of a 30-year-old patient with homocystinuria who was treated with pyridoxine 1250-1750 mg/day for 20 years and developed progressive sensory neuropathy with ataxia and impaired sensation in the extremities. Electrodiagnostic testing demonstrated non-length-dependent abnormalities of sensory nerve potentials, and sensory ganglionopathy was diagnosed. Pyridoxine dosage was reduced to 500 mg/day, resulting in the disappearance of sensory symptoms and ataxia, and the normalisation of sensory nerve potentials. Our case indicates that pyridoxine-induced sensory ganglionopathy may be reversible, even after prolonged ingestion of high doses of vitamin B6 for more than 20 years.
吡哆醇（维生素B6）是一种必需维生素，在氨基酸代谢中起关键作用。吡哆醇用于预防异烟肼副作用、治疗吡哆醇依赖性癫痫以及治疗胱硫醚β-合酶缺乏症（同型胱氨酸尿症）。然而，维生素B6过量会产生神经毒性，通常在每日摄入量超过50毫克时，可能引发进行性感觉神经元病（感觉神经节病）。我们描述了一名30岁同型胱氨酸尿症患者的病例，该患者每天服用1250 - 1750毫克吡哆醇进行治疗，持续20年，随后出现了伴有共济失调和四肢感觉障碍的进行性感觉神经病变。电诊断测试显示感觉神经电位存在非长度依赖性异常，诊断为感觉神经节病。吡哆醇剂量减至每日500毫克后，感觉症状和共济失调消失，感觉神经电位恢复正常。我们的病例表明，即使长期高剂量摄入维生素B6超过20年，吡哆醇诱发的感觉神经节病仍可能是可逆的。
