Refractory Seizures Secondary to Vitamin B6 Deficiency in Parkinson Disease: The Role of Carbidopa-Levodopa

• Published in: Case reports in neurology 2022-06, Vol.14 (2), p.291-295
• Main Authors: Wise, Adina, Lemus, Hernan Nicolas, Fields, Madeline, Swan, Matthew, Bressman, Susan
• Format: Article
• Language: English
• Subjects: Adults; Anorexia; Blood; carbidopa-levodopa; Case reports; convulsions; Convulsions & seizures; Dopamine; Epilepsy; Hemodialysis; Metabolism; parkinson disease; Parkinson's disease; Patients; Peripheral neuropathy; pyridoxine; seizure; sinemet; Single Case – General Neurology; Single Case − General Neurology; status epilepticus; Steroids; Vitamin B; vitamin b6; Vitamin deficiency; Weaning
• ISSN: 1662-680X; 1662-680X
• DOI: 10.1159/000525234

Carbidopa-levodopa has been used for more than 50 years in the treatment of Parkinson disease (PD) and other movement disorders. Pyridoxal 5′-phosphate (PLP), an active form of vitamin B6 (pyridoxine), is involved in the decarboxylation of levodopa to dopamine; carbidopa, which is combined with levodopa to reduce peripheral levodopa conversion and minimize peripheral dopamine side effects, binds irreversibly with PLP. As a result, carbidopa-levodopa may cause vitamin B6 deficiency and associated sequelae, including seizures, especially in high doses. A 78-year-old gentleman with a 6-year history of PD on carbidopa-levodopa therapy and recent weight loss presented with new-onset myoclonus and focal to bilateral tonic-clonic seizures. Workup for vascular, infectious, malignant, metabolic, and autoimmune causes of seizure was unrevealing. The folate level was critically low at