Chapter 33 - Pyridoxine-dependent epilepsy

Summary

Pyridoxine-dependent epilepsy (PDE) occurs as a result of an inborn error of metabolism where patients are dependent upon regular pharmacologic doses of pyridoxine. While it is possible that unrecognized phenotypes of PDE may present with only encephalopathy and developmental disability, the author's current understanding of this condition indicates that all patients present with lifelong anticonvulsant-resistant epileptic seizures. Patients with PDE may have normal findings on brain imaging studies, a variety of abnormal neuroradiologic features have been described in patients with PDE. It is important for clinicians to realize that a clinical diagnosis of PDE should not be made solely by examining the concurrent effects of pyridoxine administration on the interictal electroencephalographic (EEG). Clinical effectiveness, as well as biochemical and/or genetic confirmation of PDE, are necessary. While the neurodevelopmental outcome of PDE patients is multifactorial, early diagnosis and treatment is clearly important.