Plasma Pyridoxal 5´-Phosphate Level in Children with Intractable and Controlled Epilepsy.

OBJECTIVE: Intractable epilepsy is a serious neurologic problem with different etiologies. Decreased levels of pyridoxal phosphate in cerebral spinal fluid of patients with intractable epilepsy due to pyridoxine dependency epilepsy are reported. The aim of this study was to compare plasma pyridoxal 5´-phosphate level in patients with intractable and controlled epilepsy.

MATERIALS & METHODS: This cross- sectional analytic study included 66 epileptic children, 33 patients with controlled and 33 patients with intractable epilepsy, after neonatal period up to 15 yr old of age. Thirty-three patients with intractable epilepsy (10- 162 months) and 33 patients with controlled epilepsy (14-173 months) were enrolled. The study was conducted in Pediatric Neurology Clinic of Mofid Children Hospital, Tehran, Iran from January 2010 to December 2010. Patients' clinical manifestations, laboratory and neuroimaging findings were collected. Non-fasting plasma 5´- pyridoxal phosphate levels of these subjects were assessed by high-pressure liquid chromatography.

RESULTS: Mean plasma 5´- pyridoxal phosphate level (PLP) in patients with controlled epilepsy was 76.78±37.24 (nmol/l) (15.5-232.4). In patients with intractable epilepsy, mean plasma 5´- pyridoxal phosphate was 98.67± 80.58 (25.5- 393) nmol/l. There was no statistically significant difference between plasma pyridoxal phosphate levels of these two groups (P═0.430).

CONCLUSION: Pyridoxine dependent epilepsy is under diagnosed because it is manifested by various types of seizures. Plasma pyridoxal phosphate levels did not differ in our patients with intractable or controlled epilepsy. If PDE is suspected on clinical basis, molecular investigation of ALDH7A1 mutations, as feasible test, until PDE biomarkers becomes available is recommended.