Epilepsy Phenotypes of Vitamin B6-Dependent Diseases: An Updated Systematic Review.
Study Goal
The researchers aimed to characterize the clinical features, treatment responses, and outcomes of pediatric patients with vitamin B6-dependent epilepsies.
Results Summary
The study found that pyridoxine treatment led to complete seizure freedom in 160 patients and significant seizure reduction in 38, with variable efficacy of other treatments like PLP and dietary interventions. Developmental delay was noted in 30.5% of tested patients.
Population
Pediatric patients with confirmed molecular genetic diagnoses of vitamin B6-dependent epilepsies.
Effective Dosage
1-55 mg/kg/day (pyridoxine)
Duration
Not specified
Interactions
None mentioned
| Intervention | Direction | Endpoint | Population | Dosage | Impact | Claim # |
|---|---|---|---|---|---|---|
pyridoxine | decrease | vitamin B6-dependent epilepsies | patients | - | responding to | #1 |
pyridoxal-5-phosphate | decrease | vitamin B6-dependent epilepsies | patients | - | responding to | #2 |
pyridoxine | neutral | - | 312 patients | - | administered to | #3 |
pyridoxine | neutral | dosage | patients | 1 and 55 mg/kg/die | dosage ranged between | #4 |
pyridoxine | increase | seizure freedom | 160 patients | - | Complete seizure freedom was achieved in | #5 |
pyridoxine | decrease | seizure reduction | 38 patients | - | a significant seizure reduction occurred in | #6 |
PLP | neutral | seizures | patients | - | used in a small proportion of patients with variable efficacy | #7 |
lysine-restricted diet | neutral | seizures | patients | - | used in a small proportion of patients with variable efficacy | #8 |
arginine supplementation | neutral | seizures | patients | - | used in a small proportion of patients with variable efficacy | #9 |
BACKGROUND: Vitamin B6-dependent epilepsies include treatable diseases responding to pyridoxine or pyridoxal-5Iphosphate (ALDH7A1 deficiency, PNPO deficiency, PLP binding protein deficiency, hyperprolinemia type II and hypophosphatasia and glycosylphosphatidylinositol anchor synthesis defects). PATIENTS AND METHODS: We conducted a systematic review of published pediatric cases with a confirmed molecular genetic diagnosis of vitamin B6-dependent epilepsy according to PRISMA guidelines. Data on demographic features, seizure semiology, EEG patterns, neuroimaging, treatment, and developmental outcomes were collected. RESULTS: 497 published patients fulfilled the inclusion criteria. Seizure onset manifested at 59.8 ± 291.6 days (67.8% of cases in the first month of life). Clonic, tonic-clonic, and myoclonic seizures accounted for two-thirds of the cases, while epileptic spasms were observed in 7.6%. Burst-suppression/suppression-burst represented the most frequently reported specific EEG pattern (14.4%), mainly in PLPB, ALDH7A1, and PNPO deficiency. Pyridoxine was administered to 312 patients (18.5% intravenously, 76.9% orally, 4.6% not specified), and 180 also received antiseizure medications. Pyridoxine dosage ranged between 1 and 55 mg/kg/die. Complete seizure freedom was achieved in 160 patients, while a significant seizure reduction occurred in 38. PLP, lysine-restricted diet, and arginine supplementation were used in a small proportion of patients with variable efficacy. Global developmental delay was established in 30.5% of a few patients in whom neurocognitive tests were performed. CONCLUSIONS: Despite the wide variability, the most frequent hallmarks of the epilepsy phenotype in patients with vitamin B6-dependent seizures include generalized or focal motor seizure semiology and a burst suppression/suppression burst pattern in EEG.