Review Article
Metabolic Causes of Epileptic Encephalopathy
Table 6
Pyridoxine and pyridoxal-5′-phosphate-dependent Epilepsies.
| | Pyridoxine- or folinic-acid-dependent epilepsies (PDE) | Pyridoxal-5′-phosphate (PLP-) dependent epilepsy |
| Deficient enzyme | Antiquitin (ATQ) | Pyridox(am)ine phosphate oxidase (PNPO) | Blood chemistry | Normal, but hypoglycemia and lactic acidosis have been reported | Hypoglycemia and lactic acidosis common | Vanillactic acid (Urine) | Absent | Present | Pipecolic acid (blood, CSF) | ↑ | Normal | AASA* (blood, urine, CSF) | ↑ | Normal | Neurotransmitter metabolites (CSF) | (Possible) ↑ 3-Methoxytyrosine | ↑ L-DOPA, 3-Methoxytyrosine ↓ Homovanillic acid, 5-Hydroxyindoleacetic acid | Clinical signs | Postnatal refractory seizures, gastrointestinal symptoms, encephalopathy with hyperalertness, sleeplessness | Fetal distress and in utero fetal seizures, postnatal refractory seizures and encephalopathy |
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*AASA: alpha-aminoadipic semialdehyde. Adapted from Pearl [2].
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