- Main clinical, EEG, and MRI findings suggesting inherited metabolic epilepsies.
| Features | |
|---|---|
| Onset | Early: neonatal, infancy or early childhood |
| Seizure types | Myoclonic, tonic, infantile spasms Seizures worsening with fasting (GLUT1) or with high protein meals (urea cycle defects) Progressive myoclonic epilepsy phenotype Seizures refractory to anti-epileptic drugs Seizures worsening with anti-epileptic drugs |
| Neurological features | Developmental delay /regression Movement disorders Fluctuating course of illness |
| Systemic symptoms | Dysmorphic features Organomegaly Ophthalmological abnormalities (cataracts, retinitis pigmentosa,cherry red spot, optic nerve atrophy) |
| Family history | Parental consanguinity Metabolic or unexplained neurological disorder Death of unknown etiology |
| EEG | Burst-suppression, multifocal spike discharges, hypsarrhythmia Comb-like rhythm (maple syrup urine disease) |
| MRI/MRS | Normal / non specific abnormalities Corpus callosum dysgenesis (pyruvate dehydrogenase deficiency) Abnormal MRS in cerebral creatine deficiency or GABA transaminase deficiency |