Overview
- Early myoclonic encephalopathy is a syndrome characterized by:
- Frequent intractable seizures
- Severe early encephalopathy
- Limited development and reduced life expectancy
Clinical Context
- Onset of seizures typically occurs within the first two months of life.
- More than half of the cases have seizure onset by 10 days of life.
Causes
- Overlap exists between the etiologies of Ohtahara syndrome and early myoclonic encephalopathy:
- Metabolic etiologies are common:
- Non-ketotic hyperglycinemia (most common cause)
- Amino and organic acidopathies
- Urea cycle disorders
- Mitochondrial disorders
- Pyridoxine and pyridoxal-5-phosphate disorders
- Molybdenum cofactor deficiency
- Sulfite oxidase deficiency
- Menke syndrome
- Zellweger syndrome
- Other disorders
Seizures
- Metabolic etiologies are common: