Early myoclonic encephalopathy (EME) is a rare  neonatal-onset epilepsy developmental and epileptic encephalopathy (DEE) with an onset at neonatal period or during the first 3 months of life. It is marked by the presence of myoclonic seizures but multiple seizure types may occur. The electroencephalographic recording is abnormal with eitherusually a suppression-burst pattern or other significantly abnormal patterns. On most occasions the seizures are drug-resistant. After several months, the seizure pattern may develop into infantile spasms syndrome (West syndrome). The neurological exam is abnormal with a significant risk of early death. Various genetic and metabolic disorders are responsible. At present, EME and Ohtahara syndrome are recorded as distinct patterns in the categorization of epilepsies but both neonatal-onset epilepsy syndromes are considered to be merged in one unique entity. It is a severe type of epilepsy syndrome associated with high level of resistance to treatment and a high risk for cognitive impairment. The myoclonic seizures could be seen in other epilepsy syndromes. Multiple types of childhood epilepsies are usually mentioned as myoclonic epilepsies when the myoclonic seizures are a predominant feature. Signs and symptoms
It is characterized by early-onset myoclonic seizures that can vary from erratic movements of a single limb or a part of the face (focal) to bilateral myoclonic movement of the whole body. The myoclonus may occur at any time (sleep, wakefulneess) from few times per day to very frequent or even continuous myoclonus.
The symptoms may start appearing as early as a few hours after birth and up to three months of age. Around three-fourths of affected children present with neonatal seizure. Other seizure types such as focal or generalized tonic seizures, epileptic  spasms or other epileptic manifestations may occur at the course of the disease. The distinctive feature of the phenotype is severe progressive encephalopathy with delay in development and abnormal neurological examination delay (hypotonia, lethargy, poor eye contact, difficulties in feeding) usually being present even before the onset of other symptoms. Head circumference is usually normal at onset but microcephaly may develop over time. Family history is usually normal. Causes
There are varied etiologies related to EME that are mainly genetic abnormalities (mutations), brain structure abnormalities, or inborn metabolic defects. Another common reason rather than structural brain abnormality is inborn metabolic defects. Sometimes a metabolic disorder that affects how the brain works may lead to EME. While most of these metabolic disorders cannot be reversed, sometimes treating the underlying disorder can help. Vitamin-responsive epileptic encephalopathies are rare but significant reasons. Genetics
A growing number of genetic aetiologies have been linked to the phenotype of EME and Otahara syndrome and diagnosis by genetic testing can nowadays be achieved in around 50 percent of cases. Some examples of well described genetic aetiologies include: KCNQ2- DEE. • SCN2A-DEE • STXBP1-DEE. • CDKL5-DEE• KCNT1-DEE and UBA5-DEE. Acquired
No acquired aetiologies are known for EME although etiology remains unknown for a small percentage of patients after genetic, metabolic, and imaging workup.