Ohtahara syndrome

Ohtahara Syndrome, also known as Early Infantile Epileptic Encephalopathy with Burst-Suppression (EIEE), is the earliest-developing age-related epileptic encephalopathy. The syndrome is outwardly characterized by tonic spasms and partial seizures, and receives its more elaborate name from the pattern of burst activity in an EEG. It is an extremely debilitating progressive neurological disorder, involving intractable seizures and severe mental retardation. No single cause has been identified, although in many cases structural brain damage is present.

Characteristics
OS is the earliest-appearing age-related epileptic encephalophy, with seizure onset occurring within the first three months (and often first 10 days) of life. Many, but not all, cases of OS evolve into other seizure disorders, namely West Syndrome and Lennox-Gastaut Syndrome.

The primary outward manifestation of OS is seizures, usually presenting as tonic seizures (a generalized seizure involving a sudden stiffening of the limbs). Other seizure types that may occur include partial seizures and, rarely, myoclonic seizures. In addition to seizures, children with OS exhibit profound mental and physical retardation.

Clinically, OS is characterized by a “burst suppression” pattern on an electroencephalogram (EEG). This pattern involves high voltage spike wave discharge followed by little brain wave activity.

Causes and Treatment
No single cause of OS has been identified. In most cases, there is severe atrophy of both hemispheres of the brain. Less often, the root of the disorder is an underlying metabolic syndrome. No genetic connection has been established.

Treatment outlook is poor. Anti-epileptic drugs and steroids may be used to try to control the seizures, but their effectiveness is limited. Most therapies are related to symptoms and day-to-day living.