Ohtahara syndrome
Encyclopedia
Ohtahara syndrome also known as Early Infantile Epileptic Encephalopathy with Burst-Suppression (EIEE), is a progressive
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 on an electroencephalogram
(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.
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, clusters of infantile spasms, 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 EEG. This pattern involves high voltage spike wave discharge followed by little brain wave activity.
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. Anticonvulsant
drugs and glucocorticoid
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.
When the cause of the seizures is a malformation of either the left or right hemisphere of the brain then a surgical procedure, a functional hemispherectomy, can significantly improve the developmental outcome of the child and even completely stop the seizures.
It can be associated with ARX
.
Progressive illness
The term progressive illness describes the course of an illness that gradually progresses and changes mode, generally to the worse. In contrast, non-progressive or chronic illnesses are relatively constant.-Examples:...
epileptic
Epilepsy
Epilepsy is a common chronic neurological disorder characterized by seizures. These seizures are transient signs and/or symptoms of abnormal, excessive or hypersynchronous neuronal activity in the brain.About 50 million people worldwide have epilepsy, and nearly two out of every three new cases...
encephalopathy
Encephalopathy
Encephalopathy means disorder or disease of the brain. In modern usage, encephalopathy does not refer to a single disease, but rather to a syndrome of global brain dysfunction; this syndrome can be caused by many different illnesses.-Terminology:...
. The syndrome is outwardly characterized by tonic spasms and partial seizures, and receives its more elaborate name from the pattern of burst activity on an electroencephalogram
Electroencephalography
Electroencephalography is the recording of electrical activity along the scalp. EEG measures voltage fluctuations resulting from ionic current flows within the neurons of the brain...
(EEG). It is an extremely debilitating progressive neurological disorder, involving intractable seizures and severe mental retardation
Mental retardation
Mental retardation is a generalized disorder appearing before adulthood, characterized by significantly impaired cognitive functioning and deficits in two or more adaptive behaviors...
. No single cause has been identified, although in many cases structural brain damage is present.
Characteristics
Ohtahara syndrome is rare and the earliest-appearing age-related epileptic encephalophy, with seizure onset occurring within the first three months of life, and often in the first ten days. Many, but not all, cases of OS evolve into other seizure disorders, namely West syndromeWest syndrome
West syndrome or West's Syndrome is an uncommon to rare epileptic disorder in infants. It is named after the English physician, William James West , who first described it in an article published in The Lancet in 1841. The original case actually described his own son, James Edwin West...
and Lennox-Gastaut syndrome
Lennox-Gastaut syndrome
Lennox–Gastaut syndrome , also known as Lennox syndrome, is a difficult-to-treat form of childhood-onset epilepsy that most often appears between the second and sixth year of life, and is characterized by frequent seizures and different seizure types; it is often accompanied by developmental delay...
.
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, clusters of infantile spasms, and, rarely, myoclonic seizures
Myoclonus
Myoclonus is brief, involuntary twitching of a muscle or a group of muscles. It describes a medical sign and, generally, is not a diagnosis of a disease. Brief twitches are perfectly normal. The myoclonic twitches are usually caused by sudden muscle contractions; they also can result from brief...
. In addition to seizures, children with OS exhibit profound mental and physical retardation.
Clinically, OS is characterized by a “burst suppression” pattern on an 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 hemispheresCerebral hemisphere
A cerebral hemisphere is one of the two regions of the eutherian brain that are delineated by the median plane, . The brain can thus be described as being divided into left and right cerebral hemispheres. Each of these hemispheres has an outer layer of grey matter called the cerebral cortex that is...
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. Anticonvulsant
Anticonvulsant
The anticonvulsants are a diverse group of pharmaceuticals used in the treatment of epileptic seizures. Anticonvulsants are also increasingly being used in the treatment of bipolar disorder, since many seem to act as mood stabilizers, and in the treatment of neuropathic pain. The goal of an...
drugs and glucocorticoid
Glucocorticoid
Glucocorticoids are a class of steroid hormones that bind to the glucocorticoid receptor , which is present in almost every vertebrate animal cell...
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.
When the cause of the seizures is a malformation of either the left or right hemisphere of the brain then a surgical procedure, a functional hemispherectomy, can significantly improve the developmental outcome of the child and even completely stop the seizures.
It can be associated with ARX
Aristaless related homeobox
Aristaless related homeobox, also known as ARX is a protein associated with mental retardation and lissencephaly....
.
Notable sufferers
- Ivan Cameron, son of David CameronDavid CameronDavid William Donald Cameron is the current Prime Minister of the United Kingdom, First Lord of the Treasury, Minister for the Civil Service and Leader of the Conservative Party. Cameron represents Witney as its Member of Parliament ....
, leader of the British Conservative PartyConservative Party (UK)The Conservative Party, formally the Conservative and Unionist Party, is a centre-right political party in the United Kingdom that adheres to the philosophies of conservatism and British unionism. It is the largest political party in the UK, and is currently the largest single party in the House...
and Prime Minister of the UK, was born with the condition. He died aged six on 25 February 2009, while his father was still opposition leader.
External links
- Ohtahara syndrome information from Epilepsy ActionEpilepsy ActionEpilepsy Action is a UK based charity providing information, advice and support for people with epilepsy.The organisation was founded in 1950 as the British Epilepsy Association and adopted Epilepsy Action as its working name in 2002....
- Aarons Ohtahara, an organization dedicated to helping families with children diagnosed with Ohtahara Syndrome. from Aarons Ohtahara