Early Infantile Epileptic Encephalopathy

Alternate names

Ohtahara syndrome

Definition

Early Infantile Epileptic Encephalopathy (EIEE) is a neurological disorder characterized by seizures.

Cause

• Ohtahara syndrome is classically caused by very abnormal brain structure that may be due to damage or abnormal development.
• It also can be due to metabolic disorders or genetic epilepsy syndromes, although the cause or causes for many cases can’t be determined.
• Recent studies suggest that there is often an identifiable genetic cause of Ohtahara syndrome.

Onset

The disorder affects newborns, usually within the first three months of life (most often within the first 10 days) in the form of epileptic seizures.

Signs and symptoms

• Infants have primarily tonic seizures (which cause stiffening of muscles of the body, generally those in the back, legs, and arms), but may also experience partial seizures, and rarely, myoclonic seizures (which cause jerks or twitches of the upper body, arms, or legs).
• Episodes may occur more than a hundred times per day.
• Most infants with the disorder show underdevelopment of part or all of the cerebral hemispheres or structural anomalies.

Clinical presentation

For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. 80%-99% of people have these symptoms

• Global developmental delay
• Intellectual disability(Mental deficiency)

30%-79% of people have these symptoms

• EEG with burst suppression
• Hypsarrhythmia
• Infantile muscular hypotonia(Decreased muscle tone in infant)
• Poor head control
• Sleep disturbance(Difficulty sleeping)

5%-29% of people have these symptoms

• Atonic seizure
• Autistic behavior
• Bilateral tonic-clonic seizure
• Grand mal seizure
• Cerebellar atroph(Degeneration of cerebellum)
• Choreoathetosis
• Delayed myelination
• Developmental regression(Loss of developmental milestones)
• Diffuse cerebral atrophy
• Diffuse white matter abnormalities
• Dyskinesia(Disorder of involuntary muscle movements)
• EEG with spike-wave complexes
• Episodic ataxia
• Febrile seizure (within the age range of 3 months to 6 years)
• Fever induced seizures
• Focal-onset seizure(Seizure affecting one half of brain)
• Generalized clonic seizure
• Generalized non-motor (absence) seizure(Brief seizures with staring spells)
• Generalized tonic seizure
• Hyperactivity(More active than typical)
• Hypoplasia of the corpus callosum(Underdevelopment of part of brain called corpus callosum)
• Infantile spasms
• Myoclonus
• Pachygyria(Fewer and broader ridges in brain)
• Self-injurious behavior(Self-injurious behaviour)
• Spasticity(Involuntary muscle stiffness, contraction, or spasm)
• Tremor
• Uni- and bilateral multifocal epileptiform discharges

1%-4% of people have these symptoms

• Absent thumbnail
• Anteverted nares(Nasal tip, upturned)
• Broad finger(Broad fingers)
• Broad phalanx of the toes(Wide toe bones)
• Cleft palate(Cleft roof of mouth)
• Depressed nasal bridge (Depressed bridge of nose)
• Dystonia
• Failure to thrive(Faltering weight)
• Microcephaly(Abnormally small skull)
• Micropenis(Short penis)
• Precocious puberty(Early onset of puberty)
• Renal dysplasia
• Short finger(Stubby finger)
• Sloping forehead(Inclined forehead)
• Strabismus(Cross-eyed)
• Umbilical hernia
• Ureterocele
• Ventricular septal defect(Hole in heart wall separating two lower heart chambers)

Diagnosis

Electroencephalogram (EEG) displaying burst suppression patterns. Onset of bursts are indicated by solid arrows; offset, by open arrows. In both A and B, the interval between each vertical dotted line is one second

• The EEGs reveal a characteristic pattern of high voltage spike wave discharge followed by little activity.
• This pattern is known as “burst suppression.”
• The seizures associated with this disease are difficult to treat and the syndrome is severely progressive.

Treatment

• Antiseizure drugs are used to control seizures, but are unfortunately not usually very effective for this disorder.
• Corticosteroids (prednisolone or ACTH) are occasionally helpful and sometimes the ketogenic diet (high fat, low carbohydrate) is appropriate.
• In cases where there is a focal brain lesion (damage or abnormal development of one area/side of the brain), epilepsy surgery may be beneficial. Other therapies are symptomatic and supportive; these can include treatments for abnormal muscle tone, irritability, or stomach or lung problems.
• Physical, speech, and occupational therapies are usually offered.
• Consultation with a palliative care team is often helpful in order to define goals of care and ensure the infant's family and medical team are working toward the same set of goals.

Prognosis

The course of Ohtahara syndrome is severely progressive. If epilepsy surgery is not feasible, seizures become more frequent and are accompanied by delays in physical and cognitive development. Some children will die in infancy; others will survive but usually have severe handicaps. As they grow, some children will progress into other epilepsy syndromes such as West syndrome and Lennox-Gastaut syndrome.

NIH genetic and rare disease info

• NIH info on Early Infantile Epileptic Encephalopathy

Early Infantile Epileptic Encephalopathy is a rare disease.

Early Infantile Epileptic Encephalopathy Resources
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