Ohtahara Syndrome and Early Infantile DEE

By Dovy Paukstys, Founder, Komori Care

This article is educational and is not medical advice. It does not diagnose, treat, prevent, or cure any condition. Komori is not a medical device, is not FDA-cleared, does not detect seizures, and is not intended for people with epilepsy. Talk with a neurologist or epileptologist about personal medical decisions. Households living with epilepsy should use clinically validated seizure-detection devices as directed by their care team.

If a neonatologist says Ohtahara, they mean a brutal early epilepsy. Tonic stiffening. An EEG that looks like bursts, then flat, then bursts. Developmental trouble from the start.

ILAE now files that under a wider name: early-infantile developmental and epileptic encephalopathy. EIDEE. Ohtahara and early myoclonic encephalopathy sit inside it.

I'm not a neurologist. I don't have epilepsy. I read both labels so this hub does not pretend the old name vanished from clinics. It didn't. The paperwork changed.

Two names, one age window

NINDS, on the general epilepsy page, still defines Ohtahara as a DEE. Rare. Seizures and developmental delays usually in the first three months of life. A brain abnormality, a metabolic disorder, or a gene change may be the cause. Some cases have no found cause. Tonic seizures most often. Focal and myoclonic seizures also happen.

ILAE's EIDEE page is the current rulebook. Frequent drug-resistant seizures starting at or before 3 months. Abnormal interictal EEG. Abnormal neurological exam. That syndrome encompasses the previous Ohtahara and early myoclonic encephalopathy labels.

Their reason: the two old pictures overlap, share causes, and no longer change decisions or prognosis enough to keep them split. I'm not going to defend a split the Task Force retired.

Treatable metabolic causes get called out first. Pyridoxine and pyridoxal-5-phosphate disorders. Exclude those early. That's ILAE, not me inventing a protocol.

How it looks

Onset: 0 to 3 months. Adjusted for prematurity. Boys and girls equally. Family, pregnancy, and birth history usually normal. Head size depends on the cause. Can be normal at birth.

Tone is usually off. Central hypotonia is the one they mention most. Posture is off. Development can already be wrong before anyone notices a seizure. Hard to see in a two-week-old. Movement disorders are common, at onset or later.

Most children end up with moderate to profound developmental impairment. Cortical visual impairment. Orthopedic problems. Feeding trouble. Life expectancy can be reduced. ILAE says that without dressing it up.

Seizures stay drug-resistant unless someone finds a treatable structural, genetic, or metabolic cause. Some infants later meet criteria for infantile epileptic spasms syndrome or Lennox-Gastaut syndrome. Different age. Different EEG. Same hard family of epilepsies.

NINDS's older Ohtahara sketch matches the tonic-first picture. Stiffening. The EEG pattern they still mention in public materials is burst-suppression: high-voltage discharges, then little activity.

EEG

ILAE mandatory EEG: burst-suppression, or multifocal discharges with diffuse slowing. Background is abnormal in all states.

Burst-suppression, when it's that pattern: high-voltage bursts of mixed spikes and sharp waves, about 1 to 5 seconds, then a quiet stretch of about 3 to 10 seconds.

You cannot diagnose this syndrome without an interictal EEG. ILAE is explicit. MRI is not required to name it and is strongly recommended to look for a structural cause. Ictal EEG is not required if the interictal tracing already shows the required mess.

A "normal exam at onset" or "reported normal development" is an alert, not the usual story. Developmental impairment should be obvious at or shortly after seizure onset. Abnormal development persists and later includes intellectual impairment. That's the course row on their table.

Mandatory seizures: tonic and/or myoclonic.

Causes. They find one more often than not.

ILAE: structural brain abnormality is the most common. Then genetic: chromosomal disorders, copy-number changes, pathogenic gene variants. Then metabolic: mitochondrial disease, non-ketotic hyperglycinemia, pyridoxine or pyridoxal-5-phosphate disorders, carnitine palmitoyl transferase deficiency, others.

A cause can be found in about 80 percent of cases. That's their number. The leftover 20 percent is still a lot of families waiting on a name.

The gene list overlaps the long-tail DEEs. STXBP1. KCNQ2. Others. Those pages are on Rare Epilepsy Long Tail. This hub is the electroclinical syndrome, not one gene.

NINDS says some Ohtahara cases have no known cause. Compatible with ILAE's 20 percent.

Outlook

Hard. Say it.

ILAE: most children, moderate to profound impairment. Seizures usually stay unless the cause is treatable. Some evolve to IESS or LGS. Life expectancy can be shorter.

NINDS's general DEE language: seizures often drug-resistant, development delayed or skills lost.

I'm not going to paste a survival percent I did not fetch from these pages. Older reviews talk about high infant mortality. I didn't open those papers this run. So I won't quote them.

Treatment talk stays general

NINDS, on the old Ohtahara material that now lives inside the epilepsy page: no cure. Treatment may include corticosteroids, a ketogenic diet, and physical, speech, and occupational therapies. Surgery if there is a focal brain lesion.

ILAE's first move is the metabolic screen, especially the vitamin B6-related disorders, because those can change the plan.

I'm not dosing ACTH or pyridoxine. A neonatologist and a pediatric epileptologist own that.

Households living with epilepsy should use clinically validated seizure-detection devices as directed by their care team. A consumer gadget does not detect burst-suppression. It does not detect seizures. It does not prevent SUDEP.

CDC first aid still applies if you are looking at a tonic event: stay, safe, side if they're down, 911 if it goes past five minutes, repeats, or the person is having trouble breathing. In a neonate you are already in medical care. Good.

FAQ

Is Ohtahara syndrome the same as EIDEE?

EIDEE is ILAE's current umbrella. It includes what used to be called Ohtahara syndrome and early myoclonic encephalopathy. Clinics still say Ohtahara. The age window is the same: onset by 3 months, ugly EEG, abnormal exam, drug-resistant seizures.

What EEG pattern is classic?

Burst-suppression is the one people remember. ILAE also accepts multifocal discharges with diffuse slowing. Either way the background is not normal.

Can this turn into West syndrome or LGS?

Yes. ILAE says children with EIDEE may evolve to infantile epileptic spasms syndrome or Lennox-Gastaut syndrome. Those are later, separate diagnoses. Same child can collect more than one label over time.

Who diagnoses this?

A physician. Neonatology plus pediatric neurology, usually. Interictal EEG is required. MRI and a metabolic/genetic workup look for a cause. No parent video replaces that EEG.

Sources

• ILAE / epilepsydiagnosis.org, Early-infantile DEE overview: https://www.epilepsydiagnosis.org/syndrome/eme-overview.html
• ILAE / epilepsydiagnosis.org, EIDEE diagnostic criteria: https://www.epilepsydiagnosis.org/syndrome/eme-diagcriteria.html
• ILAE / epilepsydiagnosis.org, EIDEE EEG: https://www.epilepsydiagnosis.org/syndrome/eme-eeg.html
• NINDS, Epilepsy and Seizures (Ohtahara / DEE section): https://www.ninds.nih.gov/health-information/disorders/epilepsy-and-seizures
• ILAE / epilepsydiagnosis.org, Encephalopathy: https://www.epilepsydiagnosis.org/encephalopathy.html
• Scheffer et al., ILAE classification of the epilepsies, Epilepsia (2017): https://www.ilae.org/files/dmfile/ClassificationOfEpilepsies_Scheffer_et_al-2017-Epilepsia.pdf
• CDC, First Aid for Seizures: https://www.cdc.gov/epilepsy/first-aid-for-seizures/index.html