An Overview of Ohtahara Syndrome

Ohtahara syndrome is a rare type of epilepsy that begins during infancy. It is also called early infantile epileptic encephalopathy. Children who have Ohtahara syndrome experience seizures and have severe developmental problems. 

This type of epilepsy is associated with a characteristic pattern that can be recognized on an electroencephalogram (EEG). Anti epilepsy drugs (AEDs) are usually needed to help manage the seizures.

This condition is not curable, and children who have Ohtahara syndrome are not usually expected to survive beyond early childhood. There are exceptions, and some people with this syndrome may continue to live into adulthood, but they tend to have persistent epilepsy and physical and cognitive deficits.

Symptoms

Children who have Ohtahara syndrome experience their earliest seizures before the age of 3 months. They may seem healthy at birth, but can start to have jerking movements within a few weeks. In some cases, mothers may recall that their baby actually started having erratic movements during the pregnancy.

Babies who have Ohtahara syndrome may experience several types of seizures. The most common seizure types in Ohtahara syndrome include:

Tonic seizures: This is the most common type of seizure that occurs in Ohtahara syndrome. It is characterized by a stiffening of the arms and legs, usually lasting a few seconds.

Generalized tonic-clonic seizures: This type of seizure involves movements of the arms and legs, usually involving both sides of the body.

Babies may have jerking eye or head movements during a generalized tonic-clonic seizure. These seizures involve impaired consciousness as well, but it can be difficult to recognize that an infant has impaired consciousness.

Focal seizures: These are seizures that generally involve only one part of the body or one side of the body. They include repetitive jerking movements and they last for a few seconds. Focal seizures may involve impaired consciousness, and as with generalized tonic-clonic seizures, it may be difficult to recognize whether an infant’s consciousness is impaired.

Infantile spasms: These are brief, sudden movements that may last for only a second. They can involve the neck, and/or one or both arms or legs.

Myoclonic seizures: These seizures generally involve repetitive jerking movements affecting one or both sides of the body. They may last for a few minutes and are generally followed by exhaustion and a period of sleeping.

Developmental Problems

Developmental problems, such as a lack of motor and cognitive skills, are usually present as well. For example, babies might not reach for objects as would be expected for their age. Babies with this condition might not pay attention to parents and often do not turn to look at objects with their eyes or head. 

Recognizing Ohtahara Syndrome

It can be challenging for parents of new babies to recognize developmental problems and seizures. Even if you have had other children before, it can be difficult to determine whether your newborn is developing as expected.

 Even completely healthy infants often have muscle movements that don’t seem well controlled. However, seizures are different than most babies’ movements because they are usually more erratic. Seizures generally last for a few seconds and are typically followed by a period of extreme exhaustion or sleep. 

Causes

Ohtahara syndrome is associated with abnormalities in the baby’s brain. This condition is a type of encephalopathy.

Encephalopathy is an abnormality in the structure and function of the brain. It can be mild or severe. Ohtahara syndrome is a severe type of encephalopathy. The altered brain structure of this syndrome interferes with a baby’s ability to learn how to use their muscles. As they grow, babies with this type of encephalopathy cannot learn to walk, talk, see, and interact with others.

Encephalopathy also causes seizures. Seizures are episodes in which the neurons in the brain are activated in an unpredictable manner. When a child has encephalopathy, the neurons are not arranged as they normally would be, and this leads to disordered and chaotic neuron activation, which causes the involuntary muscle jerking and impaired consciousness of a seizure.

Babies with this syndrome have been found to have damage to proteins in the brain. This damage may be the cause of the structural changes that occur as the brain is developing.

Risk Factors

There have not been any risk factors identified with this condition. There have been a few gene mutations linked to Ohtahara syndrome, including mutations of the STXBP1 gene, the SCN2A gene, and the ARX gene. The inheritance pattern, however, is not clear.

Some children who have the condition do not have the associated gene mutations, so it is sometimes believed to occur sporadically (without explanation) as well.

Diagnosis

Ohtahara syndrome is diagnosed based on a combination of the child’s history of seizures and developmental problems, physical examination, EEG, and brain imaging tests. If there is any concern about other illnesses, such as encephalitis (a brain infection), then additional tests may be needed so the illness can be identified and treated.

Physical Examination

Infants who have Ohtahara syndrome can have increased or decreased muscle tone. Their muscles may be somewhat stiff, or they can be floppy. Babies with this condition can also have abnormal reflexes and might not follow objects with their eyes. Their eye motion can be jerky as well.

Examination of young infants is a very subtle process. Your child will need to be examined by a pediatrician, a pediatric neurologist, or a neonatologist (a pediatrician specialized in caring for young or premature infants) for evaluation of this fairly complex neurological condition.

Diagnostic Tests

Several diagnostic tests can help with diagnosing the cause of your child’s seizures. Diagnostic tests that may be used in Ohtahara syndrome include: 

Electroencephalogram (EEG): An EEG is a non-invasive brain wave test. This test involves the placement of flat metal discs on your child’s scalp. These discs detect brain wave activity, which is read as a wave pattern on a computer or a printout. The EEG pattern seen in Ohtahara syndrome is described as a burst suppression pattern. This is seen as large spikes alternating with small waves and low brain activity.

Brain imaging: Brain imaging tests that are usually done for the evaluation of Ohtahara syndrome include brain magnetic resonance imaging (MRI) and brain computerized tomography (CT). These tests create a picture of the structure of the brain.

Most children who have Ohtahara syndrome have underdeveloped areas of the brain and altered brain structure, which is identified on these imaging tests.

Lumbar puncture (LP): This test is not a common part of the evaluation for Ohtahara syndrome, but it is often needed in the evaluation of other types of encephalopathy. If your child has a fever or other signs of infection, they may need to have an LP to find out is there is a treatable infection.

Treatment

There are several treatment options used to manage Ohtahara syndrome, but there is not a cure. These treatments can help reduce the frequency and severity of the seizures, but they are not effective in managing developmental problems.

AEDs

Several medications can be used to help control your child’s seizures. The AEDs recommended for management of Ohtahara syndrome include Topamax (topiramate), Zonegran (zonisamide), Sabril (vigabatrin), and Felbatol (felbamate), and others. Because your baby is young and may not be able to swallow, the medications may be given in liquid or injectable form.

Steroid Treatment

Encephalopathy is often treated with steroids. High dose steroids such as adrenocorticotrophic hormone (ACTH) or methylprednisone have been used to treat Ohtahara syndrome. Because steroids work very differently from AEDs, it is possible for children to receive both.

Ketogenic Diet

This diet is high in fat and low in protein and carbohydrates. It prevents seizures through a metabolic process called ketosis that occurs in response to this nutritional combination. Because your child might yet not be able to eat and chew, the diet may be administered in a liquid form.

Transcranial Stimulation

Another technique, high-definition transcranial direct current stimulation (HD-tDCS) is a non-invasive method of administering electrical stimulation to the brain using electrodes that are placed superficially on the scalp. Studies have been done using daily sessions of stimulation for treatment of Ohtahara syndrome, but it is not used as a standard treatment.

Epilepsy Surgery

Refractory epilepsy is epilepsy that does not improve with medical management. In some cases, refractory epilepsy is treated with surgery. Surgery for seizures in Ohtahara syndrome may include cortical transection, which involves cutting an area of the brain to prevent the spread of chaotic nerve activity.

Physical and Cognitive Therapy

As your child gets older, self-care can become an issue. Some children with Ohtahara syndrome may have a mild form of the condition. If this is the case for your child, therapy can maximize their ability to walk, talk, learn, and interact with others. Therapy is individualized based on your child’s needs and abilities. 

Palliative Care

For some families, palliative care is an option. This type of care involves comfort and pain control. While it is an approach often used in the treatment of people with a short life expectancy, palliative care can also be important for families who are dealing with a major disability.

A Word From Verywell

If your child has been diagnosed with severe developmental problems, refractory seizures, or Ohtahara syndrome as an infant, it is normal for you to be very anxious. This is a devastating condition, and it is emotionally difficult for parents

You are likely to need help in coping with all of your questions and anxieties. Often, family members and friends want to be supportive, but don’t know how. As you take care of your baby, it can help to find a parent support group and to utilize any professional support and counseling that is available to you.