- Age of onset is in the first 6 months of life (average 3 months of age).
- Boys and girls are equally affected.
- Seizures are characterized by focal tonic seizures that later evolve into focal clonic seizures.
- Children may be developmentally normal at onset of seizures, but regression and severe developmental disabilities are the norm.
- Causes of this epilepsy syndrome are frequently found to be genetic.
- Other names: migrating focal seizures of infancy or malignant migrating partial seizures of infancy.
What is the syndrome epilepsy of infancy with migrating focal seizures?
Epilepsy of infancy with migrating focal seizures is a very rare form of epilepsy.
- The typical age of onset is before 6 months with an average age of onset of 3 months of age.
- It equally affects boys and girls.
- These seizures move from one lobe of the brain to another and from one brain hemisphere to another.
- Though seizures may be infrequent at onset, they quickly evolve into frequent daily and prolonged seizures with status epilepticus. Status epilepticus is common in this type of epilepsy syndrome.
- Infants may be developmentally normal at onset of seizures, but regression and severe developmental disabilities are the norm.
What do the seizures in epilepsy of infancy with migrating focal seizures look like?
The seizures in this syndrome are characterized by focal tonic seizures that later evolve into focal clonic seizures. The focal clonic seizures involve the arms and eyelids, the head turns to either side, and some people may stop and stare before the clonic activity starts.
Also autonomic changes (stop breathing, turning blue, sweating, and hiccups) can frequently be seen during the seizures.
Is epilepsy of infancy with migrating focal seizures inherited?
- The cause of this epilepsy syndrome is unknown. Several genetic mutations have been found in people with epilepsy of infancy with migrating focal seizures, including: KCNT1, SCN1A, SCN2A, PLCB1, TBC1D24 and CHD2.
- Family history of seizures or epilepsy is usually not present.
How is it diagnosed?
- Your doctor will take a good history and examine your child.
- Your doctor will order an electroencephalogram (EEG). The EEG in children with this epilepsy syndrome may be normal at the beginning. However, the EEG background becomes slow over time as well as multifocal spike wave.
- Genetic tests are usually ordered by your doctor.
- Magnetic resonance imaging (MRI) scans are usually normal at onset, but it is required to exclude a brain abnormality. MRI scans may show brain atrophy as condition progresses. Mesial temporal sclerosis and cerebellar atrophy have been reported.
How is it treated?
Seizures in children with epilepsy of infancy with migrating focal seizures are frequent and occur multiple times a day. Seizures tend to be resistant to anti-seizure medication.
- Medications often tried are phenobarbital, topiramate (Topamax), levetiracetam (Keppra), zonisamide (Zonegran), felbamate (Felbatol), valproic acid (Depakote/Depakene), rufinamide (Banzel), clonazepam, clobazam (Onfi), amongst others. There are some reports of stiripentol and bromides helping some children. Other medications that have been used to treat this epilepsy syndrome include adrenocorticotrophic hormone and prednisone. Medications are typically used in combination, but seizures remain resistant to medications.
- Ketogenic diet and vagus nerve stimulation (VNS) may be treatment options.
- Resective brain surgery is not usually an option.
- Children with epilepsy of infancy with migrating focal seizures commonly have status epilepticus and prolonged seizures that may need emergency medical treatment or treatment with a rescue therapy, such as diazepam rectal gel (Diastat) or another form of benzodiazepine given into the nose (intranasally) or under the tongue.
- Parents of children with epilepsy of infancy with migrating focal seizures should talk to the treating neurologist or health care provider to learn about seizure emergencies.
- Talk to the health care team about what kind of rescue therapy could be used and when to use it.
- Develop a seizure response plan and share it with the child’s other caregivers (such as other family members, day care providers, or school officials)
- When seizures last longer than usual or if a generalized seizure lasts too long (generally considered 5 minutes or longer), a child may need emergency medical care.
What is the outlook for people with epilepsy of infancy with migrating focal seizures?
- Children may be developmentally normal at onset of seizures, but relentless regression and severe developmental disabilities are the norm.
- Prognosis is poor for children with this epilepsy syndrome as seizures are never fully controlled.
- Many children with this epilepsy syndrome die in childhood due to complications of the disorder, including repeated infections. Those who do survive are severely disabled and will continue to have seizures despite treatment.