Convulsion (Seizure disorders/ Epilepsy)
About one third children with cerebral palsy generally have epilepsy as one of the associated factors.
The incidence of epilepsy is more seen in CP spastic hemiplegia followed by CP spastic quadriplegia and then CP spastic diplegia.
The mean age of onset of seizures is 18 months. 60% have seizures onset before the age of 1 year. Children with myoclonic seizures and infantile spasms have seizure onset significantly early in life.
All types of seizures are seen in children with cerebral palsy.
There is increased risk of epilepsy in children with cerebral palsy if the child has any of the following associated factors:
- Low birth weight
- Neonatal seizure
- Seizure during first year of life
- Family history of epilepsy
- Severe form of cerebral palsy
Anticonvulsants work in the brain to suppress abnormal or hyperactive brain activity. The seizures suffered by cerebral palsy children are typically caused by overloads of "messages" sent from the brain to the nerves and muscles. Anticonvulsants help in stopping these seizures in cerebral palsy sufferers by blocking these messages.
Most seizures that happen in cerebral palsy children are either complex-partial or tonic-clonic. Seizures are fairly common in cerebral palsy children, up to one quarter have tonic-clonic seizures and about half of people with cerebral palsy have complex-partial seizures.
Tonic-clonic seizures usually involve a full loss of motor function. The person falls to the ground after briefly crying out. Their muscles become very tight and stiff and their hands and feet begin to twitch. Afterwards, the person may be confused for some time that can be up to a few weeks.
A complex partial seizure doesn't involve the convulsions that a tonic-clonic seizure has. Some complex partial seizures may lead to grand mal seizures. A complex partial seizure manifests in varying degrees of severity but is usually marked by a partial lack of consciousness. This may be as slight as being forgetful, but may be as serious as to cause impaired walking. Most people who suffer a complex partial seizure do not remember the event.
Anticonvulsants help stop these seizures in cerebral palsy children. There are different types of anticonvulsant medications available. These anticonvulsants tend to limit the excessive electrical activity that occurs in cerebral palsy related seizures. There have been many successes in treating these seizures with anticonvulsants.
Conventional antiepileptic drugs:
Phenytoin, Phenobarbitone, Carbamazipine, Valporic acid.
Newer antiepileptic drugs:
Oxcarbazepine, Gabapentine, Lamotrizine, Clobazam, Topramate, Levitiracetam, Zonisamide, Pregabalin, Tiagabine, Vigabatrin.
Side effects of anticonvulsant medication include drowsiness, dizziness, irritability, confusion, vomiting, uncontrolled eye movements, gingivitis, and itching or a rash. Anticonvulsants may also interact negatively with other medications that you may be taking.
Discontinuation of antiepileptic drugs (AED) in children with cerebral palsy can and should be practiced when possible after patients have been seizure free for at least 2 years. AED discontinuation in children with spastic hemi paresis is significantly more likely to lead to seizures relapse than children with other form of cerebral palsy.
It is often difficult to control seizures particularly if the child has mental retardation as an associated factor.
Neurological deficits and mental retardation are poor prognostic factors for seizure relapse after AED discontinuation.
Polytherapy commonly used in children with cerebral palsy and seizures.
Long term use of AED which might predispose to osteoporosis is very important issue in cerebral palsy.
Before starting medicines for epilepsy, it is necessary to diagnose the kind and severity of the seizures as some other common condition can mimic as seizures. Such as: breathe holding spell, gastro esophageal reflux, syncope, movement disorders, behavioral events and parasomnias.