Epilepsy surgery is often pursued. Sturge-Weber syndrome is caused by an activating somatic mutation in the GNAQ gene and it affects approximately 1 in 20,000-50,000 live births. The mutation results in vascular malformations affecting the brain, skin and eyes. The typical presentation includes a facial port-wine birthmark, ocular angiomas and cerebral vascular malformations which are most often unilateral but are bilateral in 15% of cases. The prevalence of epilepsy is 75-100% and is higher in those with bilateral involvement. Seizures typically occur within the first two years of life and are refractory in nearly half of cases. However, high rates of seizure freedom with surgery have been reported in as many as 83%.Neurofibromatosis type 1 is the most common phakomatoses and occurs in approximately 1 in 3,000 live births. It is caused by autosomal dominant mutations in the Neurofibromin 1 gene. Clinical manifestations are variable but may include hyperpigmented skin marks, hamartomas of the iris called Lisch nodules, neurofibromas, optic pathway gliomas and cognitive impairment. The prevalence of epilepsy is estimated to be 4-7%. Seizures are typically easier to control with anti-seizure medications relative to other phakomatoses but in some refractory cases surgery may need to be pursued. Acquired
Epilepsy may occur as a result of several other conditions, including tumors, strokes, head trauma, previous infections of the central nervous system, genetic abnormalities, and as a result of brain damage around the time of birth. Of those with brain tumors, almost 30% have epilepsy, making them the cause of about 4% of cases.
A cry may be heard due to contraction of the chest muscles, followed by a shaking of the limbs in unison (clonic phase). Tonic seizures produce constant contractions of the muscles. A person often turns blue as breathing is stopped. In clonic seizures there is shaking of the limbs in unison. After the shaking has stopped it may take 10–30 minutes for the person to return to normal; this period is called the "postictal state" or "postictal phase." Loss of bowel or bladder control may occur during a seizure. People experiencing a seizure may bite their tongue, either the tip or on the sides; in tonic-clonic seizure, bites to the sides are more common. Tongue bites are also relatively common in psychogenic non-epileptic seizures.Myoclonic seizures involve very brief spasms of muscles in either a few areas or all over. These sometimes cause the person to fall, which can cause injury. Absence seizures can be subtle with only a slight turn of the head or eye blinking with impaired consciousness; typically, the person does not fall over and returns to normal right after it ends. Atonic seizures involve losing muscle activity for greater than one second, typically occurring on both sides of the body. Rarer seizure types can cause involuntary unnatural laughter (gelastic), crying (dyscrastic), or more complex experiences such as déjà vu.About 6% of those with epilepsy have seizures that are often triggered by specific events and are known as reflex seizures. Those with reflex epilepsy have seizures that are only triggered by specific stimuli.