Just as there are generalized epilepsies of unidentifiable, presumably genetic, cause, there are also partial epilepsy syndromes of unknown or idiopathic cause, or Idiopathic Partial Epilepsies. An idiopathic disease is a disorder that cannot be attributed to a known underlying condition. So, while other types of epilepsy may be caused by a brain tumor, stroke, or other neurological disorder, idiopathic epilepsy is a primary brain disorder of unknown cause. In fact, most idiopathic epilepsy syndromes are presumed to be due to a genetic cause, but in most cases the specific genetic defect is not known and a family history of epilepsy may not be present.
There are a few idiopathic partial epilepsy syndromes. Each individual syndrome generally has its own characteristic seizure type(s), typical age of onset, and specific EEG patterns. Some of these syndromes are:
The seizures in idiopathic partial epilepsy typically respond well to medications used for other partial epilepsy syndromes. However, depending on the seizure type, time of day, and frequency, some doctors and parents choose not to treat the child with medication at all. For example, a patient with benign rolandic epilepsy who experiences rare nocturnal seizures consisting of only brief face and arm twitching may do well without any medication treatment.
Though the prognosis of these syndromes varies by syndrome type, it is usually quite good. Most patients with these syndromes “outgrow” their seizures by teenage years or young adulthood, and also have normal intelligence and motor skills.