Hemimegalencephaly
From Wikipedia, the free encyclopedia
| Hemimegalencephaly | |
|---|---|
 | |
| Left-sided hemimegalencephaly in a person with neurofibromatosis[1] | |
| Specialty | Neurology, rheumatology  |
| Symptoms | Frequent seizures often resistant to medicine |
| Usual onset | Congenital |
| Duration | Long term |
| Treatment | Hemispherectomy |
| Medication | Anti-epileptic drugs |
Hemimegalencephaly (HME), or unilateral megalencephaly, is a rare congenital disorder affecting all or a part of a cerebral hemisphere.[2] It causes severe seizures, which are often frequent and hard to control. A minority might have seizure control with medicines, but most will need removal or disconnection of the affected hemisphere as the best chance. Uncontrolled, they often cause progressive intellectual disability and brain damage and stop development.[3]
Other symptoms
Genetics
Pathophysiology
It is a disorder related to excessive neuronal proliferation and hamartomatous overgrowth affecting the cortical formation.[7] The excessive proliferation is postulated to occur early and to possibly continue beyond the normal proliferative period. Epidermal growth factor is thought to play an important role in the excessive proliferation and the pathogenesis of HME.[8]
Diagnosis
It should be suspected in infants or children with intractable, frequent seizures.[4] On a CT scan, the affected part is distorted and enlarged.[9] It can be diagnosed prenatally, but a lot of cases go undiagnosed until seizures begin. Ultrasound can display asymmetrical brain hemispheres.[5]