In general,<unk>  is fixed in both its occurrence and symptoms; that is, once symptoms occur, it does not tend to progress. Varying results from surgical resection of the affected area have been reported. Although such surgery cannot reverse developmental disabilities, it may provide full or partial relief from seizures.<unk>  are most commonly isolated anomalies, but may be part of a number of syndromes, including chromosomal abnormalities and fetal exposure to toxins (including alcohol).
Gray matter heterotopia
Germinal matrix hemorrhage
Periventricular leukomalacia
Nasal glial heterotopia
Subependymal giant cell astrocytoma
Fibrillary astrocytoma
Basilar invagination
Dysembryoplastic neuroepithelial tumour