The patient presented with flickering movements of the right eye and face. Patient also had a left facial nevus.
There is reduction in the volume of the left temporal and parietal lobes, with a paucity of the sulci and gyri in the left occipito-temporo-parietal regions. The white matter in these regions shows a hyperintense signal on the T1W images that turns hypointense on the T2W images and may represent calcium or hemoglobin breakdown products. Enhancement along the sulci and gyri in the left occipito-temporo-parietal regions is seen. The choroid plexus in the left ventricle is prominent and hyperintense on the T2W images. It is seen to enhance intensely. Also seen is an arachnoid cyst in the left anterior temporal region.
It is also known as encepalotrigeminal angiomatosis or meningofacial angiomatosis. It is a congenital disorder affecting either sex. There is angiomatosis involving the face, leptomeninges or choroid of the eye. Patients may present with mental retardation, seizures, hemiparesis or hemianopsia.
Pathology:
The facial nevus is composed of a bunch of thin walled vessels and does not change with advancing age. The meningeal angioma is usually confined to the pia mater. It comprises of multiple venous channels that are plastered together along the surface of the brain. The arteries usually undergo fibrosis. Calcifications usually start in the subcortical white matter and later develop in the cortex. They are the result of chronic ischemia due to impaired venous drainage.
On MRI:
Contrast enhanced MRI is the most sensitive imaging modality.
The enhancement is seen along the gyral surface of the gyri and within the
cortical sulci. The exact extent needs to be demonstrated prior to surgery.
Occasionally the lesions are burned out and the hemisphere shrunken and heavily
calcified. There may be a lack of enhancement due to the angioma getting
thrombosed. Calcium may be seen as a ribbon of low signal intensity along the
cortex on the T2W images.
The ipsilateral choroid plexus is usually enlarged and hyperintense on the T2W
images. It is a result of hyperplasia due to increased venous flow. Angiomas
involving the choroid plexus may also be seen. It is seen to enhance intensely.
Vascular malformations may be seen. Enlarged deep and dural venous sinuses may
also be seen due to slow blood flow or thrombosis of the dysgenetic superficial
venous system.
Occasionally the ipsilateral calvarium be thickened due to cerebral hemiatrophy.
There may be a shift of the midline structures to the same side. Subdural
hematomas, secondary to the atrophy may be seen.
Angiomata may involve the globes (choroid and sclera) in about 30% of the
patients. They may have glaucoma and present with buphthalmos (large, elongated
globe). The posterior wall of the globe is thickened and shows crescentic
enhancement.