The patient presented with a history of headaches. There were no focal neurological signs or history of seizures. There was a history of stroke in the family.
Cavernous angiomas (cavernomas) are “mulberry”-like vascular malformations which may occur spontaneously or within families. Histologically, they are endothelial lined sinusoidal spaces , which have no muscular component to their wall, and have no intervening neurological tissue between these spaces.
The quoted prevalence is 0.4% and they tend to present in the 20-40 year old age group with seizures(most commonly), headaches and/or focal neurological signs. They are commonly seen in the frontotemporal region, deep white matter, basal ganglia and at the cortico medullary junction. In the posterior fossa they are seen in the pons and cerebellar hemispheres. They are also seen in the spinal cord, where they frequently coexist with multiple brain lesions. In spontaneous cases 50% have multiple lesions, whereas in familial cases 80% are found to have more then one lesion, and this latter group tend to present at a younger age.
The lesions often have repeated episodes of haemorrhage which are clinically occult, but the reported incidence of clinically overt haemorrhage is between 0.5% and 1%. The risk of neurological disability as a result of an occult bleed is significantly higher when the lesion is in the posterior fossa or when there has been a previous gross haemorrhage.
The lesions are not necessarily static. In one study 20% were seen to change is size and 40% were seen to have different signal intensity when followed up serially. The lesions increase in size as a result of haemorrhage (which may be occult) and may decrease in size as resolution of haemorrhage occurs. In some cases, new lesions have been seen to develop over serial MRI scans.
The repeated small bleeds that occur, lead to the deposition of haemosiderin giving the characteristic magnetic resonance (MRI) appearances, making this the imaging modality of choice. These lesions are not seen on angiography and computed tomography shows iso- or hyperdense lesions with variable calcification and minimal enhancement, but does not demonstrate all lesions. MRI shows four types of appearance. Type 1 lesions are high signal on T2 with high or low signal on T1 and is due to subacute hamorrhage. Type 2 lesions have a reticulated mixed signal core on T1 and T2 but has a prominent low signal rim on T2 due to haemosiderin. These lesions are formed by cavernomas with haemorrhages of different ages. Type 3 lesions are of low signal on T2 and low signal or iso-intense to brain on T1 and are due to chronic haemorrhage. Type 4 lesions are only seen on Gradient Echo sequences (T1 or T2 weighted). These are small cavernomas or telangiectasia and are seen due to the susceptibility artefact produced by the small amounts of haemosiderin present.
Treatment of the lesions is expectant with surgery recommended for clinically significant haemorrhage, refractory seizures or progressive neurological deficit, especially with cavernomas in the brain stem. Asymptomatic lesions, in general, have a lower mortality and morbidity compared to risks of surgery.
Differential Diagnosis List