Cerebral proliferative angiopathy (CPA), previously known as diffuse nidus type arteriovenous malformation, is a cerebral vascular malformation separated from classic brain arteriovenous malformation (AVM) and characterized by the presence of normal brain parenchyma interspersed throughout the scattered regions of vascular malformation 1,2,4.
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Epidemiology
Cerebral proliferative angiopathy is more common affecting women, in a ratio of up to 2:1 2,4 and is reported as a rare entity 4, corresponding to 3.4% of all cerebral arteriovenous malformations 1,3.
Clinical presentation
The most common presenting clinical features are headaches, seizures (including epilepsy), and stroke-like symptoms 1,4. Hemorrhagic stroke is uncommon, but when it occurs is often recurrent 4.
Pathology
Cerebral proliferative angiopathy is thought to occur as a result of disorganized angiogenesis secondary to focal regions of chronic hypoperfusion and ischemia 4. It is unclear what incites this, but it is thought that the condition is not congenital but develops during childhood or adolescence in most patients 4.
Radiographic features
Cerebral angiography (DSA) continues to be the gold standard for cerebral proliferative angiopathy diagnosis, especially due to its dynamic flow evaluation capability, however, CTA and MRA can also be accurate in making the diagnosis of the other cerebral vascular malformations.
The characteristic features of cerebral proliferative angiopathy are 1-4:
the absence of early venous drainage, which helps to differentiate cerebral proliferative angiopathy from a classical brain AVM
absence of shunt
large areas of parenchymal involvement, often an entire lobe or even a hemisphere is affected
the nidus (which may be lobar or hemispheric) is fed by multiple arteries with an absence of a dominant arterial feeder
feeder arteries tend to be of normal size or moderately enlarged, including development of flow-related aneurysms
stenoses of feeder arteries is often present
classical nidus appearance with scattered “puddling” of contrast which persists into the late arterial and early venous phases
the nidus usually has a fuzzy appearance and is not well-circumscribed
Treatment and prognosis
Most patients are managed in a supportive manner, with symptomatic treatments such as antiseizure medications 4. When treatment is required, endovascular management is the preferred option 4. Given that endovascular or surgical (similar to moyamoya syndrome) treatments for cerebral proliferative angiopathy carry the risk of damage to the normal brain tissue intermingled in the nidus, they are generally reserved for cases in which there are flow-related aneurysms posing significant risk of intracerebral hemorrhage, or in cases of treatment-refractory epilepsy 3,4.