Cerebral proliferative angiopathy (CPA) is a relatively recently described entity and differs from other arterio-venous malformations (AVMs) in its angio-morphology, histology, epidemiology, natural history and clinical presentation. In a case series, CPA was diagnosed in 3.4% of brain AVMs and was more common in young females. The natural history of CPA differs from other AVMs in that haemorrhagic events are less common. On histology, CPA is characterised by the presence of normal- appearing neural tissue intermingled between the vascular channels. Ischaemia is the major cause of symptoms and is multifactorial in origin, possibly secondary to incompetent angiogenesis, ‘steal’ phenomena, arterial stenosis and capillary wall involvement.
We describe a 16-year-old, right-handed, white girl who was referred with progressively worsening episodic headaches associated with right-sided motor weakness, ongoing since the age of 8 years. They would be followed by intense, bi-frontal, pulsatile headaches that would last for anything from 30 minutes to a few hours. General physical and neurological examination was normal.
Magnetic resonance imaging (MRI) showed a diffuse network of densely enhancing vascular spaces over the left parietal region with intermingled normal brain parenchyma (Fig. 1). Cerebral angiography demonstrated a widespread angiopathy supplied by numerous arterial branches and a diffuse network of vascular spaces with relatively slow shunting, suggestive of CPA (Fig. 1).
The episodes of transient weakness in our patient were likely to be secondary to ischaemia, and the risk of stroke due to haemorrhage was low. Surgical intervention was not felt to be appropriate because of relatively low risk of haemorrhage in the long term without intervention and high risk of significant morbidity due to interspersed normal neural tissue with intervention.
Clinically, patients with CPA are more likely to present with headaches, seizures and progressive neurological deficits rather than acute haemorrhage, when compared with other AVMs. Primary indications for invasive intervention in CPA include haemorrhage, identifiable fragile angio-architecture and persistent disabling symptoms. Various treatment options include partially targeted embolisation in non-eloquent areas or calvarial burr-holes in cases where the spontaneous transdural supply is poor. Burr-holes increase the cortical blood supply by recruiting additional blood vessels as employed in other similar conditions such as moyamoya disease.
Evidence of ongoing angiogenesis with elevated levels of vascular endothelial growth factor (VEGF) has been described in patients with CPA; however, it is currently not clear if treatment with monoclonal antibody against VEGF could be of benefit.