Clinical History
The patient had a history of attacks of left-sided headache associated with a tingling sensation in the left arm and leg.
Imaging Findings
Non-contrast CT of the brain (figure 1) showed para-falcine and right peri-ventricular hyperdense lesions as well as sulcal effacement involving the entire right hemisphere. MRI of the brain showed a large abnormal congress of multiple dilated tortuous tubular serpigenous signal void vascular structures (figure 2a) implicating the right high parietal region, seen surrounded by a rounded area of abnormal bright T1 and T2 signal intensities, surrounded by a perifocal brain oedema (figure 2b) exerting mass effect in the form of effacement of the overlying cortical sulci. Diagnostic Cerebral Angiography (figure 3) showed abnormal parenchymal vessels with diffuse nidus appearance and no early draining veins were seen.
Discussion
Background: Brain arteriovenous malformations (AVMs) are abnormal vascular connections within the brain that are presumably congenital in nature [1]. They are characterized by dilated tortuous vessels with direct connection between arteries and veins without intervening capillary network [2]. They are sub-classified according to the presence or absence of: a nidus and/or early draining veins [1]. The presence of a diffuse nidus with no early draining veins suggests 'Cerebral Proliferative Angiopathy', previously known as diffuse nidus type AVM [1].
Clinical Perspective:
Cerebral Proliferative Angiopathy has a female predilection of 2:1, with a rather young mean patient age (20 years) [1]. It usually presents with headaches, seizures, transient ischemic attacks or progressive neurologic deficits and rarely presents with haemorrhage, unlike other Cerebral AVMs [1]. The disease is characterized by endothelial proliferation and angiogenesis, likely as a response to cortical ischemia which was proven to exist in these cases by perfusion weighted studies [1]. Compared with cerebral AVMs, the exclusive characteristic of Cerebral Proliferative Angiopathy is the presence of identifiable neurons and normal brain tissue intermingled with the abnormal vessels, which has been proven histologically [3].
Imaging Perspective:
The typical MR imaging and CT findings include a proliferative type nidus in which normal brain parenchyma is interspersed between the abnormal vessels [1]. Often, an entire lobe or even brain hemisphere is affected [1]. At cerebral angiography, which is the gold standard for diagnosis, no dominant arterial feeders could usually be detected [1]. The lack of clear early venous drainage on dynamic images is the key to differentiating this disease from classic cerebral AVMs [1].
Outcome: No intervention is usually undertaken in these patients with trials of medical control, yet there have been reports of successful treatment with pial synangiosis or burr-hole therapy to enhance supply to healthy brain tissue from the external carotid artery [4].
Differential Diagnosis List
Cerebral Proliferative Angiopathy
Cerebral AVM
Developmental Venous Anomaly
Final Diagnosis
Cerebral Proliferative Angiopathy
