Intracranial Gorgon: Surgical Case Report of a Large Calcified Brain Arteriovenous Malformation

Abstract

BACKGROUND Brain arteriovenous malformations (AVMs) are benign intracranial vascular anomalies that, under certain circumstances, may become life-threatening. Diffuse calcifications found in the vessel walls, interposing tissue or adjacent cerebral parenchyma are not uncommon, however, intense calcifications of AVMs that render them into veritable "brain stones" are scarcely reported in the literature and a genuine neurosurgical nightmare. CASE REPORT A 55 years-old male patient lacking any personal history of serious morbidities or surgical interventions was referred to our department for several epileptic seizures and severe chronic headache in the parieto-occipital region. Upon clinical examination, the patient was aware, right-handed, and had no motor or sensory deficits. Computed tomography angiography scan showed a large densely calcified frontal AVM. The patient was subjected to neurosurgical removal of the lesion and was discharged a week later with a minor motor deficit of the left arm. CONCLUSIONS Intracranial AVMs are a rare pathology, but a genuine microsurgical trial. The difficulty level soars when the malformed vessels become atherosclerotic and calcified, rendering bipolar ligation or permanent clipping unfeasible. An incomplete resection in the case of a highly calcified lesion can only result in an uncontrollable hemorrhage.

Figure 1.

Preoperative computed tomography (CT) and CT angiography (CTA). (A) Non-contrasted CT scan showing the highly dense right paraventricular formation representing the deep calcified portion of the arteriovenous malformation (AVM) (blue star). (B) The bone window more clearly demonstrates the calcium deposits (white star). (C) CTA revealing the superficial, “soft” part of the nidus (blue arrow) as well as its relationship with the calcified region (blue star). (D) 3-dimensional reconstruction of the CTA, showing the “soft” nidus (cyan arrow), calcified portion (cyan star), feeders and draining veins.

Figure 2.

Immediate postoperative computed tomography scan. (A–C) Axial slices demonstrating the removal of the lesion, hemostatic material and a small amount of hemorrhage in place of the nidus, a hematic collection in the subarachnoid and subdural spaces, as well as a minimal pneumocephalus. The subaponeurotic drainage can be observed in the lower right.

Figure 3.

Control non-contrasted computed tomography scans. These scans were performed on the third postoperative day (A–C), showing marked reduction of the hemorrhage and perilesional edema.

Figure 4.

Control Computed tomography angiography at 3 months (A) and 6 months (B) respectively. The imaging studies reveal no sign of patent nidus or hemorrhage remaining, only a small amount of perilesional calcium deposits in the brain parenchyma.