Pial arteriovenous fistula as a cause of bilateral thalamic hyperintensities--an unusual case report and review of the literature.

INTRODUCTION: Isolated bilateral thalamic congestion due to an arteriovenous malformation (AVM) is a rare entity. Few case reports of dural arteriovenous fistula associated with it have been reported in the literature. The association of pial arteriovenous fistula (pial AVF) with thalamic hyperintensities has never been described before. The pial AVF is a recently recognized lesion in which the multiple pial arterial feeders drain into a single venous channel without a nidus like in conventional AVM. In spite of being congenital in origin, these lesions may have expression in adulthood due to abrupt change in the venous drainage system. Successful management of pial AVF associated with bilateral thalamic hyperintensities is described here with review of the literature. CASE PRESENTATION: A 60-year-old man presented with rapidly progressive gait disturbance and cognitive decline. Magnetic resonance imaging (MRI) showed hyperintensities in the thalami on T2-weighted and fluid attenuated inversion recovery image. Digital subtraction angiography revealed a pial AVF near the splenium of corpus callosum. It had feeders from posterior choroidal arteries and drained into the vein of Galen through an abnormal mesencephalic vein. The stagnation and increase of pressure in the deep venous system led to congestion in the thalami. He was treated by partial transarterial embolization of the feeders followed by gamma knife therapy (GKT). The clinical symptoms and MRI improved rapidly after embolization and further reduction in shunt flow was observed after GKT. CONCLUSION: Strong suspicion of vascular malformation as a cause of bilateral thalamic hyperintensities helps in early detection. Such lesions like pial AVF presented here require active intervention by surgery or endovascular therapy. GKT is an important adjuvant in lesions refractory to either of them.

Fenestration of a supraclinoid internal carotid artery associated with dual aneurysms: case report.

BACKGROUND AND IMPORTANCE: We present a rare case of fenestration of the left supraclinoid intracranial internal carotid artery with 2 associated aneurysms arising proximally and distally from the fenestration that were successfully treated with endovascular coil embolization. This is the first report of these types of aneurysms treated with coiling alone. CLINICAL PRESENTATION: A 47-year-old woman underwent a diagnostic workup; magnetic resonance angiography incidentally revealed 2 tandem aneurysms at the supraclinoid and paraclinoid portion of the left internal carotid artery. Angiography revealed fenestration of the left supraclinoid internal carotid artery with 2 aneurysms both proximal and distal to the fenestration. The patient underwent endovascular coil embolization of the aneurysms simultaneously. The smaller trunk was intentionally occluded to achieve complete packing of the proximal aneurysm. Both aneurysms were totally occluded, and no neurological deficits developed in the patient. CONCLUSION: Based on previous reports, fenestration has the potential to form an aneurysm, and there seemed to be a relatively high incidence of rupture if accompanied by aneurysm. Coiling is one good option to treat aneurysms and should be considered when multiple aneurysms exist because all aneurysms can be treated simultaneously. Proximal occlusion of the smaller trunk is acceptable because of a retrograde flow from the distal end, even if one exists.