Introduction: The treatment of arteriovenous malformations (AVMs) of the basal ganglia, the thalamus, and the insula is complex, due to the eloquence of the neural structures involved. They constitute between 4.3% and 11% of all AVMs and are associated with a high rate of morbidity and mortality due to the high risk of bleeding due to their inaccessible location Recent advances in endovascular therapy have allowed obtaining good results with curative potential.

Clinical case: 7-year-old male patient with headache, nausea, and left hemiparesis (Daniels 4/5). The cerebral tomography showed an unruptured thalamic-mesencephalic vascular lesion, with slight ventricular dilation due to partial collapse of the Monroe foramen. A brain angioCT showed an arteriovenous malformation with a large bilobed venous aneurysm with mass effect. Subtraction angiography revealed a right thalamic-midbrain AVM with afferents from perforating branches of P1, P2, and right PComA, the largest with a diameter of 0.88 mm, with a single thick venous drainage and a large venous aneurysm, reaching the internal cerebral vein already Galen's vein. It was embolized with Squid ® 4.5cc in a single session via the arterial route, with almost total occlusion (95%) of the nest, as well as the closure of the ostium to the efferent vein.

Conclusion: Embolization is a curative treatment strategy in selected cases of patients with deep AVMs, with good results and complication rates comparable to other therapeutic strategies.