Abstract
Deep-seated lesions of the basal ganglia and thalamus are among the most challenging to access without disruption of critical neural elements. We report a basal ganglia cavernous malformation resected with a supracerebellar transtentorial approach. The patient was in his mid-50s and presented with acute unsteadiness and left-sided weakness. Magnetic resonance imaging revealed a large, heterogeneous, partially enhancing lesion involving the right basal ganglia, internal capsule, thalamus, and geniculate. Neurosurgical resection was recommended. Patient consent was obtained. Institutional Review Board approval was waived for this single case report. The patient was positioned sitting, a bipedicular myocutaneous flap was raised, and a 2-piece torcular craniotomy was performed. Adhesions between the tentorial undersurface and superior cerebellar surface were released, and the supracerebellar and quadrigeminal arachnoid were widely dissected, allowing identification of the P3 segment, which was followed to the right ambient cistern. The tentorium was incised, flapped superiorly, and retained in place with an aneurysm clip, widening the lateral corridor. An entry point was selected at the intersection of the posteroinferior thalamus and medial geniculate, the transparenchymal dissection was carried down to the cavernous malformation, and the lesion was entered, internally debulked, and resected in a piecemeal fashion. The paramedian and contralateral corridors were used in tandem to access the medial and lateral aspects of the lesion, respectively, and a gross total resection was achieved. The patient recovered without new neurological deficit, highlighting the utility of the unique supracerebellar transtentorial approach for accessing deep supratentorial lesions, including those within the anterior basal ganglia.