The superior cerebellar artery arises from the basilar artery just before its terminal bifurcation into the posterior cerebral arteries. It curves around the brainstem below the oculomotor nerve (CN III) and above the trigeminal nerve (CN V), supplies the superior cerebellum, the cerebellar nuclei, the superior cerebellar peduncle, and the lateral dorsal pons.
The SCA is the vessel whose pulsatile contact with the trigeminal nerve root entry zone (REZ) is the most common identified cause of trigeminal neuralgia. Microvascular decompression (MVD) surgery targets the SCA-nerve contact point to pad the vessel away from the nerve with a Teflon sponge. SCA infarction produces ipsilateral cerebellar ataxia, ipsilateral Horner syndrome, and contralateral spinothalamic loss, a presentation similar but superior in distribution to PICA territory infarction. The SCA also contacts the facial nerve REZ in hemifacial spasm.
Pulsatile contact of the SCA against the trigeminal nerve root entry zone produces lancinating electric-shock facial pain in a trigeminal distribution, triggered by light touch, speaking, or eating, managed medically with carbamazepine or surgically with microvascular decompression moving the SCA from the nerve.
Superior cerebellar artery territory ischaemia from basilar or SCA occlusion produces ipsilateral cerebellar ataxia, Horner syndrome, and contralateral temperature loss, typically from cardioembolic or atheromatous disease of the basilar artery.
