Peter Jannetta

The operation is particularly associated with trigeminal neuralgia, which causes severe facial pain. It may also be used for conditions such as hemifacial spasm when a blood vessel compresses the relevant cranial nerve.

A surgeon identifies a vessel contacting a cranial nerve near the brainstem and separates the two, often placing a small cushioning material between them. Unlike destructive procedures, the goal is to relieve pressure while preserving nerve function.

Jannetta advanced the idea that pulsating blood vessels can cause certain cranial-nerve syndromes by compressing nerves near their brainstem entry zones. The operating microscope made it possible to examine and treat these delicate relationships.

Microvascular decompression is open surgery that addresses the suspected vessel-nerve contact directly. Gamma Knife radiosurgery targets the trigeminal nerve with focused radiation and avoids a craniotomy, but it uses a different mechanism.