How do you counsel patients who do you not experience early relief of hemifacial spasm after microvascular decompression surgery?

From a neurology standpoint, I counsel patients (preferably ahead of time) that surgery has a reasonable chance of improving hemifacial spasm but is not always effective. There can also be both early and late (reemergent) persisting spasm.

I have treated some patients after MVD with botulinum toxin, and there can be some improvement.

HFS is unique in that neurovascular compression is always the cause, and the location of NVC is almost always at the initial segment of the emerging facial nerve at the pontomedullary junction. High-resolution imaging pre-op using sub-millimeter voxel T2 MRI (BFFE) and MRA (source images) is recommended to identify the location and source of the compression. While the location of NVC is consistent, the source of NVC is variable and often very challenging. Please note that the approach to the NVC...