Etiology of Hemifacial Spasm

The facial nerve is inherently vulnerable at its exit point from the brainstem due to physiological reasons. If adjacent arteries become tortuous, elongated, and displaced—commonly as a result of arteriosclerosis—they may compress the nerve, leading to demyelination and consequent disruption of neural conduction, thereby triggering facial spasm.

In simple terms, nerves function like electrical wires; when blood vessels “touch” or press against these “wires,” it causes short-circuiting—abnormal signal transmission—and forms aberrant neural loops, resulting in facial spasm.

How is facial spasm treated? Since hemifacial spasm results from vascular compression of the facial nerve causing abnormal neural conduction, definitive treatment involves surgically separating the nerve from the offending vessel—thereby addressing the root cause and achieving cure.

Microvascular decompression (MVD) is a minimally invasive procedure. A 4-cm incision is made behind the ear, and a bone opening—approximately the size of a one-yuan coin—is created in the skull. Through this opening, the compressing vessel is carefully separated from the facial nerve. Because neither the nerve nor the vessel sustains any damage during the procedure, no postoperative sequelae occur. Moreover, the incision lies within the hairline behind the ear, preserving cosmetic appearance: female patients need only shave a palm-sized area of hair behind the ear; afterward, with hair down, the surgical scar remains completely concealed.

The entire operation is performed under an operating microscope, ensuring exceptional safety.