Recovery of Normal Excitability of the Facial Motor Nucleus Following Facial Nerve Decompression in Hemifacial Spasm

In a previous study it was shown that a central and widespread hyperexcitability of the facial motor nucleus was a common feature of the affected side of patients with hemifacial spasm (HFS). It was thus concluded that the patients’ abnormal reactions would depend on the existence or not of a background activity in the facial motoneurons. This background activity would be increased in HFS by a permanent neuronal antidromic excitation originating from the ectopic focus and ephaptic transmission on the facial nerve itself. These data raise the following question: what happens to the facial motoneuron hyperexcitability when the ectopic ephaptic excitation of the facial nerve has been removed?