Syndromes of vascular cranial nerve compression are treatable surgically with microvascular decompression (MVD). In order to lower the occurrence of unsuccessful procedures and early recurrences, intraoperative monitoring is utilised. In facial hemispasm (HFS), ephaptic transmission and abnormal muscle response of mimic muscles are monitored. In trigeminal neuralgia (TN), trigeminal evoked potentials (TSEP) are monitored. As responses that allow evaluation we consider those that are „near-field“, registered directly from trigeminal root in the cerebellopontine angle. The aim of this work was to create a methodology suitable for intraoperative monitoring MVD of the trigeminal nerve, as it is in facial hemispasm.

        Key words: facial hemispasm, trigeminal neuralgia, peroperative monitoring, abnormal muscle response, TSEP, intracranial registration