Microvascular decompression and MRI findings in trigeminal neuralgia and hemifacial spasm. A single center experience.

OBJECTIVE: For patients with medically unresponsive trigeminal neuralgia (TIC) and hemifacial spasm (HS), surgical microvascular decompression (MVD) is the procedure of choice. The authors of this report sought to review their outcomes with MVD in patients with TIC and HS, and the success of preoperative magnetic resonance imaging (MRI) in identifying the offending vascular compression.

METHODS: Since 2004, there were a total of 51 patients with TIC and 12 with HS with available MRI scans. All patients underwent preoperative MRI to rule out non-surgical etiologies for facial pain and facial spasm, and confirm vascular compression. Follow-up after surgery was 13 ± 22 months for the patients with TIC and 33 ± 27 months for the patients with HS.

RESULTS: There were 45 responders to MVD in the TIC cohort (88%), with a Visual Analog Score (VAS) of 1 ± 3. All patients with HS responded to MVD between 25 and 100%, with a mean of 75 ± 22%. Wound complications occurred in 10% of patients with MVD for TIC, and 1 patient reported hearing loss after MVD for HS, documented by audiogram. The congruence rate between the preoperative MRI and operative findings of vascular compression was 84% in TIC and 75% in HS.

CONCLUSION: MVD is an effective and safe modality of treatment for TIC and HS. In addition to ruling out structural lesions, MRI can offer additional information by highlighting vascular loops associated with compressions. On conventional scans as obtained here, the resolution of MRI was congruent with operative findings in 84% in TIC and 75% in HS. This review emphasizes that the decision to undertake MVD in TIC or HS should be based on clinical diagnosis and not visualization of a compressing vessel by MRI. Conversely, the presence of a compressing vessel by MRI demands perseverance by the surgeon until the nerve is decompressed.