Effect of botulinum neurotoxin treatment in the lateral spread monitoring of microvascular decompression for hemifacial spasm

Abstract

HFS patients treated with BtNtx prior to MVD demonstrated higher LSR baseline amplitudes during IONM. This could be related to muscle poly-reinnervation after recovery from repeated BtNtx use.

Effect of previous botulinum neurotoxin treatment on microvascular decompression for hemifacial spasm

“…2,12 In our series, there were significantly more patients with preoperative facial weakness in Group I than in Group II. There was a greater number of patients with left HFS in Group II than in Group I, which was inconsistent with the results previously reported by Revuelta-Gutiérrez et al 21 In addition, our data reveal a higher incidence of patients with platysma muscle involvement and tonus in the facial muscles, when compared with people with HFS not treated by previous botulinum neurotoxin.…”

“…10,13,14 In our study there was no significant difference in postoperative complications between the 2 groups, consistent with results previously reported. 12 Based on our data, MVD is an effective and safe procedure for patients with HFS previously treated by botulinum neurotoxin. Study limitations include retrospective analysis of data and lack of objective evaluation of long-term data.…”

“…In our previous study we found that HFS patients treated with botulinum neurotoxin prior to MVD demonstrated higher LSR baseline amplitudes during intraoperative monitoring. 12 These data could be related to muscle poly-reinnervation after recovery from repeated botulinum neurotoxin use. Based on our previously published results 27 and the current study, the use of LSR in MVDs may be very valuable, irrespective of botulinum neurotoxin treatment.…”

“…17,24,27 Since the use of botulinum neurotoxin in HFS was approved by the US FDA in 1989, it has been used as a minimally invasive treatment option for HFS. 12 Botulinum neurotoxin type A, the most commonly used botulinum neurotoxin for HFS, produces muscle atrophy that only persists for 3-4 months, so almost all of these patients undergo multiple injections prior to MVD. Although it is not curative, some practitioners, and patients with HFS, prefer botulinum neurotoxin injection therapy.…”

The Significance of Intraoperative Electromyographic “Lateral Spread” in Predicting Outcome of Microvascular Decompression for Hemifacial Spasm

“…Evaluating 282 patients undergoing MVD for HFS and comparing intraoperative findings and clinical outcome in patients with previous botulinum toxin injections, the Pittsburgh group found higher LSR baseline amplitudes, attributed to poly-reinnervation after recovery from repeated botulinum toxin use, but they did not see any significant differences in LSR changes and clinical outcome. 31 In our series a clear majority of patients have had previous botulinum toxin treatment although usually not within 3 months prior to undergoing MVD; in most other larger series prior treatment with botulinum toxin is not discussed. 15,22,30 We have updated the previously mentioned meta-analysis from 2009 22 and have added four additional studies and our own for a total of 1301 patients.…”