Elsevier

World Neurosurgery

Volume 110, February 2018, Pages e560-e566
World Neurosurgery

Original Article
Observation of Effects of Different Surgical Treatments on Unilateral Masticatory Muscle Spasm

https://doi.org/10.1016/j.wneu.2017.11.050Get rights and content

Background

Unilateral masticatory muscle spasm is a rare disease without a generally accepted and efficacious treatment plan.

Objective

We sought to compare the effects of different surgical treatments on unilateral masticatory muscle spasm.

Methods

A retrospective analysis of the surgical treatment and effects of 10 cases of unilateral masticatory muscle spasm occurred between February 2010 and September 2016. Three cases underwent complete amputation of the trigeminal motor branch, 3 cases underwent partial amputation of the trigeminal motor branch, and 4 cases received only vascular decompression. All patients were followed up by telephone interview after surgery.

Results

In the simple vascular decompression group, 3 cases were cured and 1 was cured after a delay. Of these 3 cases, 1 case became aggravated 2 years after the operation, 1 case became aggravated 5 years after the operation, and 1 case showed no change during the follow-up period. In the partial amputation group, 2 cases were cured and 1 case was alleviated. Of the 2 patients who were cured, 1 suffered recurrence 2 years later, while the other case showed no recurrence during the follow-up period. In the complete amputation group, 1 case was cured with a delay and 2 cases were cured immediately with no recurrence during the follow-up. Mild atrophy of the temporal muscle occurred gradually with no restriction of the mouth opening in 2 cases.

Conclusions

Complete amputation of the trigeminal nerve did achieve better effects than pure microvascular decompression and partial amputation of the trigeminal motor branch, but it may lead to mild temporal muscle atrophy.

Introduction

Masticatory muscle spasm is a disease involving masticatory muscle movement disorders. The main clinical manifestations of this condition include sudden and nonrandom tension contraction of the masticatory muscle resulting in sudden closure of the lower jaw and difficulty in mouth opening and deflection. Persistent sudden spasm can cause trismus, which can affect eating and speaking, and is usually unilateral. Only scattered electromyographic studies1, 2, 3 have been reported worldwide, and there is no generally accepted treatment that is efficacious for the treatment of masticatory muscle spasm. The present literature includes a limited number of reports relating to the treatment of unilateral masticatory spasm by microvascular decompression,4, 5, 6 although these studies involved a small number of cases and lacked patient follow-up data. In the present study, we report the neurosurgical treatment and efficacy of 10 patients suffering unilateral masticatory muscle spasm.

Section snippets

General Information

From February 2010 to September 2016, a total of 10 patients with unilateral masticatory muscle spasm were enrolled, including 2 males and 8 females. Seven of these cases involved the left side, and 3 cases involved the right side. Mean patient age was 45.5 years (range: 37–50 years) with a history of spasm for 2–30 years and a follow-up time of 5–77 months.

Clinical Manifestations

All patients manifested with sudden onset of unilateral muscle spasm with no obvious cause. This condition may also have been triggered by

Methods

The local ethics committee approved this study, and all subjects provided informed consent. Under general anesthesia, all of the patients received microvascular decompression of the trigeminal motor root through the suboccipital retrosigmoid approach. The responsible vessels were separated, and a Teflon pad was used to separate the responsible vessels from the trigeminal motor branch. Intraoperative electrophysiologic monitoring was used to identify the trigeminal motor branch. Four patients

Results

As shown in Table 1, of the 4 patients with simple vascular decompression, 1 case was cured with a delay and 3 cases were improved. Of these 3 cases, 1 case was worsened 2 years after the operation, 1 case was worsened 5 years after the operation, and 1 case showed no change during the follow-up period.

In the cases involving partial amputation of the trigeminal motor branch, 1 case was improved and 2 cases were cured after operation. Of these 2 patients, 1 recurred 2 years after surgery and 1

Discussion

Masticatory muscle spasm is a rare disorder of masticatory muscle movement with unknown etiology, which has been rarely reported in the literature. This condition manifests as paroxysmal involuntary movements of the involved muscle, usually on a unilateral basis, and can be either a short-term twitch or a long-term spasm of muscle. Severe spasm can lead to difficulty in mouth opening. Except for the muscle spasm under investigation, or accompanying local muscle hypertrophy, neurologic

Conclusion

Microvascular decompression and partial amputation of the trigeminal motor branches has been unable to achieve a satisfactory treatment effect on unilateral masticatory muscle spasm. Complete amputation of the trigeminal motor branch can achieve satisfactory results but may lead to mild temporal atrophy, which does not affect the face or restrict mouth opening. Surgical effects should be followed up and evaluated after a minimum of 2 years after surgery.

References (20)

  • P. Mir et al.

    Alteration of central motor excitability in a patient with hemimasticatory spasm after treatment with botulinum toxin injections

    Mov Disord

    (2006)
  • H.A. Teive et al.

    Hemimasticatory spasm treated with botulinum toxin: case report

    Arquivos Neuro-psiquiatria

    (2002)
  • Y.W. Wang et al.

    Hemimasticatory muscle spasm: an electromyogram analysis

    Chin J Stomatol

    (2004)
  • K.H. Chon et al.

    Hemimasticatory spasm treated with microvascular decompression of the trigeminal nerve

    Acta Neurochir

    (2012)
  • N.N. Dou et al.

    Microvascular decompression of trigeminal nerve root for treatment of a patient with hemimasticatory spasm

    J Craniofac Surg

    (2014)
  • Y.N. Wang et al.

    Treatment of hemimasticatory spasm with microvascular decompression

    J Craniofac Surg

    (2013)
  • P.D. Thompson et al.

    Hemimasticatory spasm—a peripheral paroxysmal cranial neuropathy?

    J Neurol Neurosurg Psychiatry

    (1983)
  • R.G. Auger et al.

    Hemimasticatory spasm: clinical and electrophysiologic observations

    Neurology

    (1992)
  • G. Cruccu et al.

    Pathophysiology of hemimasticatory spasm

    J Neurol Neurosurg Psychiatry

    (1994)
  • G. Ebersbach et al.

    Hemimasticatory spasm in hemifacial atrophy: diagnostic and therapeutic aspects in two patients

    Mov Disord

    (1995)
There are more references available in the full text version of this article.

Cited by (0)

Conflict of interest statement: The authors declare that the article content was composed in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

View full text