Microvascular Decompressive Surgery for Hemifacial Spasm

Microvascular Decompressive Surgery for Hemifacial Spasm: Nuances of Technique and Outcome

• Review the clinical outcomes of Micro vascular decompression of Hemi facial Spasm.
• Assess safety and efficacy of Micro vascular decompression.
• Improve the outcome of these patients and decease rate of recurrence and complications.

Study Overview

• Status: Not yet recruiting
• Conditions: Hemifacial Spasm
• Intervention / Treatment: Other: Microvascular Decompressive Surgery

Detailed Description

Hemi facial spasm (HFS), a term described in 1905 by Babinski but first reported by Schultz in 1875, is a highly morbid movement disorder characterized by intermittent involuntary movement of muscles innervated by the facial nerve.

(HFS) affects roughly 10 in 100,000 individuals in fifth or sixth decades of life.

Primary HFS is commonly attributed to vascular loops compressing the seventh cranial nerve at its exit zone from the brainstem. The facial nerve compression is thought to lead to ephaptic transmission and to hyperactivity of the facial nucleus, resulting in the involuntary facial movements.

Secondary HFS frequently follows peripheral facial palsy or may arise from facial nerve damage produced by tumours, demyelinating disorders, traumatisms, and infections accounting for 1-2 & of HFS.

Over four in five primary HFS cases involve either anterior or posterior inferior cerebellar artery as the primary offender although vertebral artery, multiple vessels and veins may be involved.

EMG recordings confirm the diagnosis by showing a typical electrophysiological signature: clonic facial muscle contractions, hyperactivity, and synkinesis, lateral spread evoked responses.

Imaging can be useful for confirming that HFS is primary in nature and due to a neurovascular compression. In most cases (95% of the patients) the compressive vessel, generally an artery, is seen on MRI combined with MR-Angiography (MRA). High resolution T2-sequence is to be used to get good delineation of the facial nerve.

Many treatments for HFS have been reported, including pharmacological agents, botulinum toxin injection, facial nerve blockage, physical therapy, radiofrequency ablation, acupuncture, as well as facial nerve combing and microvascular decompression (MVD).

However, while MVD is effective, there are still significant postoperative complications.

• Study Type: Observational
• Enrollment (Anticipated): 30

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 16 years to 56 years (Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Probability Sample

Study Population

The sample size calculated by sample size calculator software according to:

1. confidence interval : 95%
2. power : 80%
3. P-value : 5%
4. Prevalence : 0.79/100000
5. Population size: 110,000 referenced by Assiut health directory statistics 2018 All cases that fulfil the selection criteria that will be admitted in the department of neurosurgery at Assiut university hospital with expected size of at least 30 patients

Description

Inclusion Criteria:

Primary Hemi facial spasm Unilateral Adults 20-60 years Clinical Diagnosis confirmed by Facial Evoked potential & Neuroimaging

Exclusion Criteria:

Secondary Hemi facial spasm caused by intracranial masses or other lesions Recurrent Hemi facial spasm Patients who are unfit for any neurosurgical interventions.

Study Plan

How is the study designed?

Design Details

• Observational Models: Case-Only
• Time Perspectives: Prospective

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Samsung Medical center Grading system for Severity of Hemifacial Spasm	Success rate by assessing the degree of hemifacial spasm pre and post-operative using the SMC grading system proposed by Lee et all	one month
Hearing Affection	Audiometry: to detect the degree of post-operative hearing affection using WHO Grading system For Hearing Loss	one month
Recurrence	Recurrence rate within the duration of follow up	Six Month
Morbidity and mortality	Morbidity and mortality rates related to the procedure using modified Rankin Scale	Six Month

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
changes in facial evoked EMG	Detect the changes in facial evoked EMG preoperative and postoperative and its correlation to outcomes (esp. disappearance of lateral spread response)	one month

Collaborators and Investigators

• Sponsor: Assiut University

Publications and helpful links

General Publications

• THUREL R. [Peripheral facial hemispasm, trigeminal neuralgia and masticatory spasm on the same side]. Rev Neurol (Paris). 1951;85(4):288-9. No abstract available. Undetermined Language.
• Wu Y, Davidson AL, Pan T, Jankovic J. Asian over-representation among patients with hemifacial spasm compared to patients with cranial-cervical dystonia. J Neurol Sci. 2010 Nov 15;298(1-2):61-3. doi: 10.1016/j.jns.2010.08.017.
• Auger RG. Hemifacial spasm: clinical and electrophysiologic observations. Neurology. 1979 Sep;29(9 Pt 1):1261-72. doi: 10.1212/wnl.29.9_part_1.1261.
• Cui Z, Ling Z. Advances in microvascular decompression for hemifacial spasm. J Otol. 2015 Mar;10(1):1-6. doi: 10.1016/j.joto.2015.06.002. Epub 2015 Jul 26.
• Hyun SJ, Kong DS, Park K. Microvascular decompression for treating hemifacial spasm: lessons learned from a prospective study of 1,174 operations. Neurosurg Rev. 2010 Jul;33(3):325-34; discussion 334. doi: 10.1007/s10143-010-0254-9. Epub 2010 Mar 27.
• Sindou M, Mercier P. Microvascular decompression for hemifacial spasm: Outcome on spasm and complications. A review. Neurochirurgie. 2018 May;64(2):106-116. doi: 10.1016/j.neuchi.2018.01.001. Epub 2018 Feb 15.

Study record dates

Study Major Dates

• Study Start (Anticipated): September 1, 2020
• Primary Completion (Anticipated): September 1, 2022
• Study Completion (Anticipated): March 1, 2023

Study Registration Dates

• First Submitted: July 14, 2020
• First Submitted That Met QC Criteria: July 16, 2020
• First Posted (Actual): July 17, 2020

Study Record Updates

• Last Update Posted (Actual): July 17, 2020
• Last Update Submitted That Met QC Criteria: July 16, 2020
• Last Verified: July 1, 2020

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Nervous System Diseases; Neurologic Manifestations; Stomatognathic Diseases; Mouth Diseases; Neuromuscular Manifestations; Spasm; Hemifacial Spasm
• Other Study ID Numbers: Hemifacial Spasm

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: No

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No