Diagnostic Test of Choice for HELPS Syndrome

Study Overview
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Brief Summary
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Our team recently described a new medical condition called HELPS (Hemi-Laryngo-Pharyngeal-Spasm) syndrome(1). HELPS syndrome is a condition caused by a blood vessel pinching the nerve rootlets of the Vagus nerve (Xth cranial nerve). It is similar to the well recognized hemifacial spasm syndrome but the nerve involved is the Vagus instead of the Facial nerve. As a result, the symptoms are episodic throat contractions and cough. The throat contractions become stronger and more frequent over the years and can lead to a terrifying inability to breath. Patients may end up intubated in the Emergency Department or with a tracheostomy because of inability to breath during a severe episode. Some but not all of our patients can tell which side of their throat (left or right) contracts during a choking episode. In between these choking episodes, patients feel normal. A surgical cure for these patients is Microvascular Decompression of the Xth nerve.

Detailed Description
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The treatment of HELPS syndrome begins with the correct diagnosis. Some patients are able to localize the side of their symptoms in HELPS syndrome while others are unable to. The purpose of this study is to prospectively study which of the following is the diagnostic test of choice for patients who are unable to localize their HELPS: 1. CISS MRI sequences, 2. interictal laryngoscopy, and 3. unilateral and contralateral Botox injections separated 3-months apart. Both neuroradiologist and otolaryngologist will be blinded to the outcome of surgery and be asked based on your diagnostic test, which side do you believe we should perform MVD surgery?

Official Title
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Microvascular Decompression for HELPS Syndrome: What is the Best Diagnostic Test?

Conditions
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HELPS Syndrome

Intervention / Treatment
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* Diagnostic Test: Pre-Operative CISS-MRI Sequences
* Diagnostic Test: Pre-Operative Interictal Laryngoscopy
* Diagnostic Test: Pre-Operative Unilateral and Contralateral Botox


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients diagnosed with HELPS as described in our initial publication (Honey et al. 2016) Patients unable to localize the side of their HELPS syndrome Exclusion Criteria: - Unable to provide informed consent

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 65 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| HELPS Syndrome unable to lateralize contractions<br>Each patient will have the following 3 diagnostic pre-operative tests: i) MRI (CISS sequence), ii) video laryngoscopy, and iii) sequential Botox injections in their throat (left side and then 3 months later on the right side). | Diagnostic Test: Pre-Operative CISS-MRI Sequences<br>* Compare pre-operative MRI diagnosis to intra-operative findings on if both are in agreement<br>Diagnostic Test: Pre-Operative Interictal Laryngoscopy<br>* Compare pre-operative laryngoscopy diagnosis to intra-operative findings on if both are in agreement<br>Diagnostic Test: Pre-Operative Unilateral and Contralateral Botox<br>* Compare pre-operative diagnosis using Botox to intra-operative findings on if both are in agreement<br>* Other names: Injections spaced 3-months apart;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Pre-Operative CISS MRI (One month before surgery) compared to Intraoperative Findings | Determine if CISS MRI sequence lateralization in concordance with intraoperative findings | Pre-Operative and Intra-Operative | 
| Pre-Operative Interictal Laryngoscopy (One month before surgery) compared to Intraoperative Findings | Determine if interictal laryngoscopy in concordance with intraoperative findings | Pre-Operative vs. Intra-Operative | 
| Pre-Operative 3 and 6-month Botox Injections compared to Intraoperative Findings | Determine if unilateral vs contralateral Botox-induced symptom reduction in concordance with intraoperative findings | Pre-operative 3 and 6 months vs. Intra-Operative | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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microvascular decompression, Xth nerve