Reactivity of the Vestibular System to Caloric Vestibular Stimulation in Schizophrenia

• Sponsor: Centre for Addiction and Mental Health (Other)
• Overall Status: Recruiting
• CT.gov ID: NCT03048370
• Collaborator: (none)
• Enrollment: 40
• Location: 1
• Arms: 6
• Anticipated Duration (Months): 60
• Patients Per Site Per Month: 0.7

Study Details

Study Description

Brief Summary

This study aims to determine if individuals with schizophrenia have greater reactivity to vestibular stimulation than healthy controls. The physiological response of vestibular stimulation will be assessed with electronystagmography, which provides a measure of the intensity of the nystagmus via PSPV. Positive results would suggest greater vestibular system reactivity to vestibular stimulation may be a biomarker of schizophrenia. Pathophysiologically, increased vestibular reactivity to vestibular stimulation may reflect abnormal vestibular function or impaired central suppression of the vestibular ocular reflex.

Condition or Disease	Intervention/Treatment	Phase
Schizophrenia; Healthy	Procedure: Left body temperature VS; Procedure: Right body temperature VS; Procedure: Left warm CVS; Procedure: Right warm CVS; Procedure: Left cold CVS; Procedure: Right cold CVS	N/A

Detailed Description

In schizophrenia, there is no conclusive link between psychopathology and vestibular dysfunction and we are not aware of any data that exists on the range of responses to caloric vestibular stimulation (CVS) in persons with schizophrenia. Initial data from another CVS study from our group suggests individuals with schizophrenia have greater reactivity to body temperature (37°C) CVS, as measured by the peak slow phase velocity of the resulting nystagmus (PSPV), than would be expected from individuals without schizophrenia versus healthy participants. Intriguingly, CVS at 37°C should not theoretically produce a significant vestibulocular reflex response due to the stimulus' approximation to body temperature. Hence, the primary aim of this study is to determine if individuals with schizophrenia will have greater vestibular reactivity, as measured by nystagmus PSPV, to CVS in comparison with healthy participants. The secondary aim is to assess illness awareness pre and post CVS administration in attempts to replicate our previous observation. A total of 20 patients with schizophrenia and 20 healthy control participants will be recruited. All participants will receive three conditions bilaterally: (1) body temperature (37°C) vestibular stimulation; (2) warm CVS (44°C), and (3) cold CVS (30°C).

Study Design

• Study Type: Interventional
• Anticipated Enrollment: 40 participants
• Allocation: Randomized
• Intervention Model: Crossover Assignment
• Intervention Model Description: Each participant will successively receive 6 vestibular stimulation conditions. Side of stimulation will be randomized.Each participant will successively receive 6 vestibular stimulation conditions. Side of stimulation will be randomized.
• Masking: Double (Participant, Outcomes Assessor)
• Masking Description: The participant will be blinded to the order of experimental conditions, as well as the person conducting specific ratings assessments.
• Primary Purpose: Basic Science
• Official Title: Reactivity of the Vestibular System to Caloric Vestibular Stimulation in Schizophrenia
• Actual Study Start Date: Jan 1, 2019
• Anticipated Primary Completion Date: Dec 31, 2023
• Anticipated Study Completion Date: Dec 31, 2023

Arms and Interventions

Arm	Intervention/Treatment
Experimental: Left body temperature VS Left body temperature (37°C) vestibular stimulation	Procedure: Left body temperature VS; Caloric vestibular stimulation (CVS), which involves the irrigation of cold or warm water into the external ear canal, induces a temperature gradient across the semicircular canals of the vestibular apparatus stimulating the vestibular nerve. It is commonly used in both otolaryngology to assess vestibular function and neurology to test brain stem function
Experimental: Right body temperature VS Right body temperature (37°C) vestibular stimulation	Procedure: Right body temperature VS; Caloric vestibular stimulation (CVS), which involves the irrigation of cold or warm water into the external ear canal, induces a temperature gradient across the semicircular canals of the vestibular apparatus stimulating the vestibular nerve. It is commonly used in both otolaryngology to assess vestibular function and neurology to test brain stem function
Experimental: Left warm CVS Left warm (44°C) caloric vestibular stimulation	Procedure: Left warm CVS; Caloric vestibular stimulation (CVS), which involves the irrigation of cold or warm water into the external ear canal, induces a temperature gradient across the semicircular canals of the vestibular apparatus stimulating the vestibular nerve. It is commonly used in both otolaryngology to assess vestibular function and neurology to test brain stem function
Experimental: Right warm CVS Right warm (44°C) caloric vestibular stimulation	Procedure: Right warm CVS; Caloric vestibular stimulation (CVS), which involves the irrigation of cold or warm water into the external ear canal, induces a temperature gradient across the semicircular canals of the vestibular apparatus stimulating the vestibular nerve. It is commonly used in both otolaryngology to assess vestibular function and neurology to test brain stem function
Experimental: Left cold CVS Left cold (30°C) caloric vestibular stimulation	Procedure: Left cold CVS; Caloric vestibular stimulation (CVS), which involves the irrigation of cold or warm water into the external ear canal, induces a temperature gradient across the semicircular canals of the vestibular apparatus stimulating the vestibular nerve. It is commonly used in both otolaryngology to assess vestibular function and neurology to test brain stem function
Experimental: Right cold CVS Right cold (30°C) caloric vestibular stimulation	Procedure: Right cold CVS; Caloric vestibular stimulation (CVS), which involves the irrigation of cold or warm water into the external ear canal, induces a temperature gradient across the semicircular canals of the vestibular apparatus stimulating the vestibular nerve. It is commonly used in both otolaryngology to assess vestibular function and neurology to test brain stem function

Outcome Measures

Primary Outcome Measures

1. Nystagmus response (peak slow phase velocity) [Between 30 and 60 sec after each CVS condition]

   Nystagmus response will be measured at between thirty and 60 seconds post irrigations, looking for the highest velocities.

Secondary Outcome Measures

1. Illness awareness [Before CVS session and10 min after CVS session]

   Changes in illness awareness will be assessed using a questionnaire.

Eligibility Criteria

Criteria

• Ages Eligible for Study: 18 Years and Older
• Sexes Eligible for Study: All
• Accepts Healthy Volunteers: Yes

Inclusion Criteria for Schizophrenia group:

1. Male or female inpatients or outpatients age ≥18

2. Having a DSM-5 diagnosis of schizophrenia or schizoaffective disorder

3. Voluntary and capable of consenting to participation in the research study

4. Fluent in English

Inclusion Criteria for Healthy Controls group:

1. Male or female and age ≥18

2. Voluntary and capable of consenting to participation in the research study

3. Fluent in English

4. Absence of history of psychiatric illness using the Mini-International Neuropsychiatric Interview (MINI)

Exclusion Criteria for all participants:

1. Serious unstable medical illness or any concomitant major medical or neurological illness

2. Acute suicidal and/or homicidal ideation

3. Formal thought disorder rating of over 2 on the Scale for Assessment of Positive Symptoms (SAPS) [patients only]

4. DSM-IV substance dependence (except caffeine and nicotine) within one month prior to entering the study

5. Pregnant women

6. Positive urine drug screen

7. History of external or middle ear pathology

8. History or signs of middle ear surgery (e.g. Tympanoplasty, mastoidectomy)

9. Signs of active ear disease

Contacts and Locations

Locations

	Site	City	State	Country	Postal Code
1	Centre for Addiction and Mental Health	Toronto	Ontario	Canada	M5S 2S1

Sponsors and Collaborators

• Centre for Addiction and Mental Health

Investigators

• Principal Investigator: Philip Gerretsen, MD, PhD, Centre for Addiction and Mental Health

Study Documents (Full-Text)

None provided.

More Information

Additional Information:

• Information about research at the Centre for Addiction and Mental Health, Canada's largest mental health and addiction teaching hospital, fully affiliated with the University of Toronto, and a PAHO/WHO Collaborating Centre

Publications

None provided.

• Responsible Party: Philip Gerretsen, Principal Investigator, Centre for Addiction and Mental Health
• ClinicalTrials.gov Identifier: NCT03048370
• Other Study ID Numbers: 042-2016
• First Posted: Feb 9, 2017
• Last Update Posted: Jun 3, 2022
• Last Verified: Jun 1, 2022

• Individual Participant Data (IPD) Sharing Statement: No
• Plan to Share IPD: No
• Studies a U.S. FDA-regulated Drug Product: No
• Studies a U.S. FDA-regulated Device Product: No
• Additional relevant MeSH terms: Schizophrenia

Study Results

No Results Posted as of Jun 3, 2022