Measurement of the Hippocampal Theta Rhythm From the Outer Ear Canal

What this study is about

New technologies are needed to help diagnose anxiety disorders. EVestG has facilitated the identification of numerous possible biomarkers of several psychiatric disorders. Some EVestG features seem to be caused by differences in low-frequency modulation that is consistent (both in frequency and behaviour) with the hippocampal rhythm (theta), which is known to play a role in anxiety. Critically, there is ample support in the literature for an anatomical and functional basis for the modulation of vestibular signals via theta. If anxiety could be measured continuously, perhaps throughout a patient's day, or throughout a task, it might be able to confirm an anxiety disorder. However, current techniques for measuring theta are highly invasive, performed rarely, and only in epilepsy patients. EVestG technology, however, is non-invasive, and could potentially record anxiety levels in any subject for extended periods of time. The proposed study will attempt to identify hippocampal theta in vestibular signals in healthy participants through a double-blind administration of two different drugs that are dissimilar both pharmacologically and in acute clinical effects but which are known to reduce the theta rhythm.

Who can join (things the study team will check)

✅ You may be able to join if…

• Males and females who are between 18 and 40 years of age.

🚫 You may not be able to join if…

• Psychological treatment in the past year or taking any psychiatric drug.
• Drugs that interact with the study drugs or that have anxiolytic/anxiogenic properties.
• Antibiotics or natural health products that inhibit/induce CYP3A4 or CYP2D6.
• History of substance use disorder or family history of substance use disorder.
• Pregnancy (or breastfeeding), left handedness, or colour blindness.
• Individuals who have a current diagnosis, or history of, a neurological illness.
• A history of stroke, head injury, loss of consciousness, epilepsy.
• Kidney or liver disease/impairment.
• COPD or sleep apnea.
• Skin lesions involving the ear canal, self-reported or as assessed in examination at the lab.
• Any unknown balance disorders, as assessed by investigator via balance test.
• Major hearing loss, self-reported or as assessed by investigator via audiogram.
• Allergic skin reactions to chemical agents including detergents.
• Heart disease, lung disease or diabetes.
• Influenza, Covid-19, or flu-like symptoms.
• Recovering from an accident, injury, or operation.

Where this trial is running

• Riverview Health Centre, Winnipeg, Manitoba, Canada

Who to contact

Zeinab A Dastgheib, PhD · 204-229-3923 · Zeinab.Dastgheib@umanitoba.ca

It's completely normal to call and ask questions before deciding anything. Mention the study ID: NCT03954483.