Verapamil vs. Sertraline for Vestibular Migraine & Chronic Subjective Dizziness

Chronic dizziness and recurrent vertigo are frequent complaints in primary and specialty
medical care settings. Two common causes of these symptoms are vestibular migraine (VM) and
chronic subjective dizziness (CSD), which may be seen in up to 25% of patients examined in
tertiary neurotology centers. However, VM and CSD are relatively new diagnoses that have not
yet been validated. Furthermore, recent research found that they co-exist 30% of the time
with overlap in several features. From a clinical standpoint, this makes it difficult to
diagnose and treat them well. From a research standpoint, it confounds subject selection for
mechanistic investigations.

The primary goal of this study was to dissect VM and CSD in order to identify the key
features and clarify the diagnostic criteria of each condition. Subjects diagnosed with
coexisting VM-CSD were treated with either verapamil or sertraline. It was hypothesized that
a differential treatment response to these two pharmacologic probes would help to tease
apart the unique clinical features of VM and CSD and identify risk factors that are shared
or separate between the two conditions. It was hoped that the different mechanisms of action
of the two study medications might also shed light on the physiologic underpinnings of VM
and CSD.

This project was a 14-week, prospective, randomized, double-blind, parallel group,
pharmacologic dissection (PD) trial. A 12-week treatment period followed 2 weeks of baseline
observation. Patients charted daily headache and vestibular symptoms. VM and CSD symptoms
and potential confounds such as anxiety and depression were measured at two week intervals.
Data were analyzed for differential and shared treatment effects that align with or oppose
current concepts of VM and CSD.

A PD trial uses response to one or more pharmaceutical probes (drugs) to study physiologic
mechanisms of illness. A PD trial may provide data to separate overlapping manifestations of
comorbid illnesses. This is useful for conditions that lack biomarkers. It also may provide
data to identify characteristics of illnesses (symptoms, signs, cellular processes) that are
associated with specific pharmacologic mechanisms.

Inclusion criteria:

1. Neurotologic diagnoses of both vestibular migraine and chronic subjective dizziness

2. All other co-existing medical or psychiatric conditions are stable, and no greater
than moderate severity

3. Able to complete study assessments in person and by phone

4. Able to travel to Mayo Clinic, Rochester, Minnesota for first and last study visits

5. Willing to avoid pregnancy during study (abstinence or acceptable birth control)

Exclusion criteria:

1. Presence of any other active neurotologic diagnoses

2. Medical or psychiatric conditions that would preclude or confound study drugs

3. Use of medications or supplements that would preclude or confound study drugs

4. Past treatment of headache or dizziness with a full trial of a calcium channel
blocker or selective serotonin reuptake inhibitor

5. Allergy to verapamil or sertraline