Functional Effects of Botox on the Brain Using MRS and fMRI

Phase 4

Completed

Brief Summary: The injection of BOTOX into peripheral muscles has been shown to have therapeutic effects in a growing number of indications including disorders involving skeletal muscle (e.g., strabismus, blepharospasm, cervical dystonia, spasticity, cosmetic), smooth muscle (e.g., bladder), glands (axillary hyperhidrosis) and nociceptive pain (e.g. migraine) (Brin. 2014). Recently, several studies have suggested that peripheral BOTOX injections in the region of the glabellar lines (muscles around the eyes) may be effective in treating major depression and chronic migraine. However, the mechanism underlying the effect of peripheral BOTOX injections on the brain is not well understood. Therefore, the Investigators propose to further explore the functional effects of BOTOX injections on brain in healthy controls. The approach will involve the measurement of brain metabolites in the brainstem using MRS as well as an investigation of the functioning and connectivity between regions of the brain using resting state MRI and high resolution fMRI.

Detailed Description: Participants will receive one MRI scan session prior to a standardized, clinical dose of BOTOX injected into the forehead per FDA-approved procedures. Participants will then undergo a second MRI scan session 2-3 weeks later, after the BOTOX has taken maximal effect. Examining fMRI of the brainstem and the functional connectivity of the brainstem and connections to cortex, may provide additional insight into the effects of BOTOX on neurologic and psychiatric disorders.

Recruitment & Eligibility

Inclusion Criteria

Females
Ages 30-40 years of age
Right-handed
Normal or corrected-to-normal vision
No history of psychiatric, neurological, or medical co-morbidities that might interfere with normal brain functioning
Fluent in English
Moderate to severe glabellar lines

Exclusion Criteria

Pregnancy
Ferrous metal, a pacemaker, or other battery-operated device implanted in the body
Claustrophobia
Known hypersensitivity to Botulinum Toxin
Infection on the forehead or between the eyes
Urinary tract infection

Arm && Interventions

Group	Intervention	Description
MRI Scans Pre and Post-Botox Injection	onabotulinumtoxinA	Participants will receive MRI scans pre and post-Botox injection, including magnetic resonance spectroscopy, structural, and functional MRI.

Primary Outcome Measures

Name	Time	Method
Glutamate + Glutamine (Glx)/Creatine Ratio as Measured by MRS in the Brainstem Pre and Post-Botox	15-33 days between pre and post-Botox scans	Determine whether there are metabolic differences in the brain stem in healthy individuals as a result of BOTOX using MRS. Participants were scanned 1-13 days prior to Botox injections in the glabellar region and then again 14-21 days post-injection when the Botox had reached effectiveness. Metabolite FIDs were averaged within each task and processed using TARQUIN (v.4.3.6) software for spectral fitting. The acquired MRS spectra was corrected for tissue type and T2 relaxation differences. Using TARQUIN we obtained values for Glutamate + Glutamine (Glx), normalized by Creatine.
Change From Baseline in Functional MRI Mean Blood Oxygen Level Dependent (BOLD) Response in the Amygdala	15-33 days between pre and post-Botox scans	Understand the effect of BOTOX on functional activity (measured using fMRI) in the brain. Participants were scanned 1-13 days prior to Botox injections in the glabellar region and then again 14-21 days post-injection when the Botox had reached effectiveness. Participants viewed Happy and Angry faces and rated each one as pleasant or unpleasant. We then masked activity in the amygdala to investigate the difference in BOLD response for collapsed across emotion following Botox injections.

Secondary Outcome Measures

Name	Time	Method
Number of Participants With Structural Brain Volume Change Following Botox Injections	15-33 days between pre and post-Botox scans	Participants were scanned 1-13 days prior to Botox injections in the glabellar region and then again 14-21 days post-injection when the Botox had reached effectiveness. Structural scans for each participant were segmented using Freesurfer's automatic software for volumetric measures and then normalized by dividing by total intracranial volume for each participant. We then conducted t-tests for pre- vs. post- BOTOX injections to investigate any structural changes.