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Effects of Sensory Flicker and Electrical Flicker Stimulation

Primary Purpose

Brain Diseases

Status
Completed
Phase
Not Applicable
Locations
United States
Study Type
Interventional
Intervention
Customized version of DAVID device
Blackrock CereStim
Sponsored by
Emory University
About
Eligibility
Locations
Arms
Outcomes
Full info

About this trial

This is an interventional basic science trial for Brain Diseases focused on measuring Sensory Flicker Stimulation, Electrical Flicker Stimulation, Neurophysiological Effects, Behavioral Effects, Brain circuits modulation, Steady-state evoked potentials

Eligibility Criteria

18 Years - undefined (Adult, Older Adult)All SexesDoes not accept healthy volunteers

Inclusion Criteria:

  • Adult (>18 years, regardless of gender, race or ethnicity).
  • To be implanted with intracranial depth or grid/strip electrodes for surgical evaluation.
  • Patient was not shown, during phase I seizure monitoring, to exhibit abnormal EEG activity in response to photic stimulation, and is not clinically suspected to be susceptible to photic-induced seizures.
  • Patient has no pre-existing diagnosis of autism.
  • Patient is not considered at risk for psychogenic nonepileptic seizures (PNES) triggered by sensory stimulation.
  • Fluent in English.
  • Able to understand an informed consent (comprehend potential risks and benefits).
  • Give written and verbal informed consent to all experiments patient would participate in.

Exclusion Criteria:

  • Failure to meet any one inclusion criteria.

Sites / Locations

  • Emory University Hospital

Arms of the Study

Arm 1

Arm 2

Arm Type

Experimental

Active Comparator

Arm Label

Sensory Flicker Stimulation

Electrical Flicker Stimulation

Arm Description

Patients will be exposed to Sensory Flicker Stimulation. In one experiment, patients will be exposed, for about 10 minutes at a time, to a sequence of sensory flicker trials each lasting a few seconds. Each trial may include the following modalities and frequencies of flicker: Modalities: auditory only, visual only, or audiovisual combined. Subjects may be exposed to individual pulses of light and/or sound (i.e. around or less than 1 pulse per second). Frequencies: random, or anywhere from 5Hz to 100Hz. Subjects may be exposed to sensory flicker at a given frequency or random frequency for up to 1h at a time In another experiment, patients will undergo a behavioral task in which they will be exposed to one of 2 flicker conditions on separate days. Comfortable parameters (e.g., light intensity and volume intensity) for the subject will be found. If such parameters cannot be found, exposure of the patient to visual and/or auditory stimuli will be stopped.

Patients will be exposed to direct electrical brain stimulation with low-amplitude current, at given flicker frequencies. Patients will be exposed to frequencies ranging from 5-100Hz, for up to 10 seconds at a time. Initially, frequencies of 5.5Hz and 40Hz will be tested. During brain stimulation sessions, bipolar electrical stimulation will be applied to one or more areas of the brain at a time either with or without associated behavioral task. Stimulation in the absence of any behavioral task will be applied in order to assess the subject's neurophysiological response to stimulation and to identify the optimal stimulation parameters for use during behavioral task. Stimulation during behavioral task will be applied in an attempt to affect the subject's behavior.

Outcomes

Primary Outcome Measures

Effect of sensory flicker exposure on local field potential (LFP): comparing mean power spectral density at the frequency of flicker being presented and nearby frequencies
Power spectral density of the LFP will be measured across stimulus frequencies and modalities of sensory flicker stimuli in auditory areas, hippocampus and medial prefrontal cortex. Comparisons will be drawn between the mean power spectral density measured in dB/Hz at the frequency of flicker being presented, and nearby frequencies (+/- 20Hz).

Secondary Outcome Measures

Effects of sensory flicker on interictal epileptiform discharges (IEDs)
The effect of the sensory flicker will be evaluated by the comparison of the rate of IEDs between a given sensory flicker stimulation condition (involving specific frequency and modality of stimulation) and baseline (no stimulation) condition.

Full Information

First Posted
December 4, 2019
Last Updated
September 27, 2023
Sponsor
Emory University
Collaborators
Georgia Institute of Technology
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1. Study Identification

Unique Protocol Identification Number
NCT04188834
Brief Title
Effects of Sensory Flicker and Electrical Flicker Stimulation
Official Title
Neurophysiological and Behavioral Effects of Sensory Flicker and Electrical Flicker Stimulation
Study Type
Interventional

2. Study Status

Record Verification Date
September 2023
Overall Recruitment Status
Completed
Study Start Date
January 10, 2020 (Actual)
Primary Completion Date
November 22, 2022 (Actual)
Study Completion Date
November 22, 2022 (Actual)

3. Sponsor/Collaborators

Responsible Party, by Official Title
Principal Investigator
Name of the Sponsor
Emory University
Collaborators
Georgia Institute of Technology

4. Oversight

Studies a U.S. FDA-regulated Drug Product
No
Studies a U.S. FDA-regulated Device Product
Yes
Product Manufactured in and Exported from the U.S.
No
Data Monitoring Committee
No

5. Study Description

Brief Summary
The study will evaluate whether sensory flicker can modulate neural activity of deep brain regions in humans, and whether it can have relevant effects on behavior. Moreover, it will compare those effects to the gold-standard method of modulating brain circuits, direct electrical stimulation of the brain (the same mechanism as deep brain stimulation), using a powerful within-subjects design.
Detailed Description
Clinical trials have explored the modulation of brain circuits to treat several brain disorders, including Parkinson's Disease, Alzheimer's Disease (AD), depression, and Obsessive-Compulsive Disorder (OCD). However, current means to non-invasively modulate brain activity are limited. The study will evaluate whether sensory flicker can modulate neural activity of deep brain regions in humans, and whether it can have relevant effects on behavior. Moreover, it will compare those effects to the gold-standard method of modulating brain circuits, direct electrical stimulation of the brain (the same mechanism as deep brain stimulation), using a powerful within-subjects design.

6. Conditions and Keywords

Primary Disease or Condition Being Studied in the Trial, or the Focus of the Study
Brain Diseases
Keywords
Sensory Flicker Stimulation, Electrical Flicker Stimulation, Neurophysiological Effects, Behavioral Effects, Brain circuits modulation, Steady-state evoked potentials

7. Study Design

Primary Purpose
Basic Science
Study Phase
Not Applicable
Interventional Study Model
Crossover Assignment
Masking
None (Open Label)
Allocation
Non-Randomized
Enrollment
23 (Actual)

8. Arms, Groups, and Interventions

Arm Title
Sensory Flicker Stimulation
Arm Type
Experimental
Arm Description
Patients will be exposed to Sensory Flicker Stimulation. In one experiment, patients will be exposed, for about 10 minutes at a time, to a sequence of sensory flicker trials each lasting a few seconds. Each trial may include the following modalities and frequencies of flicker: Modalities: auditory only, visual only, or audiovisual combined. Subjects may be exposed to individual pulses of light and/or sound (i.e. around or less than 1 pulse per second). Frequencies: random, or anywhere from 5Hz to 100Hz. Subjects may be exposed to sensory flicker at a given frequency or random frequency for up to 1h at a time In another experiment, patients will undergo a behavioral task in which they will be exposed to one of 2 flicker conditions on separate days. Comfortable parameters (e.g., light intensity and volume intensity) for the subject will be found. If such parameters cannot be found, exposure of the patient to visual and/or auditory stimuli will be stopped.
Arm Title
Electrical Flicker Stimulation
Arm Type
Active Comparator
Arm Description
Patients will be exposed to direct electrical brain stimulation with low-amplitude current, at given flicker frequencies. Patients will be exposed to frequencies ranging from 5-100Hz, for up to 10 seconds at a time. Initially, frequencies of 5.5Hz and 40Hz will be tested. During brain stimulation sessions, bipolar electrical stimulation will be applied to one or more areas of the brain at a time either with or without associated behavioral task. Stimulation in the absence of any behavioral task will be applied in order to assess the subject's neurophysiological response to stimulation and to identify the optimal stimulation parameters for use during behavioral task. Stimulation during behavioral task will be applied in an attempt to affect the subject's behavior.
Intervention Type
Device
Intervention Name(s)
Customized version of DAVID device
Intervention Description
A customized version of the DAVID device will be used to expose patients to sensory flicker. The device consists of opaque glasses containing LEDs to present flickering light, as well as earbuds or headphones to present flickering sound.
Intervention Type
Device
Intervention Name(s)
Blackrock CereStim
Intervention Description
The Blackrock CereStim is a fully programmable neurostimulator. The current pulses generated by the Blackrock CereStim are intended to stimulate neurons in proximity to a set of electrodes.
Primary Outcome Measure Information:
Title
Effect of sensory flicker exposure on local field potential (LFP): comparing mean power spectral density at the frequency of flicker being presented and nearby frequencies
Description
Power spectral density of the LFP will be measured across stimulus frequencies and modalities of sensory flicker stimuli in auditory areas, hippocampus and medial prefrontal cortex. Comparisons will be drawn between the mean power spectral density measured in dB/Hz at the frequency of flicker being presented, and nearby frequencies (+/- 20Hz).
Time Frame
Up to 6 weeks
Secondary Outcome Measure Information:
Title
Effects of sensory flicker on interictal epileptiform discharges (IEDs)
Description
The effect of the sensory flicker will be evaluated by the comparison of the rate of IEDs between a given sensory flicker stimulation condition (involving specific frequency and modality of stimulation) and baseline (no stimulation) condition.
Time Frame
Up to 6 weeks

10. Eligibility

Sex
All
Minimum Age & Unit of Time
18 Years
Accepts Healthy Volunteers
No
Eligibility Criteria
Inclusion Criteria: Adult (>18 years, regardless of gender, race or ethnicity). To be implanted with intracranial depth or grid/strip electrodes for surgical evaluation. Patient was not shown, during phase I seizure monitoring, to exhibit abnormal EEG activity in response to photic stimulation, and is not clinically suspected to be susceptible to photic-induced seizures. Patient has no pre-existing diagnosis of autism. Patient is not considered at risk for psychogenic nonepileptic seizures (PNES) triggered by sensory stimulation. Fluent in English. Able to understand an informed consent (comprehend potential risks and benefits). Give written and verbal informed consent to all experiments patient would participate in. Exclusion Criteria: Failure to meet any one inclusion criteria.
Overall Study Officials:
First Name & Middle Initial & Last Name & Degree
Robert Gross, MD, PhD
Organizational Affiliation
Emory University
Official's Role
Principal Investigator
Facility Information:
Facility Name
Emory University Hospital
City
Atlanta
State/Province
Georgia
ZIP/Postal Code
30322
Country
United States

12. IPD Sharing Statement

Plan to Share IPD
Yes
IPD Sharing Plan Description
Individual participant and data that underlie the results reported after de-identification (text, tables, figures, and appendices) will be available. The study protocol, statistical analysis plan, analytic code will be made available immediately following publication with no end date.
IPD Sharing Time Frame
Immediately following publication. No end date.
IPD Sharing Access Criteria
Data will be made available to anyone who wishes to access the data for any purpose. Data may be requested by contacting Dr. Annabelle Singer at annabelle.singer@bme.gatech.edu.

Learn more about this trial

Effects of Sensory Flicker and Electrical Flicker Stimulation

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