Effects of Sensory Flicker and Electrical Flicker Stimulation

Emory University

Status: Completed

Conditions: Brain Diseases

Treatments: Device: Customized version of DAVID device; Device: Blackrock CereStim

Study type: Interventional

Funder types: Other

Identifiers

NCT04188834

IRB00107577

Details and patient eligibility

About

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.

Full 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.

Enrollment: 23 patients

Sex: All

Ages: 18+ years old

Volunteers: No 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.

Trial design

Primary purpose: Basic Science

Allocation: Non-Randomized

Interventional model: Crossover Assignment

Masking: None (Open label)

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23 participants in 2 patient groups

Sensory Flicker Stimulation

Experimental group

Description:

Participants will be exposed for about 10 to 60 minutes at a time, to a sequence of sensory flicker trials each lasting a few seconds to 5 minutes, while their eyes are open or closed. Each trial may include the following modalities and frequencies of flicker: * Modalities: auditory only, visual only, or audiovisual combined. * Frequencies: random, or anywhere from 3Hz to 200Hz. Additionally, subjects may be exposed to individual pulses of light and/or sound, i.e. around or less than 1 pulse /second, for up to 20 minutes at a time.

Treatment:

Device: Customized version of DAVID device

Electrical Flicker Stimulation

Active Comparator group

Description:

Participants will be exposed to direct electrical brain stimulation with low-amplitude current, at given flicker frequencies. Participants 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 memory tasks. Stimulation in the absence of any memory task will be applied to assess the subject's neurophysiological response to stimulation and to identify the optimal stimulation parameters for use during memory tasks. Stimulation during behavioral tasks will be applied in an attempt to affect the subject's memory.

Treatment:

Device: Blackrock CereStim