Photic Blink Reflex in People With Blepharospasm and Increased Blinking

Stopped early

Conditions studied: Blepharospasm

In brief

Background: Some people who have increased blinking may later develop blepharospasm. Blepharospasm is a neurological disorder that causes involuntary closing of the eyes. Researchers want to learn more about how eyes close in response to different stimuli. They want to study this in healthy people, people with increased blinking, and people with blepharospasm. Objective: To learn how light exposure affects people with blepharospasm. Eligibility: People ages 18 and older with blepharospasm or increased blinking, and healthy volunteers Design: Participants will be screened with: Medical history Physical exam Neurological exam Participants will have up to 5 visits. The number of visits will depend on the number of tests they opt to have. They can opt to have up to 4 tests. Visits last 60-90 minutes. They cannot drink alcohol or caffeinated drinks for at least 12 hours before visits. Visits could include the following tests: Evaluation of eyelid movements. This will be video recorded. Electromyography: Small sticky electrodes are placed on the lower eyelid skin. These are attached to wires. Muscle activity is recorded during blink reflex procedures. Electrical stimulation: An electrode is placed close to the eyebrow. It will deliver small electrical shocks. The strength of the shocks will be enough to provoke a blink. Photic stimulation: A lamp is placed in front of the face. It will deliver single or paired flashes. The flashes will be at various intervals and intensities. Participants will wear a patch over one eye during this test. Combination of electrical and photic stimulation ...

Key facts

Study ID

NCT03263000

Run by

National Institute of Neurological Disorders and Stroke (NINDS)

People needed

17

Starts

2017-10-30

Expected to finish

2019-04-24

Last updated by the study team

2019-04-26

Who can join

Age: 18 and older. Sex: any. Healthy volunteers: accepted.

You may not qualify if…

• Any of the following will exclude PATIENTS from the study:
• Secondary causes of excessive involuntary eyelid closure such as ophthalmologist disorders involving the ocular surface, tear film, or eyelids.
• Any evidence suggesting a psychogenic movement disorder such as persisting unilateral or asymmetric symptoms, paroxysmal symptoms, and other inconsistencies such as pain, associated somatizations, blinking diminished by distraction, unusual sensory tricks, or unexpected response.
• Botulinum toxin treatment < 3 months prior to a testing visit.
• History of chronic exposure (>3 month) to dopamine receptor blocking agents before the onset of increased blinking alone or BPS.
• Any of the following will exclude BOTH patients and healthy controls from the study:
• Has any major medical problem other than increased blinking or dystonia in patient groups (such as decompensated chronic diseases or conditions that cause serious disability such as congestive heart failure/NYHA score greater than or equal to 2, severe COPD, advanced neoplasia, severe arthritis, HIV/AIDS, blindness).
• Employees, staff or fellows of HMCS in NINDS.
• Has used illegal drugs within the past 6 months based on history. The intent is to exclude those with drug use that may affect study results.
• Self-reported consumption of more than 7 alcoholic drinks a week in the case of a woman and 14 alcoholic drinks a week in the case of a man.
• Abnormal findings on neurologic exam (other than increased blinking or dystonia in patient groups).
• Presence of anatomical or functional eyelid abnormalities other than involuntary eyelid closure or OOs spasms (including apraxia of eyelid opening, and other disorders such as tics or tardive syndromes).
• Has a neurologic disorder other than increased blinking or dystonia.
• Has major depression or any major mental disorders (axis I disorders).
• Has had a head injury where there was a loss of consciousness for more than a few seconds.
• Has a deep brain stimulator, pacemaker or other implantable electronic device subject to malfunction by electrical stimulation.

Where it is running

• National Institutes of Health Clinical Center — Bethesda, Maryland, United States

Full record on ClinicalTrials.gov

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