An observational study in Blepharospasm, sponsored by National Institute of Neurological Disorders and Stroke (NINDS). Terminated at 1 site in United States. Open to participants aged 18 Years and older, including healthy volunteers. Per ClinicalTrials.gov, last updated 2019-04-26.
Sponsored by National Institute of Neurological Disorders and Stroke (NINDS) · Observational
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
...
Objective:
Study population:
We plan to recruit 24 patients with blepharospasm, 24 healthy volunteers (HVs) and 24 patients with increased blinking alone.
Design:
In two different studies, we will compare all the results from the EBR rc, PBR rc and MBR rc between BPS patients (first study) or increased blinking patients (second study) and HVs. We will also look for possible correlation between the neurophysiologic data and the clinical scales acquired during a clinical assessment. In the EBR rc procedure, the supraorbital nerve will be stimulated with paired electrical stimuli at varying ISIs and the EMG response from the orbicularis oculi muscles will be recorded. In the PBR rc procedure, paired light stimuli will be given at varying interstimulus intervals (ISIs) and the EMG responses from the orbicularis oculi will be recorded. In the MBR rc study a weak light stimulation will be given at varying ISIs before an electrical stimulation of the supraorbital nerve. Each experimental procedure will last about 1 hour. There will be one screening visit and up to 4 testing visits per participant. However, participant can either undergo all the experimental procedures or participate in only some of them and will be allowed to participate in two experimental procedures per testing visit.
Outcome measurements:
These results will be compared between the two patient groups and HVs. We will look for possible correlations between neurophysiological and clinical data.
We plan to recruit 24 patients with blepharospasm, 24 healthy volunteers (HVs) and 24 patients with increased blinking alone.
For patients only: fulfill the criteria of
EXCLUSION CRITERIA:
Any of the following will exclude PATIENTS from the study:
Any of the following will exclude BOTH patients and healthy controls from the study:
24 healthy volunteers (HVs)
24 patients with blepharospasm
24 patients with increased blinking alone.
Photic blink reflex recovery cycle
Time frame: Single determination
Electrocutaneous blink reflex recovery cycle; Blink rate; Light Questionnaire Scale
Time frame: Single determination
This study is terminated, as verified in Apr 2019. You cannot join it, but the record below documents what was studied.
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National Institute of Neurological Disorders and Stroke (NINDS)