A Research Study to Examine Cutaneous Allodynia and Cluster Headache

Study Overview
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Brief Summary
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This is a research study examining cutaneous allodynia and cluster headaches. Cutaneous allodynia means the feeling of pain or unpleasant sensation when normally non-painful stimuli (e.g. light touch) are applied to the skin. Many studies have been performed looking at the presence of cutaneous allodynia in patients with migraines; however, few studies have examined it in cluster headache patients. There is still much to be learned about the brain and how it functions if the investigators are to understand the underlying causes of cluster headache. It is important to explore cutaneous allodynia in cluster headache as it may help guide physicians with the care of these individuals. Sixty patients will be screened for this study. Thomas Jefferson University is the only center enrolling patients in this research study.

Conditions
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Cluster Headache

Intervention / Treatment
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* Other: There are no interventions in the observational study. The symptom of allodynia was measured.


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Male and female patients aged 18-75, inclusive Diagnosis of cluster headache, episodic or chronic. Patients with episodic CH can be either in active cluster period or not. Ability to read and understand an informed consent form, where the study protocol is described. Exclusion Criteria: Patients with abnormal sensory findings on examination, or any known neurological disease that may affect skin sensation (peripheral neuropathy, multiple sclerosis, stroke, etc). Patients who are cognitively impaired, as determined by investigator Patients with significant psychiatric disorder that may affect their understanding of the study protocol and/or their cooperation with the investigators. Patients who had taken an acute pain medication within 24 hours prior to allodynia testing. Patients with skin diseases that may cause abnormal skin sensation. Patients who had been treated with a nerve block in the 4 week period prior to allodynia testing Patients who had been treated with Botulinum neurotoxin within the 4 month period prior to allodynia testing

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 75 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Subjects with cluster headache<br>Subjects with both episodic and chronic cluster (as defined by the International Headache Society-IHS) were enrolled. | Other: There are no interventions in the observational study. The symptom of allodynia was measured.<br>* No intervention. Description of allodynia testing appears elsewhere in this document<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Prevalence of Allodynia in Subjects With Cluster Headache | Allodynia (discomfort to normal sensation) was assessed by brushing at constant rate of 2 brushes/sec and pressure allodynia with Von Frei hairs. Outcome (discomfort) was measured on a 100 mm visual analogue scale. | Allodynia was assessed at the screening visit |