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The trigemino-pupillary response in cluster headache
G Micieli1, C Tassorelli, L Ruiz
1Department of Neurology, C Mondino Foundation, University of Pavia, Italy.
Cephalalgia : an International Journal of Headache
|October 1, 1993
Summary
Cluster headache (CH) involves impaired neural control of pain and vegetative functions. This study found reduced pupillary responses to pain in CH patients, suggesting a bilateral, sympathetic nervous system issue.
Area of Science:
- Neuroscience
- Ophthalmology
- Pain Medicine
Background:
- Cluster headache (CH) is characterized by central nervous system dysfunction affecting pain perception and autonomic functions.
- Previous research established a method to measure the human pupillary response to corneal stimulation.
Purpose of the Study:
- To evaluate the trigeminal reflex and pupillary response in individuals with episodic cluster headache.
- To investigate potential alterations in autonomic nervous system function related to pain processing in CH.
Main Methods:
- Assessed the trigeminal reflex and pupillary response in 26 episodic cluster headache subjects.
- Utilized quantified corneal stimulation with neurophysiological and pharmacological techniques.
- Evaluated responses during both active and remission phases of the disease.
Main Results:
- Reduced mydriasis (pupil dilation) was observed on the pain side at corneal reflex threshold intensity.
- Bilateral reduction in mydriasis occurred at pain threshold intensity.
- No significant differences were found in the miotic (pupil constriction) phase amplitude.
Conclusions:
- Disordered pupillary activation in response to pain, likely sympathetic in origin, is present in cluster headache.
- These pupillary abnormalities are bilateral and detectable even during remission.
- The findings suggest a central neural system impairment beyond simple pain-peptide release.