Related Experiment Video
Updated: Jul 11, 2026

Pupillometry to Assess Auditory Sensation in Guinea Pigs
Published on: January 6, 2023
Pupil diameter in darkness differentiates progressive supranuclear palsy (PSP) from other extrapyramidal syndromes
Claudia Schmidt1, Birgit Herting, Silke Prieur
1Autonomic and Neuroendocrinological Laboratory, University Clinic Carl Gustav Carus, Dresden University of Technology, Germany.
Abstract:
The most important features that characterize and differentiate progressive supranuclear palsy from other Parkinsonian syndromes are postural instability, supranuclear gaze palsy, pseudobulbar palsy, parkinsonism, and cognitive disturbances. In this article, we demonstrate that progressive supranuclear palsy patients exhibit pathologically decreased pupil diameters after dark adaptation recorded by TV pupillography. A cut off value of 3.99 mm was defined to differentiate progressive supranuclear palsy patients from patients with other extrapyramidal disorders like Parkinson's disease and multiple system atrophy with a specificity of 86.4% and a sensitivity of 70.8%. Other pupil abnormalities could not be described in patients with extrapyramidal syndromes.
Related Concept Videos
Parkinson Disease ll: Pathophysiology
Parkinson's Disease: Overview
Parkinson Disease l: Introduction
Postsynaptic Potential (PSP)
There are two types of receptors: ionotropic and metabotropic.
The ionotropic receptor is the membrane protein that has an...
Neural Regulation
Photoreceptors and Visual Pathways

