The posterior commissure is a rounded band of axons crossing the cerebral aqueduct.
The posterior commissure is responsible for controlling the pupillary response to light.
It is usually observed through MRI. Disease results in abnormal pupillary response. It is also been found to have abnormalities in Parkinson’s disease and Niemann-Pick disease.
Treatments for the alleviation of symptoms and discomfort are in general medical and surgical depending on th disease.