How to Assess the Autonomic Nervous System By George Newman, MD, PhD, Albert Einstein Medical Center Reviewed / Revised May 2020 | Modified Sep 2022 View Patient Education Assessment of the autonomic nervous system involves checking for the following: Postural hypotension Heart rate changes in response to the Valsalva maneuver Decreased or absent sweating Evidence of Horner syndrome (unilateral ptosis, pupillary constriction, facial anhidrosis) Disturbances of bowel, bladder, sexual, and hypothalamic function should be noted.