Abstract Details

Title Diminished autonomic nervous system responses to acoustic startle in progressive supranuclear palsy

Topic Aging, Dementia, and Behavioral Neurology

Presentation(s) S8 - Behavioral and Cognitive Neurology (3:54 PM-4:06 PM)

Poster/Presentation
Number 003

Objective To examine possible autonomic changes associated with progressive supranuclear palsy in response to a strong, unanticipated stimulus.

Background Progressive supranuclear palsy (PSP) is a neurodegenerative disorder that causes serious problems in eye movements, walking, and balance, and is also often associated with cognitive, emotional, and behavioral changes. In other movement disorders such as Parkinson’s disease, similar symptoms have often been associated with changes in autonomic nervous system (ANS) functioning. Despite this, previous studies have rarely examined ANS functioning in PSP. .In the present study, we determined whether ANS responses to an emotionally provocative stimulus were altered in PSP. We tested the hypothesis that ANS responses to an unanticipated aversive auditory stimulus (i.e., a brief, loud burst of white noise) designed to induce a startle response would differ between patients with PSP compared to healthy controls (HC).

Design/Methods Participants included 33 PSP patients and 38 HC. Participants sat still for a 60 second baseline and heard a brief (100-ms) loud (115-dB) burst of white noise without warning. Continuous measures of cardiac interbeat intervals (IBI; decreases in IBI correspond to increases in heart rate) and skin conductance levels (SCL) were obtained throughout the task.

Results Compared to HC, PSP patients showed significantly less decrease in IBI (i.e., less increase in heart rate) and less increase in SCL from baseline during the 10 seconds after stimulus onset.

Conclusions Less decrease in IBI and less increase in SCL in the face of a strong external stimulus suggests a diminished sympathetic nervous system response. In light of previous research suggesting that peripheral sympathetic responses are relatively preserved in the setting of orthostatic postural testing in PSP, we suspect this relates to a brainstem degeneration in a pontine circuit that is critical for startle reflexes during emotional challenges.

Authors/Disclosures
Peter S. Pressman, MD (Univeristy of Colorado School of Medicine) PRESENTER	The institution of Dr. Pressman has received research support from the Doris Duke Fund to Retain Clinical Scientists . Dr. Pressman has received personal compensation in the range of $100,000-$499,999 for serving as a Associate Professor with University of Colorado School of Medicine.
Kuan-Hua Chen (University of Nebraska Medical Center)	No disclosure on file
	No disclosure on file
Katherine P. Rankin, PhD (University of California San Francisco)	The institution of Dr. Rankin has received research support from Marcus Foundation.
	No disclosure on file

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