Dynamic pupillometry as an autonomic testing tool
- PDF / 365,863 Bytes
- 7 Pages / 595.276 x 790.866 pts Page_size
- 96 Downloads / 269 Views
RESEARCH ARTICLE
Dynamic pupillometry as an autonomic testing tool Srikanth Muppidi • Beverley Adams-Huet • Emil Tajzoy Maggie Scribner • Paul Blazek • Elaine B. Spaeth • Elliott Frohman • Scott Davis • Steven Vernino
•
Received: 13 December 2012 / Accepted: 9 July 2013 Ó Springer-Verlag Berlin Heidelberg 2013
Abstract Objective To determine normal values for pupillometry indices in healthy control subjects and to examine these indices in patients with autonomic dysfunction and healthy controls. Methods Infrared video pupillometry was used to investigate the pupil response to a brief light flash in 79 healthy controls, 28 patients with normal autonomic function (composite autonomic severity score, CASS \ 2), and 26 patients with moderate to severe autonomic failure (CASS [ 4) seen in our autonomic laboratory from January 2008 to June 2011. In six subjects, we examined the effects of varying light stimulus intensity and light stimulus duration. Descriptive analysis, correlation, and ANCOVA adjusted for age were performed. Results We determined eight indices corresponding to parasympathetic and sympathetic pupil function. Baseline pupil diameter (BPD), maximum constriction velocity (MCV), absolute constriction amplitude (ACA), and maximum dilation velocity (MDV) negatively correlated with age (p \ 0.01) among controls. MCV and ACA increased with increasing intensity of light stimulus from 3.5 to 112 lW. Indices of parasympathetic pupil innervation S. Muppidi (&) E. Tajzoy M. Scribner P. Blazek E. B. Spaeth E. Frohman S. Vernino Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, 5323 Harry Hives Blvd, Dallas, TX 75390-9129, USA e-mail: [email protected] B. Adams-Huet Department of Clinical Sciences, University of Texas Southwestern, Dallas, TX, USA S. Davis Southern Methodist University, Dallas, TX, USA
(MCV and ACA) were lower in the high CASS group compared to others (p \ 0.0001). Indices of sympathetic pupil function, time to reach 75 % of initial resting diameter during pupillary dilation (T), and dilation velocity at T (DV) did not differ significantly in the three study groups. However, T corrected for the magnitude of pupillary constriction (T:ACA) was higher in the high CASS group suggesting sympathetic dysfunction in that group (p = 0.0003). Conclusions Indices of pupillomotor function significantly differ between patients with moderate to severe autonomic failure and healthy controls. Keywords
Autonomic dysfunction Pupillary reflex
Introduction Disorders of autonomic function are common and can affect multiple organ systems including the eye. While impaired pupil function does not lead to the same degree of disability as autonomic impairments in cardiovascular control, gastrointestinal motility or thermoregulation, the examination of pupillomotor function may improve diagnostic accuracy in the autonomic laboratory. It is likely that disorders affecting brainstem autonomic centers or peripheral autonomic ganglia will be a
Data Loading...
