Lack of a relationship between the pupillary light reflex response and state/trait anxiety in remitted patients with...

Recently, some studies have indicated that pupillary function only correlates with state/trait anxiety in healthy subjects. In the present study, we examined whether or not there were relationships between the PLR functions and state/trait anxiety in remitted (the absence of panic attack (PA) symptoms for at least 6 months) PD patients compared to normal control (NC) subjects.

Before and after audiovisual stimulation (AS) that induced mental stress through exposure to video images of high stress experiences, such as driving motor vehicles, the pupillary light reflex (PLR) was measured with an infrared pupillometer in 30 remitted PD patients and 30 age- and gender-matched NC subjects. In order to examine the relationships between the 8 PLR parameters (initial pupillary diameter in darkness, pupillary diameter at maximum constriction, constriction ratio, latency of the reflex, time to reach maximum constriction and time constant of redilation) and state/trait anxiety, we used the State-Trait Anxiety Inventory (STAI) and stepwise multiple regression analysis.

There was no significant group difference in the STAI-T score and STAI-S scores before and after AS. We confirmed the significant relationships between pupillary function and state/trait anxiety in NC subjects, but not in PD patients.

These findings suggest that in contrast to NCs, even remitted PD patients may have dysfunctional PLR regulation with mental loading, such as AS. Moreover, it is possible that the abnormalities of ANS exist extensively in PD, since almost all panic symptoms, including PA, are involved in cardiovascular symptoms, but not pupillary ones.