INS NYC 2024 Program

Poster	Poster Session 09 Program Schedule 02/16/2024 03:30 pm - 04:45 pm Room: Shubert Complex (Posters 1-60) Poster Session 09: Epilepsy \| Oncology \| MS \| Infectious Disease Final Abstract #14 Pupillometry as an Indicator of Fatigue in Multiple Sclerosis Caroline Armknecht, Kessler Foundation, East Hanover, United States Diana Maloku, Kessler Foundation, East Hanover, United States Tien Tong, Kessler Foundation, East Hanover, United States Lauren Hendrix, Kessler Founation, East Hanover, United States Nick Pek, Kessler Foundation, East Hanover, United States Silvana Costa, Kessler Foundation, East Hanover, United States Category: Multiple Sclerosis/ALS/Demyelinating Disorders Keyword 1: fatigue Keyword 2: multiple sclerosis Objective: Fatigue is prevalent among individuals with multiple sclerosis (MS), affecting as many as 80% of diagnosed individuals. Currently, fatigue is most frequently measured via self-reports which are subjective and can vary across individuals. Pupillometry, the measure of pupil size, presents an alternative objective measure of fatigue. This study aimed to explore the association between pupillometry and self-reported fatigue in individuals with MS. Participants and Methods: Participants were 72 individuals with MS (confirmed by medical records) and 37 healthy controls (HC). Pupillometric data was collected via an EyeLink 1000 Duo tracker during a pro-saccade task with three different conditions of increasing difficulty: Gap, Step, and Overlap. Pro-saccadic tasks are frequently used in pupillometric studies due to their ability to produce mental fatigue. The task involves participants fixating on a central dot, then directing their gaze toward a target dot appearing to the periphery. Within a pro-saccade trial, in all conditions, participants first saw a central fixation for 500ms (baseline). In the Gap condition, after the 500ms baseline, there was a 200ms blank screen followed by the target. In the Step condition, the target immediately followed the 500ms baseline. Lastly, in the Overlap condition, after the baseline, there was a 200ms screen in which both the target and the central fixation were simultaneously presented, which was followed by the target. Pupillometric data were calculated from 2 interest periods: 1) average pupil size during the 500ms baseline, and 2) change in pupil size during pro-saccadic movements relative to baseline. A sub-sample of the participants also had self-reported fatigue data in the past month measured using the Modified Fatigue Impact Score (MFIS). Results: The Condition (Gap, Step, and Overlap) x Group (MS, HC) ANOVA was run for both pupillometric variables (baseline pupil and pupil change from baseline to pro-saccade). There was no significant main effects or interaction for baseline pupil size. Interestingly, we found a significant effect of Condition such that compared to Gap and Step, the Overlap condition, which is the most fatiguing condition, showed the smallest pupil size (i.e., the largest decrease during saccade relative to baseline; p’s<.05). The Condition x Group interaction was also significant (p=.03) such that pupil size during the Gap condition was significantly smaller in MS compared to HC. Furthermore, there seemed to be a trend showing smaller pupil size in MS across conditions (p=.09). Most importantly, in a sub-sample of both MS and HC, smaller pupil size in the Gap condition was significantly associated with increased fatigue (MFIS total, r(73)=-0.29, p=.01). Conclusions: Our results showed that that smaller pupil size (smaller size during pro-saccade relative to baseline) is indicative of more impairment. Particularly, MS showed smaller pupil size compared to HC. The most difficult pro-saccade condition, and presumably the most fatiguing, showed the smallest pupil size. Importantly, smaller pupil size was significantly associated increased self-reported past month fatigue. Our findings are consistent with past research and showed that pupillometry is a promising measure of objective fatigue.

Poster

02/16/2024
03:30 pm - 04:45 pm
Room: Shubert Complex (Posters 1-60)

Poster Session 09: Epilepsy | Oncology | MS | Infectious Disease

Final Abstract #14

Pupillometry as an Indicator of Fatigue in Multiple Sclerosis

Caroline Armknecht, Kessler Foundation, East Hanover, United States
Diana Maloku, Kessler Foundation, East Hanover, United States
Tien Tong, Kessler Foundation, East Hanover, United States
Lauren Hendrix, Kessler Founation, East Hanover, United States
Nick Pek, Kessler Foundation, East Hanover, United States
Silvana Costa, Kessler Foundation, East Hanover, United States

Category: Multiple Sclerosis/ALS/Demyelinating Disorders

Keyword 1: fatigue
Keyword 2: multiple sclerosis

Objective:

Fatigue is prevalent among individuals with multiple sclerosis (MS), affecting as many as 80% of diagnosed individuals. Currently, fatigue is most frequently measured via self-reports which are subjective and can vary across individuals. Pupillometry, the measure of pupil size, presents an alternative objective measure of fatigue. This study aimed to explore the association between pupillometry and self-reported fatigue in individuals with MS.

Participants and Methods:

Participants were 72 individuals with MS (confirmed by medical records) and 37 healthy controls (HC). Pupillometric data was collected via an EyeLink 1000 Duo tracker during a pro-saccade task with three different conditions of increasing difficulty: Gap, Step, and Overlap. Pro-saccadic tasks are frequently used in pupillometric studies due to their ability to produce mental fatigue. The task involves participants fixating on a central dot, then directing their gaze toward a target dot appearing to the periphery. Within a pro-saccade trial, in all conditions, participants first saw a central fixation for 500ms (baseline). In the Gap condition, after the 500ms baseline, there was a 200ms blank screen followed by the target. In the Step condition, the target immediately followed the 500ms baseline. Lastly, in the Overlap condition, after the baseline, there was a 200ms screen in which both the target and the central fixation were simultaneously presented, which was followed by the target. Pupillometric data were calculated from 2 interest periods: 1) average pupil size during the 500ms baseline, and 2) change in pupil size during pro-saccadic movements relative to baseline. A sub-sample of the participants also had self-reported fatigue data in the past month measured using the Modified Fatigue Impact Score (MFIS).

Results:

The Condition (Gap, Step, and Overlap) x Group (MS, HC) ANOVA was run for both pupillometric variables (baseline pupil and pupil change from baseline to pro-saccade). There was no significant main effects or interaction for baseline pupil size. Interestingly, we found a significant effect of Condition such that compared to Gap and Step, the Overlap condition, which is the most fatiguing condition, showed the smallest pupil size (i.e., the largest decrease during saccade relative to baseline; p’s<.05). The Condition x Group interaction was also significant (p=.03) such that pupil size during the Gap condition was significantly smaller in MS compared to HC. Furthermore, there seemed to be a trend showing smaller pupil size in MS across conditions (p=.09). Most importantly, in a sub-sample of both MS and HC, smaller pupil size in the Gap condition was significantly associated with increased fatigue (MFIS total, r(73)=-0.29, p=.01).

Conclusions:

Our results showed that that smaller pupil size (smaller size during pro-saccade relative to baseline) is indicative of more impairment. Particularly, MS showed smaller pupil size compared to HC. The most difficult pro-saccade condition, and presumably the most fatiguing, showed the smallest pupil size. Importantly, smaller pupil size was significantly associated increased self-reported past month fatigue. Our findings are consistent with past research and showed that pupillometry is a promising measure of objective fatigue.