P300 latency prolongation and executive dysfunction in systemic sclerosis: A multimodal cognitive assessment

Objectives: The objective of the study is to evaluate cognitive functions in patients with systemic sclerosis (SSc) using auditory event-related potentials (P300) and the Stroop colour-word test, and to determine their correlation with disease status. Materials and Methods: This cross-sectional observational study included 30 clinically diagnosed SSc patients (mean age 36.93 ± 6.27 years, 96.7% females) and 30 age- and sex-matched healthy controls. P300 auditory event-related potentials were recorded at Fz, Cz and Pz electrode sites using an oddball paradigm. Cognitive performance was assessed using the computerised Stroop colour-word test, measuring reaction times in congruent and incongruent conditions. Correlation analysis assessed relationships between cognitive parameters and disease duration. Results: SSc patients demonstrated significantly prolonged P300 latencies compared to controls at all electrode sites: Fz (345.47 ± 27.31 ms vs. 326.97 ± 27.61 ms, p = 0.012), Cz (344.00 ± 25.59 ms vs. 324.77 ± 24.53 ms, p = 0.004) and Pz (349.87 ± 25.63 ms vs. 328.63 ± 28.21 ms, p = 0.003). Stroop test revealed significantly longer reaction times in patients for both congruent (1186.33 ± 184.53 ms vs. 1073.37 ± 154.49 ms, p = 0.001) and incongruent conditions (1466.97 ± 255.25 ms vs. 1308.70 ± 163.96 ms, p = 0.002). Correlation analysis revealed significant associations between prolonged P300 latencies at Cz and Pz sites with slower congruent Stroop performance in patients. Conclusion: Patients with SSc exhibit measurable cognitive dysfunction characterised by delayed neurophysiological processing and impaired executive functions, even in the absence of overt neurological symptoms. P300 latency prolongation and slowed Stroop performance suggest subclinical central nervous system involvement. These findings underscore the importance of routine cognitive screening in SSc management.