Automated quantitative analysis of saccadic characteristics in patients with spontaneous and head-shaking nystagmus

Objective: To explore the saccadic wave parameters of patients with spontaneous nystagmus (SN) and head-shaking nystagmus (HSN) by developing a new quantitative assessment software, so as to reveal the saccadic characteristics and variations in patients with vestibular dysfunction across different compensatory states. Methods: A retrospective analysis was conducted on clinical data of patients from the Dizziness Treatment Center of the First Medical Center of the Chinese PLA General Hospital between September 2023 and June 2024. The“Saccades All in One (v1.0)”software, developed in-house, was used to process the raw data from the video head impulse test (vHIT). Detailed analyses of saccadic wave parameters were performed for patients in the SN, HSN, and non-nystagmus (None) groups. Results: In the SN and HSN groups, the affected side showed significantly higher counts, amplitudes, and gains in the first and second saccadic waves compared to the unaffected side. With the progression of compensation, the number and amplitude of saccades on the affected side gradually decreased, and their latencies were earlier, whereas changes on the unaffected side were not pronounced. Statistical analyses further confirmed significant differences in saccadic parameters among the three groups, especially in terms of saccades count and amplitude. Conclusion: The quantitative tool developed in this study effectively evaluates and distinguishes the characteristics of saccades in compensated and uncompensated states, thereby facilitating the diagnosis and treatment of patients with vestibular dysfunction.