Quantitative Evaluation of Olfactory Function in Spinocerebellar Ataxia Type3 and Type1 in China: A Clinical Study

Objectives: This study investigates olfactory function and clinical characteristics in spinocerebellar ataxia (SCA) patients, exploring the link between motor and nonmotor symptoms. Methods: In a study conducted at the Neurology Institute Affiliated Hospital of Anhui University of Chinese Medicine, 30 spinocerebellar ataxia (SCA) patients diagnosed from August 2020 to August 2023 were matched with 30 controls. Olfactory functions were evaluated using the Institute of Psychology's olfactory test. The SCA group's ataxia severity was assessed with the International Cooperative Ataxia Rating Scale (ICARS). Variations in Hamilton Anxiety Scale (HAMA), Hamilton Depression Scale (HAMD), Pittsburgh Sleep Quality Index (PSQI) scores were compared between groups, and correlations between olfactory function and SCA symptoms were examined. Results: In the SCA group, olfactory scores were significantly lower compared to controls ( P < 0.001). SCA patients had higher HAMA ( P = 0.005), HAMD ( P = 0.02), and PSQI ( P < 0.001) scores. However, Olfactory identification correlated negatively with age (r = −0.377, P = 0.041) in SCA patients. No significant correlations were found between olfactory function and disease duration, ICARS, HAMA, HAMD, or PSQI scores in the SCA group. Conclusion: The olfactory dysfunction is prevalent in SCA patients, But there was no significant correlation between motor symptoms and non-motor symptoms.