Olfactory Function in SCA10

Although the main clinical manifestations of spinocerebellar ataxias (SCAs) result from damage of the cerebellum, other systems may also be involved. Olfactory deficits have been reported in other types of ataxias, especially in SCA3; however, there are no studies on olfactory deficits in SCA type 10 (SCA10). To analyze olfactory function of SCA10 patients compared with that of SCA3, Parkinson's, and healthy controls. Olfactory identification was tested in three groups of 30 patients (SCA10, SCA3, and Parkinson's disease (PD)) and 44 healthy controls using the Sniffin' Sticks (SS16) test. Mean SS16 score was 11.9 ± 2.9 for the SCA10 group, 12.3 ± 1.9 for the SCA3 group, 6.6 ± 2.8 for the PD group, and 12.1 ± 2.0 for the control group. Mean SS16 score for the SCA10 group was not significantly different from the scores for the SCA3 and control groups but was significantly higher than the score for the PD group (p < 0.001) when adjusted for age, gender, and history of smoking. There was no association between SS16 scores and disease duration in the SCA10 or SCA3 groups or number of repeat expansions. SS16 and Mini Mental State Examination scores were correlated in the three groups: SCA10 group (r = 0.59, p = 0.001), SCA3 group (r = 0.50, p = 0.005), and control group (r = 0.40, p = 0.007). We found no significant olfactory deficits in SCA10 in this large series.