[Olfactory testing with "sniffin' sticks" for clinical diagnosis of Parkinson disease]. / Riechprüfung mit "sniffin' sticks" zur klinischen Diagnostik des Morbus Parkinson.

Olfactory dysfunction seems to be one of the most frequent symptoms in idiopathic parkinsonian syndrome (IPS). In contrast to the increasing number of studies providing evidence of the usefulness of olfactory tests in the diagnosis of IPS, clinical assessment of olfactory function is rarely performed. This may be due to the lack of an easy-to-use, inexpensive, standardized, and reliable test. In this study, we administered the newly developed "sniffin' sticks" test to a group of 40 nondemented IPS patients and compared the results with 40 healthy controls matched for age, gender, and smoking habits. In all three subtests including odor identification, odor detection threshold, and odor discrimination, the control group scored significantly better than the IPS group, yielding a specificity and sensitivity of 90% each. Our results indicate that olfactory disturbances in IPS can be found at early stages of the disease, appear bilaterally, and do not correlate with the dominant side of parkinsonism. Therefore, we emphasize that olfactory testing may be a useful tool in the diagnosis of IPS.

Visually guided exploration in Huntington disease.

We compared 24 patients in various stages of Huntington disease (HD) with 26 control patients free from cerebral disorders using a simple visual saccadic tracking test. The two groups were well matched in regard to age, sex, verbal IQ and years of schooling. Test results differed widely. On a time versus error plot, sensitivity (96%) and specificity (100%) were high and the results did not depend on age, education, or disease duration, although an influence of disease stage could be observed. This study shows that a simple saccadic tracking task may be useful in detecting visuomotor disturbances in HD.