The use of a color coded probability scale to interpret smell tests in suspected parkinsonism

Abstract

Smell identification tests (SITs) have been suggested as useful in the differential diagnosis of Parkinson's disease (PD). We have applied the 40 item University of Pennsylvania SIT (UPSIT-40) and/or the 16 item SIT from Sniffin Sticks (SS-16) to 193 nondemented PD patients and 157 controls and used logistic regression analysis to associate the SIT result with the probability of an individual patient having PD (''PD probability''). Reliability measures (95% CI) using the clinical diagnosis as a gold standard and a dichotomized result of the smell test into high (50% or more) or low (<50%) ''PD probability'' were: sensitivity 85.0% (78.8-89.7%), specificity 84.6% (77.3-89.9%) for the UPSIT-40; sensitivity 90.4% (83.5-94.7%), specificity 85.5% (76.2-91.7%) for the SS-16.Based on these findings we have created color coded visual tools (PD probability rulers) and applied them to 39 clinically uncertain parkinsonian syndromes (CUPS) patients who had been investigated with dopamine transporter SPECT scanning using [123-I]-FP-CIT SPECT (DaTSCAN) for suspected Parkinson's disease. In 32 of 36 CUPS cases (88.9%, kappa 5 0.72) the probability ruler predicted the result of the DaTS-CAN. We suggest smell tests could be used routinely in challenging cases where there is diagnostic uncertainty and help inform decision making relating to the need for neuro imaging.2009 Movement Disorder Society

Extended extraocular phenotype of PROM1 mutation in kindreds with known autosomal dominant macular dystrophy

“…Olfactory testing was undertaken using the UPSIT 1 (Sensonics Inc, Haddon Heights, NJ, USA), with age-matched control data based upon North American subjects, shown to be applicable to British populations. 20,21 Blood and vascular investigations After a 12-h overnight fast, venous blood was taken from three subjects from kindred A and one from kindred B. After subjects had rested for 415 min, recumbent right brachial artery blood pressure was recorded using an automated sphygmomanometer (Dinamap, Critikon, FL, USA).…”

Preclinical Biomarkers of Parkinson Disease

“…[23][24][25] An association between impaired olfaction and the future development of PD has also been found in populationbased prospective studies. 24 Furthermore, results of odor discrimination measures have been found to be related to disease severity, possibly indicating that at least some aspects of olfactory dysfunction in PD may be secondary to ongoing degenerative processes in PD.…”

High-Accuracy Detection of Early Parkinson's Disease through Multimodal Features and Machine Learning

“…Using SS test: 85.3% accuracy, 81.1% sensitivity and 89% specificity; and using UPSIT: 82.8% accuracy, 82.1% sensitivity and 83.5% specificity. [15] improved the same study by including more subjects, from 193 PD and 157 normal subjects, and using logistic regression, they observed an enhanced classification accuracy with both SS test and UPSIT with highest performance obtained with the SS test as 88.4% accuracy, 90.4% sensitivity and 85.5% specificity. [16] used non-motor features such as cognitive impairment, psychiatric complications, autonomic dysfunction or sleep disturbance, from 410 PD patients, to classify subjects based on disease severity as mild, moderate and severe, and they obtained classification accuracies in the range of 72%−92%.…”

“…In comparison to the related works [11,[14][15][16][17][18][19][20], all of them used features which are either non-motor features or CSF measurements or dopaminergic imaging markers, but none of them involved combination of premotor features with CSF and imaging markers for the detection of PD. In our study, we use combination of these three entities to perform classification and observe an enhanced accuracy in classifying early PD from healthy normal.…”

“…There are studies which use these features to classify subjects as early PD and healthy normal [11,[14][15][16][17][18][19][20][21][22]. [14] performed smell identification tests using culturally adapted translations of the University of Pennsylvania Smell Identification Test (UPSIT) and Sniffin' Sticks (SS) test in 106 PD and 118 normal subjects.…”