TY - JOUR T1 - Olfactory testing combined with dopamine transporter imaging as a method to detect prodromal Parkinson's disease JF - Journal of Neurology, Neurosurgery & Psychiatry JO - J Neurol Neurosurg Psychiatry SP - 396 LP - 399 DO - 10.1136/jnnp.2009.183715 VL - 81 IS - 4 AU - Mirthe M Ponsen AU - Diederick Stoffers AU - Erik Ch Wolters AU - Jan Booij AU - Henk W Berendse Y1 - 2010/04/01 UR - http://jnnp.bmj.com/content/81/4/396.abstract N2 - Objective Olfactory dysfunction is an early and common symptom in Parkinson disease (PD). Previously, the authors demonstrated that idiopathic olfactory dysfunction in first-degree relatives of PD patients is associated with an increased risk of developing PD within 2 years. The aim of the present study was to determine the value of combined olfactory testing and SPECT scanning in predicting future PD in the same population of relatives over a 5-year period.Methods In a cohort of 361 non-parkinsonian, non-demented first-degree relatives of PD patients, a combination of olfactory processing tasks was used to select groups of hyposmic (n=40) and normosmic (n=38) individuals for a 5-year clinical follow-up evaluation and sequential SPECT scanning, using a dopamine transporter ligand to assess nigrostriatal dopaminergic function at baseline and 5 years from baseline. A validated questionnaire, sensitive to the presence of parkinsonism, was used in the follow-up of the remaining 283 relatives.Results Five years from baseline, five out of the 40 hyposmic relatives fulfilled clinical diagnostic criteria for PD. None of the other 349 relatives available for follow-up developed PD. All hyposmic individuals developing PD had an abnormal baseline SPECT scan.Discussion In conclusion, idiopathic hyposmia in first-degree relatives of PD patients is associated with an increased risk of developing clinical PD of 12.5% over a 5-year period. The present data suggest that a two-step approach using olfactory testing followed by SPECT scanning in hyposmic individuals has a very high sensitivity and specificity in detecting PD. The usefulness of this two-step approach needs to be confirmed in larger populations. ER -