Taste preferences in Parkinson's disease patients

Parkinson's disease (PD) can affect both sensory and motor function.Sensory dysfunction has been reported in the visual, olfactoryand somatosensory systems. Although several experimental animalstudies report a change in sucrose preference following treatmentwith dopamine antagonists, there have been no reports of gustatorydysfunction in PD patients. The present study was undertakento determine if PD patients (n = 25) varied in their preferenceratings for sweet stimuli compared to an age- and sex-matchedcontrol group (n = 16). Subjects rated their degree of liking(preference) for seven concentrations of sucrose and NaCl usinga 6-point fixed category scale. An ANOVA indicated that PD patientsdid not differ significantly from the control group in theirpreferences for NaCl. The preference concentration functionfor sucrose, however varied between the PD and control groups.The preference curve for the normal group was an inverted U-shapedcurve which peaked at 0.3 M sucrose. In contrast, the preferencecurve for the PD patients was a monotonically increasing functionof concentration. An ANOVA for the sucrose ratings revealedno main effect for disease state, but there was a significantdisease state X concentration effect (P < 0.001). Futuretesting is necessary to determine if this change in preferenceis accompanied by changes in the magnitude ratings for sucrose.