The relationship between anosmia, constipation, and orthostasis and Parkinson's disease duration: results of a pilot study

Autonomic symptomatology is prevalent in Parkinson's disease (PD) and impacts quality of life, yet little data exist on the presentation of autonomic dysregulation. This study measures orthostasis, constipation, and anosmia in 58 PD patients and 51 age-matched controls enrolled in the University of Florida's Movement Disorders Center. Patients had their blood pressure measured while seated and in standing position, performed the University of Pennsylvania Smell Identification Test (UPSIT), and completed a constipation survey. Our PD patients had a significantly different average decrease in systolic BP from a seated to standing position compared with their age-matched controls (5.90 mmHg (SD 17.03) vs. 2.6 mmHg (SD 11.28); p = .05). The difference in heart rate from seated to standing positions was not significant. Reflexive tachycardia was inversely proportional to levodopa equivalent daily dose (LEDD) score (p = .002). Anosmia occurred in 96.4% of the PD group and 49% of the controls (p < .001). Constipation was also more prevalent in the PD population than in the controls (67.3% vs. 21.6%; p < .001). Both anosmia and constipation were correlated with disease duration (p = .038 and .04 respectively). Our study suggests that increasing levels of dopaminergic therapy inhibits reflexive tachycardia. Furthermore, our study suggests that anosmia and constipation progress with the primary disease process.