PREVALENCE OF ORTHOSTATIC HYPOTENSION IN PARKINSONS-DISEASE

Objectives-To investigate the prevalence of orthostatic hypotension an d the nature of the postural events related to a fall in blood pressur e in patients with Parkinson's disease. Methods-Blood pressure was mea sured first in a supine position after a rest of at least 15 minutes a nd every minute during 10 minutes of an active standing up procedure. Orthostatic hypotension was considered as present when a fall of at le ast 20 mm Hg of systolic blood pressure was recorded. Postural events which occurred during the standing test were identified from a questio nnaire and self reporting. Statistical analysis was performed to deter mine the relation between orthostatic hypotension and disease characte ristics (duration, severity) and the use of antiparkinsonian drugs. Ni nety one consecutive patients with Parkinson's disease (48 women, 43 m en, mean age 66 (SD 9) years) participated to the study. Results-A fal l of at least 20 mm Hg of systolic blood pressure was found in 58.2% o f the patients. Orthostatic hypotension was asymptomatic in 38.5% and associated with postural events in 19.8% of the patients. Symptomatic (but not asymptomatic) orthostatic hypotension was related to duration and severity of the disease and with the use of higher daily levodopa and bromocriptine doses. The analysis of the relation between the pos tural symptoms (and the need for standing test abortion) with the fail in systolic blood pressure allowed the identification of six clinical criteria specific of orthostatic hypotension. A direct relation betwe en the postural changes in systolic blood pressure and the number of c linical events in this clinical scale was found. Conclusion-The freque ncy of orthostatic hypotension in Parkinson's disease is high and it i s possible to establish a clinical rating scale which could be used to assess the effects of drugs employed in the management of orthostatic hypotension.