High norepinephrinergic orthostatic hypotension in early Parkinson's disease

Abstract

IntroductionPlasma norepinephrine concentration reflects lesions causing OH. We investigate whether patients with high norepinephrinergic orthostatic hypotension (OH) whose supine plasma norepinephrine concentration (NEsupine) is above the mean value in all patients with Parkinson's disease (PD) have central sympathetic denervation. MethodsWe analyzed data from 110 non-demented patients with early de novo PD who underwent cardiovascular examinations. We divided the patients into three groups according to the presence or absence of orthostatic hypotension and NEsupine: patients without OH, patients with OH+high NEsupine, and patients with OH+low NEsupine. ResultsThe mean NEsupine in all patients was 251.6 pg/ml. Twelve patients (10.9%) had OH+high NEsupine (≥251.6 pg/ml), and 45 patients (40.9%) had OH+low NEsupine (<251.6 pg/ml). OH was more pronounced in patients with OH+high NEsupine than in those with OH+low NEsupine (p = 0.024). Vasopressin release and percent increase of NE after orthostatic stress were well preserved in patients with OH+low NEsupine, but not in patients with OH+high NEsupine. Cognition was lower in patients with OH+high NEsupine than in patients with OH+low NEsupine (p = 0.019) and was associated with vasopressin release during orthostatic stress on multiple regression analysis. The degree of cardiac sympathetic denervation did not differ between two groups with OH. ConclusionsPatient with PD and high norepinephrinergic OH are a subset of patients who have early cognitive decline and impaired vasopressin release. Vasopressin release after orthostatic stress was closely related to global cognition in PD.