Orthostatic Hypotension Is Associated With Cognitive Decline in Parkinson Disease

Abstract

Introduction: Cognitive impairment and orthostatic hypotension (OH) are common, disabling Parkinson disease (PD) symptoms that are strongly correlated. Whether the relationship is causative or associative remains unknown. OH may occur without classic orthostatic symptoms of cerebral hypoperfusion (i.e., lightheadedness or dizziness). Whether longitudinal differences in cognition occur between symptomatic and asymptomatic OH patients has not been explored. Objectives: We characterized the prevalence of OH, orthostatic symptoms, and cognitive impairment among PD patients and compared cognition between patients with and without OH, and between patients with symptomatic and asymptomatic OH. Methods: Our cross-sectional, retrospective, observational study included 226 clinically diagnosed PD patients who underwent repeated standardized evaluations. Among these, 62 had longitudinal follow-up of > 3.5 years. We compared longitudinal Montreal Cognitive Assessment (MoCA) scores between patients remaining OH-free ( n = 14) and those without baseline OH that developed OH ( n = 28), matched for age, sex, education, and PD duration. We also compared MoCA scores between groups with asymptomatic OH ( n = 13) and symptomatic OH ( n = 13) matched for the same factors. Results: In the cross-sectional analysis, OH patients had worse cognition. In the longitudinal analysis (mean follow-up = 5.3 years), OH patients had worse cognitive decline ( p = 0.027). Cognitive impairment was similar between asymptomatic and symptomatic OH patients in the cross-sectional and longitudinal analyses. Conclusions: OH is associated with cognitive impairment in PD. Further studies are needed in larger cohorts to expand our findings and to determine whether treating OH can prevent or delay cognitive dysfunction.

Parkinson disease-associated cognitive impairment

“…similar association between a reduction in MRI signal in the locus coeruleus and RBD 58 and, in those patients with PD and RBD, this signal reduction is associated with cog nitive deterioration and orthostatic hypotension 59 . Moreover, a reduction in brain noradrenaline trans porter availability correlates with cognitive decline and orthostatic hypotension in PD 59 and neurogenic ortho static hypotension in PD owing to noradrenergic den ervation of the heart is independently associated with cognitive decline 60 . The underlying mechanism of this association is due to cerebral hypoperfusion caused by orthostatic hypotension, which impairs cognitive function, with noradrenalineenhancing drugs recom mended for the treatment of orthostatic hypotension 61,62 .…”

Cardiovascular dysautonomia and cognition in Parkinson’s Disease — a possible relationship

“…Lower Montreal Cognitive Assessment (MoCA) scores and worse decline during follow-up period were observed among PD-OH group. Presence of OH symptoms did not influence cognitive deterioration [68].…”

“…The impairment is more severe when SH is combined with OH [2]. However, a few studies did not confirm this observation [68,69,73].…”

Locus Coeruleus Volume is Reduced in Early Parkinson Disease-Related Orthostatic Hypotension.

“…A secondary prediction was that LC volume would positively correlate with cognitive scores. Finally, recent work has found that PD-related OH, independent of OHSx, confers risk of cognitive decline (39). Some have proposed that OHSx may rely on function of adrenergic output by the LC (40).…”

“…Similarly, cognitive impairment, also a risk for quality of life reduction, is common in early PD (15-20% in de novo PD), with upwards of 80% of MCI-PD patients progressing to dementia (8-10). Interestingly, several studies have found those with OH, irrespective of OHSx, have a greater risk of cognitive impairment (11)(12)(13)(14). Neuropathologic mechanisms underlying this link remain unclear.…”