Author response: Effects of orthostatic hypotension on cognition in Parkinson disease
Gibbons, Christopher H.
Canova, Alexander O.
MetadataShow full item record
Citation (published version)Justin Centi, Roy Freeman, Christopher H Gibbons, Sandy Neargarder, Alexander O Canova, Alice Cronin-Golomb. 2017. "Author response: Effects of orthostatic hypotension on cognition in Parkinson disease." Neurology, Volume 89, Issue 20, pp. 2122 - 2122. https://doi.org/10.1212/WNL.0000000000004658
OBJECTIVE: To investigate the relation between orthostatic hypotension (OH) and posture-mediated cognitive impairment in persons with Parkinson's disease (PD) without dementia. METHODS: There were 55 participants: 37 non-demented individuals with idiopathic PD, including 18 with OH (PDOH), and 19 without (PDWOH), and18 control participants (C). All participants completed neuropsychological tests in the supine and in the upright tilted position. Blood pressure was assessed in each posture using a standardized oscillometric cuff at the right brachial artery. RESULTS: The two PD groups performed similarly while supine, with a profile notable for executive dysfunction consisting of deficits in sustained attention, response inhibition, and semantic verbal fluency, as well as reduced verbal memory encoding and retention. When upright, these deficits were exacerbated and broadened to include additional cognitive functions in the PDOH group: deficits in phonemic verbal fluency, psychomotor speed, and both basic and complex aspects of auditory working memory. When group-specific supine scores were used as baseline anchors, both PD groups showed cognitive changes following tilt, though the PDOH group had a wider range of deficits in the executive functioning and memory domains and was the only group to show significant changes in visuospatial skills. CONCLUSIONS: Cognitive deficits in idiopathic PD have been widely reported, though assessments are typically performed in the supine position. While both PD groups had supine deficits that aligned with prior studies and clinical findings, we demonstrated that those with PD and orthostatic hypotension had transient, posture-mediated changes in excess of those found in PD without autonomic failure. These observed changes suggest an acute, reversible effect, and as orthostatic hypotension is a significant comorbid factor in PD, an independent target for clinical intervention. Further understanding of the effects of autonomic failure on cognition in other disorders is desirable, particularly in the context of neuroimaging studies and clinical assessments where data are collected only in the supine or seated positions. Identification of a distinct neuropsychological profile in PD with autonomic failure also has implications for functional activities of daily living and overall quality of life.