Association of cognitive dysfunction with neurocirculatory abnormalities in early Parkinson disease

Abstract

Objective: Cognitive impairment and neurocirculatory abnormalities such as orthostatic hypotension (OH), supine hypertension (SH), and failure to decrease blood pressure at night (nondipping) occur relatively commonly in Parkinson disease (PD); however, whether cognitive dysfunction in early PD is related to neurocirculatory abnormalities has not been established. Cognitive dysfunction in PD is associated with white matter hyperintensities on MRI. We report results of an analysis of neuropsychological and hemodynamic parameters in patients with early PD.Methods: Among 87 patients, 25 had normal cognition, 48 had mild cognitive impairment, and 14 had dementia, based on comprehensive neuropsychological tests. Orthostatic vital signs and ambulatory 24-hour blood pressure monitoring were recorded, and brain magnetic resonance scans were obtained for all patients. Results:Cognitive impairment was associated with OH, SH, and white matter hyperintensities but not with nondipping. Dementia and white matter hyperintensities were common in SH. Of 13 patients with OH ϩ SH, every one had mild cognitive impairment or dementia. Conclusions:Cognitive dysfunction is related to neurocirculatory abnormalities, especially OH ϩ SH, in early PD, raising the possibility that early detection and effective treatment of those abnormalities might slow the rate of cognitive decline. Neurology It is increasingly being recognized that Parkinson disease (PD) involves prominent nonmotor manifestations such as dementia and autonomic failure.A variety of neurocirculatory abnormalities have been noted in PD, including orthostatic hypotension (OH), 1-4 supine hypertension (SH), 5-7 labile blood pressure, and the absence of a decrease in pressure during the night, a phenomenon called nondipping. 8 These abnormalities are related to each other. SH is found in a substantial proportion of patients with PD with OH.

The Cardiovascular and Cerebrovascular Effects on Cognition in Persons with Parkinson’s Disease: A Systematic Review of the Literature

“…The same study also reported the presence of comorbid HTN in persons with PD resulted in decreased scores on tests of executive function (tests of executive function combined score PD + HTN-p = 0.041) compared to persons with PD + OH, PD + OH + HTN, or PD with no other vascular comorbidity [24]. The latter result is supported by Kim et al [25] who found a negative correlation between executive function scores (COWAT-grocery, p < 0.05; COWAT-phonemic, p < 0.05; Stroop Word Test, p < 0.05) and the standard deviation of systolic blood pressure (SBP) (normal cognition group = 13.0 ± 3.5, mild cognitive impairment group = 12.8 ± 2.9, dementia group = 18.8 ± 11.1). In contrast to the above studies which reported significant correlations between cardiovascular and/or cerebrovascular dysfunctions and cognitive dysfunctions, Idiaquez et al [23] reported that the presence of OH (p = 0.1) or postprandial hypotension (PPH) (p = 0.4) did not significantly affect cognitive or behavioral scores in persons with PD or Parkinson's disease dementia (PDD) (Frontal Assessment Battery (FAB) [35], Blessed Scale [36], Cornell scale for depression [37]).…”

“…Four out of seven studies included for analysis stated a significant p-value of less than 0.05 [23] [25] [27] [29]. In three of the seven studies, a p-value for significance was not explicitly stated, however, all p-values reported as significant by the authors were less than 0.05 [22] [24] [28].…”

“…Disease severity and motor involvement were evaluated in all seven studies using the Unified Parkinson's Disease Rating Scale (UPDRS) and its subscales [22]- [28]. Additionally, five of the seven studies used the Hoehn & Yahr scale to further measure motor symptom severity [22] [23] [25] [27] [28]. A battery of neuropsychological tests were used to assess different dimensions of cognition, the most common being the MMSE [22] [23] [25]- [28].…”

“…Additionally, five of the seven studies used the Hoehn & Yahr scale to further measure motor symptom severity [22] [23] [25] [27] [28]. A battery of neuropsychological tests were used to assess different dimensions of cognition, the most common being the MMSE [22] [23] [25]- [28]. The MMSE is a validated test for global cognition in Parkinson's disease [50].…”

“…Two studies showed correlations of BP changes in persons with PD and decreased visual memory [22] [25]. One study reported that presence of OH resulted in lower scores on tests of visual memory (Cognitive Drug Research (CDR) computerized assessment system-test of picture recognition [47], tests of visual memory combined score-p = 0.027) [22]), while the other study reports a relationship between visuospatial function (Rey-Osterrieth Complex Figure Test for non-verbal, visuospatial memory-copy (RCFT-copy) [48], p = −0.040) and changes in nocturnal BP, whereby nocturnal BP increases were associated with worsening cognitive function including visuospatial function [25].…”