Cognitive and MRI correlates of orthostatic hypotension in Parkinson's disease

Depression is associated with the nonmotor symptoms of Parkinson's disease: A comparative analysis

Background and aims

The nonmotor symptoms (NMS) of Parkinson's disease (PD) and their potential role in early diagnosis are recent debates. Herein, we aimed to investigate the association between depression and NMS of PD including sleep disorders, hyposexuality, hyposmia, constipation, and orthostatic hypotension.

Methods

A total of 93 PD patients with depression and 67 PD patients without depression were included in the study, and NMS were compared between the two groups. Furthermore, the possible associations between depression severity measured by Beck Depression Inventory (BDI) and NMS were investigated using linear regression or binary logistic regression models controlled for possible confounders. Eventually, we performed a subgroup analysis in each mild, moderate, and severe depression group.

Results

Orthostatic hypotension, constipation, and hyposexuality showed a significant difference between PD patients with and without depression (p < 0.001, p = 0.029, and p < 0.001, respectively). The BDI score was significantly associated with hyposexuality, Montreal cognitive assessment (MoCA), and Pittsburgh Sleep Quality (p = 0.016, p = 0.010, and p = 0.011, respectively); however, after adjustments for possible confounders, the associations of the BDI score with the MoCA score and hyposexuality remained significant (p = 0.015 and p = 0.019, respectively). Considering subgroup analysis, a similar pattern of significant results was observed particularly in the severe group.

Conclusions

This study suggests a possible association between depression in PD patients and some NMS observed in the course of PD. These findings could be beneficial for early diagnosis of the disease, which eventually could make a considerable difference in the management of PD patients. Additional interventional longitudinal studies are warranted to explore how controlling depression could impact the NMS of patients with PD.

Brain white matter changes and their associations with non-motor dysfunction in orthostatic hypotension in α-synucleinopathy: A NODDI study

BACKGROUND

The specific non-motor symptoms associated with α-synucleinopathies, including orthostatic hypotension (OH), cognitive impairment, and emotional abnormalities, have been a subject of ongoing controversy over the mechanisms underlying the development of a vicious cycle among them. The distinct structural alterations in white matter (WM) in patients with α-synucleinopathies experiencing OH, alongside their association with other non-motor symptoms, remain unexplored. This study employs axial diffusivity and density imaging (NODDI) to investigate WM damage specific to α-synucleinopathies with concurrent OH, delivering fresh evidence to supplement our understanding of the pathogenic mechanisms and pathological rationales behind the occurrence of a spectrum of non-motor functional impairments in α-synucleinopathies.

METHODS

This study recruited 49 individuals diagnosed with α-synucleinopathies, stratified into an α-OH group (n = 24) and an α-NOH group (without OH, n = 25). Additionally, 17 healthy controls were included for supine and standing blood pressure data collection, as well as neuropsychological assessments. Magnetic resonance imaging (MRI) was utilized for the calculation of NODDI parameters, and tract-based spatial statistics (TBSS) were employed to explore differential clusters. The fibers covered by these clusters were defined as regions of interest (ROI) for the extraction of NODDI parameter values and the analysis of their correlation with neuropsychological scores.

RESULTS

The TBSS analysis unveiled specific cerebral regions exhibiting disparities within the α-OH group as compared to both the α-NOH group and the healthy controls. These differences were evident in clusters that indicated a decrease in the acquisition of the neurite density index (NDI), a reduction in the orientation dispersion index (ODI), and an increase in the isotropic volume fraction (FISO) (p < 0.05). The extracted values from these ROIs demonstrated significant correlations with clinically assessed differences in supine and standing blood pressure, overall cognitive scores, and anxiety-depression ratings (p < 0.05).

CONCLUSION

Patients with α-synucleinopathies experiencing OH exhibit distinctive patterns of microstructural damage in the WM as revealed by the NODDI model, and there is a correlation with the onset and progression of non-motor functional impairments.

The mechanism of impaired delayed recall verbal memory function in Parkinson's disease with orthostatic hypotension: a multiple imaging study

Introduction

Orthostatic hypotension (OH) frequently accompanies autonomic dysfunction and is an important risk factor for cognitive impairment in Parkinson's disease (PD). However, the association between different cognitive functions and OH in PD patients is not yet fully understood.

Methods

This study aimed to evaluate the scores of different cognitive domains and multiple parameters using different imaging techniques on PD patients with or without OH. A total number of 31 PD patients with OH (n = 20) and without OH (n = 11) were recruited from the Department of Neurology, Beijing Xuanwu Hospital for this study. All patients underwent beat-to-beat non-invasive blood pressure recordings and an active standing test to evaluate neurogenic OH and a global neuropsychological test to assess cognitive function. All patients underwent dynamic cerebral autoregulation (dCA) measurement, brain magnetic resonance imaging (MRI), and brain 18fluorine-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT).

Results

The results showed that OH patients had poor delayed recall verbal memory when compared with the PD patients without OH (1.75 ± 1.59 vs. 3.10 ± 1.73, p = 0.042). The dCA test indicated a significant difference in the right very low-frequency (VLF) gain between two groups (1.27 ± 0.17 vs. 1.10 ± 0.26, p = 0.045) and the brain 18F-FDG PET/CT indicated a significant difference in the SUV (right medial temporal lobe) to SUV (occipital lobe) ratio (0.60 ± 0.08 vs. 0.67 ± 0.11, p = 0.049). Meanwhile, these two imaging parameters were negatively correlated (p < 0.001). Furthermore, the score of a delayed recall verbal memory in the OH group was positively correlated with the right medial temporal lobe to occipital lobe ratio (p < 0.001) and was negatively correlated with the right VLF gain (p = 0.023).

Discussion

PD with OH patients had poor delayed recall memory, which might have been caused by the decreased metabolic dysfunction of specific medial temporal lobe due to the impaired dCA ability.

A systematic review and meta-analysis on the association between orthostatic hypotension and mild cognitive impairment and dementia in Parkinson's disease

BACKGROUND

Cognitive impairment is a frequent disabling feature of Parkinson's disease (PD). Orthostatic hypotension (OH) is treatable and may be a risk factor for cognitive impairment.

OBJECTIVE

We conducted a systematic review and meta-analysis to examine the relationship between OH with PD-associated minimal cognitive impairment (PD-MCI) and dementia (PDD) and assess the mitigating effects of potential confounding factors.

METHODS

Observational studies published in English, Spanish, French, or Portuguese up to January 2022 were searched for in PubMed, EBSCO, and SciELO databases. The primary aim of this study was to revise the association between OH with PD-MCI and PDD. Alongside, we assessed OH as related to cognitive rating scales. Fixed and random models were fitted. Meta-regression was used to assess the mitigating effects of confounding variables.

RESULTS

We identified 18 studies that reported OH association with PDD or PD-MCI, 15 of them reporting OH association with cognitive rating scales. OH was significantly associated with PDD/PD-MCI (OR, 95% CI: 3.31, 2.16-5.08; k = 18, n = 2251; p < 0.01). OH association with PDD (4.64, 2.68-8.02; k = 13, n = 1194; p < 0.01) was stronger than with PD-MCI (1.82, 0.92-3.58; k = 5, n = 1056; p = NS). The association between OH and PD-MCI/PDD was stronger in studies with a higher proportion of women and in those with a lower frequency of supine hypertension. Global cognition rating scale scores were lower in patients with OH (SMD, 95% CI: - 0.55, - 0.83/ - 0.26; k = 12, n = 1427; p < 0.01).

CONCLUSIONS

Orthostatic hypotension shows as a significant risk factor for cognitive impairment in PD, especially in women and patients not suffering from hypertension.

Impaired dynamic cerebral autoregulation: A potential mechanism of orthostatic hypotension and dementia in Parkinson’s disease

Background

Orthostatic hypotension (OH) and cognitive impairment are common non-motor symptoms of Parkinson’s disease (PD). This study aimed to investigate whether impaired dynamic cerebral autoregulation (dCA) is associated with OH and Parkinson’s disease dementia (PDD), and analyze the related risk factors in patients with PDD.

Materials and methods

We enrolled 89 patients with PD and 20 age- and sex-matched healthy controls (HCs). Cognition and different cognitive domains were assessed by the Montreal Cognitive Assessment scale. Non-invasive continuous beat-to-beat blood pressure and cerebral blood flow velocity were assessed using a servo-controlled finger plethysmograph and transcranial Doppler, respectively. dCA was examined using supine and orthostatic changes with transfer function analysis to derive the autoregulatory parameters of phase, gain, and coherence. Logistic regression analysis was performed to determine the risk factors for PDD.

Results

We found that 21 (23.6%) patients with PD had OH. These patients showed worse cognitive performance in specific cognitive tasks, such as language and orientation. The patients with OH also had poorer dCA; the very low frequency (VLF) phase in two different postures was lower than that in patients without OH as well as HCs (both P < 0.05). And the normalized gain in the VLF and low frequency (LF) in standing position was higher in PD patients with and without OH than in HCs. PDD patients also had significantly higher LF normalized gain when standing than patients without dementia (P = 0.015), indicating impaired dCA. LF normalized gain in standing (odds ratio: 3.756, 95% confidence interval: 1.241–11.367) and education were significantly associated with PDD.

Conclusion

Diminished dCA may represent a potential mechanism for OH and cognitive impairment and low educational level might be a significant factor contributing to the increased risk of PDD.

Cognitive and Autonomic Dysfunction in Multiple System Atrophy Type P and C: A Comparative Study

Multiple System Atrophy (MSA) is a rare neurodegenerative disease, clinically defined by a combination of autonomic dysfunction and motor involvement, that may be predominantly extrapyramidal (MSA-P) or cerebellar (MSA-C). Although dementia is generally considered a red flag against the clinical diagnosis of MSA, in the last decade the evidence of cognitive impairment in MSA patients has been growing. Cognitive dysfunction appears to involve mainly, but not exclusively, executive functions, and may have different characteristics and progression in the two subtypes of the disease (i.e., MSA-P and MSA-C). Despite continued efforts, combining in-vivo imaging studies as well as pathological studies, the physiopathological bases of cognitive involvement in MSA are still unclear. In this view, the possible link between cardiovascular autonomic impairment and decreased cognitive performance, extensively investigated in PD, needs to be clarified as well. In the present study, we evaluated a cohort of 20 MSA patients (9 MSA-P, 11 MSA-C) by means of a neuropsychological battery, hemodynamic assessment (heart rate and arterial blood pressure) during rest and active standing and bedside autonomic function tests assessed by heart rate variability (HRV) parameters and sympathetic skin response (SSR) in the same experimental session. Overall, global cognitive functioning, as indicated by the MoCA score, was preserved in most patients. However, short- and long-term memory and attentional and frontal-executive functions were moderately impaired. When comparing MSA-P and MSA-C, the latter obtained lower scores in tests of executive functions and verbal memory. Conversely, no statistically significant difference in cardiovascular autonomic parameters was identified between MSA-P and MSA-C patients. In conclusion, moderate cognitive deficits, involving executive functions and memory, are present in MSA, particularly in MSA-C patients. In addition, our findings do not support the role of dysautonomia as a major driver of cognitive differences between MSA-P and MSA-C.

Relationship Between Orthostatic Hypotension and Cognitive Functions in Multiple System Atrophy: A Longitudinal Study

Introduction: The aim of this study is to investigate the impact of orthostatic hypotension (OH) on cognitive functions in patients with multiple system atrophy (MSA) followed over time. Methods: Thirty-two MSA patients were enrolled and underwent a comprehensive neuropsychological battery; at baseline (T₀) 15 out of 32 patients presented OH, assessed by means of orthostatic standing test. All patients underwent a follow-up (T₁) evaluation 12 months after baseline. Thirteen out of 32 patients also underwent a second follow-up (T₂) evaluation at 24 months. Changes over time on different neuropsychological tasks were compared between patients with and without OH by means of Mann-Whitney's U-test. Moreover, clinical categories of normal cognition, mild cognitive impairment, and dementia were determined, and changes at T₁ and T₂ in global cognitive status were compared between patients with and without OH. Results: At T₀, patients with OH had better performance on words/non-words repetition task (p = 0.02) compared to patients without OH. Compared to patients without OH, patients with OH performed worse on semantic association task (p < 0.01) at T₁ and on Stroop test-error effect (p = 0.04) at T₂. The percentage of patients with worsened cognitive status at T₁ was higher among patients with OH than among patients without OH (93 vs. 59%, p = 0.03). OH (β = -4.67, p = 0.01), education (β = 0.45, p = 0.02), age (β = 0.19, p = 0.03), and Montreal Cognitive Assessment battery (MOCA) score at T₀ (β = -0.26, p = 0.04) were significant predictors of global cognitive status worsening at T₁. Discussion: We found that global cognitive status worsened at 1-year follow-up in 93% of patients with OH, and OH, along with age, education, and MOCA score, predicted cognitive worsening over time. To clarify the relationship between OH and cognitive dysfunction in MSA, we suggest the use of clinical categories of normal cognition, mild cognitive impairment, and dementia in further longitudinal studies on MSA patients with and without OH.

Cognition and transcranial sonography in Parkinson's disease patients with or without orthostatic hypotension

BACKGROUND

Orthostatic hypotension (OH) is a common nonmotor symptom in patients with Parkinson's disease (PD), with an incidence ranging from 14% to 54%.

AIMS

This study explored changes in cognition and transcranial sonography (TCS) findings in patients with PD and OH.

METHODS

We enrolled PD patients who visited the outpatient or inpatient department from 2017 to 2020. Blood pressure was measured in different positions, and demographic data were collected. Motor and nonmotor symptoms were evaluated using standard scales. A subset of 107 patients underwent TCS.

RESULTS

We enrolled 66 PD-OH patients and 92 PD-no orthostatic hypotension (NOH) patients. There were no significant differences in gender, age, disease duration, or Hoehn and Yahr stage between groups. Binary logistic regression revealed age as an independent risk factor for OH in PD patients. There were statistically significant group differences in visuospatial and executive function and Unified Parkinson's Disease Rating Scale (UPDRS) I and II scores (p < .05). Among PD-OH patients, there was a statistically significant difference in UPDRS II and III scores between patients with or without clinical symptoms (p < .05). The substantia nigra (SN) area was significantly larger in PD-NOH patients (0.45 ± 0.18 cm2 ) than PD-OH patients (0.34 ± 0.16 cm2 ) (p < .05).

CONCLUSIONS

PD-OH patients had poorer visuospatial and executive function and lower UPDRS I and II scores compared with PD-NOH patients. Within the PD-OH group, there was no significant difference in cognition between patients with or without clinical symptoms. The difference in the SN area may indicate different subtypes of PD or a tendency to develop parkinsonism syndrome.

Association of Orthostatic Hypotension With Cerebral Atrophy in Patients With Lewy Body Disorders

OBJECTIVE

To evaluate whether orthostatic hypotension (OH) or supine hypertension (SH) is associated with brain atrophy and white matter hyperintensities (WMH), we analyzed clinical and radiologic data from a large multicenter consortium of patients with Parkinson disease (PD) and dementia with Lewy bodies (DLB).

METHODS

Supine and orthostatic blood pressure (BP) and structural MRI data were extracted from patients with PD and DLB evaluated at 8 tertiary-referral centers in the United States, Canada, Italy, and Japan. OH was defined as a systolic/diastolic BP fall ≥20/10 mm Hg within 3 minutes of standing from the supine position (severe ≥30/15 mm Hg) and SH as a BP ≥140/90 mm Hg with normal sitting BP. Diagnosis-, age-, sex-, and disease duration-adjusted differences in global and regional cerebral atrophy and WMH were appraised with validated semiquantitative rating scales.

RESULTS

A total of 384 patients (310 with PD, 74 with DLB) met eligibility criteria, of whom 44.3% (n = 170) had OH, including 24.7% (n = 42) with severe OH and 41.7% (n = 71) with SH. OH was associated with global brain atrophy (p = 0.004) and regional atrophy involving the anterior-temporal (p = 0.001) and mediotemporal (p = 0.001) regions, greater in severe vs nonsevere OH (p = 0.001). The WMH burden was similar in those with and without OH (p = 0.49). SH was not associated with brain atrophy (p = 0.59) or WMH (p = 0.72).

CONCLUSIONS

OH, but not SH, was associated with cerebral atrophy in Lewy body disorders, with prominent temporal region involvement. Neither OH nor SH was associated with WMH.

Arterial Blood Pressure Variability and Other Vascular Factors Contribution to the Cognitive Decline in Parkinson's Disease

Dementia is one of the most disabling non-motor symptoms in Parkinson’s disease (PD). Unlike in Alzheimer’s disease, the vascular pathology in PD is less documented. Due to the uncertain role of commonly investigated metabolic or vascular factors, e.g., hypertension or diabetes, other factors corresponding to PD dementia have been proposed. Associated dysautonomia and dopaminergic treatment seem to have an impact on diurnal blood pressure (BP) variability, which may presumably contribute to white matter hyperintensities (WMH) development and cognitive decline. We aim to review possible vascular and metabolic factors: Renin-angiotensin-aldosterone system, vascular endothelial growth factor (VEGF), hyperhomocysteinemia (HHcy), as well as the dopaminergic treatment, in the etiopathogenesis of PD dementia. Additionally, we focus on the role of polymorphisms within the genes for catechol-O-methyltransferase (COMT), apolipoprotein E (APOE), vascular endothelial growth factor (VEGF), and for renin-angiotensin-aldosterone system components, and their contribution to cognitive decline in PD. Determining vascular risk factors and their contribution to the cognitive impairment in PD may result in screening, as well as preventive measures.

Clinical Markers May Identify Patients at Risk for Early Parkinson's Disease Dementia: A Prospective Study

BACKGROUND

The study aims at identifying features predictive of early onset of dementia in Parkinson's disease (PD).

METHODS

103 non-demented PD patients were evaluated on various scales at baseline and 89 patients at 3-year follow-up.

RESULTS

By the end of the study 43.8% of patients developed dementia. The development of dementia was linked to the baseline Mini Mental State Examination score (Pearson coefficient r = .404, p = 0.013), the presence of autonomic dysfunctions (r = -.621, p < 0.001) and insomnia (r = -.526, p = 0.001). A binary logistic regression analysis showed that the development of dementia was correlated strongly with the presence of autonomic dysfunctions (95% CI 2.60 to 52.83, p < 0.001), and insomnia (95% CI 0.60 to 0.95, p = 0.017).

CONCLUSION

Patients with signs of autonomic dysfunction and insomnia are at higher risk for developing dementia and deserve closer monitoring of cognitive symptoms.

Management of Orthostatic Hypotension

PURPOSE OF REVIEW

This article reviews the management of orthostatic hypotension with emphasis on neurogenic orthostatic hypotension.

RECENT FINDINGS

Establishing whether the cause of orthostatic hypotension is a pathologic lesion in sympathetic neurons (ie, neurogenic orthostatic hypotension) or secondary to other medical causes (ie, non-neurogenic orthostatic hypotension) can be achieved by measuring blood pressure and heart rate at the bedside. Whereas fludrocortisone has been extensively used as first-line treatment in the past, it is associated with adverse events including renal and cardiac failure and increased risk of all-cause hospitalization. Distinguishing whether neurogenic orthostatic hypotension is caused by central or peripheral dysfunction has therapeutic implications. Patients with peripheral sympathetic denervation respond better to norepinephrine agonists/precursors such as droxidopa, whereas patients with central autonomic dysfunction respond better to norepinephrine reuptake inhibitors.

SUMMARY

Management of orthostatic hypotension is aimed at improving quality of life and reducing symptoms rather than at normalizing blood pressure. Nonpharmacologic measures are the key to success. Pharmacologic options include volume expansion with fludrocortisone and sympathetic enhancement with midodrine, droxidopa, and norepinephrine reuptake inhibitors. Neurogenic supine hypertension complicates management of orthostatic hypotension and is primarily ameliorated by avoiding the supine position and sleeping with the head of the bed elevated.

Kinematic but not clinical measures predict falls in Parkinson-related orthostatic hypotension

OBJECTIVE

We sought to test the hypothesis that technology could predict the risk of falls in Parkinson's disease (PD) patients with orthostatic hypotension (OH) with greater accuracy than in-clinic assessment.

METHODS

Twenty-six consecutive PD patients with OH underwent clinical (including home-like assessments of activities of daily living) and kinematic evaluations of balance and gait as well as beat-to-beat blood pressure (BP) monitoring to estimate their association with the risk of falls. Fall frequency was captured by a diary collected prospectively over 6 months. When applicable, the sensitivity, specificity, and diagnostic accuracy were measured using the area under the receiver operating characteristics curve (AUC). Additional in-clinic assessments included the OH Symptom Assessment (OHSA), the OH Daily Activity Score (OHDAS), and the Movement Disorder Society Unified Parkinson's Disease Rating Scale (MDS-UPDRS).

RESULTS

The prevalence of falls was 53.8% over six months. There was no association between the risk of falls and test of gait and postural stability (p ≥ 0.22) or home-like activities of daily living (p > 0.08). Conversely, kinematic data (waist sway during time-up-and-go, jerkiness, and centroidal frequency during postural sway with eyes-opened) predicted the risk of falls with high sensitivity and specificity (> 80%; AUC ≥ 0.81). There was a trend for higher risk of falls in patients with orthostatic mean arterial pressure ≤ 75 mmHg.

CONCLUSIONS

Kinematic but not clinical measures predicted falls in PD patients with OH. Orthostatic mean arterial pressure ≤ 75 mmHg may represent a hemodynamic threshold below which falls become more prevalent, supporting the aggressive deployment of corrective measures.

Morbidity and mortality in orthostatic hypotension

This review summarizes the current literature on the epidemiology of orthostatic hypotension (OH) in the elderly and in patients with autonomic impairment also known as neurogenic OH (nOH); these two conditions have distinct pathophysiologies and affect different patient populations. The prevalence of OH in the elderly varies depending on the study population. In community dwellers, OH prevalence is estimated at 16%, whereas in institutionalized patients, it may be as high as 60%. The prevalence of OH increases exponentially with age, particularly in those 75 years and older. Multiple epidemiological studies have identified OH as a risk factor for all-cause mortality and cardiovascular disease including heart failure and stroke. Real-world data from administrative databases found polypharmacy, multiple co-morbid conditions, and high health-care utilization as common characteristics in OH patients. A comprehensive evaluation of medications associated with OH is discussed with particular emphasis on the use of anti-hypertensive therapy from two large clinical trials on high-intensive versus standard blood pressure management. Finally, we also review the epidemiology of nOH based on the underlying neurodegenerative disorder (either Parkinson's disease or multiple system atrophy), and the presence of co-morbid conditions such as hypertension and cognitive impairment.

Orthostatic Hypotension Is Associated With Cognitive Decline in Parkinson Disease

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.

Early autonomic and cognitive dysfunction in PD, DLB and MSA: blurring the boundaries between α-synucleinopathies

Differential diagnosis between Parkinson's disease, dementia with Lewy bodies and multiple system atrophy can be difficult, especially because in early phase they might present with overlapping clinical features. Notably, orthostatic hypotension and cognitive dysfunction are common nonmotor aspects of parkinsonian syndromes and can be both present from the earliest stages of all α-synucleinopathies, indicating a common neurobiological basis in their strong relationship. In view of the increasing awareness about the prevalence of mild cognitive dysfunction in multiple system atrophy, the relevance of autonomic dysfunction in demented parkinsonian patients, the critical role of non-motor symptoms in clustering Parkinson's disease patients and the shift to studying patients in the prodromal phase, we will discuss some intrinsic limitations of current clinical diagnostic criteria, even when applied by movement disorder specialists. In particular, we will focus on the early coexistence of autonomic and cognitive dysfunction in the setting of overt or latent parkinsonism as pitfalls in the differential diagnosis of α-synucleinopathies. As early and accurate diagnosis remains of outmost importance for counselling of patients and timely enrolment into disease-modifying clinical trials, a continuous effort of research community is ongoing to further improve the clinical diagnostic accuracy of α-synucleinopathies.

Association of orthostatic blood pressure with the symptoms of orthostatic hypotension and cognitive impairment in patients with multiple system atrophy

The degree and frequency of orthostatic hypotension (OH) are high in patients with multiple system atrophy (MSA); however, the association of orthostatic blood pressure (BP) with the symptoms of OH and cognitive impairment in these patients remains unclear. The aim of this study was to clarify whether absolute BP and/or changes in BP during standing are related to OH symptoms and cognitive impairment in patients with MSA. Thirty-two patients with MSA were examined using the head-up tilt and cognitive function tests. OH symptoms were evaluated using a patient-reported scale. The results were compared with those for 15 age- and sex-matched healthy controls. Seventeen of the 32 (53.1%) patients had OH, with eight of them exhibiting OH symptoms, which were related to the absolute BP value at 60° tilt. However, OH symptoms were not related to the degree of decrease in BP during the tilt test, and they were frequently observed in patients with a mean BP of <80 mmHg at 60° tilt (sensitivity, 67%; specificity, 91%). Cognitive dysfunction assessed by the Mini-Mental State Examination (MMSE; ≤ 26) was also associated with a low mean BP at 60° tilt (odds ratio, 1.32; 95% confidence interval, 1.04-1.67; p = 0.02). The upright BP value is associated with OH symptoms and the MMSE score in patients with MSA. Thus, careful observation of OH symptoms can enable early management of BP and the detection of cognitive impairment in these patients.

Cognition in multiple system atrophy: a single-center cohort study

OBJECTIVE

Cognitive impairment in multiple system atrophy (MSA) is common, but remain poorly characterized. We evaluated cognitive and behavioral features in MSA patients and assessed between-group differences for MSA subtypes and the effect of orthostatic hypotension (OH) on cognition.

METHODS

This retrospective study included 54 patients with clinical diagnosis of possible and probable MSA referred to the Department of Neurology at Medical University of Innsbruck between 2000 and 2018. Neurological work-up included comprehensive neuropsychological testing including Consortium to Establish a Registry for Alzheimer's Disease (CERAD-plus) test battery, Frontal Assessment Battery (FAB), digit span test (DST), clock drawing task (CLOX1), and Hospital Anxiety and Depression Scale (HADS-D).

RESULTS

The mean MMSE score was 27.6 points. Overall, slight to moderate cognitive impairment was noted in up to 40% of patients, with predominant impairment of executive function and verbal memory. Patients with the cerebellar variant performed significantly worse than patients with the parkinsonian type (P < 0.05) in a screening of executive functions (FAB) and in phonemic verbal fluency. Depression and anxiety scores were elevated in 28% and 22% of MSA patients, respectively. Cognitive profile, depression, and anxiety levels were comparable between patients with and without OH.

INTERPRETATION

Cognitive deficits are relatively frequent in MSA and primarily affect executive functions and verbal memory. Future comparative studies including Parkinson dementia, Lewy body disease, and MSA cases with and without OH are required to elucidate disease-specific cognitive profiles in these synucleinopathies and to examine the influence of cardiovascular autonomic dysfunction on cognitive function in MSA.

Small vessel disease pathological changes in neurodegenerative and vascular dementias concomitant with autonomic dysfunction

We performed a clinicopathological study to assess the burden of small vessel disease (SVD) type of pathological changes in elderly demented subjects, who had clinical evidence of autonomic dysfunction, either carotid sinus hypersensitivity or orthostatic hypotension or both or had exhibited unexpected repeated falls. Clinical and neuropathological diagnoses in 112 demented subjects comprised dementia with Lewy bodies (DLB), Parkinson's disease with dementia (PDD), Alzheimer's disease (AD), Mixed dementia (mostly AD-DLB) and vascular dementia (VaD). Of these, 12 DLB subjects had no recorded unexpected falls in life and therefore no evidence of concomitant autonomic dysfunction. A further 17 subjects were assessed as aging controls without significant pathology or signs of autonomic dysfunction. We quantified brain vascular pathological changes and determined severities of neurodegenerative lesions including α-synuclein pathology. We found moderate-severe vascular changes and high-vascular pathology scores (P < 0.01) in all neurodegenerative dementias and as expected in VaD compared to similar age controls. Arteriolosclerosis, perivascular spacing and microinfarcts were frequent in the basal ganglia and frontal white matter (WM) across all dementias, whereas small infarcts (<5 mm) were restricted to VaD. In a sub-set of demented subjects, we found that vascular pathology scores were correlated with WM hyperintensity volumes determined by MRI in life (P < 0.02). Sclerotic index values were increased by ~50% in both the WM and neocortex in all dementias compared to similar age controls. We found no evidence for increased α-synuclein deposition in subjects with autonomic dysfunction. Our findings suggest greater SVD pathological changes occur in the elderly diagnosed with neurodegenerative dementias including DLB and who develop autonomic dysfunction. SVD changes may not necessarily manifest in clinically overt symptoms but they likely confound motor or cognitive dysfunction. We propose dysautonomia promotes chronic cerebral hypoperfusion to impact upon aging-related neurodegenerative disorders and characterize their end-stage clinical syndromes.

Orthostatic hypotension and cognition in older adults: A systematic review and meta-analysis

BACKGROUND

Orthostatic hypotension (OH) is common in older adults with reported prevalence rates of 5-40%. A direct link between OH and cognitive performance has been proposed due to impaired vascular autoregulation.

AIM

To systematically assess the literature of the association between OH and cognitive performance in older adults.

METHODS

Literature search of MEDLINE, Embase, Cochrane Central Register of Controlled Trials and PsycINFO from inception to May 2017. Studies were included if OH and cognition were assessed in subjects of mean or median age ≥65 years. Risk of bias was assessed with the Newcastle Ottawa Scale.

RESULTS

Of 3266 studies screened, 32 studies (22 cross-sectional; 10 longitudinal) reporting data of 28,980 individuals were included. OH prevalence ranged from 3.3% to 58%. Of the 32 studies, 18 reported an association between OH and worse cognitive performance and 14 reported no association. Mini Mental State Examination (MMSE) was the most commonly used cognitive assessment tool. Studies using more than one cognitive assessment tool were more likely to find an association between OH and worse cognition. OH was significantly associated with a lower MMSE mean score (mean difference - 0.51 (95% CI: -0.85, -0.17, p = 0.003)) and an increased risk of cognitive impairment (OR 1.19 (95% CI, 1.00-1.42, p = 0.048)).

CONCLUSIONS

OH is common in older populations and is associated with worse cognition expressed as lower MMSE scores. Use of MMSE alone as a cognitive assessment tool may underestimate the association. It is yet unclear whether the association between OH and worse cognitive performance is causative.

Dysautonomia is associated with structural and functional alterations in Parkinson disease

Objective

To investigate whether the presence of autonomic dysfunction is associated with white matter and functional connectivities and the level of cognitive performance in patients with de novo Parkinson disease (PD).

Methods

Seventy-five patients with de novo PD underwent a comprehensive autonomic function test and were classified into 2 groups according to the Composite Autonomic Severity Score (CASS; 30 with moderate to severe autonomic dysfunction [CASS 4–10, PD-AUT+] and 45 without significant autonomic dysfunction [CASS 0–3, PD-AUT−]). Network-based statistics and a graph theoretical analysis were performed to assess the interregional white matter connectivity using diffusion tensor imaging. We also performed analyses of resting-state functional connectivity and compared cognitive performance between the 2 groups.

Results

There were no significant differences in demographic characteristics and vascular risk factors between the PD-AUT+ and PD-AUT− groups. The PD-AUT+ group showed poorer cognitive performance on frontal/executive function than the PD-AUT− group. The PD-AUT+ group exhibited severely disrupted white matter connectivity in both fronto-subcortical and posterior cortical regions, which was well correlated with the severity of autonomic dysfunction assessed by the CASS. In addition, functional connectivity within the executive control network and dorsal attention network negatively correlated with the CASS.

Conclusions

Our results suggest that autonomic dysfunction is associated with disrupted white matter and functional brain connectivity as well as cognitive impairment in de novo patients with PD.

Orthostatic hypotension and dementia incidence: links and implications

Orthostatic hypotension (OH) is a common condition, particularly in patients with α-synucleinopathies such as Parkinson's disease, and has a significant impact on activities of daily living and quality of life. Recent data suggest an association with cognitive impairment. Herein, we review the evidence that OH increases the odds of incident mild cognitive impairment and dementia. Potential mechanisms underlying the putative relationship are discussed, including cerebral hypoperfusion, supine hypertension, white matter hyperintensities, and neurodegeneration. Finally, we highlight the challenges with respect to treatment and the negative impact on the quality of life and long-term prognosis presented by the coexistence of OH and dementia. Large population-based studies have reported that OH is associated with about a 20% increased risk of dementia in the general population, while smaller cohort studies suggest an even greater effect in patients with α-synucleinopathies (3- to 7-fold higher than controls). Ultimately, OH exposure is difficult to quantify, predominantly limited to pressure regulation during a one-time orthostatic challenge, and the causative association with dementia may turn out to be bidirectional, especially in α-synucleinopathies. Early diagnosis and treatment of OH may improve long-term prognosis.

The association between orthostatic hypotension and dementia: A meta-analysis of prospective cohort studies

OBJECTIVES

As for the association between orthostatic hypotension (OH) and dementia, results of published studies are inconsistent; therefore, current substantive conclusions have yet been obtained. This meta-analysis was conducted in hopes of producing progress in this topic.

METHODS

A systematic database search was performed towards electronic databases including Chinese Biomedical Database, PubMed, Web of Science, Wiley Online Library, ScienceDirect, and the Cochrane Library. Five prospective cohort studies were included. Summary hazard ratio (HR) estimates with 95% confidence intervals (CIs) were calculated by random-effects model. Statistical heterogeneity was assessed with the Cochran Q test and I² statistic. A sensitivity analysis was also conducted in this meta-analysis.

RESULTS

A 22.4% higher prevalence of dementia in subjects with OH was obtained (adjusted pooled HR was 1.224; 95% CI: 1.106-1.354; P < .001). This meta-analysis also showed significant associations between OH and 2 dementia subtypes: Alzheimer disease (adjusted pooled HR was 1.175; 95% CI: 1.022-1.351; P = .023) and Vascular dementia (adjusted pooled HR was 1.403; 95% CI: 1.042-1.889; P = .026), respectively.

CONCLUSIONS

Orthostatic hypotension is positively associated with the overall prevalence of dementia, and it may contribute to the prevalence of Alzheimer disease and Vascular dementia as well.

Consensus statement on the definition of neurogenic supine hypertension in cardiovascular autonomic failure by the American Autonomic Society (AAS) and the European Federation of Autonomic Societies (EFAS) : Endorsed by the European Academy of Neurology (EAN) and the European Society of Hypertension (ESH)

PURPOSE

Patients suffering from cardiovascular autonomic failure often develop neurogenic supine hypertension (nSH), i.e., high blood pressure (BP) in the supine position, which falls in the upright position owing to impaired autonomic regulation. A committee was formed to reach consensus among experts on the definition and diagnosis of nSH in the context of cardiovascular autonomic failure.

METHODS

As a first and preparatory step, a systematic search of PubMed-indexed literature on nSH up to January 2017 was performed. Available evidence derived from this search was discussed in a consensus expert round table meeting in Innsbruck on February 16, 2017. Statements originating from this meeting were further discussed by representatives of the American Autonomic Society and the European Federation of Autonomic Societies and are summarized in the document presented here. The final version received the endorsement of the European Academy of Neurology and the European Society of Hypertension.

RESULTS

In patients with neurogenic orthostatic hypotension, nSH is defined as systolic BP ≥ 140 mmHg and/or diastolic BP ≥ 90 mmHg, measured after at least 5 min of rest in the supine position. Three severity degrees are recommended: mild, moderate and severe. nSH may also be present during nocturnal sleep, with reduced-dipping, non-dipping or rising nocturnal BP profiles with respect to mean daytime BP values. Home BP monitoring and 24-h-ambulatory BP monitoring provide relevant information for a customized clinical management.

CONCLUSIONS

The establishment of expert-based criteria to define nSH should standardize diagnosis and allow a better understanding of its epidemiology, prognosis and, ultimately, treatment.

Cognitive Status, Gray Matter Atrophy, and Lower Orthostatic Blood Pressure in Older Adults

BACKGROUND

Associations between orthostatic blood pressure and cognitive status (CS) have been described with conflicting results.

OBJECTIVE

We hypothesize that long-term exposure to lower orthostatic blood pressure is related to having worse CS later in life and that atrophy of regions involved in central regulation of autonomic function mediate these associations.

METHODS

Three-to-four measures of orthostatic blood pressure were obtained from 1997-2003 in a longitudinal cohort of aging, and average systolic orthostatic blood pressure response (ASOBPR) was computed as % change in systolic blood pressure from sit-to-stand measured at one minute post stand. CS was determined in 2010-2012 by clinician-adjudication (n = 240; age = 87.1±2.6; 59% women; 37% black) with a subsample also undergoing concurrent structural neuroimaging (n = 129). Gray matter volume of regions related to autonomic function was measured. Multinomial regression was used to compare ASOBPR in those who were cognitively intact versus those with a diagnosis of mild cognitive impairment or dementia, controlling for demographics, trajectories of seated blood pressure, incident cardiovascular risk/events and medications measured from 1997 to 2012. Models were repeated in the subsample with neuroimaging, before and after adjustment for regional gray matter volume.

RESULTS

There was an inverse association between ASOBPR and probability of dementia diagnosis (9% lower probability for each % point higher ASOBPR: OR 0.91, CI95%  = 0.85-0.98; p = 0.01). Associations were similar in the subgroup with neuroimaging before and after adjustment for regional gray matter volume.

CONCLUSION

ASOBPR may be an early marker of risk of dementia in older adults living in the community.

Pharmacotherapy of Cardiovascular Autonomic Dysfunction in Parkinson Disease

Cardiovascular autonomic dysfunctions, including neurogenic orthostatic hypotension, supine hypertension and post-prandial hypotension, are relatively common in patients with Parkinson disease. Recent evidence suggests that early autonomic impairment such as cardiac autonomic denervation and even neurogenic orthostatic hypotension occur prior to the appearance of the typical motor deficits associated with the disease. When neurogenic orthostatic hypotension develops, patients with Parkinson disease have an increased risk of mortality, falls, and trauma-related to falls. Neurogenic orthostatic hypotension reduces quality of life and contributes to cognitive decline and physical deconditioning. The co-existence of supine hypertension complicates the treatment of neurogenic orthostatic hypotension because it involves the use of drugs with opposing effects. Furthermore, treatment of neurogenic orthostatic hypotension is challenging because of few therapeutic options; in the past 20 years, the US Food and Drug Administration approved only two drugs for the treatment of this condition. Small, open-label or randomized studies using acute doses of different pharmacologic probes suggest benefit of other drugs as well, which could be used in individual patients under close monitoring. This review describes the pathophysiology of neurogenic orthostatic hypotension and supine hypertension in Parkinson disease. We discuss the mode of action and therapeutic efficacy of different pharmacologic agents used in the treatment of patients with cardiovascular autonomic failure.

Neurogenic orthostatic hypotension and supine hypertension in Parkinson's disease and related synucleinopathies: prioritisation of treatment targets

Neurogenic orthostatic hypotension and supine hypertension are common manifestations of cardiovascular dysautonomia in Parkinson's disease and related synucleinopathies. Because these disorders are haemodynamic opposites, improvement in one might be achieved at the expense of worsening of the other. Thus, management decisions necessitate assessment of the individual risks for patients with coexistent neurogenic orthostatic hypotension and supine hypertension. Whereas neurogenic orthostatic hypotension poses risks for falls and can be associated with cognitive impairment in the short term, chronic supine hypertension can be associated with stroke and myocardial infarction in the long term. Because few clinical trial data exist for outcomes in patients with coexistent neurogenic orthostatic hypotension and supine hypertension, clinicians need to balance, on the basis of comorbidities and disease staging, the potential immediate benefits of treatment for neurogenic orthostatic hypotension and the long-term risks of supine hypertension treatment in each patient. Future research needs to focus on ascertaining a safe degree of supine hypertension when treating neurogenic orthostatic hypotension; the effectiveness of nocturnal antihypertensive therapy in patients with coexistent neurogenic orthostatic hypotension and supine hypertension; and the prevalence, scope, and therapeutic requirements for managing neurogenic orthostatic hypotension that manifests with falls or cognitive impairment, but without postural lightheadedness or near syncope.

Orthostatic Hypotension Predicts Cognitive Impairment in the Elderly: Findings from a Cohort Study

BACKGROUND

Orthostatic hypotension (OH) is a known risk factor for cerebral ischemia, but its correlation with cognitive impairment (CI) is not well established.

OBJECTIVE

The aim of this study is to explore the relationship between OH and CI in the elderly.

METHODS

The study group consisted of 44 OH patients who presented with drowsiness, vertigo, and fatigue between January 2009 and December 2011 (OH group). Eighty-eight healthy elderly were paired with those in the OH group in a 1:2 based on their education levels (NOH group). Baseline sociodemographic information and cognition-related measures were collected for both groups. Cognitive function was assessed 4 years later using MMSE.

RESULTS

The overall incidence of CI was 14.0% among the 114 subjects who completed the follow-up assessment. There was a significant difference in the incidence of CI between the OH group (23.7%) and the NOH group (9.2%) (χ² = 4.399, P = 0.036). After excluding the influence of age (OR = 1.199, 95% CI: 1.072-1.340, P = 0.001) and education years (OR = 0.568, 95% CI: 0.371-0.869, P = 0.009), OH (OR = 4.047, 95% CI: 1.144-14.313, P = 0.030) became an independent risk factor for CI.

CONCLUSION

OH can lead to CI. We suggest that future studies, with a larger sample size, use OH exposure time instead of OH exposure population to verify the conclusion of this study.

The association between orthostatic hypotension and cognitive state among adults 65 years and older who underwent a comprehensive geriatric assessment

The prevalence of cognitive impairment and orthostatic hypotension (OH) increases with age, but the results of studies that assessed possible associations between them are inconsistent.The aim of this study is to assess possible associations between cognitive impairment and OH in patients ≥65 years of age who underwent a comprehensive geriatric assessment.A retrospective analysis was conducted of the computerized medical records of the study population from 2005 to 2013. Data collected included blood pressure measurements that enabled the calculation of OH, results of the mini-mental state examination (MMSE), results of the Montreal cognitive assessment (MoCA) test, and cognitive diagnoses that were determined over the course of the assessment.The rate of OH in the study population of 571 adults was 32.1%. The mean MMSE score was 22.5 ± 5.2 among participants with OH and 21.6 ± 5.8 among those without OH (P = 0.09). The absence of a significant association between OH and MMSE remained after adjusting the MMSE score for age and education level. The mean MoCA score was 16.4 ± 5.0 among participants with OH and 16.4 ± 4.8 among those without (P = 0.33). The prevalence of OH was 39% among participants without cognitive impairment, 28.9% among those with mild cognitive impairment (MCI), and 30.6% among those with dementia (P = 0.13).There was no association between OH and cognitive impairment in adults who underwent a comprehensive geriatric assessment.

Cardiovascular Autonomic Dysfunction in Mild and Advanced Parkinson's Disease

Objective

The purpose of the present study was to investigate cardiovascular autonomic dysfunction in patients with Parkinson’s disease (PD) with mild to severe stages of motor symptoms and to compare cardiovascular autonomic dysfunction between drug-naïve and dopaminergic drug-treated groups.

Methods

This study included 188 PD patients and 25 age-matched healthy controls who underwent head-up tilt-testing, 24-h ambulatory blood pressure (BP) monitoring and 24-h Holter monitoring. Autonomic function test results were evaluated among groups categorized by motor symptom severities (mild vs. moderate vs. severe) and treatment (drug-naïve or dopaminergic drug treatment).

Results

Orthostatic hypotension and supine hypertension were more frequent in patients with PD than in healthy controls. The frequencies of orthostatic hypotension, supine hypertension, nocturnal hypertension and non-dipping were not different among groups. Additionally, no significant differences were detected in supine BP, orthostatic BP change, nighttime BP, nocturnal BP dipping, or heart rate variabilities among groups.

Conclusions

Cardiovascular autonomic dysfunction is not confined to moderate to severe PD patients, and starts early in the course of the disease in a high proportion of PD patients. In addition, dopaminergic drug treatments do not affect cardiovascular autonomic function.

Clinical Relevance of Orthostatic Hypotension in Neurodegenerative Disease

The autonomic nervous system appears to be uniquely susceptible to degeneration in disorders of α-synuclein pathology. Clinically, autonomic dysfunction in these disorders manifests as neurogenic orthostatic hypotension (nOH), a condition that results in substantial morbidity and mortality. nOH results from pathology affecting either the central autonomic pathways or peripheral autonomic nerve fibers. Determining the localization and pathophysiology of nOH is critical in effectively managing this disorder and selecting appropriate treatment options. In this review, we discuss the pathophysiology of nOH with respect to the various α-synuclein-related neurodegenerative conditions. We highlight the associated clinical features, including gait instability, rapid eye movement behavior disorder, and hyposmia. We also review the current pharmacologic treatment options for nOH. Overall, the goals of therapy are to improve symptoms and prevent syncope and falls. Non-pharmacologic interventions should be introduced first, followed by carefully selected pharmacologic therapies. Treatment decisions should be directed by an understanding of the underlying pathophysiology, as well as the comorbidities and potential contributing factors present in each individual patient.

Supine hypertension in Parkinson's disease and multiple system atrophy

OBJECTIVE

Supine hypertension (SH) is a feature of cardiovascular autonomic failure that often accompanies orthostatic hypotension and may represent a negative prognostic factor in parkinsonian syndromes. Here we investigated the frequency rate as well as the clinical and tilt test correlates of SH in Parkinson's disease (PD) and multiple system atrophy (MSA).

METHODS

197 PD (33 demented) and 78 MSA (24 MSA-Cerebellar, 54 MSA-Parkinsonian) patients who had undergone a tilt test examination were retrospectively included. Clinical-demographic characteristics were collected from clinical records at the time of the tilt test examination.

RESULTS

SH (>140 mmHg systolic, >90 mmHg diastolic) occurred in 34 % of PD patients (n = 66, mild in 71 % of patients, moderate in 27 %, severe in 2 %) and 37 % of MSA ones (n = 29, mild in 55 % of patients, moderate in 17 %, severe in 28 %). No difference was observed in SH frequency between demented versus gender-, age- and disease duration-matched non-demented PD patients, or between patients with the parkinsonian (MSA-P) versus the cerebellar (MSA-C) variant of MSA. In PD, SH was associated with presence of cardiovascular comorbidities (p = 0.002) and greater systolic (p = 0.007) and diastolic (p = 0.002) orthostatic blood pressure fall. Orthostatic hypotension (p = 0.002), and to a lesser degree, lower daily dopaminergic intake (p = 0.01) and use of anti-hypertensive medications (p = 0.04) were associated with SH in MSA.

INTERPRETATION

One-third of PD and MSA patients suffer from mild to severe SH, independently of age, disease duration or stage. In PD, cardiovascular comorbidities significantly contribute to the development of SH, while in MSA, SH appears to reflect cardiovascular autonomic failure.

Diagnosing and treating neurogenic orthostatic hypotension in primary care

In response to a change in posture from supine or sitting to standing, autonomic reflexes normally maintain blood pressure (BP) by selective increases in arteriovenous resistance and by increased cardiac output, ensuring continued perfusion of the central nervous system. In neurogenic orthostatic hypotension (NOH), inadequate vasoconstriction and cardiac output cause BP to drop excessively, resulting in inadequate perfusion, with predictable symptoms such as dizziness, lightheadedness and falls. The condition may represent a central failure of baroreceptor signals to modulate cardiovascular function, a peripheral failure of norepinephrine release from cardiovascular sympathetic nerve endings, or both. Symptomatic patients may benefit from both non-pharmacologic and pharmacologic interventions. Among the latter, two pressor agents have been approved by the US Food and Drug Administration: the sympathomimetic prodrug midodrine, approved in 1996 for symptomatic orthostatic hypotension, and the norepinephrine prodrug droxidopa, approved in 2014, which is indicated for the treatment of symptomatic neurogenic orthostatic hypotension caused by primary autonomic failure (Parkinson's disease, multiple system atrophy and pure autonomic failure). A wide variety of off-label options also have been described (e.g. the synthetic mineralocorticoid fludrocortisone). Because pressor agents may promote supine hypertension, NOH management requires monitoring of supine BP and also lifestyle measures to minimize supine BP increases (e.g. head-of-bed elevation). However, NOH has been associated with cognitive impairment and increases a patient's risk of syncope and falls, with the potential for serious consequences. Hence, concerns about supine hypertension - for which the long-term prognosis in patients with NOH is yet to be established - must sometimes be balanced by the need to address a patient's immediate risks.

Dysautonomia in Parkinson disease

Dysautonomias are conditions in which altered function of one or more components of the autonomic nervous system (ANS) adversely affects health. This review updates knowledge about dysautonomia in Parkinson disease (PD). Most PD patients have symptoms or signs of dysautonomia; occasionally, the abnormalities dominate the clinical picture. Components of the ANS include the sympathetic noradrenergic system (SNS), the parasympathetic nervous system (PNS), the sympathetic cholinergic system (SCS), the sympathetic adrenomedullary system (SAS), and the enteric nervous system (ENS). Dysfunction of each component system produces characteristic manifestations. In PD, it is cardiovascular dysautonomia that is best understood scientifically, mainly because of the variety of clinical laboratory tools available to assess functions of catecholamine systems. Most of this review focuses on this aspect of autonomic involvement in PD. PD features cardiac sympathetic denervation, which can precede the movement disorder. Loss of cardiac SNS innervation occurs independently of the loss of striatal dopaminergic innervation underlying the motor signs of PD and is associated with other nonmotor manifestations, including anosmia, REM behavior disorder, orthostatic hypotension (OH), and dementia. Autonomic dysfunction in PD is important not only in clinical management and in providing potential biomarkers but also for understanding disease mechanisms (e.g., autotoxicity exerted by catecholamine metabolites). Since Lewy bodies and Lewy neurites containing alpha-synuclein constitute neuropathologic hallmarks of the disease, and catecholamine depletion in the striatum and heart are characteristic neurochemical features, a key goal of future research is to understand better the link between alpha-synucleinopathy and loss of catecholamine neurons in PD.

Predictors of dementia in Parkinson disease: a prospective cohort study

OBJECTIVE

We investigated an array of possible markers of early dementia in Parkinson disease.

METHODS

We performed a comprehensive assessment of autonomic, sleep, psychiatric, visual, olfactory, and motor manifestations in 80 patients with Parkinson disease who were dementia-free at baseline. After 4.4 years' follow-up, patients were evaluated for dementia. Predictive variables were assessed using logistic regression adjusting for disease duration, follow-up duration, age, and sex.

RESULTS

Of 80 patients, 27 (34%) developed dementia. Patients destined to develop dementia were older and more often male (odds ratio [OR] = 3.64, p = 0.023). Those with baseline mild cognitive impairment had increased dementia risk (OR = 22.5, p < 0.001). REM sleep behavior disorder at baseline dramatically increased dementia risk (OR = 49.7, p = 0.001); however, neither daytime sleepiness nor insomnia predicted dementia. Higher baseline blood pressure increased dementia risk (OR = 1.37 per 10 mm Hg, p = 0.032). Orthostatic blood pressure drop was strongly associated with dementia risk (OR = 1.84 per 10 mm Hg, p < 0.001); having a systolic drop of >10 mm Hg increased dementia odds 7-fold (OR = 7.3, p = 0.002). Abnormal color vision increased dementia risk (OR = 3.3, p = 0.014), but olfactory dysfunction did not. Among baseline motor variables, proportion of gait involvement (OR = 1.12, p = 0.023), falls (OR = 3.02, p = 0.042), and freezing (OR = 2.63, p = 0.013), as well as the Purdue Pegboard Test (OR = 0.67, p = 0.049) and alternate tap test (OR = 0.97, p = 0.033) predicted dementia.

CONCLUSION

Cardiovascular autonomic dysfunction, REM sleep behavior disorder, color discrimination ability, and gait dysfunction strongly predict development of dementia in Parkinson disease.

Aortic stiffness and hypotension episodes are associated with impaired cognitive function in older subjects with subjective complaints of memory loss

OBJECTIVE

Though CV risk factors and markers of arterial aging are recognized risky for cognition, no study has simultaneously investigated the impact of multiple cardiac, arterial (large and small vessels), and hemodynamic parameters on cognitive function in older subjects.

METHODS

Two hundred eighty older subjects with subjective complaints of memory loss and no previous stroke (mean age 78.3 ± 6.3 years) were studied. Global cognitive function was evaluated with the Mini-Mental State Examination (MMSE). Cognitive impairment was defined as a MMSE < 21. We measured: traditional CV risk factors; aorta stiffness (Pulse Wave Velocity, PWV); LV mass; presence of WML at neuroimaging; episodes of hypotension (SBP <100 mmHg during 24 h Ambulatory Blood Pressure Monitoring).

RESULTS

In both cross-sectional and longitudinal analyses PWV, WML, and episodes of hypotension were significantly associated with poorer cognitive function-controlling for age, sex, education, depression, traditional CV risk factors, and medications. LV mass was no longer associated with cognition in multiple regression. Older subjects with stiffer arteries or episodes of hypotension presented a 4-fold and an 11-fold, respectively, greater odds for progression from normal cognitive function to cognitive impairment. A synergistic effect between PWV, WML, and hypotension was observed: the occurrence of any two of PWV, WML, or hypotension was accompanied by lower MMSE; in the presence of all three factors, a further significant decline in cognitive function was observed.

INTERPRETATION

Systemic hemodynamic parameters (higher PWV and hypotension) together with cerebral microvascular damage (WML) are significantly associated with poorer cognitive function and may identify older subjects with subjective complaints of memory loss at higher risk of cognitive decline.

Orthostatic hypotension in Parkinson’s disease

SUMMARY Orthostatic hypotension (OH) is a frequent non-motor symptom in Parkinson’s disease (PD), affecting between 22.9 and 38.4% of patients. In PD, OH is related to an increased risk of falls, and possibly to cognitive dysfunction and increased mortality. These data emphasize the importance of its prompt recognition and treatment. OH is related to pre- and post-ganglionic adrenergic denervation, but other factors, such as drugs, heat, meals or alcohol intake, might also induce or aggravate it. Evidence about the efficacy and safety of pharmacological or nonpharmacological strategies for OH treatment in PD is weak. Nonpharmacological measures include liberal addition of salt to the diet, exercise, compression stockings or physical maneuvers. Severe cases may be treated with midodrine or fludrocortisone. Some results suggest that droxidopa and fipamezole may be effective treatments. We finish this review article by discussing the most important unanswered questions about PD-related OH, which may be the focus of future research.

Dementia and neuroimaging

Early diagnosis of dementing conditions and an accurate monitoring of their progression are important clinical and research goals, especially given the improving prospects of disease-modifying therapies. Neuroimaging has played and is playing an important role in detecting reversible, treatable causes of dementia, and in characterizing the dementia syndromes by demonstrating structural and functional signatures that can aid in their differentiation. Many new imaging techniques and modalities are also available that allow the assessment of specific aspects of brain structure and function, such as positron emission tomography with new ligands, diffusion tensor magnetic resonance imaging (MRI) and functional MRI. In this review, we report the most recent findings from the papers published in the Journal of Neurology that used conventional and advanced neuroimaging techniques for the study of various dementing conditions.