Differential neuropsychological profiles in Parkinsonian patients with or without vascular lesions

The clinical and neuroimaging differences between vascular parkinsonism and Parkinson's disease: a case-control study

BACKGROUND

Parkinson's disease (PD) and vascular parkinsonism (VaP) have highly overlapping phenotypes, and different prognosis. This study comprehensively investigated the clinical, brain MRI and transcranial sonography differences between VaP and PD.

METHODS

Forty-eight patients with PD, 27 patients with VaP, and 29 healthy controls were compared. All patients were assessed using the MDS-UPDRS, Berg Balance Scale (BBS), Ten-Meter Walking Test (10-MWT), Time Up and Go Test, and Non-Motor Symptoms Scale. Beck Depression Inventory, PD questionnaire- 39, international urine incontinence scale, cognitive assessment scales, MRI brain and transcranial colour-coded doppler. The study was registered on clinical-Trial.gov (NCT04308135) on 03/12/2020.

RESULTS

VaP patients showed significantly older age of onset, shorter disease duration, lower drug doses and levodopa responsiveness, higher On and Off axial scores, On and Off BBS, higher On scores for PIGD, rigidity, bradykinesia and total motor MDS-UPDRS, lower On and Off tremor, lower-half predominance, lower asymmetrical presentation and symmetric index than PD patients. VaP patients had worse non-motor symptoms Scale (NMSS) than controls except for perceptual problems/hallucinations but better symptoms than PD patients except for urinary dysfunction. Quality of life (QoL) was impaired in VaP patients and was correlated with motor function and NMSs. The VaP group had significantly higher white matter lesions and brain atrophy, with lower hyperechogenicity of the substantia nigra and more impaired cerebral vascular resistance and vasoreactivity than the PD group.

CONCLUSIONS

VaP has a characteristic motor and non-motor profile, with impaired QoL, white matter, and transcranial sonography abnormalities that differentiate it from PD. Further studies are warranted to explore the role of vascular lesions in the pathogenesis of VaP.

TRIAL REGISTRATION

The registered identifier NCT04308135 on clinical-Trial.gov. Registered on 03/12/2020.

Prevalence of Concomitant Pathologies in Parkinson's Disease: Implications for Prognosis, Diagnosis, and Insights into Common Pathogenic Mechanisms

Pathologies characteristic of Alzheimer's disease (i.e., hyperphosphorylated tau and amyloid-β (Aβ) plaques), cardiovascular disease, and limbic predominant TDP-43 encephalopathy (LATE) often co-exist in patients with Parkinson's disease (PD), in addition to Lewy body pathology (α-synuclein). Numerous studies point to a putative synergistic relationship between hyperphosphorylation tau, Aβ, cardiovascular lesions, and TDP-43 with α-synuclein, which may alter the stereotypical pattern of pathological progression and accelerate cognitive decline. Here we discuss the prevalence and relationships between common concomitant pathologies observed in PD. In addition, we highlight shared genetic risk factors and developing biomarkers that may provide better diagnostic accuracy for patients with PD that have co-existing pathologies. The tremendous heterogeneity observed across the PD spectrum is most likely caused by the complex interplay between pathogenic, genetic, and environmental factors, and increasing our understanding of how these relate to idiopathic PD will drive research into finding accurate diagnostic tools and disease modifying therapies.

Neuroimaging approaches to cognition in Parkinson's disease

While direct visualization of Lewy body accumulation within the brain is not yet possible in living Parkinson's disease patients, brain imaging studies offer insights into how the buildup of Lewy body pathology impacts different regions of the brain. Unlike biological biomarkers and purely behavioral research, these brain imaging studies therefore offer a unique opportunity to relate brain localization to cognitive function and dysfunction in living patients. Magnetic resonance imaging studies can reveal physical changes in brain structure as they relate to different cognitive domains and task specific impairments. Functional imaging studies use a combination of task and resting state magnetic resonance imaging, as well as positron emission tomography and single photon emission computed tomography, and can be used to determine changes in blood flow, neuronal activation and neurochemical changes in the brain associated with PD cognition and cognitive impairments. Other unique advantages to brain imaging studies are the ability to monitor changes in brain structure and function longitudinally as patients progress and the ability to study changes in brain function when patients are exposed to different pharmacological manipulations. This is particularly true when assessing the effects of dopaminergic replacement therapy on cognitive function in Parkinson's disease patients. Together, this chapter will describe imaging studies that have helped identify structural and functional brain changes associated with cognition, cognitive impairment, and dementia in Parkinson's disease.

Parkinsonism and cerebrovascular disease

The relationship between cerebrovascular disease and parkinsonism is commonly seen in everyday clinical practice but remains ill-defined and under-recognised with little guidance for the practising neurologist. We attempt to define this association and to illustrate key clinical, radiological and pathological features of the syndrome of Vascular Parkinsonism (VaP). VaP is a major cause of morbidity in the elderly associated with falls, hip fractures and cognitive impairment. Although acute parkinsonism is reported in the context of an acute cerebrovascular event, the vast majority of VaP presents as an insidious syndrome usually in the context of vascular risk factors and radiological evidence of small vessel disease. There may be an anatomic impact on basal ganglia neuronal networks, however the effect of small vessel disease (SVD) on these pathways is not clear. There are now established reporting standards for radiological features of SVD on MRI. White matter hyperintensities and lacunes have been thought to be the representative radiological features of SVD but other features such as the perivascular space are gaining more importance, especially in context of the glymphatic system. It is important to consider VaP in the differential diagnosis of Parkinson disease (PD) and in these situations, neuroimaging may offer diagnostic benefit especially in those patients with atypical presentations or refractoriness to levodopa. Proactive management of vascular risk factors, monitoring of bone density and an exercise program may offer easily attainable therapeutic targets in PD and VaP. Levodopa therapy should be considered in patients with VaP, however the dose and effect may be different from use in PD. This article is part of the Special Issue "Parkinsonism across the spectrum of movement disorders and beyond" edited by Joseph Jankovic, Daniel D. Truong and Matteo Bologna.

White Matter Hyperintensities Related to Parkinson's Disease Executive Function

BACKGROUND

People with Parkinson's disease (PD) can develop multidomain cognitive impairments; however, it is unclear whether different pathologies underlie domain-specific cognitive dysfunction.

OBJECTIVES

We investigated the contribution of vascular copathology severity and location, as measured by MRI white matter hyperintensities (WMHs), to domain-specific cognitive impairment in PD.

METHODS

We studied 85 PD (66.6 ± 9.2 years) and 18 control (65.9 ± 6.6) participants. Using the Fazekas scale for rating the severity of WMH, we subdivided PD into 14 PD-WMH+ and 71 PD-WMH-. Participants underwent global, executive, visuospatial, episodic memory, and language testing. We performed nonparametric permutation testing to create WMH probability maps based on PD-WMH group and cognitive test performance.

RESULTS

The PD-WMH+ group showed worse global and executive cognitive performance than the PD-WMH- group. On individual tests, the PD-WMH+ group showed worse Montreal Cognitive Assessment (MoCA), Stroop, Symbol Digit Modalities Test (SDMT), and Digit Span scores. WMH probability maps showed that in the PD-WMH+ group, worse Stroop was associated with lesions centered around the corticospinal tract (CST), forceps major, inferior-fronto-occipital fasciculus, and superior longitudinal fasciculus; worse SDMT with lesions around the CST, forceps major, and posterior corona radiata; worse Digit Span with lesions around the posterior corona radiata; and worse MoCA with lesions around the CST.

CONCLUSIONS

We found that WMH severity was associated with PD executive dysfunction, including worse attention, working memory, and processing speed. Disruption of key white matter tracts in proximity to vascular lesions could contribute to these specific cognitive impairments. Early treatment of vascular disease might mitigate some executive dysfunction in a subset of patients with PD.

Cardiovascular factors are related to dopamine integrity and cognition in aging

Objective

The aging brain undergoes several changes, including reduced vascular, structural, and dopamine (DA) system integrity. Such brain changes have been associated with age‐related cognitive deficits. However, their relative importance, interrelations, and links to risk factors remain elusive.

Methods

The present work used magnetic resonance imaging and positron emission tomography with ¹¹C‐raclopride to jointly examine vascular parameters (white‐matter lesions and perfusion), DA D2‐receptor availability, brain structure, and cognitive performance in healthy older adults (n = 181, age: 64–68 years) from the Cognition, Brain, and Aging (COBRA) study.

Results

Covariance was found among several brain indicators, where top predictors of cognitive performance included caudate and hippocampal integrity (D2DR availability and volumes), and cortical blood flow and regional volumes. White‐matter lesion burden was negatively correlated with caudate DA D2‐receptor availability and white‐matter microstructure. Compared to individuals with smaller lesions, individuals with confluent lesions (exceeding 20 mm in diameter) had reductions in cortical and hippocampal perfusion, striatal and hippocampal D2‐receptor availability, white‐matter microstructure, and reduced performance on tests of episodic memory, sequence learning, and processing speed. Higher cardiovascular risk as assessed by treatment for hypertension, systolic blood pressure, overweight, and smoking was associated with lower frontal cortical perfusion, lower putaminal D2DR availability, smaller grey‐matter volumes, a larger number of white‐matter lesions, and lower episodic memory performance.

Interpretation

Taken together, these findings suggest that reduced cardiovascular health is associated with poorer status for brain variables that are central to age‐sensitive cognitive functions, with emphasis on DA integrity.

Cross-sectional and longitudinal associations between total and regional white matter hyperintensity volume and cognitive and motor function in Parkinson's disease

BACKGROUND

White matter hyperintensities (WMH) are frequently observed on T2-weighted brain magnetic resonance imaging studies of healthy older adults and have been linked with impairments in balance, gait, and cognition. Nonetheless, few studies have investigated the longitudinal effects of comorbid WMH on cognition and motor function in Parkinson's disease.

METHODS

The Lesion Segmentation Tool for Statistical Parametric Mapping was used to obtain total lesion volume and map regional WMH probabilities in 29 PD and 42 control participants at two study visits 18 months apart. Both cross-sectional and longitudinal comparisons were made between composite scores in the domains of executive function, memory, and language, and Unified Parkinson's Disease Rating Scale (UPDRS) scores.

RESULTS

We found no difference between disease and control groups in total WMH volume or progression during the study. Greater regional and global WMH at baseline was more strongly associated with lower executive function in PD subjects than in controls. Increased regional WMH was also more strongly associated with impaired memory performance in PD relative to controls. Longitudinally, no associations between cognitive change and total or regional WMH progression were detected in either group. A positive relationship between baseline regional WMH and total UPDRS scores was present in the control group, but not PD. However, greater WMH increase was associated with a greater increase in UPDRS motor sub-scores in PD.

CONCLUSIONS

These findings suggest that although PD patients do not experience greater mean WMH load than normal aged adults, comorbid WMH do exacerbate cognitive and motor symptoms in PD.

Nonmotor Symptoms in Vascular and Other Secondary Parkinsonism

Vascular parkinsonism (VP) is a relatively frequent variant of secondary parkinsonism caused by ischemic or hemorrhagic lesions of basal ganglia, midbrain, or their links with frontal cortex. According to different investigations, various forms of cerebrovascular disease cause 1%-15% of parkinsonism cases. Nonmotor symptoms are frequently found in VP and may negatively influence on quality of life. However, nonmotor symptoms such as hallucinations, orthostatic hypotension, REM-sleep behavior disorder, and anosmia are rarely revealed in VP, which may be noted to another diagnosis or mixed pathology. Clinical value of nonmotor symptoms in normal pressure hydrocephalus, toxic, and drug-induced parkinsonism is also discussed.

Cognitive Impairment and Basal Ganglia Functional Connectivity in Vascular Parkinsonism

BACKGROUND AND PURPOSE

Patients with vascular parkinsonism have higher cognitive decline and more basal ganglia lesions. We aimed to evaluate the relationship of cognitive impairment with functional connectivity between the basal ganglia and cingulate cortex in vascular parkinsonism.

MATERIALS AND METHODS

Thirty patients (8 with vascular parkinsonism and 22 with Parkinson disease) and 23 controls were enrolled. The Mattis Dementia Rating Scale and the Stroop Task were used to assess cognitive decline. MR imaging examinations included T1-MPRAGE, FLAIR, and resting-state fMRI sequences. MPRAGE was segmented to obtain basal ganglia and cingulate cortex volumes. FLAIR was segmented to obtain white matter hyperintensity lesion volume. Resting-state fMRI sequences were used to compare basal ganglia functional connectivity with the cingulate cortex between patients and controls.

RESULTS

Patients with vascular parkinsonism exhibited impaired attention, resistance to interference, and inhibitory control and an increased number of errors on the Stroop Task. They also had higher caudate nucleus and white matter hyperintensity lesion volumes, which were positively correlated (ρ = 0.75, P < .0001). Caudate nucleus functional connectivity with the perigenual anterior cingulate cortex was increased in patients with vascular parkinsonism compared with controls and patients with Parkinson disease, and it was positively correlated with the caudate nucleus volume (ρ = 0.44, P = .016). Caudate nucleus functional connectivity with the posterior cingulate cortex was decreased in patients with vascular parkinsonism compared with controls and negatively correlated with the number of errors on the Stroop test (ρ = -0.51, P = .0003).

CONCLUSIONS

In patients with vascular parkinsonism, cognitive decline could be related to changes of caudate nucleus functional connectivity with the cingulate cortex at resting-state, which may be induced by ischemia-related remodelling.

The contribution of white matter lesions to Parkinson's disease motor and gait symptoms: a critical review of the literature

White matter lesions (WML) associated with cerebrovascular disease (CVD) may be observed on magnetic resonance imaging in Parkinson's disease (PD) patients. WML are an important factor contributing to postural, gait, and cognitive impairment in the elderly without PD and worsening the course of Alzheimer's disease (AD). Numerous articles are available on this topic. Whether WML modify and negatively influence the clinical symptoms, and course of PD is a subject of debate. The aim of this review is to examine the available literature on the contribution of WML to PD motor symptoms in relation to clinical characteristics and methods of assessing WML on MRI. After reviewing the database, we identified 19 studies reporting the relationship between WML and PD; ten studies focusing on the impact of WML on the cognitive status in PD were excluded. We analysed altogether nine studies reporting the relationship between WML and motor signs of PD. The review found association between WML severity and freezing of gait, less significant to responsiveness to dopaminergic treatment and postural instability; no negative impact on tremor and falls was observed. The impact of WML on bradykinesia and rigidity was inconsistent. Comorbid WML is associated with worsening axial motor performance, probably independently from the degree of nigrostriatal dopaminergic denervation in PD. Reducing the vascular risk factors that cause WML may be helpful in preventing the development of axial symptoms and ultimately in improving the quality of life of patients with PD. Given the lack of systematic studies, additional research in this field is needed.

The contribution of white matter lesions (WML) to Parkinson's disease cognitive impairment symptoms: A critical review of the literature

We reviewed the impact of white matter lesions (WML) of cerebrovascular origin on cognitive impairment in Parkinson's disease (PD) patients. A search of PUBMED and Googlescholar.com revealed eleven studies that met the inclusion criteria: diagnosis based on the United Kingdom Brain Bank criteria (UK BBC); cognitive assessment; WML assessed on magnetic resonance imaging (MRI) by semiquantitative visual scales or automated method. Eight studies described the negative impact of WML on cognition in PD. Patients with mild cognitive impairment (MCI) and dementia had significantly more WML than the group without MCI and dementia. There was significant relationship between increasing total WML volume and worse performance on executive function, memory and language. Patients with vascular parkinsonism and dopaminergic denervation had more severe frontal lobe dysfunctions than patients with PD. In contrast in three studies there was no negative correlation between WML and cognition. Although the progression of neurodegenerative process in advanced stage of PD has been recognized as being mainly responsible for cognitive impairment in PD, WML may also be a contributing factor. It is possible that by reducing the vascular risk factors that cause WML cognitive impairment could be prevented or slowed down.

Clinicoradiological comparison between vascular parkinsonism and Parkinson's disease

OBJECTIVE

To compare the clinical and radiological features of vascular parkinsonism (VP) and Parkinson's disease (PD).

METHODS

Cross-sectional study where 15 patients with VP (8 (53.3%) men; aged 75.7 ± 10.4 years) and 30 patients with PD (17 (56.7%) men; aged 67.3 ± 7.5 years) underwent motor and cognitive evaluation and brain MRI.

RESULTS

Patients with VP were, on average, 8.4 years older (p = 0.004); all had arterial hypertension. They presented with a sudden onset of parkinsonism (80%) and a rapidly progressive clinical course (53.3%). Predominant lower body parkinsonism (p<0.001), postural instability (p=0.003) with freezing of gait (p<0.001) and falls (p<0.001), urinary incontinence (p < 0.001) and pyramidal signs (p<0.001) were more common in patients with VP. Movement Disorders Society's Unified PD Rating Scale (MDS-UPDRS) scores were higher in patients with VP (p=0.005 in 'OFF' state and p<0.001 in 'ON' state). They had greater cognitive impairment and 12 (80%) fulfilled diagnostic criteria for probable vascular dementia. Most patients with VP had brain MRI changes: multiple lacunar infarcts (66.7%) or extensive white matter disease (26.7%).

CONCLUSIONS

VP can be clinically distinguished from PD based on sudden onset of parkinsonism at an older age, characterised by lower body predominance, urinary incontinence, pyramidal signs, postural instability with freezing of gait and falls, and dementia.

[(18)F] FP-CIT PET study in parkinsonian patients with leukoaraiosis

BACKGROUNDS

Leukoaraiosis may present with slowly progressive parkinsonism indistinguishable from primary degenerative parkinsonism. Both leukoaraiosis and degenerative parkinsonism are an age-related disorder. Thus, comorbidity is expected to be common in elderly patients with parkinsonism. However, no systematic study has been reported on the clinical features indicating concomitant nigrostriatal dopaminergic denervation (NDD) in parkinsonian patients with leukoaraiosis.

METHODS

We performed [(18)F] FP-CIT positron emission tomography studies in 42 consecutive parkinsonian patients with diffuse leukoaraiosis, but no basal ganglia vascular lesions.

RESULTS

Twenty (48%) of the 42 patients had coexisting NDD. Compared to parkinsonian patients with isolated leukoaraiosis, those with coexisting NDD more frequently had asymmetric onset. They had similar degree of parkinsonian motor deficits in the legs, but greater rigidity and resting tremor in the arms. Consequently, they had less prominent lower body parkinsonism. They more frequently showed favorable response to levodopa treatment. They had similar burden of regional and total leukoaraiosis. Among a variety of clinical variables and MRI findings, only asymmetric onset and more than 30% improvement in UPDRS motor score by levodopa treatment were valuable indicators of coexisting NDD.

CONCLUSIONS

We would like to recommend dopaminergic functional imaging studies for all parkinsonian patients with leukoaraiosis. Further studies are needed to confirm sensitivity and specificity of asymmetric onset and good levodopa response for the prediction of coexisting NDD in a different group of parkinsonian patients with leukoaraiosis.

Apathy in untreated, de novo patients with Parkinson's disease: validation study of Apathy Evaluation Scale

Apathy is a behavioural disturbance occurring alone or in concomitance with depression in Parkinson's disease (PD). Here we present a validation study for the self-report version of the Apathy Evaluation Scale (AES-S), carried out in a sample of 60 non-demented, non-depressed untreated, drug-naïve, de novo PD patients; 20 patients of the sample (33.3%) were classified as apathetic according to current clinical criteria. All enrolled patients completed the AES-S and a neurological and cognitive assessment. Mean AES-S score was 34.43. AES-S did not show floor or ceiling effect. Cronbach's alpha was 0.872. Principal component analysis revealed three factors: the first (34.4% of the variance) represented constitutive aspects of the construct of apathy; the second (8.5% of the variance) represented a social dimension; the third factor (7.9% of the variance) represented a dimension related to insight. With respect to clinical criteria for apathy considered as the gold standard, receiver operating characteristics curve analysis showed that a cut-off of 36/37 has the maximum discrimination power. High sensitivity and negative predictive values were obtained with cut-off scores of 33/34 or lower; high specificity and positive predictive values were obtained with cut-off scores of 38/39 or higher. AES-S score correlated with scores on frontal tasks, but not on Beck Depression Inventory, Unified Parkinson's Disease Rating Scale, Hoehn and Yahr scale. The AES-S is a reliable and valid questionnaire for detecting apathy in PD. For screening purposes a 33/34 cut-off score is indicated, but a 38/39 cut-off score is necessary when a high specificity is desired.

Clinical features and neuropsychological profile in vascular parkinsonism

BACKGROUND

The clinical profile in vascular parkinsonism (VP) patients is well described in the literature, but little is known about the neuropsychological features of this disease. The aim of our study was to evaluate the clinical characteristics and the profile of cognitive impairment in patients with VP.

METHODS

We prospectively evaluated 12 patients with VP, 15 with Parkinson's disease (PD) and 13 healthy controls (HC) with similar age and sex distribution. Different clinical and demographic details were collected. All subjects underwent detailed neurological and neuropsychological examinations. The neuropsychological tests included analysis of global efficiency, executive function, verbal memory, language and visuospatial function.

RESULTS

VP patients exhibited lower disease duration, older age at onset and higher frequency of cardiovascular risk factors. Non-motor symptoms were found to be more frequent in PD. We found that VP patients developed cognitive impairment with a significantly higher frequency than HC of a similar age. Additionally, we found that these patients had a global pattern of cognitive impairment, including executive function, verbal memory and language. Only visuospatial function was more impaired in PD than in HC.

CONCLUSIONS

Our data contribute to clarify the pattern of neuropsychological impairment in VP. Therefore, in the clinical evaluation, besides assessing the motor status of the patient, given that these symptoms are frequently found not to be self-reported complaints, the neurologist should evaluate them routinely as a comprehensive assessment of this disease.

Vascular parkinsonism: a case series of 17 patients

Objective To report the clinical and neuroimaging findings in a case series of vascular parkinsonism (VP). Methods Seventeen patients with VP were evaluated with motor, cognitive, and neuroimaging standardized tests and scales. Results All patients had arterial hypertension. Ten patients were male and the mean age of the whole sample was 75.8±10.1 years. The mean age of parkinsonism onset was 72.2±10.0 years. Common clinical features were urinary incontinence (88.2%), lower limb parkinsonism with freezing of gait and falls (82.3%), and pyramidal signs (76.4%). The mean Unified Parkinson’s Disease Rating Scale (UPDRS) and Hoehn-Yahr scores were 72.5±21.6 points and 3.3±0.9 points, respectively. Sixteen (94.1%) patients had freezing of gait and executive dysfunction. Twelve (70.5%) patients had probable vascular dementia. The mean dose of levodopa was 530.9 mg/day. Unresponsiveness to the drug was confirmed by a 6.9 mean point reduction in the UPDRS score after the “practically defined off” test. Conclusion This series provides a profile of VP with predominant lower-limb involvement, freezing of gait and falls, pyramidal signs, executive dysfunction, concomitant vascular dementia, and poor levodopa response.

The effects of silent cerebral ischemic lesions on the prognosis of idiopathic Parkinson's disease

INTRODUCTION

Recent studies have shown that the presence of cerebrovascular lesions may play an important role in determining the presence and severity of neurodegenerative disease. However, the relationship between cerebrovascular disease and idiopathic Parkinson's disease (IPD) has received little attention. Several reports on the impact of cerebrovascular disease on the clinical status of patients with IPD remain controversial. We conducted a 2-year follow-up study to evaluate whether or not silent cerebral ischemic lesions (SIL) contribute to the progression of IPD.

METHODS

Thirty IPD patients without SIL (only-IPD) and twenty-six IPD patients with SIL (IPDS) were enrolled in this study. All patients underwent brain magnetic resonance imaging (MRI) twice, once at baseline and again at 2-years, to evaluate brain lesions including SIL. The progression of motor severity between the two groups was compared and analyzed.

RESULTS

Two years after the first visit, there was no significant difference in the daily dose of dopamine agonist and levodopa between only-IPD and IPDS patients. Changes in motor severity during the 2-year period were not significantly different between the only-IPD and IPDS group.

CONCLUSIONS

The results of our study suggest that minor cerebral ischemic changes in patients with IPD do not have significant effects on the progression of motor severity in IPD. However, to verify and strengthen these findings, brain MRI and clinicopathological studies involving a large cohort of IPD patients to explore further the relative contribution of vascular and neurodegenerative factors to the prognosis of IPD.

Impact of subcortical white matter lesions on dopamine transporter SPECT

Subcortical arteriosclerotic encephalopathy (SAE) can affect the nigrostriatal system and presumably cause vascular parkinsonism (VP). However, in patients with SAE, the differentiation of VP from idiopathic Parkinson's disease (IPS) is challenging. The aim of the present study was to examine the striatal dopamine transporter (DAT) density in patients with parkinsonism and SAE. Fifteen consecutive patients with parkinsonian symptoms displayed SAE, as detected by magnetic resonance imaging (MRI). Fifteen retrospectively chosen, matched patients with diagnosis of IPS without any abnormalities in MRI served as a reference group. DAT SPECT was performed using the tracer ¹²³I-FP-CIT. Scans were acquired on a triple-head SPECT system (Multispect 3, Siemens) and analysed using the investigator-independent BRASS™ software (HERMES). In the SAE group, a DAT deficit was observed in 9/15 patients. In contrast, all patients from the IPS group showed a reduced DAT binding (p = 0.008). The specific binding ratios (BR) of putamen contralateral to the side of the more affected limb versus occipital lobe were in trend higher in patients with SAE versus patients in the IPS-group (p = 0.053). Indices for putaminal asymmetry (p = 0.036) and asymmetry caudate-to-putamen (p = 0.026) as well as the ratio caudate-to-putamen (p = 0.048) were significantly higher in IPS patients having no SAE. DAT deficit was less pronounced in patients with SAE and parkinsonism than in patients with IPS without any abnormalities in the MRI. A potential role of DAT SPECT in the differential diagnosis of VP and IPS requires more assessments within prospective studies.

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

Orthostatic hypotension (OH) is a frequent nonmotor feature of Parkinson's disease (PD), and its occurrence has been associated with cognitive impairment. The underlying mechanism could be mediated by development of cerebrovascular disease induced by chronic or episodic hypoperfusion, but the extent of brain vascular load in PD patients with OH has never been investigated. This study aimed to assess the relationship between OH and cognitive function in PD patients and to investigate the contribution of brain vascular lesions. Forty-eight PD patients underwent a tilt table test (TT) to assess supine and orthostatic blood pressure as well as an extensive neuropsychological evaluation to evaluate cognitive function. Brain magnetic resonance imaging was acquired in 44/48 patients and analyzed by a visual semiquantitative scale. Twenty-three patients presented OH at TT (13/23 were symptomatic), and 25 did not. There were no differences in motor severity or disease duration between patients with and without OH. In patients with OH we found significantly worse cognitive performance in specific tasks, such as sustained attention, visuospatial and verbal memory, compared with patients without OH. However, there were no differences in vascular burden between the two groups. Our study confirms that there is an association between OH and selective cognitive deficits in PD, but rebuts the hypothesis that this is underlined by the development of cerebrovascular disease.

Vascular Parkinsonism and cognitive impairment: literature review, Brazilian studies and case vignettes

Vascular Parkinsonism (VP) is a form of secondary Parkinsonism resulting from cerebrovascular disease. Estimates of the frequency of VP vary greatly worldwide; 3% to 6% of all cases of Parkinsonism are found to have a vascular etiology. In a Brazilian community-based study on Parkinsonism, 15.1% of all cases were classified as VP, the third most common form, with a prevalence of 1.1% in an elderly cohort. Another Brazilian survey found a prevalence of 2.3% of VP in the elderly. VP is usually the result of conventional vascular risk factors, particularly hypertension, leading to strategic infarcts of subcortical gray matter nuclei, diffuse white matter ischaemic lesions and less commonly, large vessel infarcts. Patients with VP tend to be older and present with gait difficulties, symmetrical predominant lower-body involvement, poor levodopa responsiveness, postural instability, falls, cognitive impairment and dementia, corticospinal findings, urinary incontinence and pseudobulbar palsy. This article intends to provide physicians with an insight on the practical issues of VP, a disease potentially confounded with vascular dementia, idiopathic Parkinson's disease, dementia with Lewy bodies and other secondary causes of Parkinsonism.

Impairment of brain vessels may contribute to mortality in patients with Parkinson's disease

BACKGROUND

The effect of brain-vessel pathology on mortality in 57 consecutive PD patients was studied.

METHODS

Baseline clinical, neuropsychological, ultrasonographic (US), and MR data obtained from patients who died (n = 18) during a 4-year follow-up period were compared with the data of patients who survived.

RESULTS

US/MRI data displayed a more-severe vascular impairment in deceased patients. Differences were significant between both groups with respect to age, clinical and cognitive status, intima-media thickness, and resistance index (indicators of large and small vessel impairment). The sum score of white-matter hyperintensities was significantly higher among decedents. A cluster analysis displayed two clusters that differed in the two parameters (i.e. in age and in sum score).

CONCLUSIONS

This study provides evidence that comorbid atherosclerosis and otherwise subclinical impairment of brain vessels may contribute to mortality in PD. The vascular pathology may act in association with other comorbidities on the terrain of progressive neurodegenerative pathology.

The impact of silent vascular brain burden in cognitive impairment in Parkinson's disease

BACKGROUND AND PURPOSE

White matter hyperintensities (WMHs) detected by magnetic resonance imaging (MRI) of the brain are associated with dementia and cognitive impairment in the general population and in Alzheimer's disease. Their effect in cognitive decline and dementia associated with Parkinson's disease (PD) is still unclear.

METHODS

We studied the relationship between WMHs and cognitive state in 111 patients with PD classified as cognitively normal (n = 39), with a mild cognitive impairment (MCI) (n = 46) or dementia (n = 26), in a cross-sectional and follow-up study. Cognitive state was evaluated with a comprehensive neuropsychological battery, and WMHs were identified in FLAIR and T2-weighted MRI. The burden of WMHs was rated using the Scheltens scale.

RESULTS

No differences in WMHs were found between the three groups in the cross-sectional study. A negative correlation was observed between semantic fluency and the subscore for WMHs in the frontal lobe. Of the 36 non-demented patients re-evaluated after a mean follow-up of 30 months, three patients converted into MCI and 5 into dementia. Progression of periventricular WMHs was associated with an increased conversion to dementia. A marginal association between the increase in total WMHs burden and worsening in the Mini Mental State Examination was encountered.

CONCLUSIONS

White matter hyperintensities do not influence the cognitive status of patients with PD. Frontal WMHs have a negative impact on semantic fluency. Brain vascular burden may have an effect on cognitive impairment in patients with PD as WMHs increase overtime might increase the risk of conversion to dementia. This finding needs further confirmation in larger prospective studies.

White matter lesions in Parkinson disease

Pure vascular parkinsonism without evidence of nigral Lewy body pathology may occur as a distinct clinicopathological entity, but a much more frequent occurrence is the comorbid presence of age-associated white matter lesions (WMLs) in idiopathic Parkinson disease (PD). WMLs are associated with motor and cognitive symptoms in otherwise normal elderly individuals. Comorbid WMLs are, therefore, expected to contribute to clinical symptoms in PD. Studies of WMLs in PD differ with regard to methods of assessment of WML burden and the patient populations selected for analysis, but converging evidence suggests that postural stability and gait motor functions are predominantly affected. WMLs are described to contribute to dementia in Alzheimer disease, and emerging but inconclusive evidence indicates similar effects in PD. In this article, we review the literature addressing the occurrence and impact of WMLs in PD, and suggest that WMLs may exacerbate or contribute to some motor and cognitive deficits associated with PD. We review existing and emerging methods for studying white matter pathology in vivo, and propose future research directions.