Extrapyramidal features in Parkinson's disease with and without dementia and dementia with Lewy bodies: A cross-sectional comparative study

Cognitive profile of the earliest stage of dementia in Parkinson's disease

Recently, a strong interest has emerged in recognizing Parkinson's disease dementia (PDD) at a very early stage. However, the specific profile of the earliest stages of PDD is still unclear and a matter of considerable controversy. The objective of this study was to find out early neuropsychological markers for progression of dementia in this population. Fifty-eight patients with PDD were divided into 2 subgroups on the basis of the Mini-Mental State Examination: very mild and mild. The comparison with 26 normal controls shows that very mild PDD had deficits on attention/executive functions, naming, visuospatial/constructional abilities and retrieval of the episodic memory. Patients with mild PDD showed additional deficits on coding of episodic memory. Moreover, we found that in this early stage of PDD, the progression of dementia is mainly related to deterioration of attention/executive functions as well as retrieval and coding of episodic memory.

Dementia with Lewy bodies

Dementia with Lewy bodies (DLB) is the second most common cause of neurodegenerative dementia in older people, accounting for 10% to 15% of all cases, it occupies part of a spectrum that includes Parkinson's disease and primary autonomic failure. All these diseases share a neuritic pathology based upon abnormal aggregation of the synaptic protein α-synuciein. It is important to identify DLB patients accurately because they have specific symptoms, impairments, and functional disabilities thai differ from other common dementia syndromes such as Alzheimer's disease, vascular cognitive impairment, and frontotemporal dementia. Clinical diagnostic criteria for DLB have been validated against autopsy, but fail to detect a substantial minority of cases with atypical presentations that are often due to the presence of mixed pathology. DLB patients frequently have severe neuroleptic sensitivity reactions, which are associated with significantly increased morbidity and mortality. Cholinesterase inhibitor treatment is usually well tolerated and substantially improves cognitive and neuropsychiatrie symptoms. Although virtually unrecognized 20 years ago, DLB could within this decade become one of the most treatable neurodegenerative disorders of late life.

Depression in mild dementia: associations with diagnosis, APOE genotype and clinical features

BACKGROUND

Depression is common in dementia, with important clinical implications. Few studies of depression in dementia with Lewy bodies are available, and the results are inconsistent.

OBJECTIVE

To examine the frequency of depression and its characteristics and correlates, in people with mild dementia.

METHODS

All referrals for patients with a first time diagnosis of dementia to geriatric and older psychiatry outpatient clinics in the counties of Rogaland and Hordaland in Western Norway from March 2005 to March 2007 were screened for the study. Participants and their caregivers underwent a comprehensive and standardised diagnostic and assessment procedure. The depression subitem of the neuropsychiatric inventory (NPId) and Montgomery and Åsberg depression rating scale (MADRS) were used to estimate depression. Cut-off scores for any depression were 0/1 (NPId) and 6/7 (MADRS), and for clinically significant depression 3/4 and 14/15, respectively.

RESULTS

Two hundered and twenty-three subjects with dementia participated, of whom 59 and 50% showed symptoms of depression assessed by NPI or MADRS, respectively, and 25 and 16% had clinically significant depression as measured by NPI and MADRS, respectively. Depression was more frequent in dementia with Lewy bodies (DLB) than in Alzheimer's disease (AD; p < 0.05). APOE genotype was available in 153 patients, and in AD, but not in DLB, a general linear model showed that the presence of APOEε4 allele was significantly associated with depression (F = 4.14; p = 0.045).

CONCLUSION

Depression is common even in mild dementia, and more common and severe in DLB compared to AD. Future studies should explore the longitudinal course of depression in DLB, and the neural underpinnings of depression in DLB.

Relation of Parkinson's disease subtypes to visual activities of daily living

Visual perceptual problems are common in Parkinson's disease (PD) and often affect activities of daily living (ADLs). PD patients with non-tremor symptoms at disease onset (i.e., rigidity, bradykinesia, gait disturbance or postural instability) have more diffuse neurobiological abnormalities and report worse non-motor symptoms and functional changes than patients whose initial symptom is tremor, but the relation of motor symptom subtype to perceptual deficits remains unstudied. We assessed visual ADLs with the Visual Activities Questionnaire in 25 non-demented patients with PD, 13 with tremor as the initial symptom and 12 with an initial symptom other than tremor, as well as in 23 healthy control participants (NC). As expected, the non-tremor patients, but not the tremor patients, reported more impairment in visual ADLs than the NC group, including in light/dark adaptation, acuity/spatial vision, depth perception, peripheral vision and visual processing speed. Non-tremor patients were significantly worse than tremor patients overall and on light/dark adaptation and depth perception. Environmental enhancements especially targeted to patients with the non-tremor PD subtype may help to ameliorate their functional disability.

Vascular risk factors and the effect of white matter lesions on extrapyramidal signs in Alzheimer's disease

BACKGROUND

Extrapyramidal signs (EPSs), which are important characteristics of Parkinson's disease (PD), occur frequently in Alzheimer's disease (AD). Although AD and PD share common clinical features such as EPSs, these diseases vary with respect to vascular risk factors. The presence of vascular risk factors increases the risk of AD; however, these factors have been known to be inversely associated with PD. We aimed to assess the effect of vascular risk factors and white matter lesions (WMLs) on EPSs in AD.

METHODS

We recruited 1,187 AD patients and 333 controls with neither cognitive impairment nor EPSs. All participants underwent detailed clinical evaluations which included assessments of vascular risk factors, cognitive function, and EPSs, as well as WMLs on brain MRIs. EPS subtypes were classified into tremor-dominant, postural instability gait difficulty, or indeterminate; WMLs subtypes were classified into periventricular WML (pvWML) or deep WML (dWML).

RESULTS

EPSs were present in 17.9% of subjects with AD and were significantly associated with vascular risk factors such as age, male gender, diabetes mellitus, and WMLs. Additionally, a multivariate logistic regression analysis showed that EPSs in AD were associated with pvWML (odds ratio (OR), 1.61-2.52), not with dWML. With respect to EPS subtypes, the majority (78.4%) of EPSs in AD were postural instability gait difficulty, which was also associated with WMLs (OR 1.84-2.41), pvWML (OR 2.09-3.14), and dWML (OR 1.83-3.42).

CONCLUSIONS

EPSs in AD are associated with selected vascular risk factors as well as WMLs.

Motor sequence learning performance in Parkinson's disease patients depends on the stage of disease

It is still unclear, whether patients with Parkinson's disease (PD) are impaired in the incidental learning of different motor sequences in short succession, although such a deficit might greatly impact their daily life. The aim of this study was thus to clarify the relation between disease parameters of PD and incidental motor learning of two different sequences in short succession. Results revealed that the PD patients were able to acquire two sequences in short succession but needed more time than healthy subjects. However, both the severity of axial manifestations, as assessed on a subsection of the Unified Parkinson's Disease Rating Scale III (UPDRS III) and the Hoehn and Yahr score, and the levodopa-equivalent dose (LED) were negatively correlated with the sequence learning performance. These findings indicate that, although PD patients are able to learn two sequences in short succession, they need more time and their overall sequence learning performance is strongly correlated with the stage of disease.

Levodopa response in dementia with lewy bodies: a 1-year follow-up study

PURPOSE

To evaluate levodopa responsiveness in patients with probable dementia with Lewy bodies (DLB) compared to early Parkinson's disease (PD) patients.

METHODS

Twenty four cases with DLB and 21 with PD underwent a baseline assessment with UPDRS (sub-item II and III) and an acute levodopa challenge test. Positive response to acute levodopa test was defined as an improvement of at least 15% in the tapping test, and at least 25% in the walking test and rigidity or tremor score. Subsequently, all patients were treated continuously with levodopa and evaluated after 6 and 12 months by means of UPDRS II/III.

RESULTS

Positive response to the acute levodopa test was observed in 55% of DLB patients (acute DLB responders), and in 90% of PD patients (acute PD responders). Acute DLB responders showed increased latency, and reduction of both duration and amplitude of response to acute levodopa in comparison with acute PD responders. At the 6-month follow-up visit, acute DLB responders showed a greater motor benefit compared with acute DLB non-responders. This improvement was similar to that observed in PD patients. However, at 1-year follow-up acute DLB responders showed a faster worsening of UPDRS III scores compared with acute PD responders, implying a reduction of levodopa efficacy.

CONCLUSIONS

Positive response to acute levodopa test can occur in DLB patients and may be predictive of long-term benefit of chronic levodopa therapy, although the motor improvement is less impressive than in PD patients.

Biomarkers: Parkinson disease with dementia and dementia with Lewy bodies

Dementia is a common feature in Parkinson disease (PD), the time of onset determining how patients are classified. Those patients where dementia develops prior to parkinsonism or during the first year of disease are designated as having dementia with Lewy bodies (DLB). In those where dementia develops over a year after the onset of motor signs, the condition is known as Parkinson's disease with dementia (PDD). While this seems at first sight to be a definitive way to distinguish these conditions, reality is rather different. The overlap between them is considerable, and there is much uncertainty associated with patients who have both motor symptoms and early cognitive impairment. The diagnosis is still based on medical history and clinical evaluation. It is not even certain that they can be accurately distinguished at autopsy. For this reason, the data concerning these entities have been reviewed, to examine various markers employed or measured in clinical, neuropathological, neuroimaging, and biochemical investigations. The concept of PDD and DLB being separate conditions is comparatively new, and the most promising tools with which to separate them at present are cerebrospinal fluid (CSF) markers and positron emission tomography (PET) scanning that indicate increased amyloid-beta burden in DLB compared to PDD. However as yet there are no markers that unequivocally distinguish between PDD and DLB.

Motor phenotype of LRRK2 G2019S carriers in early-onset Parkinson disease

OBJECTIVE

To determine the motor phenotype of LRRK2 G2019S mutation carriers. LRRK2 mutation carriers were previously reported to manifest the tremor dominant motor phenotype, which has been associated with slower motor progression and less cognitive impairment compared with the postural instability and gait difficulty (PIGD) phenotype.

DESIGN

Cross-sectional observational study.

SETTING

Thirteen movement disorders centers.

PARTICIPANTS

Nine hundred twenty-five early-onset Parkinson disease cases defined as age at onset younger than 51 years.

MAIN OUTCOME MEASURES

LRRK2 mutation status and Parkinson disease motor phenotype: tremor dominant or PIGD. Demographic information, family history of Parkinson disease, and the Unified Parkinson's Disease Rating Scale score were collected on all participants. DNA samples were genotyped for LRRK2 mutations (G2019S, I2020T, R1441C, and Y1699C). Logistic regression was used to examine associations of G2019S mutation status with motor phenotype adjusting for disease duration, Ashkenazi Jewish ancestry, levodopa dose, and family history of Parkinson disease.

RESULTS

Thirty-four cases (3.7%) (14 previously reported) were G2019S carriers. No other mutations were found. Carriers were more likely to be Ashkenazi Jewish (55.9% vs 11.9%; P < .001) but did not significantly differ in any other demographic or disease characteristics. Carriers had a lower tremor score (P = .03) and were more likely to have a PIGD phenotype (92.3% vs 58.9%; P = .003). The association of the G2019S mutation with PIGD phenotype remained after controlling for disease duration and Ashkenazi Jewish ancestry (odds ratio, 17.7; P < .001).

CONCLUSION

Early-onset Parkinson disease G2019S LRRK2 carriers are more likely to manifest the PIGD phenotype, which may have implications for disease course.

Motor patterns in Parkinson's disease: a data-driven approach

To identify patterns of motor disturbances in Parkinson's disease (PD) and evaluate their relation with other PD domains. A cohort of 399 PD patients was randomly divided into two samples. Factors within the motor section of the SPES/SCOPA were identified by exploratory factor analysis on data from the first sample and next tested by confirmatory factor analysis in the second sample. Relations with other PD domains were evaluated by regression analyses. A four factor model was found to be valid. This included a tremor, a bradykinetic-rigid, and two axial factors. One axial factor ("rise", "gait", "postural instability") was associated with age and cognition, while the other axial factor ("freezing", "speech", "swallowing") was related to dopaminergic medication and complications of therapy. Both other factors showed no relevant associations with demographic and clinical characteristics. The identification of motor factors and their relation with other domains of the disease may help to elucidate the mechanisms responsible for these associations and provide an objective base for further research on subtypes in PD.

Parkinson's disease dementia: definitions, guidelines, and research perspectives in diagnosis

Cognitive impairment is common in Parkinson's disease (PD) and involves attentional, executive, visuospatial, and memory dysfunctions. Dementia is more frequently encountered in PD than in age-matched control populations, and whereas operational definitions of Alzheimer's disease and dementia with Lewy bodies have been developed, Parkinson's disease dementia (PD-D) has remained undefined. The Movement Disorder Society developed a task force to define and develop diagnostic guidelines for PD-D. This effort was based on existing descriptive studies with special emphasis on drawing distinction among Alzheimer's disease, dementia with Lewy bodies and PD-related cognitive impairment without dementia whenever possible. The second goal was to provide practical diagnostic procedures to diagnose PD-D. This effort emphasized available bedside tools that do not require neuropsychological expertise to administer or interpret. This work recently has been completed, and two primary articles have been published. The suggested clinical diagnostic criteria for PD-D involve four domains and are anchored in core features, associated clinical features, features that make the diagnosis uncertain, and features that are not compatible with the diagnosis of PD-D. When all four criteria are satisfactorily met, probable PD-D is designated; when the first and last criteria are met, but clinical characteristics are atypical or uncertainty factors exist, possible PD-D is designated. Whereas these definitions are operative and subject to change based on future data, they are based on widely available tests. The inclusion criteria can be applied internationally and in multicenter research on treatment interventions, clinicopathological correlations, and studies of cognitive and other nonmotor elements of PD.

Levodopa responsiveness in disorders with parkinsonism: a review of the literature

A literature review was conducted to investigate whether or not levodopa (LD) responsiveness (LR) is a useful criterion in the diagnosis of parkinsonian disorders. Although LR does appear to differ among the parkinsonian disorders, there is considerable confusion in the literature. While most patients with Parkinson's disease (PD) have a sustained benefit from LD, a small minority of patients with documented PD do not respond. The literature suggests that the LR rate is higher for multiple system atrophy (MSA), progressive supranuclear palsy (PSP), and corticobasal degeneration (CBD) than based on published diagnostic criteria. Magnitude and duration of response to LD and tolerability (time course, type and distribution of dyskinesias, mental effects and motor worsening) may be useful features in distinguishing PD, MSA, PSP, and CBD. Efforts should be directed toward better defining LR when used for diagnostic purposes and in scientific publications.

Clinical diagnostic criteria for dementia associated with Parkinson's disease

Dementia has been increasingly more recognized to be a common feature in patients with Parkinson's disease (PD), especially in old age. Specific criteria for the clinical diagnosis of dementia associated with PD (PD-D), however, have been lacking. A Task Force, organized by the Movement Disorder Study, was charged with the development of clinical diagnostic criteria for PD-D. The Task Force members were assigned to sub-committees and performed a systematic review of the literature, based on pre-defined selection criteria, in order to identify the epidemiological, clinical, auxillary, and pathological features of PD-D. Clinical diagnostic criteria were then developed based on these findings and group consensus. The incidence of dementia in PD is increased up to six times, point-prevelance is close to 30%, older age and akinetic-rigid form are associated with higher risk. PD-D is characterized by impairment in attention, memory, executive and visuo-spatial functions, behavioral symptoms such as affective changes, hallucinations, and apathy are frequent. There are no specific ancillary investigations for the diagnosis; the main pathological correlate is Lewy body-type degeneration in cerebral cortex and limbic structures. Based on the characteristic features associated with this condition, clinical diagnostic criteria for probable and possible PD-D are proposed.

Depression rating scales in Parkinson's disease: critique and recommendations

Depression is a common comorbid condition in Parkinson's disease (PD) and a major contributor to poor quality of life and disability. However, depression can be difficult to assess in patients with PD due to overlapping symptoms and difficulties in the assessment of depression in cognitively impaired patients. As several rating scales have been used to assess depression in PD (dPD), the Movement Disorder Society commissioned a task force to assess their clinimetric properties and make clinical recommendations regarding their use. A systematic literature review was conducted to explore the use of depression scales in PD and determine which scales should be selected for this review. The scales reviewed were the Beck Depression Inventory (BDI), Hamilton Depression Scale (Ham-D), Hospital Anxiety and Depression Scale (HADS), Zung Self-Rating Depression Scale (SDS), Geriatric Depression Scale (GDS), Montgomery-Asberg Depression Rating Scale (MADRS), Unified Parkinson's Disease Rating Scale (UPDRS) Part I, Cornell Scale for the Assessment of Depression in Dementia (CSDD), and the Center for Epidemiologic Studies Depression Scale (CES-D). Seven clinical researchers with clinical and research experience in the assessment of dPD were assigned to review the scales using a structured format. The most appropriate scale is dependent on the clinical or research goal. However, observer-rated scales are preferred if the study or clinical situation permits. For screening purposes, the HAM-D, BDI, HADS, MADRS, and GDS are valid in dPD. The CES-D and CSDD are alternative instruments that need validation in dPD. For measurement of severity of depressive symptoms, the Ham-D, MADRS, BDI, and SDS scales are recommended. Further studies are needed to validate the CSDD, which could be particularly useful for the assessment of severity of dPD in patients with comorbid dementia. To account for overlapping motor and nonmotor symptoms of depression, adjusted instrument cutoff scores may be needed for dPD, and scales to assess severity of motor symptoms (e.g., UPDRS) should also be included to help adjust for confounding factors. The HADS and the GDS include limited motor symptom assessment and may, therefore, be most useful in rating depression severity across a range of PD severity; however, these scales appear insensitive in severe depression. The complex and time-consuming task of developing a new scale to measure depression specifically for patients with PD is currently not warranted.

A novel locus for dementia with Lewy bodies: a clinically and genetically heterogeneous disorder

Dementia with Lewy bodies (DLB) represents the second most frequent type of neurodegenerative dementia in the elderly. Although most patients have sporadic DLB, a limited number of DLB families have been described, suggesting that genetic factors may contribute to DLB pathogenesis. Here, we describe a three-generation Belgian family with prominent dementia and parkinsonism, consistent with a diagnosis of DLB, that was autopsy confirmed for the index patient. In a genome-wide scan and subsequent finemapping of candidate loci we obtained significant linkage to 2q35-q36 (Z = 3.01 at D2S1242). Segregation analysis defined a candidate region of 9.2 Mb between D2S433 and chr2q36.3-8, adjacent to the previously reported PARK11 locus. In addition, haplotype sharing studies in another DLB family of close geographical origin with similar clinical and neuropathological features highlighted the specificity of a 2q35-q36 haplotype harbouring a pathogenic mutation that causes DLB in the Belgian family. So far, extensive sequence analysis of five candidate genes within the 2q35-q36 region has not revealed a disease-causing mutation. Together, our data re-emphasize the genetic heterogeneity of DLB, and strongly support the existence of a gene for familial DLB on 2q35-q36. Once identified this will be the first novel causal gene for DLB and can be expected to open new avenues for biological studies of the disease process.

Evolution of cognitive dysfunction in an incident Parkinson's disease cohort

We have previously performed detailed clinical and neuropsychological assessments in a community-based cohort of patients with newly diagnosed parkinsonism, and through analysis of a subcohort with idiopathic Parkinson's disease (PD), we have demonstrated that cognitive dysfunction occurs even at the time of PD diagnosis and is heterogeneous. Longitudinal follow-up of the cohort has now been performed to examine the evolution of cognitive dysfunction within the early years of the disease. One hundred and eighty (79%) eligible patients from the original cohort with parkinsonism were available for re-assessment at between 3 and 5 years from their initial baseline assessments. PD diagnoses were re-validated with repeated application of the UKPDS Brain Bank criteria in order to maximize sensitivity and specificity, following which a diagnosis of idiopathic PD was confirmed in 126 patients. Thirteen out of 126 (10%) had developed dementia at a mean (SD) of 3.5 (0.7) years from diagnosis, corresponding to an annual dementia incidence of 30.0 (16.4-52.9) per 1000 person-years. A further 57% of PD patients showed evidence of cognitive impairment, with frontostriatal deficits being most common amongst the non-demented group. However, the most important clinical predictors of global cognitive decline following correction for age were neuropsychological tasks with a more posterior cortical basis, including semantic fluency and ability to copy an intersecting pentagons figure, as well as a non-tremor dominant motor phenotype at the baseline assessment. This work clarifies the profile of cognitive dysfunction in early PD and demonstrates that the dementing process in this illness is heralded by both postural and gait dysfunction and cognitive deficits with a posterior cortical basis, reflecting probable non-dopaminergic cortical Lewy body pathology. Furthermore, given that these predictors of dementia are readily measurable within just a few minutes in a clinical setting, our work may ultimately have practical implications in terms of guiding prognosis in individual patients.

Autonomic and cognitive dysfunction in Parkinson's disease

OBJECTIVE

To investigate whether there is an association between autonomic failure and cognitive impairment in patients with idiopathic Parkinson's disease (PD) METHODS: 40 PD patients and 30 age matched controls were assessed for cognitive and behavioral manifestations using the Mini-Mental State Examination (MMSE), the Frontal Assessment Battery (FAB), the Blessed scale and Cornell scale for depression. The subjects were also assessed for orthostatic hypotension (OH), postprandial hypotension (PPH), heart rate responses to deep breathing (HR(DB)) and autonomic symptoms using the Scale for Outcomes in PD for autonomic symptoms (SCOPA AUT).

RESULTS

There was a correlation between the severity of motor symptoms and cognitive impairment in our PD patients. Eleven of the 40 PD patients fulfilled the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) criteria of dementia. The presence of OH or PPH did not correlate with the severity of cognitive impairment in our PD cases. However, PD patients with dementia reported more cardiovascular symptoms than PD patients without dementia. There was no correlation between gastrointestinal or urologic symptoms and cognitive impairment in our PD cases.

CONCLUSION

The results of this limited study indicate that despite the higher incidence of cardiovascular symptoms in PD patients with dementia than in those without dementia, there is no consistent association between OH or PPH and cognitive deficits in PD. The lack of correlation between OH, gastrointestinal and urinary symptoms with cognitive impairment suggests that cognitive and autonomic involvement progresses independently from each other and variably among PD patients.

Changes in motor subtype and risk for incident dementia in Parkinson's disease

The objective of this study was to assess the temporal relationship between changes in predominant motor symptoms and incident dementia in Parkinson's disease (PD). A community-based sample of 171 nondemented patients with PD was followed prospectively and examined at baseline and after 4 and 8 years. The motor subtype of Parkinsonism was classified into tremor-dominant (TD), indeterminate, or postural instability gait difficulty (PIGD) subtype at each visit, based on defined items in the Unified Parkinson's Disease Rating Scale, subscales II and III. Dementia was diagnosed according to DSM-III-R criteria, based on clinical interview, cognitive rating scales, and neuropsychological examination. Logistic regression was used to analyze the relationship between subtype of Parkinsonism and dementia. Transition from TD to PIGD subtype was associated with a more than threefold increase in the rate of Mini-Mental State Examination decline. Compared to patients with persistent TD or indeterminate subtype, the odds ratio for dementia was 56.7 (95% CI: 4.0-808.4; P = 0.003) for patients changing from TD or indeterminate subtype to PIGD subtype, and 80.0 (95% CI: 4.6-1400.1; P = 0.003) for patients with persistent PIGD subtype. Patients with TD subtype at baseline did not become demented until they developed PIGD subtype, and dementia did not occur among patients with persistent TD subtype of Parkinsonism. In a substantial proportion of PD patients who develop postural instability and gait disorder during the course of the disease, this transition is associated with accelerated cognitive decline and highly increased risk for subsequent dementia. These findings raise the question whether PIGD and dementia share common or parallel neuropathology.

Regional cerebral blood flow in Parkinson??s disease as an indicator of cognitive impairment

OBJECTIVE

To investigate the pattern of regional cerebral blood flow (rCBF) deficits in Parkinson's disease patients in relation to cognitive decline and to assess the clinical usefulness of single photon emission tomography (SPET) scanning in differentiation between Parkinson's disease patients with dementia and those without cognitive deficits.

METHODS

We performed Tc-ECD SPET in 60 patients with idiopathic Parkinson's disease (F: 25, M: 35), with average age of 68.4 years (SD+/-7.3, range 51-81 years). All patients were examined neurologically with the assessment of stage and severity of Parkinson's disease (Hoehn-Yahr scale, UPDRS, Schwab-England scale). Detailed neuropsychological examination was performed in each Parkinson's disease patient. On the basis of DSM-IV criteria of dementia and the results obtained in psychological examination, the whole group was divided into three subgroups: I, with no cognitive changes (n = 17); II, with mild cognitive impairment (n = 25); and III, with dementia (n = 18).

RESULTS

There was noticeable significant decrease of perfusion in all areas in Parkinson's disease patients when compared to the age-matched control group of healthy volunteers (n = 20). In group III, perfusion was significantly decreased (when compared to groups I and II), particularly in parietal and temporal areas with the predominance of the left side. Regression analysis revealed two independent factors related to dementia: decrease of perfusion within left temporal lobe and its increase within left thalamus.

CONCLUSION

Parkinson's disease patients with dementia showed left temporo-parietal hypoperfusion as compared to a group of patients without dementia, which resembles perfusion deficits described in Alzheimer's disease. The hypoperfusion of the left temporal lobe with increase of rCBF within the left thalamus might be clinically useful in discrimination of Parkinson's disease patients with dementia against those without cognitive impairment.

Arrestins and two receptor kinases are upregulated in Parkinson's disease with dementia

Arrestins and G proteins-coupled receptor kinases (GRKs) regulate signaling and trafficking of G protein-coupled receptors. We investigated changes in the expression of arrestins and GRKs in the striatum of patients with Parkinson's disease without (PD) or with dementia (PDD) at postmortem using Western blotting and ribonuclease protection assay. Both PD and PDD groups had similar degree of dopamine depletion in all striatal regions. Arrestin proteins and mRNAs were increased in the PDD group throughout striatum. Protein and mRNA of GRK5, the major subtype in the human striatum, and GRK3 were also upregulated, whereas GRK2 and 6 were mostly unchanged. The PD group had lower concentration of arrestins and GRKs than the PDD group. There was no statistical link between the load of Alzheimer's pathology and the expression of these signaling proteins. Upregulation of arrestins and GRK in PDD may confer resistance to the therapeutic effects of levodopa often observed in these patients. In addition, increased arrestin and GRK concentrations may lead to dementia via perturbation of multiple signaling mechanisms.

More severe functional impairment in dementia with lewy bodies than Alzheimer disease is related to extrapyramidal motor dysfunction

OBJECTIVE

The objective of this study was to compare functional impairments in dementia with Lewy bodies (DLB) and Alzheimer disease (AD) and their relationship with motor and neuropsychiatric symptoms.

METHODS

The authors conducted a cross-sectional study of 84 patients with DLB or AD in a secondary care setting. Patients were diagnosed according to published criteria for DLB and AD. The Bristol Activities of Daily Living Scale (BADLS) was used to assess functional impairments. Participants were also assessed using the Unified Parkinson's Disease Rating Scale (motor section), the Neuropsychiatric Inventory, and the Mini-Mental Status Examination.

RESULTS

Patients with DLB were more functionally impaired and had more motor and neuropsychiatric difficulties than patients with AD with similar cognitive scores. In both AD and DLB, there were correlations between total BADLS scores and motor and neuropsychiatric deficits. There was more impairment in the mobility and self-care components of the BADLS in DLB than in AD, and in DLB, these were highly correlated with UPDRS score. In AD, orientation and instrumental BADLS components were most affected.

CONCLUSION

The nature of functional disability differs between AD and DLB with additional impairments in mobility and self-care in DLB being mainly attributable to extrapyramidal motor symptoms. Consideration of these is important in assessment and management. Activities of daily living scales for use in this population should attribute the extent to which functional disabilities are related to cognitive, psychiatric, or motor dysfunction.

Motor subtype and cognitive decline in Parkinson's disease, Parkinson's disease with dementia, and dementia with Lewy bodies

BACKGROUND

A previous cross sectional study found over-representation of a postural instability gait difficulty (PIGD) motor subtype in Parkinson's disease patients with dementia (PDD) and dementia with Lewy bodies (DLB), compared with Parkinson's disease (PD).

AIMS

(1) To examine rates of cognitive and motor decline over two years in PD (n=40), PDD (n=42) and DLB (n=41) subjects, compared with age matched controls (n=41), (2) to record whether motor phenotypes of PD, PDD, and DLB subjects changed during the study, (3) to find out if cognitive and motor decline in PD was associated with baseline motor subtype, and (4) to report the incidence of dementia in PD patients in relation to baseline motor subtype.

RESULTS

Most of PDD and DLB participants were PIGD subtype at baseline assessment. In the non-demented PD group, tremor dominant (TD) and PIGD subtypes were more evenly represented. Cognitive decline over two years was greater in PDD and DLB groups (mean decline in MMSE -4.5 and -3.9, respectively), compared with PD (-0.2) and controls (-0.3). There was an association between PIGD subtype and increased rate of cognitive decline within the PD group. Of 40 PD patients, 25% of the 16 PIGD subtype developed dementia over two years, compared with none of the 18 TD or six indeterminate phenotype cases (chi2=6.7, Fisher's exact test p<0.05).

CONCLUSION

A PIGD motor subtype is associated with a faster rate of cognitive decline in PD and may be considered a risk factor for incident dementia in PD.

Lewy body disease: thalamic cholinergic activity related to dementia and parkinsonism

Within the spectrum of Lewy body disease cognitive impairment occurs in PD with dementia (PDD) and dementia with Lewy bodies (DLB). Although neocortical cholinergic deficits are associated with cognitive impairments in PDD and DLB, no neurochemical study has been published describing the thalamic cholinergic activity whereas the thalamus plays a major role in modulating cortical activity. Choline acetyltransferase (ChAT) activity was analyzed in reticular (Re), mediodorsal (MD) and centromedian (CM) thalamic nuclei in series of nine controls, five DLB with parkinsonism (DLB + P), five DLB without parkinsonism (DLB - P), six PD without dementia and 14 PDD cases. Significant reductions in ChAT were apparent in PDD as follows: in Re and MD nuclei compared with controls; in MD and CM nuclei compared with DLB + P; and in MD compared with PD. Increased ChAT activity was found in CM nuclei in DLB + P compared with DLB - P. These findings show that significant thalamic presynaptic cholinergic deficits occur only in cases of combined cortical and subcortical neurodegeneration in which dementia developed after prolonged parkinsonism.

Characteristics of visual hallucinations in Parkinson disease dementia and dementia with lewy bodies

OBJECTIVE

Parkinson disease dementia (PDD) and dementia with Lewy bodies (DLB) have overlapping clinical and pathologic features. Recurrent visual hallucinations (RVH) are common in both disorders. The authors have compared details of hallucination characteristics and associated neuropsychiatric features in DLB and PDD.

METHODS

This is a descriptive, cross-sectional study using the Institute of Psychiatry Visual Hallucinations Interview (IP-VHI) to explore self-reported frequency, duration, and phenomenology of RVH in PDD and DLB. The caregivers' ratings of hallucinations and other neuropsychiatric features were elicited with the Neuropsychiatric Inventory (NPI).

RESULTS

Fifty-six patients (35 PDD; 21 DLB) with RVH were assessed. Hallucination characteristics were similar in both disorders. Simple hallucinations were rare. Most patients experienced complex hallucinations daily, normally lasting minutes. They commonly saw people or animals and the experiences were usually perceived as unpleasant. NPI anxiety scores were higher in PDD. Neuropsychiatric symptoms coexisting with hallucinations were apathy, sleep disturbance, and anxiety.

CONCLUSIONS

Patients with mild to moderate dementia can provide detailed information about their hallucinations. Characteristics of RVH were similar in PDD and DLB, and phenomenology suggests the involvement of dorsal and ventral visual pathways in their generation. The coexistence of RVH with anxiety, apathy, and sleep disturbance is likely to impair patients' quality of life and may have treatment implications.

Update on dementia with Lewy bodies

Dementia with Lewy bodies (DLB) presents to a range of specialists and involves a number of management challenges. The nosologic status of the disorder is controversial, especially its clinical overlap with Parkinson's disease-related dementia and its pathologic distinction from Alzheimer's disease. This article considers some of the controversies surrounding DLB with reference to recent literature. Emphasis is given to clinical topics, including the clinical phenomenology, differential diagnosis, and the treatment of core features of the disease.

Clinical, diagnostic, genetic and management issues in dementia with Lewy bodies

DLB (dementia with Lewy bodies) is a syndrome associated with underlying LBD (Lewy body disease), with manifestations in the cognitive, neuropsychiatric, motor, sleep and autonomic domains. The variable symptomatology and complex array of neuronal involvement and neurotransmitter deficiencies make the diagnosis and management of patients with DLB challenging. The genetic underpinnings of DLB have only recently begun to unfold. In this review, the clinical features, diagnostic criteria, genetics and treatment issues relating to DLB will be discussed, in which a comprehensive approach to the diagnosis and management is emphasized.

Dementia with Lewy bodies: current concepts

As life expectancy continues to increase over time, dementia is becoming an increasingly more common problem and a major cause of disability in older persons. It is now more important than ever to identify and manage common causes of dementia given variations in disease course, treatments and the possibility for modification of risk factors. Dementia with Lewy bodies (DLB) is a dementia syndrome characterized by progressive cognitive decline, with fluctuating cognition, recurrent detailed and well-formed hallucinations, and parkinsonism. This article aims to provide an overview of current concepts of DLB, including a description of the key clinical features and neuropathology, neurochemistry, and genetics of DLB, then a discussion of the relationship of DLB with Alzheimer's disease and Parkinson's disease, and, finally, a summary of current management strategies available for this disorder.

A comparison of the efficacy of donepezil in Parkinson's disease with dementia and dementia with Lewy bodies

BACKGROUND

Parkinson's disease with dementia (PDD) and dementia with Lewy bodies (DLB) overlap in phenomenology and neurochemical deficits. We hypothesised they would not differ in their response to the cholinesterase inhibitor donepezil.

METHODS

We recruited 70 subjects, 30 DLB and 40 PDD, in an open label study to compare the efficacy of donepezil in these two patient groups. They were assessed at baseline, 4, 12 and 20 weeks. The main outcome measures were the Mini-Mental State Examination (MMSE), Neuropsychiatric Inventory (NPI) and motor sub-section of the Unified Parkinson's Disease Rating Scale (UPDRS III).

RESULTS

PDD patients were younger than DLB and had more severe parkinsonism at baseline. The groups were similar on all other variables of interest. By 20 weeks the mean MMSE score increased by 3.9 points in the DLB group and by 3.2 points in PDD. The mean NPI score reduced by 14.6 points for DLB and 12.0 points for PDD. These treatment effects were all significant compared to baseline (p < 0.001) but there were no significant between-group treatment differences (MMSE p = 0.56, NPI p = 0.39). UPDRS III motor scores did not change significantly from baseline values in either group. Although adverse effects were common (69%) they were usually mild and 64 patients (91%) completed the study. The four patients who did withdraw with adverse effects all had a PDD diagnosis.

CONCLUSIONS

Donepezil produced similar improvements in cognition and behaviour in DLB and PDD. This supports the hypothesis that the two disorders are closely related clinically and neurobiologically. Larger scale, placebo controlled clinical trials are needed to provide an evidence base to guide the clinical use of cholinesterase inhibitors in Lewy body disease.

The role of levodopa in the management of dementia with Lewy bodies

BACKGROUND

One of the core clinical features of dementia with Lewy bodies (DLB) is extrapyramidal syndrome (EPS). Levodopa is currently the gold standard oral therapy for Parkinson's disease (PD), but its use in DLB has been tempered by concerns of exacerbating neuropsychiatric symptoms.

AIM

To assess the efficacy and tolerability of L-dopa in managing EPS in DLB and to compare the motor response with that seen in PD and PD with dementia (PDD).

METHOD

EPS assessment consisted of the Unified Parkinson's Disease Rating Scale, motor subsection (UPDRS III), and finger tapping and walking tests. Patients with DLB were commenced on L-dopa. After 6 months, patients were examined in the "off" state, given L-dopa and assessed for motor responses. Identical assessments were performed in patients with PD and PDD also receiving L-dopa.

RESULTS

Acute L-dopa challenge in 14 DLB patients yielded a mean 13.8% (p = 0.02) improvement in UPDRS III score, compared with 20.5% in PD (n = 28, p < 0.0001) and 23% in PDD (n = 30, p<0.0001) respectively. Finger tapping scores increased (12.3% v 20% and 23%), while walking test scores decreased (32% v 41% and 67%). Of the DLB patients, 36% were classified as "responders" on L-dopa challenge, compared with 70% of the PDD and 57% of the PD patients. Nineteen DLB patients were treated for 6 months with L-dopa (mean daily dose 323 mg). Two withdrew prematurely with gastrointestinal symptoms and two with worsening confusion.

CONCLUSION

L-dopa was generally well tolerated in DLB but produced a significant motor response in only about one third of patients. Younger DLB cases were more likely to respond to dopaminergic treatment.

Brain 3D-SSP SPECT analysis in dementia with Lewy bodies, Parkinson's disease with and without dementia, and Alzheimer's disease

OBJECTIVES

Cerebral blood flow was compared among patients with dementia with Lewy bodies (DLB), Parkinson's disease with dementia (PDD), Parkinson's disease without dementia (PD), and Alzheimer's disease (AD) using three-dimensional stereotactic surface projection (3D-SSP) analysis.

PURPOSE

We attempt to clarify the difference of reduction pattern on SPECT among patients having DLB, PDD, PD, AD.

PATIENTS AND METHODS

Six patients with DLB, 7 patients with PDD who were matched with the DLB patients for age, unified Parkinson's disease rating scale-III (UPDRS-III) score, and degree of cognitive function disorders, 21 patients with PD who were matched with the DLB patients for age, UPDRS-III score, 12 patients with AD who were matched with the DLB patients for age and degree of cognitive function disorders, and 12 control subjects. All patients were examined by N-isopropyl-p[123I] iodoamphetamine single photon emission computed tomography (123I-IMP SPECT), and obtained images were analyzed with 3D-SSP using an image-analysis software, iSSP ver. 3.5.

RESULTS

Although DLB and PDD showed similar cerebral perfusion reduction pattern at the lateral parietal association and lateral temporal association and precuneus on SPECT by the pixel-by-pixel comparison, greater perfusion reduction was observed in DLB than in PDD. Cerebral perfusion was decreased at the occipital lobe of the DLB patients compared with the AD patients.

CONCLUSIONS

The regional pattern of blood flow reduction in the brain was found to be different among DLB, PD, and AD. Greater blood flow reduction was observed in DLB, although DLB and PDD showed similar reduction pattern. These regional differences were considered to suggest different and disease-specific combinations of underlying pathological and neurochemical processes.

Longitudinal study of cerebral blood flow SPECT in Parkinson's disease with dementia, and dementia with Lewy bodies

BACKGROUND

People with Parkinson's disease (PD) have an increased risk of developing dementia (PDD), which often has clinical features similar to dementia with Lewy bodies (DLB). Whilst perfusion studies have shown parieto-occipital hypoperfusion in DLB and PDD relative to controls, there have not been any longitudinal studies of perfusion changes in PDD and DLB.

METHODS

In this study, we measured brain perfusion using Tc99m HMPAO SPECT over one year in 17 PDD, 18 DLB and 34 healthy subjects. We used SPM99 to compare perfusion changes in the two dementia groups against the control group.

RESULTS

We did not see any reductions in perfusion in either of the dementia groups. However, in the DLB, but not PDD group, there was a significant increase in putamen perfusion relative to controls over the year. In both DLB and PDD groups, there was a correlation between striatal perfusion increase over the year, and worsening of parkinsonism. Perfusion changes were not secondary to changes in antiparkinsonian medication.

CONCLUSION

The increase in striatal perfusion may be a compensatory change related to decreasing striatal dopaminergic input from the substantia nigra in PDD and DLB, consistent with the increased predominance of rigidity over tremor symptoms in these groups compared with non-demented PD.

Change in perfusion, hallucinations and fluctuations in consciousness in dementia with Lewy bodies

Fluctuations in consciousness and visual hallucinations are common neuropsychiatric features of dementia with Lewy bodies and Parkinson's disease dementia. To investigate potential neural correlates, we compared how changes in brain perfusion over a 1-year period were related to changes in the severity of these key clinical features. We recruited 29 subjects with either Parkinson's disease with dementia (15 subjects) or dementia with Lewy bodies (14 subjects). Cerebral perfusion was measured using HMPAO SPECT at baseline, and repeated 1 year later. The presence of hallucinations (Neuropsychiatric Inventory), severity of fluctuations in consciousness (fluctuation assessment scale) and cognitive ability (CAMCOG) were assessed at both time points. After controlling for changes in cognitive ability and effect of cholinesterase medication, we found a significant correlation between an increase in perfusion in midline posterior cingulate and decrease in hallucination severity. There was also a significant correlation between increased fluctuations of consciousness and increased thalamic and decreased inferior occipital perfusion. We have identified important neural correlates of key clinical features in Lewy body dementia and postulate that the associations can be understood through the influence of the cholinergic system on attention.

Progression of dopaminergic degeneration in dementia with Lewy bodies and Parkinson’s disease with and without dementia assessed using 123I-FP-CIT SPECT

PURPOSE

The objective of this study was to investigate the rate of progression of nigrostriatal dopaminergic loss in subjects with dementia with Lewy bodies (DLB), Parkinson's disease (PD) and PD with dementia (PDD) using serial 123I-FP-CIT SPECT imaging. We hypothesised that striatal rates of decline in patients would be greater than in controls, and that DLB and PDD would show similar rates, reflecting the similarity in neurobiological mechanisms of dopaminergic loss between the two disorders.

METHODS

We studied 20 patients with DLB, 20 with PD, 15 with PDD and 22 healthy age-matched controls. Semi-automated region of interest (ROI) analysis was performed on both baseline and repeat scans for each subject and mean striatal uptake ratios (caudate, anterior and posterior putamen) were calculated.

RESULTS

Rates of decline in striatal binding between groups were assessed using ANCOVA. Significant differences between patients and controls were observed in caudate (DLB, PD, PDD, p< or =0.01), anterior putamen (DLB, PDD, p< or =0.05; PD, p=0.07) and posterior putamen (DLB, PD, PDD, p<0.006). Rates of decline were similar between DLB, PD and PDD.

CONCLUSION

In conclusion, this is the first study to show that significant progressive dopaminergic loss occurs in DLB and PDD using serial 123I-FP-CIT SPECT. Dementia severity and motor impairment were correlated with decline, suggesting that dopaminergic loss may play an important role in cognitive as well as motor features.

Saccadic eye movement changes in Parkinson's disease dementia and dementia with Lewy bodies

Neurodegeneration in Parkinson's disease dementia (PDD) and dementia with Lewy bodies (DLB) affect cortical and subcortical networks involved in saccade generation. We therefore expected impairments in saccade performance in both disorders. In order to improve the pathophysiological understanding and to investigate the usefulness of saccades for differential diagnosis, saccades were tested in age- and education-matched patients with PDD (n = 20) and DLB (n = 20), Alzheimer's disease (n = 22) and Parkinson's disease (n = 24), and controls (n = 24). Reflexive (gap, overlap) and complex saccades (prediction, decision and antisaccade) were tested with electro-oculography. PDD and DLB patients had similar impairment in all tasks (P > 0.05, not significant). Compared with controls, they were impaired in both reflexive saccade execution (gap and overlap latencies, P < 0.0001; gains, P < 0.004) and complex saccade performance (target prediction, P < 0.0001; error decisions, P < 0.003; error antisaccades: P < 0.0001). Patients with Alzheimer's disease were only impaired in complex saccade performance (Alzheimer's disease versus controls, target prediction P < 0.001, error decisions P < 0.0001, error antisaccades P < 0.0001), but not reflexive saccade execution (for all, P > 0.05). Patients with Parkinson's disease had, compared with controls, similar complex saccade performance (for all, P > 0.05) and only minimal impairment in reflexive tasks, i.e. hypometric gain in the gap task (P = 0.04). Impaired saccade execution in reflexive tasks allowed discrimination between DLB versus Alzheimer's disease (sensitivity > or =60%, specificity > or =77%) and between PDD versus Parkinson's disease (sensitivity > or =60%, specificity > or =88%) when +/-1.5 standard deviations was used for group discrimination. We conclude that impairments in reflexive saccades may be helpful for differential diagnosis and are minimal when either cortical (Alzheimer's disease) or nigrostriatal neurodegeneration (Parkinson's disease) exists solely; however, they become prominent with combined cortical and subcortical neurodegeneration in PDD and DLB. The similarities in saccade performance in PDD and DLB underline the overlap between these conditions and underscore differences from Alzheimer's disease and Parkinson's disease.

Treatment of dementia with Lewy bodies and Parkinson's disease dementia

Cognitive decline and dementia affect approximately 30% to 40% of patients with idiopathic Parkinson's disease during the course of their illness. PD-dementia (PDD) and dementia with Lewy bodies (DLB) are second to Alzheimer's disease in causing degenerative dementia in the elderly. The nosological distinction of the conditions has remained controversial because of broad clinical and pathological overlap. Treatment issues in both clinical settings are virtually identical. Treatment of Parkinsonism is often complicated by drug-induced psychosis and reduced levodopa responsiveness. Cognition, alertness, attention, as well as apathy or aggressive behavior have been shown to respond to treatment with cholinesterase inhibitors in randomized controlled trials both in DLB and PDD. Such treatment may also improve hallucinosis, but many patients will require add-on treatment with atypical neuroleptics to control drug-induced psychotic reactions. Clozapine and quetiapine are the drugs most commonly used and, contrary to classic neuroleptics, risperidone or olanzapine do not seem to cause severe side effects according to published data.

Dementia with Lewy Bodies

The neurobehavioral and pathologic features of Parkinson disease dementia (PDD) are virtually identical to those of dementia with Lewy bodies (DLB), suggesting that they represent different phenotypes of the same underlying disease. Both are characterized clinically by a "frontal-subcortical" dementia, fluctuating confusion, and, often, psychotic symptoms. Pathologically they are characterized by disseminated Lewy bodies and multiple transmitter deficits. These dementias with Lewy bodies constitute the second leading cause of dementia after Alzheimer disease (AD), and are thus an important treatment target. No drug has yet been approved for these indications, but treatment options are emerging. This paper addresses the conduct of clinical trials for this indication, including definition of target populations, screening metrics, outcome measures, and clinical trial designs. As the pathophysiology of these cognitive and behavioral changes becomes better understood, symptomatic as well as disease-modifying therapy may become possible, requiring an inclusive and consistent approach to clinical trials in this area.

Are Parkinson's disease with dementia and dementia with Lewy bodies the same entity?

The diagnosis of Parkinson's disease with dementia (PDD) or dementia with Lewy bodies (DLB) is based on an arbitary distinction between the time of onset of motor and cognitive symptoms. These syndromes share many neurobiological similarities, but there are also differences. Deposition of beta-amyloid protein is more marked and more closely related to cognitive impairment in DLB than PDD, possibly contributing to dementia at onset. The relatively more severe executive impairment in DLB than PDD may relate to the loss of frontohippocampal projections in DLB. Visual hallucinations and delusions associate with more abundant Lewy body pathology in temporal cortex in DLB. The differential involvement of pathology in the striatum may account for the differences in parkinsonism. Longitudinal studies with neuropathological and neurochemical evaluations will be essential to enable more robust comparisons and determine pathological substrates contributing to the differences in cognitive, motor, and psychiatric symptoms.

Role of cholinesterase inhibitors in Parkinson's disease and dementia with Lewy bodies

This article reviews the cholinergic changes in Parkinson's disease and dementia (PDD) and dementia with Lewy bodies (DLB), their potential clinical implications, and the available evidence for cholinesterase inhibitors in the treatment of PDD and DLB. Marked neuronal loss of cholinergic nuclei, reduced cholinergic markers in the neocortex, hippocampus, and selected thalamic nuclei, and receptor changes have been reported. One large and 2 small placebo-controlled trials and nearly 20 open-label studies suggest that cholinesterase inhibitors have a positive effect on cognition, psychiatric symptoms, and global function in patients with DLB and PDD. The treatment is well tolerated in most patients without any apparent worsening of extrapyramidal motor features. Given the high risk of severe sensitivity reactions and increased risk of cerebrovascular incidents during treatment with neuroleptics, more clinical trials of cholinesterase inhibitors are encouraged to establish their precise role in DLB and PDD.

Regional cerebral blood flow in Parkinson's disease with and without dementia

Tc99 HMPAO SPECT and T1 weighted 3D MRI scans were acquired in cognitively intact subjects with Parkinson's disease (PD) (n = 31), and in PD subjects with dementia (PDD) (n = 34), healthy controls (n = 37), those with Alzheimer's disease (AD) (n = 32), and those with dementia with Lewy bodies (DLB) (n = 15). We used SPM99 to look for regions which showed a reduction in perfusion on SPECT not related to associated structural brain changes assessed by a MRI scan. The precuneus and inferior lateral parietal regions showed a perfusion deficit in Parkinson's disease with dementia, similar to the pattern observed in DLB. In comparison, AD showed a perfusion deficit in the midline parietal region, in a more anterior and inferior location than in PDD, involving the posterior cingulate as well as the precuneus. The perfusion deficits in PDD are similar those in DLB, and in a location associated with visual processing, and may be associated with the visuospatial perception deficits which are present in persons with DLB and PDD.