Risk of dementia in Parkinson's disease: a community-based, prospective study

Frequency of dementia, depression, and other neuropsychiatric symptoms in 1,449 outpatients with Parkinson's disease

Neuropsychiatric symptoms (NPS) of Parkinson's disease (PD) are of growing diagnostic and therapeutic importance. Data on their prevalence and characteristics have been primarily derived from highly selective clinical populations. We have conducted a national study in the outpatient care sector to provide a fuller characterization of the frequency of dementia, depression, and other NPS in PD outpatients. We also examined associations with biosocial and neurological variables. A nationwide representative sample of 1,449 PD outpatients was examined with a standardized clinical interview. PD severity was rated with the Hoehn and Yahr (HY) scale and the Unified Parkinson's Disease Rating Scale. Depression was measured with the Montgomery-Asberg Depression Rating Scale. Cognitive impairment and dementia were assessed with the Mini-Mental State Exam and according to diagnostic criteria. Logistic regression analyses were used to investigate associations. At least one NPS occurred in 71% of all patients with PD. The estimated prevalences (ranges) by age group and HY-stage were: depression, 25% (13.2-47.9%), dementia, 29% (12.2-59.4%), and psychotic syndromes, 12.7% (3.1-40.9%). Other frequent complications were sleep disturbances (49%) and anxiety (20%). Depression was associated with gender but not with age. Dementia was associated with age. The rates and comorbidity of depression and dementia were driven by PD severity. NPS were highly prevalent in our comprehensive patient sample, largely representative of management problems occurring in an outpatient setting. PD outpatients are at an increased risk for all neuropsychiatric conditions, increasing with PD severity but not with age or age of onset (except dementia), revealing challenging symptom patterns.

Glycoproteomics in neurodegenerative diseases

Protein glycosylation regulates protein function and cellular distribution. Additionally, aberrant protein glycosylations have been recognized to play major roles in human disorders, including neurodegenerative diseases. Glycoproteomics, a branch of proteomics that catalogs and quantifies glycoproteins, provides a powerful means to systematically profile the glycopeptides or glycoproteins of a complex mixture that are highly enriched in body fluids, and therefore, carry great potential to be diagnostic and/or prognostic markers. Application of this mass spectrometry-based technology to the study of neurodegenerative disorders (e.g., Alzheimer's disease and Parkinson's disease) is relatively new, and is expected to provide insight into the biochemical pathogenesis of neurodegeneration, as well as biomarker discovery. In this review, we have summarized the current understanding of glycoproteins in biology and neurodegenerative disease, and have discussed existing proteomic technologies that are utilized to characterize glycoproteins. Some of the ongoing studies, where glycoproteins isolated from cerebrospinal fluid and human brain are being characterized in Parkinson's disease at different stages versus controls, are presented, along with future applications of targeted validation of brain specific glycoproteins in body fluids.

Non-motor symptoms in Parkinson's disease

Parkinson's disease is a hypokinetic movement disorder with cardinal motor features of bradykinesia, resting tremor and rigidity. However, non-motor symptoms, such as cognitive, neuropsychiatric, sleep, autonomic and sensory disturbances are gaining increasing attention. These non-motor symptoms may be intrinsic to the disease pathology or may be results of treatment with dopaminergic agents. Given that most, if not all, patients with Parkinson's disease will experience non-motor symptoms, it is important to be sensitive to these phenomena, especially since some non-motor signs may precede motor impairment. Treatment may include interventions independent of traditional, dopaminergic anti-Parkinson therapy or may be tailored to increase or reduce dopamine responsiveness of the symptom.

Progression of Parkinson's disease in the clinical phase: potential markers

Neuromodulatory or even neuroprotective therapy could soon be available for Parkinson's disease (PD), raising the question of how we should define and measure disease progression. Reported evidence suggests that several symptoms worsen with disease duration. Bradykinesia, rigidity, and activities of daily living deteriorate faster at the beginning of the disease, and this deterioration is paralleled by a decline in functional presynaptic dopaminergic activity, as shown by imaging techniques. Cognitive, speech, sleep, and gait difficulties might progress linearly in proportion to disease duration. Reduced variability in heart rate, orthostatic dysfunction, and visual hallucinations start to develop at mid-stage disease and are more common in late stages than earlier stages. In this Review, we summarise our current understanding of the progression of PD-associated symptoms and markers and conclude that an effective measurement of progression of PD must adapt to the different stages of the disease. In addition to routine clinical rating scales, new quantitative assessments of motor and non-motor symptoms, which should be more broadly available, reasonably priced, and easy-to-use, are needed.

Depressive symptoms in Parkinson disease correlate with impaired global and specific cognitive performance

Consecutive patients in a Movement Disorders Center with Parkinson disease (PD) were offered to undergo complete neuropsychological testing and to complete the Beck Depression Inventory (BDI), regardless of their cognitive and behavioral status. A total of 82 patients were included in this cross-sectional study and had a mean age of 67.7 years, formal education of 14.8 years, PD duration of 101 months, Unified Parkinson Disease Rating Scale-Motor ''off'' score of 36.96, Mini-Mental State Examination (MMSE) score of 27.8 (range 19-30), and BDI score of 10.23 (SD 8.65). Beck Depression Inventory scores did not correlate with disease duration or motor scores but inversely correlated with the MMSE scores (r = -0.40; P < .001) and total Dementia Rating Scale (DRS) scores (r = -0.33; P < .01). Using a univariate regression analysis controlling for age, gender, education, and total Unified Parkinson Disease Rating Scales (UPDRS) score, the BDI scores had a significant and unique relationship with MMSE scores. However, when the BDI scores were correlated with specific cognitive domains, only the Boston Naming Test and the Hopkins Verbal Learning Test (HVLT) delayed recall remained significant after Bonferroni correction. Similarly, when comparing the cognitive performance of patients with PD who scored >14 on the BDI versus those who scored <14, only the mean score of the Boston Naming Test was different between the 2 groups. Our study shows that while depressive symptoms correlated with global cognitive performance, naming, verbal memory, and language are the most susceptible cognitive domains affected with depressive symptoms.

Assessing cognition in Parkinson disease: use of the cognitive linguistic quick test

OBJECTIVE

To evaluate the Cognitive Linguistic Quick Test (CLQT) as a cognitive screening tool in Parkinson disease (PD).

METHODS

A total of 93 patients with PD were evaluated with the Mini-Mental State Examination (MMSE) and the CLQT. The CLQT provides separate ratings for 5 cognitive domains. Descriptive statistics, correlations between the tests, and diagnostic value for dementia were analyzed.

RESULTS

Cognitive Linguistic Quick Test correlated well with MMSE. Diagnostic values for dementia were similar for the 2 instruments. Unlike the MMSE, the CLQT also provided domain-specific information on cognitive deficits. Cognitive domains were differentially affected between and within the demented and nondemented patient groups with PD: memory was the weakest domain in the demented group and attention in the nondemented.

CONCLUSIONS

The CLQT is a valuable instrument in assessing cognitive dysfunction in PD. The CLQT is superior to the MMSE as it also provides cognitive domain-specific information.

Incidence of and risk factors for cognitive impairment in an early Parkinson disease clinical trial cohort

OBJECTIVE

To investigate the incidence of and risk factors for cognitive impairment in a large, well-defined clinical trial cohort of patients with early Parkinson disease (PD).

METHODS

The Mini-Mental State Examination (MMSE) was administered periodically over a median follow-up period of 6.5 years to participants in the Deprenyl and Tocopherol Antioxidative Therapy of Parkinsonism trial and its extension studies. Cognitive impairment was defined as scoring 2 standard deviations below age- and education-adjusted MMSE norms.

RESULTS

Cumulative incidence of cognitive impairment in the 740 participants with clinically confirmed PD (baseline age 61.0 +/- 9.6 years, Hoehn-Yahr stage 1-2.5) was 2.4% (95% confidence interval: 1.2%-3.5%) at 2 years and 5.8% (3.7%-7.7%) at 5 years. Subjects who developed cognitive impairment (n = 46) showed significant progressive decline on neuropsychological tests measuring verbal learning and memory, visuospatial working memory, visuomotor speed, and attention, while the performance of the nonimpaired subjects (n = 694) stayed stable. Cognitive impairment was associated with older age, hallucinations, male gender, increased symmetry of parkinsonism, increased severity of motor impairment (except for tremor), speech and swallowing impairments, dexterity loss, and presence of gastroenterologic/urologic disorders at baseline.

CONCLUSIONS

The relatively low incidence of cognitive impairment in the Deprenyl and Tocopherol Antioxidative Therapy of Parkinsonism study may reflect recruitment bias inherent to clinical trial volunteers (e.g., younger age) or limitations of the Mini-Mental State Examination-based criterion. Besides confirming known risk factors for cognitive impairment, we identified potentially novel predictors such as bulbar dysfunction and gastroenterologic/urologic disorders (suggestive of autonomic dysfunction) early in the course of the disease.

The morbid anatomy of dementia in Parkinson's disease

Dementia in Parkinson's disease (PD/PDD) is a common complication with a prevalence of up to 50%, but the specific changes underlying the cognitive decline remain undefined. Neuronal degeneration resulting in the dysfunction of multiple subcortical neurochemical projection systems has been described along with Lewy body-type pathology in cortical and limbic regions. Advanced alpha-synuclein (alphaSyn) pathology is not necessarily sufficient for producing dementia and concomitant Alzheimer's disease (AD) change has also been proposed as a possible substrate of PDD. A lack of consensus in the extant literature likely stems from clinical heterogeneity and variable reliability in clinical characterisation as well as other historical and methodological issues. The concurrent presence of abnormally deposited alphaSyn, amyloid-beta and tau proteins in the PDD brain and the interaction of these molecules in a linked pathological cascade of AD and PD-related mechanisms may prove important in determining the underlying pathological process for the development of dementia in PD and this concept of combined pathologies awaits further investigation.

Biophysics of Parkinson's disease: structure and aggregation of alpha-synuclein

Parkinson's disease (PD) is a slowly progressive movement disorder that results from the loss of dopaminergic neurons in the substantia nigra, a small area of cells in the mid-brain. PD is a multifactorial disorder with unknown etiology, in which both genetic and environmental factors play important roles. Substantial evidence links alpha-synuclein, a small highly conserved presynaptic protein with unknown function, to both familial and sporadic PD. Rare familial cases of PD are associated with missense point mutations in alpha-synuclein, or with the hyper-expression of the wild type protein due to its gene duplication/triplication. Furthermore, alpha-synuclein was identified as the major component of amyloid fibrils found in Lewy body and Lewy neurites, the characteristic proteinaceous deposits that are the diagnostic hallmarks of PD. alpha-Synuclein is abundant in various regions of the brain and has two closely related homologs, beta-synuclein and gamma-synuclein. When isolated in solution, the protein is intrinsically disordered, but in the presence of lipid surfaces alpha-synuclein adopts a highly helical structure that is believed to mediate its normal function(s). A number of different conformational states of alpha-synuclein have been observed. Besides the membrane-bound form, other critical conformations include a partially-folded state that is a key intermediate in aggregation and fibrillation, various oligomeric species, and fibrillar and amorphous aggregates. A number of intrinsic and extrinsic factors that either accelerate or inhibit the rate of alpha-synuclein aggregation and fibrillation in vitro are known. There is a strong correlation between the conformation of alpha-synuclein (induced by various factors) and its rate of fibrillation. The aggregation process appears to be branched, with one pathway leading to fibrils and another to oligomeric intermediates that may ultimately form amorphous deposits. The molecular basis of Parkinson's disease appears to be tightly coupled to the aggregation of alpha-synuclein and the factors that affect its conformation. This review focuses on the contributions of Prof. Anthony L. Fink to the field and presents some recent developments in this exciting area.

Cognitive impairment in Parkinson's disease without dementia: subtypes and influences of age

Background and Purpose

Cognitive impairments are common in Parkinson's disease (PD), although the severity of these impairments does not significantly impair the patient's daily activities. The aim of this study was to determine the frequency of mild cognitive impairment (MCI) of Parkinson's disease (PDMCI) and its subtypes in nondemented PD patients. We also evaluated the influence of age on the pattern of subtypes of PDMCI.

Methods

A total of 141 consecutive, nondemented PD patients underwent a comprehensive neuropsychological assessment covering the five cognitive domains: attention, language, visuospatial, memory, and executive functions. PDMCI was defined as impaired performance in at least one of these five cognitive domains. The influence of age on the distribution of subtypes of PDMCI was assessed by comparing patients in two groups dichotomized according to their age at assessment (younger vs. older).

Results

Fifty-seven (40.4%) of the nondemented PD patients had an impairment in at least one domain, and were therefore considered as having PDMCI. The age at assessment and age at disease onset were significantly higher in the PDMCI patients. The amnestic type of PDMCI was the most frequent, followed by the visuospatial, linguistic, executive, and attention types in that order. The frequency of PDMCI was higher for all subtypes in the older group; the domain that was influenced the most by age was executive function.

Conclusions

MCI was common in PD and the subtypes were diverse. Age was found to be an important risk factor for the development of PDMCI, particularly for the executive subtype. These results indicate that the concept of MCI should be introduced in PD.

Rivastigmine in Parkinson's disease dementia

Parkinson's disease has now evolved beyond what was considered to be a traditional motor disorder. It is being increasingly recognized that non-motor symptoms such as cognitive impairment, frank dementia, psychosis, depression, autonomic dysfunction and sleep disturbances are just as integral to the disease spectrum. The cholinergic system has been proposed to play a pivotal role in cognitive dysfunction. Based on interpretation of clinical studies in patients with Alzheimer's, cholinesterase inhibitors have also been studied for dementia associated with Parkinson's disease. Most of these include large and small placebo-controlled studies and several pilot studies have indicated that cholinesterase inhibitors have a favorable effect on cognition, psychiatric symptoms and global function in Parkinson's disease dementia. A large randomized placebo-controlled clinical trial showed that rivastigmine had moderate improvement in dementia associated with Parkinson's disease. The magnitude of effects in terms of scores for the cognitive subscale of the Alzheimer's disease assessment scale and Alzheimer's disease cooperative study-clinicians global impression of change were similar to those observed among patients with Alzheimer's disease who were treated with cholinesterase inhibitors. A transdermal patch which gradually releases rivastigmine over the application period is now available for use in mild to moderate dementia associated with Parkinson's disease and Alzheimer's disease.

Randomized controlled trial of memantine in dementia associated with Parkinson's disease

The objective of this study is to investigate the safety and tolerability of memantine, a glutamatergic modulator, in patients suffering from dementia associated with Parkinson's disease (PDD), an increasingly common complication of PD. This was a 22-week trial of 25 participants with a DSM-IV diagnosis of PDD who were randomized to either placebo or 20 mg/day of memantine. Memantine was well tolerated by participants at 20 mg/day dosing. No participant was withdrawn due to memantine-related adverse events. Six weeks after drug withdrawal, a significantly greater proportion (P = 0.04) of memantine-treated participants deteriorated globally compared with those treated with placebo. These findings suggest that continued treatment with memantine may be needed to maintain global level of functioning over time. Based on the findings of this pilot study, memantine is safe and very well-tolerated in PDD.

Cognitive impairment in Parkinson's disease: tools for diagnosis and assessment

Cognitive impairment (CI) and dementia are frequent and debilitating features associated with Parkinson's disease (PD). Formal neuropsychological examination is required to ascertain the degree and pattern of CI over the course of the disease. The use of different tools may explain heterogeneous data obtained from studies to date. Normative data for extensively used scales [Mattis Dementia Rating Scale (MDRS), Mini-Mental State Examination (MMSE)] is incomplete in PD populations. According to sample characteristics, statistical analyses, and methodological quality, 33 studies using scales not specific to PD (MDRS, MMSE, Cambridge Cognitive Assessment, FAB) or PD-specific scales (Mini-Mental Parkinson, Scales for Outcomes of Parkinson's disease-Cognition, Parkinson's Disease-Cognitive Rating Scale, and Parkinson Neuropsychometric Dementia Assessment) were eligible for the critical analysis of their appropriateness to assess cognition in PD. Of the four scales specifically designed for PD, the SCOPA-COG and the PD-CRS have undergone extensive and rigorous validation processes. While the SCOPA-COG mainly assesses "frontal-subcortical" cognitive defects, the PD-CRS also assesses "instrumental-cortical" functions, allowing better characterization of the different patterns of CI that may be present in PD from the earliest stages. The MMP and PANDA scales were designed as brief screening tests for CI and have not yet been subjected to extensive clinimetric evaluations. Further research on PD-specific tools seems mandatory to help establish accurate cut-off scores for the diagnosis of mild PDD, detect cognitive profiles more prone to the future development of dementia, and allow comparisons between different descriptive or interventional studies.

The epidemiology of dementia associated with Parkinson disease

Several recent studies have shown that dementia is common in Parkinson's disease (PD), and that in some patients, cognitive impairment occurs even at the time of diagnosis. The point prevalence of dementia in PD is close to 30% and the incidence rate is increased 4-6 times as compared to controls. The cumulative prevalence is very high, at least 75% of PD patients who survive for more than 10 years will develop dementia. The mean time from onset of PD to dementia is approximately 10 years. However, there are considerable variations, and some patients develop dementia early in the disease course. Earlier onset of dementia is associated with more structural brain changes. The most established risk factors for early dementia are old age, severity of motor symptoms, in particular postural and gait disturbances, mild cognitive impairment and visual hallucinations. The genetic contributions to dementia are currently not clear and need to be explored in future studies.

Parkinson's disease and tea: a quantitative review

PURPOSE

To evaluate the risk of PD associated with tea consumption.

MATERIAL AND METHODS

We reviewed all observational studies that evaluated the association between PD risk and tea consumption. Only, 12 studies were identified: 11 case-control and 1 cohort. These studies were carried out between 1981 and 2003. The studies represented different populations from 3 continents; North America, Europe and Asia. The 3 studies from Asia were case-control studies of Chinese populations.

RESULTS

There was a clear protective effect of tea consumption in the pooled risk estimate [OR: 0.83 (95% confidence interval 0.74 to 0.92)] with 2215 cases and 145578 controls. However, the homogeneity test was significant (p value of 0.008), denoting heterogeneity across the pooled studies. Pooled analysis applying the random effect model was OR: 0.81 with 95% confidence interval nearly overlapping unity (95% confidence interval 0.67 to 0.98). Tea consumers versus non-consumers in Chinese populations had pooled OR of 0.73 with 95% confidence interval 0.60 to 0.90 (470 cases and 623 controls). The p value of homogeneity test was 0.96, denoting homogeneity across the pooled 3 studies.

CONCLUSION

Tea consumption can protect against PD and this protective effect is clearer in Chinese populations. The low rate of tea consumption among persons with PD should provide us many valuable insights into the nature of the illness.

Effects of intrahippocampal NAC 61-95 injections on memory in the rat and attenuation with vitamin E

Parkinson's disease (PD)-related dementia affects approximately 40% of PD patients and the severity of this dementia correlates significantly with the density of Lewy body (LB) deposition in the PD brain. Aggregated alpha-synuclein protein is the major component of LB's and the non-amyloid component (NAC) region of alpha-synuclein, residues 61-95, is essential for the aggregation and toxicity of this protein. The current study evaluated the effect of pre-aggregated NAC(61-95) injected into the CA3 area of the dorsal hippocampus of the brain on memory in the rat. Previous research has suggested that oxidative stress processes may play a role in the neuropathology of PD, therefore the effect of treatment with vitamin E, an antioxidant, was also evaluated. Male Sprague-Dawley rats were trained in two-lever operant chambers under an alternating-lever cyclic-ratio (ALCR) schedule of food reinforcement. When responding showed no trends, subjects were divided into four groups. Two groups were injected bilaterally into the dorsal hippocampus with aggregated NAC(61-95) (5 microl suspension), and two groups were injected bilaterally into the dorsal hippocampus with sterile water (5 microl). Subgroups were treated with either vitamin E (150 mg/kg in Soya oil) or vehicle (Soya oil) daily. Injection of NAC(61-95) induced memory deficits and vitamin E treatment alleviated these. In addition, NAC(61-95) injections induced activated astrocytes and chronic treatment with vitamin E reduced the numbers of activated astrocytes. These results suggest that aggregated NAC(61-95) and associated oxidative stress, may play a role in the pathogenesis of cognitive deficits seen in PD-induced dementia.

Dementia in Parkinson's disease

Parkinson's disease is the second most common neurodegenerative illness diagnosed in the United States. Dementia is recognized as a common component of advanced Parkinson's disease (PD). In patients with early PD, cognitive changes occur and primarily reflect impairment in executive function. It is unknown if the early cognitive changes detected on neuropsychological testing in Parkinson's disease are predictive of the subsequent development of Parkinson's disease with dementia (PDD). Many patients with PD develop dementia characterized by a wide range of cognitive deficits distinct from those seen in Alzheimer's disease (AD). Neuropsychiatric problems frequently accompany PDD. This chapter reviews the epidemiology, clinical characteristics of early and late cognitive changes, pathology, neuroimaging, diagnosis, and treatment of PDD.

The effect of onset age on the clinical features of Parkinson's disease

Many clinicians view age at onset as an important determinant of clinical phenotype in Parkinson's disease (PD) and this has been reinforced by the identification of Mendelian genes that account for some cases of younger onset PD. A systematic review of OVID Medline for articles relevant to the relationship between clinical features and age at onset in PD published in English between 1950-2007 was performed. There are very few prospective community based studies which focus on the relationship between age at onset and the features of PD and a variety of case definitions are used in the literature. Most studies of young onset PD are based on specialist clinic referral series. The available evidence suggests that PD patients with a younger age at onset have: (i) a slower disease progression, (ii) an increased rate of dystonia at onset and during treatment, (iii) a lower rate of dementia and (iv) an increased rate of dyskinesias in response to L-DOPA treatment. The majority of the available studies do not report patient genotype data, but it is probably that the clinical heterogeneity of PD will be further refined with detailed clinico-genetic studies.

Cognitive function in early Parkinson's disease: a population-based study

BACKGROUND AND PURPOSE

The study aims to describe the frequency, pattern and determinants of cognitive function in patients with newly diagnosed Parkinson's disease (PD); to compare patients with impaired cognition to patients with intact cognition; and to compare to matched healthy controls.

METHODS

Patients were identified in a longitudinal population based study of idiopathic non-drug induced parkinsonism. Eighty-eight newly diagnosed patients with PD and no dementia were included during a four year period. The patients and 30 age- and sex-matched healthy control subjects underwent a comprehensive neuropsychological assessment.

RESULTS

Patients performed significantly worse than healthy controls in a majority of neuropsychological tests. Test results in attention, psychomotor function, episodic memory (free recall), executive function and category fluency were significantly lower in the patient group. Comparison with normative data revealed that 30% of the patients had deficits in > or =1 cognitive domain (episodic memory, executive function and verbal function). Seventy per cent of the patients had normal performance. Unified Parkinson's Disease Rating Scale (UPDRS) III sub scores; speech, facial expression, rigidity and bradykinesia were significantly higher, and disease duration shorter amongst the cognitively impaired than amongst the cognitively intact patients. Tremor showed no difference. Education level was an independent predictor of dysfunction in patients with > or =2 cognitive domains affected.

CONCLUSION

Cognitive dysfunction is common in untreated patients in early PD, affecting attention, psychomotor function, episodic memory, executive function and category fluency. Education level was an independent predictor of severe cognitive dysfunction.

Evidence that folic acid deficiency is a major determinant of hyperhomocysteinemia in Parkinson's disease

In the present work we measured blood levels of total homocysteine ((t)Hcy), vitamin B(12) and folic acid in patients with Parkinson s disease (PD) and in age-matched controls and searched for possible associations between these levels with smoking, alcohol consumption, L-DOPA treatment and disease duration in PD patients. We initially observed that plasma (t)Hcy levels were increased by around 30 % in patients affected by PD compared to controls. Linear correlation, multiple regression and comparative analyses revealed that the major determinant of the increased plasma concentrations of (t)Hcy in PD patients was folic acid deficiency, whereas in controls (t)Hcy levels were mainly determined by plasma vitamin B(12) concentrations. We also observed that alcohol consumption, gender and L-DOPA treatment did not significantly alter plasma (t)Hcy, folic acid and vitamin B(12) levels in parkinsonians. Furthermore, disease duration was positively associated with (t)Hcy levels and smoking was linked with a deficit of folic acid in PD patients. Considering the potential synergistic deleterious effects of Hcy increase and folate deficiency on the central nervous system, we postulate that folic acid should be supplemented to patients affected by PD in order to normalize blood Hcy and folate levels, therefore potentially avoiding these risk factors for neurologic deterioration in this disorder.

Efficacy and safety of galantamine (reminyl) for dementia in patients with Parkinson's disease (an open controlled trial)

An open controlled trial of the use of galantamine at a maximum dose of 16 mg/day included 41 patients with Parkinson's disease with dementia randomized to a galantamine treatment group (21 patients) and a control group (20 patients). Cognitive, neuropsychiatric, and motor symptoms were assessed clinically before the trial and at 4, 12, and 24 weeks, using the Mini Mental State Examination (MMSE), the cognitive Alzheimer's Disease Assessment Scale (ADAS-cog), the clock drawing test, the Frontal Assessment Battery (FAB), and the Neuropsychiatric Inventory (NPI) with assessment of distress in relatives. Patients treated with galantamine had better scores on the MMSE (p < 0.05),ADAS-cog (p < 0.05), the clock drawing test (p < 0.05), and the FAB (p < 0.01) at the end of the study period as compared with the control group. Changes in total point scores on the NPI-12 at the ends of weeks 12 and 24, as compared with the beginning of the trial, were in favor of the group treated with galantamine, with significant changes in the hallucinations (p = 0.0002), anxiety (p = 0.04), sleep disturbance (p = 0.04), and apathy (p = 0.006) sections. Galantamine treatment was accompanied by decreases in the level of distress in patients' relatives (p = 0.007) and improvements in daily activity (p = 0.003). Improvements in gait and decreases in freezing and falls were seen in the galantamine treatment group. However, two patients of this group showed minor increases in tremor. Side effects (drooling, postural hypotension, nausea, dysuria) occurred in seven patients (30%).

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.

Functional brain changes in early Parkinson's disease during motor response and motor inhibition

Motor impairment represents the main clinical feature of Parkinson's disease (PD). Cognitive deficits are also frequently observed in patients with PD, with a prominent involvement of executive functions and visuo-spatial abilities. We used event-related functional MRI (fMRI) and a paradigm based on visual attention and motor inhibition (Go/NoGO-task) to investigate brain activations in 13 patients with early PD in comparison with 11 healthy controls. The two groups did not report behavioural differences in task performance. During motor inhibition (NoGO-effect), PD patients compared to controls showed an increased activation in the prefrontal cortex and in the basal ganglia. They also showed a reduced and less coherent hemodynamic response in the occipital cortex. These results indicate that specific cortico-subcortical functional changes, involving not only the fronto-striatal network but also the temporal-occipital cortex, are already present in patients with early PD and no clinical evidence of cognitive impairment. We discuss our findings in terms of compensatory mechanisms (fronto-striatal changes) and preclinical signs of visuo-perceptual deficits and visual hallucinations.

Brain magnetic resonance imaging (MRI) in parkinsonian disorders

Magnetic resonance imaging (MRI) is increasingly integrated into neurological diagnostics. In addition to functional MRI, a large number of sequences (T1W, T2W, PD, T2W gradient echo, diffusion-weighted imaging (DWI), and diffusion tensor imaging (DTI)), investigate CNS abnormalities. Objective quantification techniques (T1W voxel-based morphometry) can also discern subtle anatomical differences. Parkinsonian conditions such as Parkinson's disease, multiple system atrophy, progressive supranuclear palsy, corticobasal degeneration and manganese-induced parkinsonism can clinically overlap, yet have very different prognoses and treatments. Relatively little radiographic interest has focused on movement disorders. Nevertheless in the past decade, a variety of findings, often subtle and routinely overlooked, have emerged to help the clinician differentiate these conditions. This review will summarize and discuss MRI findings in parkinsonian conditions. Most data concern either structural abnormalities or the imaging sequelae of abnormal iron deposition, common in some parkinsonian conditions.

Diagnosis and management of Parkinson's disease dementia

Parkinson's disease (PD) has long been considered predominantly a motor disorder. However, its frequent association with dementia, which contributes significantly to the morbidity and mortality of the condition, is gaining increasing recognition. PD dementia (PDD) has a unique clinical profile and neuropathology, distinct from Alzheimer's disease (AD). Cholinergic deficits, a feature of both AD and PDD, underlie the rationale for cholinesterase inhibitor therapy in both conditions. In clinical practice, it is important that PDD should be recognised and appropriately treated. This review aims to outline the recently proposed clinical diagnostic criteria for PDD and to summarise the guidelines/recommendations published since 2006 on the use of cholinesterase inhibitors in the management of PDD. Although the cholinesterase inhibitor rivastigmine has recently been approved for the management of PDD, there remains a need for the development of novel therapies that can affect key mechanisms of the disease or prevent/delay patients with PD and mild cognitive impairment from progressing to PDD.

Cost effectiveness of preventing falls and improving mobility in people with Parkinson disease: protocol for an economic evaluation alongside a clinical trial

BACKGROUND

Cost of illness studies show that Parkinson disease (PD) is costly for individuals, the healthcare system and society. The costs of PD include both direct and indirect costs associated with falls and related injuries.

METHODS

This protocol describes a prospective economic analysis conducted alongside a randomised controlled trial (RCT). It evaluates whether physical therapy is more cost effective than usual care from the perspective of the health care system. Cost effectiveness will be evaluated using a three-way comparison of the cost per fall averted and the cost per quality adjusted life year saved across two physical therapy interventions and a control group.

CONCLUSION

This study has the potential to determine whether targetted physical therapy as an adjunct to standard care can be cost effective in reducing falls in people with PD.

TRIAL REGISTRATION

No: ACTRN12606000344594.

F2 isoprostane levels in plasma and urine do not support increased lipid peroxidation in cognitively impaired Parkinson disease patients

OBJECTIVE

To determine the utility of 8,12-isoprostaneF2alpha-VI (iP), a specific and sensitive index of lipid peroxidation, as a biomarker for dementia in Parkinson disease (PD).

BACKGROUND

iP is a member of the F2-isoprostanes family that has been shown to be promising biomarker for Alzheimer disease. However, iP levels have not been studied in patients with clinical diagnosis of PD or Parkinson disease with dementia (PDD).

METHODS

PD and PDD patient plasma and urine iP levels were compared with age-matched and sex-matched controls. Clinical measures including demographics and tests of motor function, affect, and cognition were assessed and compared with iP levels.

RESULTS

There were no differences in plasma iP levels between PD subjects and controls (299 vs. 306 pg/mL; P=0.6). Urine iP levels were higher in cases than controls (2.8 vs. 2.1 ng/mg Cr; P=0.003), but levels were lower than those seen in Alzheimer disease patients in prior studies. Within PD subjects, there was no association of iP levels in either the plasma or urine with performance on any clinical measure.

CONCLUSIONS

Plasma and urine iP levels do not seem to be substantially elevated in PD and are not associated with severity of cognitive impairment in PDD.

Rivastigmine in Parkinson's disease dementia

Dementia associated with Parkinson's disease (PD) ultimately develops in approximately 70% of patients with PD older than 80 years of age. The neuropathology of PD dementia (PDD) is likely multifactorial and affects several neuronal populations. There is evidence that PDD is associated with a cholinergic deficit, supporting the therapeutic role of cholinesterase inhibitors, which are already first-line agents in the treatment of Alzheimer's disease. Open-label and small controlled studies suggested a clinical efficacy of cholinesterase inhibitors in PDD. One large randomized placebo-controlled trial of 541 patients demonstrated that oral rivastigmine improved cognition, attention and executive functions, activities of daily living and behavioral symptoms after 6 months of treatment. Rivastigmine is a dual cholinesterase inhibitor, being effective on both acetylcholinesterase and butyrylcholinesterase. This paper reviews the pharmacokinetic and pharmacodynamic properties of rivastigmine (oral and transdermal administration). It also reviews evidence on clinical efficacy, safety and tolerability of the oral administration in PDD patients at doses of 3-12 mg/day.

Cognitive and behavioural impairment in Parkinson's disease

Although Parkinson's disease (PD) has been considered to primarily affect motor abilities, increasing emphasis is being placed on cognitive and behavioural impairment in this disorder. Depression, dementia, psychosis and impulse control disorders have a major impact on quality of life for both patients and families. This article reviews cognitive and behavioural disturbances in PD and their relation to affective and motor symptoms, treatment of dementia associated with PD, and treatment approaches to psychosis in PD. We also discuss similarities between the dementia of PD and dementia with Lewy bodies.