Bernard Ravina

Projected number of people with Parkinson disease in the most populous nations, 2005 through 2030

Based on published prevalence studies, we used two different methodologies to project the number of individuals with Parkinson disease (PD) in Western Europe’s 5 most and the world’s 10 most populous nations. The number of individuals with PD over age 50 in these countries was between 4.1 and 4.6 million in 2005 and will double to between 8.7 and 9.3 million by 2030.

DLB and PDD boundary issues: Diagnosis, treatment, molecular pathology, and biomarkers

For more than a decade, researchers have refined criteria for the diagnosis of dementia with Lewy bodies (DLB) and at the same time have recognized that cognitive impairment and dementia occur commonly in patients with Parkinson disease (PD). This article addresses the relationship between DLB, PD, and PD with dementia (PDD). The authors agreed to endorse “Lewy body disorders” as the umbrella term for PD, PDD, and DLB, to promote the continued practical use of these three clinical terms, and to encourage efforts at drug discovery that target the mechanisms of neurodegeneration shared by these disorders of α-synuclein metabolism. We concluded that the differing temporal sequence of symptoms and clinical features of PDD and DLB justify distinguishing these disorders. However, a single Lewy body disorder model was deemed more useful for studying disease pathogenesis because abnormal neuronal α-synuclein inclusions are the defining pathologic process common to both PDD and DLB. There was consensus that improved understanding of the pathobiology of α-synuclein should be a major focus of efforts to develop new disease-modifying therapies for these disorders. The group agreed on four important priorities: 1) continued communication between experts who specialize in PDD or DLB; 2) initiation of prospective validation studies with autopsy confirmation of DLB and PDD; 3) development of practical biomarkers for α-synuclein pathologies; 4) accelerated efforts to find more effective treatments for these diseases.

Practice Parameter: Evaluation and treatment of depression, psychosis, and dementia in Parkinson disease (an evidence-based review): Report of the Quality Standards Subcommittee of the American Academy of Neurology

Objective: To make evidence-based treatment recommendations for patients with Parkinson disease (PD) with dementia, depression, and psychosis based on these questions: 1) What tools are effective to screen for depression, psychosis, and dementia in PD? 2) What are effective treatments for depression and psychosis in PD? 3) What are effective treatments for PD dementia or dementia with Lewy bodies (DLB)? Methods: A nine-member multispecialty committee evaluated available evidence from a structured literature review using MEDLINE, and the Cochrane Database of Health and Psychosocial Instruments from 1966 to 2004. Additional articles were identified by panel members. Results: The Beck Depression Inventory-I, Hamilton Depression Rating Scale, and Montgomery Asberg Depression Rating Scale should be considered to screen for depression in PD (Level B). The Mini-Mental State Examination and the Cambridge Cognitive Examination should be considered to screen for dementia in PD (Level B). Amitriptyline may be considered to treat depression in PD without dementia (Level C). For psychosis in PD, clozapine should be considered (Level B), quetiapine may be considered (Level C), but olanzapine should not be considered (Level B). Donepezil or rivastigmine should be considered for dementia in PD (Level B) and rivastigmine should be considered for DLB (Level B). Conclusions: Screening tools are available for depression and dementia in patients with PD, but more specific validated tools are needed. There are no widely used, validated tools for psychosis screening in Parkinson disease (PD). Clozapine successfully treats psychosis in PD. Cholinesterase inhibitors are effective treatments for dementia in PD, but improvement is modest and motor side effects may occur.Objective:To make evidence-based treatment recommendations for patients with Parkinson disease (PD) with dementia, depression, and psychosis based on these questions: 1) What tools are effective to screen for depression, psychosis, and dementia in PD? 2) What are effective treatments for depression and psychosis in PD? 3) What are effective treatments for PD dementia or dementia with Lewy bodies (DLB)? Methods:A nine-member multispecialty committee evaluated available evidence from a structured literature review using MEDLINE, and the Cochrane Database of Health and Psychosocial Instruments from 1966 to 2004. Additional articles were identified by panel members. Results:The Beck Depression Inventory-I, Hamilton Depression Rating Scale, and Montgomery Asberg Depression Rating Scale should be considered to screen for depression in PD (Level B). The Mini-Mental State Examination and the Cambridge Cognitive Examination should be considered to screen for dementia in PD (Level B). Amitriptyline may be considered to treat depression in PD without dementia (Level C). For psychosis in PD, clozapine should be considered (Level B), quetiapine may be considered (Level C), but olanzapine should not be considered (Level B). Donepezil or rivastigmine should be considered for dementia in PD (Level B) and rivastigmine should be considered for DLB (Level B). Conclusions:Screening tools are available for depression and dementia in patients with PD, but more specific validated tools are needed. There are no widely used, validated tools for psychosis screening in Parkinson disease (PD). Clozapine successfully treats psychosis in PD. Cholinesterase inhibitors are effective treatments for dementia in PD, but improvement is modest and motor side effects may occur.

The Parkinson Progression Marker Initiative (PPMI)

The Parkinson Progression Marker Initiative (PPMI) is a comprehensive observational, international, multi-center study designed to identify PD progression biomarkers both to improve understanding of disease etiology and course and to provide crucial tools to enhance the likelihood of success of PD modifying therapeutic trials. The PPMI cohort will comprise 400 recently diagnosed PD and 200 healthy subjects followed longitudinally for clinical, imaging and biospecimen biomarker assessment using standardized data acquisition protocols at twenty-one clinical sites. All study data will be integrated in the PPMI study database and will be rapidly and publically available through the PPMI web site- www.ppmi-info.org. Biological samples including longitudinal collection of blood, cerebrospinal fluid (CSF) and urine will be available to scientists by application to an independent PPMI biospecimen review committee also through the PPMI web site. PPMI will rely on a partnership of government, PD foundations, industry and academics working cooperatively. This approach is crucial to enhance the potential for success of this ambitious strategy to develop PD progression biomarkers that will accelerate research in disease modifying therapeutics.

The role of radiotracer imaging in Parkinson disease

Radiotracer imaging (RTI) of the nigrostriatal dopaminergic system is a widely used but controversial biomarker in Parkinson disease (PD). Here the authors review the concepts of biomarker development and the evidence to support the use of four radiotracers as biomarkers in PD: [18F]fluorodopa PET, (+)-[11C]dihydrotetrabenazine PET, [123I]β-CIT SPECT, and [18F]fluorodeoxyglucose PET. Biomarkers used to study disease biology and facilitate drug discovery and early human trials rely on evidence that they are measuring relevant biologic processes. The four tracers fulfill this criterion, although they do not measure the number or density of dopaminergic neurons. Biomarkers used as diagnostic tests, prognostic tools, or surrogate endpoints must not only have biologic relevance but also a strong linkage to the clinical outcome of interest. No radiotracers fulfill these criteria, and current evidence does not support the use of imaging as a diagnostic tool in clinical practice or as a surrogate endpoint in clinical trials. Mechanistic information added by RTI to clinical trials may be difficult to interpret because of uncertainty about the interaction between the interventions and the tracer.

Neuroprotective agents for clinical trials in Parkinson's disease: a systematic assessment.

Background: Current therapies for PD ameliorate symptoms in the early phases of disease but become less effective over time, as the underlying disease progresses. Therapies that slow the progression of PD are needed. However, there have been relatively few clinical trials aimed at demonstrating neuroprotection. The authors sought to identify potential neuroprotective agents for testing in clinical trials. Methods: First a broad array of compounds were identified by working with clinicians and researchers in academics and industry. Specific criteria were drafted for drug evaluation, including scientific rationale, blood–brain barrier penetration, safety and tolerability, and evidence of efficacy in animal models or humans. Agents were prioritized based on these criteria. Results: The authors identified 59 potential neuroprotective compounds, proposed by 42 clinicians and scientists from 13 countries. After systematic reviews using the specified criteria they found 12 compounds to be attractive candidates for further clinical trials in PD. Conclusions: Several potential neuroprotective compounds, representing a wide range of mechanisms, are available and merit further investigation in PD.

Diagnostic criteria for psychosis in Parkinson's disease: Report of an NINDS, NIMH work group

There are no standardized diagnostic criteria for psychosis associated with Parkinsons disease (PDPsy). As part of an NIH sponsored workshop, we reviewed the existing literature on PDPsy to provide criteria that distinguish PDPsy from other causes of psychosis. Based on these data, we propose provisional criteria for PDPsy in the style of the Diagnostic and Statistical Manual of Mental Disorders IV‐TR. PDPsy has a well‐characterized temporal and clinical profile of hallucinations and delusions, which is different than the pattern seen in other psychotic disorders such as substance induced psychosis or schizophrenia. PDPsy is associated with a poor prognosis of chronic psychosis, nursing home placement, and death. Medications used to treat Parkinsons disease (PD) contribute to PDPsy but may not be sufficient or necessary contributors to PDPsy. PDPsy is associated with Lewy bodies pathology, imbalances of monoaminergic neurotransmitters, and visuospatial processing deficits. These findings suggest that PDPsy may result from progression of the disease process underlying PD, rather than a comorbid psychiatric disorder or drug intoxication. PDPsy is not adequately described by existing criteria for psychotic disorders. We established provisional diagnostic criteria that define a constellation of clinical features not shared by other psychotic syndromes. The criteria are inclusive and contain descriptions of the full range of characteristic symptoms, chronology of onset, duration of symptoms, exclusionary diagnoses, and associated features such as dementia. These criteria require validation and may be refined, but form a starting point for studies of the epidemiology and pathophysiology of PDPsy, and are a potential indication for therapy development.

Donepezil for dementia in Parkinson’s disease: a randomised, double blind, placebo controlled, crossover study

Objective: To study the safety and efficacy of a cholinesterase inhibitor, donepezil hydrochloride, for the treatment of dementia in Parkinson’s disease (PD). Methods: This was a randomised double blind, placebo controlled, crossover study in 22 subjects with PD and dementia. Participants were randomised to receive either donepezil followed by identical placebo, or placebo followed by donepezil. Donepezil was administered at 5–10 mg/day. Treatment periods were 10 weeks with a washout period of 6 weeks between the two periods. The primary outcome measure was the Alzheimer’s Disease Assessment Scale Cognitive Subscale (ADAScog). Results: Donepezil was well tolerated and most adverse events were mild. There was no worsening of PD symptoms as measured by the total or motor sections of the Unified Parkinson’s Disease Rating Scale. There was a 1.9 point trend toward better scores on the ADAScog on treatment compared with placebo that was not statistically significant. The secondary cognitive measures showed a statistically significant 2 point benefit on the Mini Mental Status Examination and no change on the Mattis Dementia Rating Scale (MDRS). The Clinical Global Impression of Change (CGI) showed a significant 0.37 point improvement on donepezil. No improvement was observed on the MDRS or the Brief Psychiatric Rating Scale. Carryover between treatment periods was observed but was not statistically significant. Conclusions: Donepezil was well tolerated and did not worsen PD. There may be a modest benefit on aspects of cognitive function. The possible clinical benefit measured by CGI was reflected in only one of the cognitive scales used in this study.

Provisional diagnostic criteria for depression in Parkinson's disease: Report of an NINDS/NIMH Work Group

Mood disorders are the most common psychiatric problem associated with Parkinsons disease (PD), and have a negative impact on disability and quality of life. Accurate diagnosis of depressive disturbances in PD is critical and will facilitate the testing and use of new interventions; however, there are no clear diagnostic criteria for depressive disorders in PD. In their current form, strict Diagnostic and Statistical Manual of Mental Disorders (DSM) criteria are difficult to use in PD and require attribution of specific symptoms to PD itself or the depressive syndrome. Additionally, DSM criteria for major depression and dysthymia exclude perhaps half of PD patients with comorbid clinically significant depression. This review summarizes an NIH‐sponsored workshop and describes recommended changes to DSM diagnostic criteria for depression for use in PD. Participants also recommended: (1) an inclusive approach to symptom assessment to enhance reliability of ratings in PD and avoid the need to attribute symptoms to a particular cause; (2) the inclusion of subsyndromal depression in clinical research studies of depression of PD; (3) the specification of timing of assessments for PD patients with motor fluctuations; and (4) the use of informants for cognitively impaired patients. The proposed diagnostic criteria are provisional and intended to be defined further and validated but provide a common starting point for clinical research in PD‐associated depression.

The Montreal cognitive assessment as a screening tool for cognitive impairment in Parkinson's disease.

Cognitive impairment is common in Parkinsons disease (PD) and can occur early in the disease course. No effective screening test exists for detection of early or mild cognitive impairment in PD. We examined the Montreal Cognitive Assessment (MoCA) as a screening tool for cognitive dysfunction in PD. The test–retest intraclass correlation coefficient was 0.79 and the interrater intraclass correlation coefficient was 0.81. The correlation coefficient between the MoCA and a neuropsychologic battery was 0.72. The MoCA is reliable and valid in the PD population and warrants further study as a screening tool for cognitive dysfunction.