Caregiver report of apathy predicts dementia in Parkinson's disease

Contribution of amyloid and putative Lewy body pathologies in neuropsychiatric symptoms

OBJECTIVES

Neuropsychiatric symptom could be useful for detecting patients with prodromal dementia. Similarities and differences in the NPSs between preclinical/prodromal Alzheimer's disease (AD) and prodromal Parkinson's disease dementia (PDD)/Dementia with Lewy bodies (DLB) may exist. This study aimed to compare the NPSs between preclinical/prodromal AD and prodromal PDD/DLB.

METHODS

One hundred and three participants without dementia aged ≥50 years were included in this study. The mild behavioral impairment (MBI) total score and the MBI scores for each domain were calculated using the neuropsychiatric inventory questionnaire score. Participants were divided into five groups based on the clinical diagnosis by neurologists or psychiatrists in each institution based on the results of the amyloid positron emission tomography and dopamine transporter single photon emission computed tomography (DAT-SPECT): Group 1: amyloid-positive and abnormal DAT-SPECT, Group 2: amyloid-negative and abnormal DAT-SPECT, Group 3: amyloid-positive and normal DAT-SPECT, Group 4: mild cognitive impairment unlikely due to AD with normal DAT-SPECT, and Group 5: cognitively normal with amyloid-negative and normal DAT-SPECT.

RESULTS

The MBI abnormal perception or thought content scores were significantly higher in Group 1 than Group 5 (Bonferroni-corrected p = 0.012). The MBI total score (Bonferroni-corrected p = 0.011) and MBI impulse dyscontrol score (Bonferroni-corrected p = 0.033) in Group 4 were significantly higher than those in Group 5.

CONCLUSION

The presence of both amyloid and putative Lewy body pathologies may be associated with psychotic symptoms.

A Randomized Clinical Trial to Evaluate the Effects of Safinamide on Apathetic Non-demented Patients With Parkinson's Disease

Background

Apathy is highly prevalent and disabling in Parkinson's disease (PD). Pharmacological options for its management lack sufficient evidence.

Objective

We studied the effects of safinamide on apathy in PD.

Methods

Prospective, 24-week, two-site, randomized, double-blind, placebo-controlled, parallel-group exploratory study in non-demented PD on stable dopaminergic therapy randomized 1:1 to adjunct safinamide (50 mg/day for 2 weeks and 100 mg/day for 22 weeks) or placebo. The primary endpoint was the mean change from baseline to week 24 on the Apathy Scale (AS) total score. Secondary endpoints included changes in cognition, activities of daily living, motor scores, the impression of change, and safety and tolerability measures.

Results

In total, 30 participants (active treatment = 15; placebo = 15; 80% showing clinically significant apathetic symptoms according to the AS) were enrolled, and included in the intention-to-treat analysis. Change in AS (ANOVA) showed a trend to significance [p = 0.059] mediated by a more marked decrease in AS score with safinamide (−7.5 ± 6.9) than with placebo (−2.8 ± 5.7). Post-hoc analysis (paired t-test) showed a significant positive change in the AS score between 12-week and 24-week [p = 0.001] only in the active group. No significant or trend changes were found for any of the secondary outcome variables. Adverse events were few and only mild in both treatment groups.

Conclusions

Safinamide was safe and well-tolerated, but failed to provide evidence of improved apathy. The positive trend observed in the post-hoc analyses deserves to be studied in depth in larger studies.

Trial Registration

EudraCT 2017-003254-17.

The epidemiology of cognitive function in Parkinson's disease

Epidemiology is the study of the distribution of disease in human populations, which is important in evaluating burden of illness, identifying modifiable risk factors, and planning for current and projected needs of the health care system. Parkinson's disease (PD) is the second most common serious neurodegenerative illness and is expected to further increase in prevalence. Cognitive changes are increasingly viewed as an integral non-motor feature in PD, emerging even in the prodromal phase of the disease. The prevalence of PD-MCI ranges from 20% to 40% depending on the population studied. The incidence of PD-dementia increases with duration of disease, with estimates growing from 3% to 30% of individuals followed for 5 years or less to over 80% after 20 years. There are several challenges in estimating the frequency of cognitive change, including only recently standardized diagnostic criteria, variation depending on exact neuropsychological evaluations performed, and differences in population sampling. Clinical features associated with cognitive decline include older age, increased disease duration and severity, early gait dysfunction, dysautonomia, hallucinations and other neuropsychiatric features, the presence of REM behavior disorder, and posterior predominant dysfunction on neuropsychological testing. There is increasing evidence that genetic risk factors, in particular GBA and MAPT mutations, contribute to cognitive change. Possible protective factors include higher cognitive reserve and regular exercise. Important sequelae of cognitive decline in PD include higher caregiver burden, decreased functional status, and increased risk of institutionalization and mortality. Many remaining uncertainties regarding the epidemiology of cognitive change in PD require future research, with improved biomarkers and more sensitive and convenient outcome measures.

Cholinergic Receptor Modulation as a Target for Preventing Dementia in Parkinson's Disease

Parkinson’s disease (PD) is a neurodegenerative condition characterized by the loss of dopaminergic neurons in the substantia nigra pars compacta (SNpc) in the midbrain resulting in progressive impairment in cognitive and motor abilities. The physiological and molecular mechanisms triggering dopaminergic neuronal loss are not entirely defined. PD occurrence is associated with various genetic and environmental factors causing inflammation and mitochondrial dysfunction in the brain, leading to oxidative stress, proteinopathy, and reduced viability of dopaminergic neurons. Oxidative stress affects the conformation and function of ions, proteins, and lipids, provoking mitochondrial DNA (mtDNA) mutation and dysfunction. The disruption of protein homeostasis induces the aggregation of alpha-synuclein (α-SYN) and parkin and a deficit in proteasome degradation. Also, oxidative stress affects dopamine release by activating ATP-sensitive potassium channels. The cholinergic system is essential in modulating the striatal cells regulating cognitive and motor functions. Several muscarinic acetylcholine receptors (mAChR) and nicotinic acetylcholine receptors (nAChRs) are expressed in the striatum. The nAChRs signaling reduces neuroinflammation and facilitates neuronal survival, neurotransmitter release, and synaptic plasticity. Since there is a deficit in the nAChRs in PD, inhibiting nAChRs loss in the striatum may help prevent dopaminergic neurons loss in the striatum and its pathological consequences. The nAChRs can also stimulate other brain cells supporting cognitive and motor functions. This review discusses the cholinergic system as a therapeutic target of cotinine to prevent cognitive symptoms and transition to dementia in PD.

Neuropsychiatric Symptoms Are Associated with Dementia in Parkinson's Disease but Not Predictive of it

Background

Neuropsychiatric symptoms in Parkinson's disease (PD) may increase dementia (PDD) risk. The predictive value of these symptoms, however, has not been compared to clinical and demographic predictors of future PDD.

Objectives

Determine if neuropsychiatric symptoms are useful markers of PDD risk.

Methods

328 PD participants completed baseline neuropsychiatric and MDS-Task Force-Level II assessments. Of these, 202 non-demented individuals were followed-up over a four-years period to detect conversion to PDD; 51 developed PDD. ROC analysis tested associations between baseline neuropsychiatric symptoms and future PDD. The probability of developing PDD was also modeled as a function of neuropsychiatric inventory (NPI)-total score, PD Questionnaire (PDQ)-hallucinations, PDQ-anxiety, and contrasted to cognitive ability, age, and motor function. Leave-one-out information criterion was used to evaluate which models provided useful information when predicting future PDD.

Results

The PDD group experienced greater levels of neuropsychiatric symptoms compared to the non-PDD groups at baseline. Few differences were found between the PD-MCI and PD-N groups. Six neuropsychiatric measures were significantly, but weakly, associated with future PDD. The strongest was NPI-total score: AUC = 0.66 [0.57-0.75]. There was, however, no evidence it contained useful out-of-sample predictive information of future PDD (delta ELPD = 1.8 (SD 2.5)); Similar results held for PDQ-hallucinations and PDQ-anxiety. In contrast, cognitive ability (delta ELPD = 36 (SD 8)) and age (delta ELPD = 11 (SD 5)) provided useful predictive information of future PDD.

Conclusions

Cognitive ability and age strongly out-performed neuropsychiatric measures as markers of developing PDD within 4 years. Therefore, neuropsychiatric symptoms do not appear to be useful markers of PDD risk.

Association Between Informant-Reported Sleep Disturbance and Incident Dementia: An Analysis of the National Alzheimer's Coordinating Center Uniform Data Set

Informants' reports can be useful in screening patients for future risk of dementia. We aimed to determine whether informant-reported sleep disturbance is associated with incident dementia, whether this association varies by baseline cognitive level and whether the severity of informant-reported sleep disturbance is associated with incident dementia among those with sleep disturbance. A longitudinal retrospective cohort study was conducted using the uniform data set collected by the National Alzheimer's Coordinating Center. Older adults without dementia at baseline living with informants were included in analysis. Cox proportional hazards models showed that participants with an informant-reported sleep disturbance were more likely to develop dementia, although this association may be specific for older adults with normal cognition. In addition, older adults with more severe sleep disturbance had a higher risk of incident dementia than those with mild sleep disturbance. Informant-reported information on sleep quality may be useful for prompting cognitive screening.

Clinical Approach to Personality Change Due to Another Medical Condition

BACKGROUND

Medical personality change (MPC) is a codable diagnosis (i.e., F07.0) that deserves consideration when a patient is inexplicably no longer "acting like him/herself." Its presentation ranges from subtle to severe and is often characterized by bafflingly poor judgment and impairment in several aspects of a person's life. Despite the global impact that MPC can have on a patient's functioning, occupation, and relationships, this condition receives far less clinical consideration than better known syndromes such as depression or anxiety and is often likely incorrectly formulated as such.

OBJECTIVE/METHODS

This article provides a clinically focused review of MPC. We review its clinical assessment followed by a review of its subtypes, which we have categorized to reflect the behavioral correlates of known frontotemporal-subcortical circuits. These include the apathetic type (ventromedial prefrontal cortex), the labile and disinhibited types (orbitofrontal cortex), and the aggressive and paranoid types (medial temporal lobes).

RESULTS

For each of these 3 categories, we describe the clinical presentation and review management strategies. For each category, we focus on 3 common causes for MPC-traumatic brain injury, Huntington disease, and brain tumors-which we have selected because clinical features of MPC due to these conditions generalize to many other etiologies of MPC.

CONCLUSIONS

MPC warrants clinical attention for the range of dysfunction and distress it can cause. It also deserves further scientific study to better characterize its phenotypes, to tailor instruments for its clinical assessment, and to identify effective treatments.

Diagnosis, treatment and management of apathy in Parkinson's disease: a scoping review

OBJECTIVE

To conduct a scoping review of the literature on apathy in Parkinson's disease (PD), to better understand how apathy in Parkinson's disease is diagnosed, treated and managed.

METHODS

MEDLINE, Embase, PsycINFO, CINAHL, Cochrane Central Register of Control Trials and Cochrane Database of Systematic Reviews were searched to 17 May 2017. An updated review was run from 17 May 2017 to 28 January 2019. The grey literature was searched using the CADTH Grey Matters tool. Original peer-reviewed research was included if it included individuals with PD and apathy. Non-original data was only included if it was in the form of meta-analysis. All information regarding diagnosis, treatment and management of PD was extracted. Citation screening and extraction were performed in duplicate.

RESULTS

From 11 375 citations, 362 articles were included in the final review. The majority of included studies focussed on prevalence, with few studies examining treatment. Twenty screening tools for apathy were identified. Fifty per cent of treatment studies were randomised control trials (RCTs). RCTs applied treatment methods including: exercise, mindfulness, rotigotine (Neupro) transdermal patch and rivastigmine (Exelon).

CONCLUSIONS

This review identified a large body of literature describing current knowledge on diagnosing, treating and managing apathy in PD. Future research should aim to detect an ideal screening tool for apathy in PD, to identify the best treatment options for apathy and the variety of comorbidities it may present with and finally aim to better understand postoperative apathy in those with deep brain stimulation.

Subjective Cognitive Complaint in Parkinson's Disease Patients With Normal Cognition: Canary in the Coal Mine?

OBJECTIVE

The objective of this study was to determine the frequency and impact of subjective cognitive complaint (SCC) in Parkinson's disease (PD) patients with normal cognition.

METHODS

Patients with PD with expert consensus-determined normal cognition at baseline were asked a single question regarding the presence of SCC. Baseline (N = 153) and longitudinal (up to 4 follow-up visits during a 5-year period; N = 121) between-group differences in patients with PD with (+SCC) and without (-SCC) cognitive complaint were examined, including cognitive test performance and self-rated and informant-rated functional abilities.

RESULTS

A total of 81 (53%) participants reported a cognitive complaint. There were no between-group differences in global cognition at baseline. Longitudinally, the +SCC group declined more than the -SCC group on global cognition (Mattis Dementia Rating Scale-2 total score, F_1,431 = 5.71, P = 0.02), processing speed (Symbol Digit Modalities Test, F_1,425 = 7.52, P = 0.006), and executive function (Trail Making Test Part B, F_1,419 = 4.48, P = 0.04), although the results were not significant after correction for multiple testing. In addition, the +SCC group was more likely to progress to a diagnosis of cognitive impairment over time (hazard ratio = 2.61, P = 0.02). The +SCC group also demonstrated significantly lower self-reported and knowledgeable informant-reported cognition-related functional abilities at baseline, and declined more on an assessment of global functional abilities longitudinally.

CONCLUSIONS

Patients with PD with normal cognition, but with SCC, report poorer cognition-specific functional abilities, and are more likely to be diagnosed with cognitive impairment and experience global functional ability decline long term. These findings suggest that SCC and worse cognition-related functional abilities may be sensitive indicators of initial cognitive decline in PD. © 2020 International Parkinson and Movement Disorder Society.

Altered EEG alpha and theta oscillations characterize apathy in Parkinson's disease during incentivized movement

Apathy is a common non-motor symptom of Parkinson's disease (PD) that is difficult to quantify and poorly understood. Some studies have used incentivized motor tasks to assess apathy, as the condition is often associated with a reduction in motivated behavior. Normally event-related desynchronization, a reduction of power in specific frequency bands, is observed in the motor cortex during the peri-movement period. Also, alpha (8–12 Hz) and theta (4–7 Hz) oscillations are sensitive to rewards that are closely related to motivational states however these oscillations have not been widely investigated in relation to apathy in PD. Using EEG recordings, we investigated the neural oscillatory characteristics of apathy in PD during an incentivized motor task with interleaved rest periods. Apathetic and non-apathetic PD subjects on dopaminergic medication and healthy control subjects were instructed to squeeze a hand grip device for a monetary reward proportional to the subject's grip force and the monetary value attributed to that trial. Apathetic PD subjects exhibited higher alpha and theta powers in the pre-trial baseline rest period compared to non-apathetic PD subjects and healthy subjects. Further, we found that both resting power and relative power in alpha and theta bands during incentivized movement predicted PD subjects' apathy scores. Our results suggest that apathetic PD patients may need to overcome greater baseline alpha and theta oscillatory activity in order to facilitate incentivized movement. Clinically, resting alpha and theta power as well as alpha and theta event-related desynchronization during movement may serve as potential neural markers for apathy severity in PD.

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Apathetic patients with Parkinson's disease on dopaminergic medication have distinct neural oscillatory characteristics.

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Apathetic patients exhibit a higher resting EEG theta and alpha power compared to non-apathetic patients.

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Both resting power and relative event-related theta and alpha desynchronization during squeezing are able to predict patient apathy scores.

Interaction Between Neuropsychiatric Symptoms and Cognitive Performance in Parkinson's Disease: What Do Clinical and Neuroimaging Studies Tell Us?

PURPOSE OF REVIEW

Parkinson's disease was studied for a long time from the prism of a motor impairment. Recent advances have outlined the importance of cognitive and neuropsychiatric symptoms (NPS) in the PD equation. This review concentrates on the present possibilities of using neuroimaging techniques in order to quantify the cognitive performance and NPS in PD patients.

RECENT FINDINGS

Mild cognitive impairment as well as many NPS have been acknowledged as important criteria for assessing the quality of life in patients with Parkinson's disease and have been shown as potential factors in predicting further evolution of PD from a clinical perspective. Some NPS strongly influence cognition (depression, REM sleep behavior disorder), while others are less specifically associated with it (impulse control disorders). Neuroimaging techniques reported specific structural, functional, and metabolic brain changes that might be specific for each NPS type. Recent neuroimaging advances report a strong interrelation between NPS and cognitive performance in PD. A special place for consideration is given to REM sleep behavior disorder, depression, and hallucinations. Nevertheless, some studies report distinct results, outlining that the neuroimaging acquisition and analysis techniques still have limitations and also likely represent the complexity of the manifestation of NPS in PD.

Behavioral Problems and Dementia

Behavioral problems decrease quality of life of people with dementia and their care providers. Three main consequences of dementia are functional impairment and in some cases also mood disorders and psychosis. These consequences, alone or in combination, result in 3 main behavioral problems: apathy, agitation, and rejection of care/aggression. Nonpharmacologic management strategies include meaningful activities and individualized comfort care, for example, Namaste Care. If needed, pharmacologic management should concentrate on treatment of main dementia consequences, especially depression, instead of treating secondary symptoms, for example, insomnia. Use of antipsychotics should be minimized but antipsychotics may be necessary for augmentation of antidepressants.

Standardised Neuropsychological Assessment for the Selection of Patients Undergoing DBS for Parkinson's Disease

DBS is an increasingly offered advanced treatment for Parkinson's disease (PD). Neuropsychological assessment is considered to be an important part of the screening for selection of candidates for this treatment. However, no standardised screening procedure currently exists. In this study, we examined the use of our standardised neuropsychological assessment for the evaluation of surgical candidates and to identify risk factors for subsequent decline in cognition and mood. A total of 40 patients were assessed before and after DBS. Evaluation of mood and case notes review was also undertaken. Before DBS, patients with PD demonstrated frequent impairments in intellectual functioning, memory, attention, and executive function, as well as high rates of mood disorder. Post-DBS, there was a general decline in verbal fluency only, and in one patient, we documented an immediate and irreversible global cognitive decline, which was associated with older age and more encompassing cognitive deficits at baseline. Case note review revealed that a high proportion of patients developed mood disorder, which was associated with higher levels of depression at baseline and greater reduction in levodopa medication. We conclude that our neuropsychological assessment is suitable for the screening of candidates and can identify baseline risk factors, which requires careful consideration before and after surgery.

Differentiating Between Apathy and Depression in Patients With Parkinson Disease Dementia

In Parkinson disease (PD), apathy and depression often overlap, making it difficult to differentiate between them. This study sought to analyze apathy and depression in patients with PD dementia (PDD). Forty patients were diagnosed with PDD using the Movement Disorder Society criteria. A statistically significant correlation was identified between worsening dementia and an improvement in depression ( r = .3695; r2 = .1365, 95% confidence interval [CI]: 0.0985 to 05.894, P = .0044) and between worsening dementia and worsening apathy ( r = -.2578, r2 = .0664, 95% CI: -0.5025 to .0251, P = .036). Depression had a greater correlation with advanced motor symptoms ( r = .4988, r2 = .2438, 95% CI: 0.2218-0.7013, P = .0005]. In conclusion, depression was associated with less advanced PDD and more intense motor features, while apathy was associated with more advanced cognitive impairment.

Psychometric properties of the apathy evaluation scale in patients with Parkinson's disease

Parkinson's disease (PD) frequently entails non-motor symptoms, worsening the course of the disease. Apathy is one of the core neuropsychiatric symptoms that has been investigated in recent years; research is however hampered by the limited availability of well-evaluated apathy scales for these patients. We evaluated the psychometric properties of the Apathy Evaluation Scale (AES) in a sample of PD patients. Psychometric properties, convergent and discriminant validity and sensitivity/specificity were evaluated in patients with (n = 582) or without dementia/depression (n = 339). Internal consistency was high in the entire sample as well as in patients without dementia/depression. Correlations were moderate for convergent validity (UPDRS I item 4: motivation). While apathy could be differentiated from cognitive decline, it was related to depression (Geriatric Depression Scale, GDS-15). The overall classification accuracy based on the UPDRS I item 4 was comparable for AES and GDS scores. The AES exhibits good psychometric properties in PD patients with and without dementia and/or depression. Commonly used screenings on the presence of apathy had low detection rates compared to the AES and reflected both apathetic and depressive symptoms. Psychometric evaluation of available instruments will support further research on the clinical relevance of apathy for disease progression and treatment approaches in PD patients.

Taking a positive spin: preserved initiative and performance of everyday activities across mild Alzheimer's, vascular and mixed dementia

OBJECTIVES

The literature commonly evaluates those daily activities which are impaired in dementia. However, in the mild stages, people with dementia (PwD) are still able to initiate and perform many of those tasks. With a lack of research exploring variations between different dementia diagnoses, this study sought to investigate those daily activities with modest impairments in the mild stages and how these compare between Alzheimer's disease (AD), vascular dementia (VaD) and mixed dementia.

METHODS

Staff from memory assessment services from nine National Health Service trusts across England identified and approached informal carers of people with mild dementia. Carers completed the newly revised Interview for Deteriorations in Daily Living Activities in Dementia 2 assessing the PwD's initiative and performance of instrumental activities of daily living (IADLs). Data were analysed using analysis of variance and Chi-square tests to compare the maintenance of IADL functioning across AD, VaD, and mixed dementia.

RESULTS

A total of 160 carers returned the Interview for Deteriorations in Daily Living Activities in Dementia 2, of which 109, 21, and 30 cared for someone with AD, VaD, and mixed dementia, respectively. There were significant variations across subtypes, with AD showing better preserved initiative and performance than VaD for several IADLs. Overall, PwD showed greater preservation of performance than initiative, with tasks such as preparing a hot drink and dressing being best maintained.

CONCLUSION

Findings can help classify dementia better into subtypes in order to receive bespoke support. It suggests that interventions should primarily address initiative to improve overall functioning. Copyright © 2016 John Wiley & Sons, Ltd.

Quality-of-life perception by Parkinson's disease patients and caregivers

BACKGROUND

The quality-of-life (QoL) perception by Parkinson's disease (PD) patients and their caregivers (CG) has not been studied in depth.

OBJECTIVE

To examine patient/proxy agreements on the PD QoL Questionnaire (PDQ-39), the Scale of Quality of Life of Care-Givers (SQLC) and the Multidimensional Caregiver Strain Index (MCSI).

METHODS

Patients with PD and their CG completed the above-mentioned questionnaires about themselves and each other. The intraclass correlations between their scores (paired t test) were compared.

RESULTS

Twelve patient-CG pairs were studied. Agreements for QoL items were strong and comparable for the total scores of the PDQ-39, SQLC and MCSI questionnaires (75.4% ± 14%; 78.1% ± 14.1% and 78.2% ± 14.3%, respectively). Agreements ranged from moderate to strong (0.57-0.88, P≤.05) for the patients' physical condition (PDQ-39 items 3, 5, 6, 8, 12-15, 23, 24, 35), mental concentration (item 31) and depression (item 17). Disagreements were apparent in 20%-25% of the pairs and were particularly significant for PDQ-39 items #33 and #25 (embarrassment of patients in public and distressing dreams or hallucinations), in which the CG gave higher scores than the patients.

CONCLUSIONS

Agreements between patients with PD and CG were generally good for most, but not all, of the PDQ-39, SQLC and MCSI domains.

Neuropathology of Nonmotor Symptoms of Parkinson's Disease

Parkinson's disease (PD), a multiorgan neurodegenerative disorder associated with α-synuclein deposits throughout the nervous system and many organs, is clinically characterized by motor and nonmotor features, many of the latter antedating motor dysfunctions by 20 or more years. The causes of the nonmotor manifestations such as olfactory, autonomic, sensory, neuropsychiatric, visuospatial, sleep, and other disorders are unlikely to be related to single lesions. They are mediated by the involvement of both dopaminergic and nondopaminergic systems, and diverse structures outside the nigrostriatal system that is mainly responsible for the motor features of PD. The nonmotor alterations appear in early/prodromal stages of the disease and its further progression, suggesting a topographical and chronological spread of the lesions. This lends further support for the notion that PD is a multiorgan proteinopathy, although the exact relationship between presymptomatic and later developing nonmotor features of PD and neuropathology awaits further elucidation.

Apathy and Reduced Speed of Processing Underlie Decline in Verbal Fluency following DBS

Objective. Reduced verbal fluency is a strikingly uniform finding following deep brain stimulation (DBS) for Parkinson's disease (PD). The precise cognitive mechanism underlying this reduction remains unclear, but theories have suggested reduced motivation, linguistic skill, and/or executive function. It is of note, however, that previous reports have failed to consider the potential role of any changes in speed of processing. Thus, the aim of this study was to examine verbal fluency changes with a particular focus on the role of cognitive speed. Method. In this study, 28 patients with PD completed measures of verbal fluency, motivation, language, executive functioning, and speed of processing, before and after DBS. Results. As expected, there was a marked decline in verbal fluency but also in a timed test of executive functions and two measures of speed of processing. Verbal fluency decline was associated with markers of linguistic and executive functioning, but not after speed of processing was statistically controlled for. In contrast, greater decline in verbal fluency was associated with higher levels of apathy at baseline, which was not associated with changes in cognitive speed. Discussion. Reduced generativity and processing speed may account for the marked reduction in verbal fluency commonly observed following DBS.

Neuropsychiatric Predictors of Cognitive Decline in Parkinson Disease: A Longitudinal Study

OBJECTIVES

To examine the relationship between anxiety, depression, apathy, and cognitive decline in Parkinson disease (PD).

DESIGN

Longitudinal study design to assess whether specific neuropsychiatric, demographic, and clinical features predict future cognitive decline.

SETTING

Veterans Affairs San Diego Medical Center and the University of California, San Diego.

PARTICIPANTS

PD patients (N = 68) and healthy controls (N = 30).

MEASUREMENTS

Participants were administered self-report measures of depression (Geriatric Depression Scale), anxiety (State Trait Anxiety Scale), and apathy (Apathy Scale), and a comprehensive neuropsychological battery assessing attention, language, visuospatial function, verbal and visual learning and memory, and executive function. Participants were tested at baseline and after an approximate 2-year period.

RESULTS

Anxiety and depression at baseline were the strongest predictors of longitudinal decline on measures of verbal and visual learning, over and above other clinical and demographic characteristics. However, baseline neuropsychiatric symptoms did not significantly correlate with decline in other cognitive domains. No significant correlations were detected between neuropsychiatric symptoms and cognition in the healthy control group.

CONCLUSIONS

These results suggest that anxiety and depression in PD may be risk factors for subsequent declines in learning. Emerging evidence suggests nonmotor symptoms are critical determinants of PD prognosis, and the results of this study highlight the importance of assessment of depression and anxiety early in PD.

Pathology of behavior in PD: What is known and what is not?

Abnormal behavior in Parkinson's disease (PD) stems from a complex orchestration of impaired neural networks that result from PD-related neurodegeneration across multiple levels. Typically, cellular and tissue abnormalities generate neurochemical changes and disrupt specific regions of the brain, in turn creating impaired neural circuits and dysfunctional global networks. The objective of this chapter is to provide an overview of the array of pathological changes that have been linked to different behavioral symptoms of PD such as depression, anxiety, apathy, fatigue, impulse control disorders, psychosis, sleep disorders and dementia.

The perception of apathy by caregivers of patients with dementia in Parkinson's disease

Background

Apathy is one of the main neuropsychiatric symptoms in patients with Parkinson's disease (PD) and is associated with Parkinson's disease dementia (PDD).

Objective

To identify the characteristics of apathy in individuals with PDD according to caregiver perception.

Methods

Thirty-nine patients with PD according to MDS criteria for PDD were included. The following scales were used: the Hoehn and Yahr, the Unified Parkinson's Disease Rating Scale III, Scales for Outcomes in Parkinson's Disease-Cognition (SCOPA Cog), the Montgomery-Åsberg Depression Rating Scale (MADRS) and the Apathy Evaluation Scale (AES).

Results

A total of 97.4% of the patients showed results consistent with apathy. Analysis of question 14 of the AES revealed no correlation with the total result of all the questions [r=-1293, r²=0.0167, 95%CI (-0.4274 to 0.1940), P=0.2162], however, there was a correlation of responses to the same question with depression data on the MADRS scale [r=-0.5213, r²=0.2718, 95%CI (-0.7186 to -0.2464), P=0.00033].

Conclusion

Apathy is a disorder associated with PDD. However, the scoring scheme of the AES questions can lead to different interpretations of caregiver responses, highlighting limitations of the tool for use in studies of PDD.

Visual Hallucinations and Amyloid Deposition in Parkinson's Disease Dementia: A Case Report

Parkinson's disease dementia (PDD) is notorious for its debilitating clinical course and high mortality rates. Consequently, various attempts to investigate predictors of cognitive decline in Parkinson's disease (PD) have been made. Here we report a case of a 75-year-old female patient with PD who visited the clinic with complaints of recurrent visual hallucinations and cognitive decline, whose symptoms were ameliorated by the titration of rivastigmine. Imaging results showed pronounced diffuse cortical amyloid deposition evidenced by 18F-florbetaben amyloid positron emission tomography (PET) imaging. This observation suggests that pronounced amyloid deposition and visual hallucinations in PD patients could be clinically significant predictors of cognitive decline in PD patients. Future research should concentrate on accumulating more evidence for possible predictors of cognitive decline and their association with PD pathology that can enable an early intervention and standardized treatment in PDD patients.