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.

Predictors of discrepancies in Parkinson's disease patient and caregiver ratings of apathy, disinhibition, and executive dysfunction before and after diagnosis.

Parkinson's disease (PD) patient and caregiver reports of patient functioning are often used interchangeably in clinical and research settings; however, the consistency of these reports is largely unknown. This study aimed to investigate the consistency and predictors of discrepancy between self- and caregiver reports of patient apathy, disinhibition, and executive dysfunction. Fifty-one pairs of nondemented PD patients and their caregivers completed the frontal systems behavior scale (FrSBe). Patients were administered a neuropsychological battery, and mood and burden were assessed in a subset of caregivers. Patients and caregivers significantly differed in their ratings of all retrospective prediagnosis behaviors and current levels of disinhibition. Current levodopa equivalent dosages predicted patient-caregiver rating differences in prediagnosis and current apathy and current executive dysfunction, while patient motor function, cognition, and mood failed to predict any disparities in ratings. Caregiver burden and depression were associated with apathy rating discrepancies, while burden was associated with discrepancies in ratings of disinhibition. These results suggest that consistency of patient and caregiver behavioral ratings may vary depending on the behavior assessed; and underscore the importance of considering the reporter when using subjective measures, as discrepancies in behavioral reports may be influenced by specific patient and/or caregiver symptoms or factors.

Cognitive and functional decline in Huntington's disease: dementia criteria revisited.

The importance of designating criteria for diagnosing dementia lies in its implications for clinical treatment, research, caregiving, and decision-making. Dementia diagnosis in Huntington's disease (HD) is often based on criteria developed for Alzheimer's disease requiring memory loss. However, it is likely that other cognitive deficits contribute to functional impairment in HD before memory declines. The goal is to identify cognitive deficits that contribute to functional impairment to support dementia criteria that reflect HD neuropathology. Eighty-four HD mutation-positive subjects completed neuropsychological tests and the Unified Huntington's Disease Rating Scale Functional Independence Scale (FIS). Functional impairment was defined as 80 or below on the FIS. Speed of processing, initiation, and attention measures accounted for 70.0% of the variance in FIS ratings (linear regression) and correctly classified 91.7% of subjects as functionally impaired or intact (logistic regression). Measures of memory, motor impairment except dysarthria, neuroleptic use, and depressed mood did not improve prediction. A definition of HD dementia that includes cognitive impairment in at least two areas of cognition but does not require a memory deficit, in the context of impaired functional abilities and a deteriorating course, more accurately reflects HD neuropathology and could lead to improved research methods and patient care.

Psychometric Properties and Characteristics of the North-East Visual Hallucinations Interview in Parkinson's Disease.

BACKGROUND: Visual Hallucinations (VH) are a common symptom experienced by individuals with Parkinson's disease (PD); however, a validated measure of VH has yet to be established for this population. The North-East Visual Hallucinations Interview (NEVHI), a promising VH measure, has not been well validated in PD. The aim of this study was to evaluate the convergent and discriminant validity of the NEVHI as well as the proportional identification and characteristics of VH in PD. METHODS: One hundred seventeen individuals with PD completed the NEVHI as well as evaluations of psychological, cognitive, motor, and visual functioning as measures of convergent and divergent validity. The hallucination items from the Neuropsychiatric Inventory (NPI) and the Movement Disorder Society-sponsored revision of the Unified Parkinson's Disease Scale (MDS-UPDRS) were used to assess convergent validity. RESULTS: The NEVHI identified 20.5% of PD patients with VH, which consisted of all individuals detected by the MDS-UPDRS and NPI and nine additional individuals not detected by the other measures. The NEVHI was strongly correlated with the MDS-UPDRS hallucinations item, and weakly correlated with the NPI VH item. Weak to non-significant correlations were found between the NEVHI and measures of psychological, cognitive, motor, visual, and demographic characteristics. DISCUSSION: The NEVHI identified a greater number of individuals with VH than either the MDS-UPDRS or NPI. Results demonstrated good convergent validity between the NEVHI and a clinician-administered-to-patient-report measure of VH and excellent divergent validity, supporting the NEVHI as a valid and preferable measure for assessing the presence of VH in PD.

Cognitive functioning in individuals with Parkinson's disease and traumatic brain injury: A longitudinal study.

OBJECTIVE: To examine longitudinal changes in cognition in individuals with Parkinson's disease (PD) with and without a history of traumatic brain injury (TBI). METHODS: Twenty-five PD participants with a history of mild-moderate post-acute (>9 months) TBI and 25 demographically-matched PD controls without a history of TBI were administered measures of cognition (Mattis Dementia Rating Scale), mood, and motor functioning at baseline and at a two-year follow-up evaluation. RESULTS: Individuals with PD and a history of TBI evidenced significantly greater decrements in overall cognition over the two year follow-up period compared to those without a history of TBI. Secondary subscale analyses suggest cognitive decrements may be mainly in the area of executive function, while a trend for group differences on the memory subscale was also observed. Groups did not differ on demographic, motor function, disease severity, cognitive, and mood profiles at baseline and evidenced comparable changes in mood and motor symptoms from baseline to follow-up. CONCLUSION: Findings suggest that a history of mild-moderate TBI is a risk factor for cognitive decline in individuals with PD.

The utility of the Mattis Dementia Rating Scale in Parkinson's disease mild cognitive impairment.

BACKGROUND: The Movement Disorders Society (MDS) recently proposed guidelines for diagnosis of mild cognitive impairment in Parkinson's disease (PD-MCI) that includes two assessment levels: abbreviated (Level I) and comprehensive (Level II). The aim of this study was to determine the utility of the Mattis Dementia Rating Scale (MDRS), a recommended Level I test, for detecting Level II PD-MCI diagnosis. METHODS: The study sample included 30 patients diagnosed with PD-MCI based on Level II MDS criteria and 68 PD patients with normal cognition (PD-NC). Receiver operator curve (ROC) analyses were generated to measure the sensitivity and specificity of various MDRS cutoff scores. To examine the utility of the MDRS as a screening tool, the optimal cutoff point was defined as the lowest value providing ≥80% sensitivity. For use of the MDRS as a diagnostic tool, the optimal cutoff point was defined as the highest value providing ≥80% specificity. RESULTS: ROC analyses showed that the optimal MDRS cutoff score for screening purposes and diagnostic purposes were ≤140 and ≤137, respectively. However, an examination of sensitivity/specificity values for the screening cutoff scores suggested that a total score of ≤139 for screening purposes yielded a better balance between sensitivity (77%) and specificity (65%). CONCLUSIONS: In a clinical setting, in which detection of PD-MCI may be important, a total MDRS score of ≤139 can be used to detect PD-MCI. In research and other settings in which diagnostic certainty is more important, a score of ≤137 may be more useful.

Instrumental activities of daily living are impaired in Parkinson's disease patients with mild cognitive impairment.

OBJECTIVE: Although it is well known that Parkinson's disease (PD) with dementia results in functional decline, little is known about the impact of mild cognitive impairment in PD (PD-MCI) on day-to-day functioning. METHOD: Forty-one individuals with PD-MCI, 56 PD patients with normal cognition (PD-NC), and 47 healthy older adults were administered two performance-based measures of instrumental activities of daily living (IADLs) that evaluated medication and financial management. Informants of the PD patients were also administered an IADL questionnaire. RESULTS: There were no significant differences between PD-NC and healthy older adults on the performance-based measures of medication and financial management. However, PD-MCI patients demonstrated significantly lower scores on the performance-based measures of medication and financial management compared with healthy older adults. PD-MCI patients were also impaired compared with PD-NC patients on performance-based medication management, but no difference between these groups was observed for ability to manage finances. Performance-based financial and medication management did not correlate with scores on neuropsychological measures in PD-MCI patients. PD-MCI and PD-NC patients showed comparable scores on the informant-based IADL questionnaire. CONCLUSIONS: Performance-based measures of IADLs, particularly medication management ability, are sensitive to subtle functional declines in PD-MCI. Although impairment in performance-based measures is associated with cognitive status in PD, IADLs may be a separate domain of functioning from cognitive functioning in PD-MCI as these measures did not correlate with performance on the neuropsychological measures. Overall, performance-based assessment of IADLs may add to the clinical evaluation of PD-MCI.

Predictors of performance-based measures of instrumental activities of daily living in nondemented patients with Parkinson's disease.

Few studies have examined instrumental activities of daily living (iADLs) in nondemented Parkinson's disease (PD), and the majority of these studies have used report-based measures, which can have limited validity. The present study had two main goals: (a) to examine the performance of nondemented PD patients on two performance-based measures of iADLs, which are considered more objective functional measures, and (b) to examine the cognitive, motor, and psychiatric correlates of iADL impairment in PD. Ninety-eight nondemented PD patients and 47 healthy older adults were administered performance-based measures that assess the ability to manage medications (Medication Management Ability Assessment) and finances (University of California, San Diego, UCSD, Performance-based Skills Assessment), the Mattis Dementia Rating Scale to assess global cognitive functioning, the Unified Parkinson's Disease Rating Scale Part III to assess motor symptom severity, and the Geriatric Depression Scale to assess depressive symptoms. Nondemented PD patients demonstrated significantly impaired scores relative to the healthy comparison group on the performance-based measure of financial management, but there were no significant group differences in medication management. Global cognitive functioning, motor severity, and depressive symptoms did not correlate with scores on either of the functional measures, except for a small correlation between depressive symptoms and financial management. The two performance-based measures of iADL functioning did not correlate with one another. These findings suggest that medication and financial management may not be predicted based on global cognitive functioning and that iADLs may not be represented by a single construct. Furthermore, these findings suggest the potential need for a multidimensional approach to assessing iADLs.