The human tau gene, which promotes assembly of neuronal microtubules, has been associated with several rare neurologic diseases that clinically include parkinsonian features. We recently observed linkage in idiopathic Parkinson disease (PD) to a region on chromosome 17q21 that contains the tau gene. These factors make tau a good candidate for investigation as a susceptibility gene for idiopathic PD, the most common form of the disease.
To investigate whether the tau gene is involved in idiopathic PD.
Design, Setting, and Participants
Among a sample of 1056 individuals from 235 families selected from 13 clinical centers in the United States and Australia and from a family ascertainment core center, we tested 5 single-nucleotide polymorphisms (SNPs) within the tau gene for association with PD, using family-based tests of association. Both affected (n = 426) and unaffected (n = 579) family members were included; 51 individuals had unclear PD status. Analyses were conducted to test individual SNPs and SNP haplotypes within the tau gene.
Main Outcome Measure
Family-based tests of association, calculated using asymptotic distributions.
Analysis of association between the SNPs and PD yielded significant evidence of association for 3 of the 5 SNPs tested: SNP 3, P = .03; SNP 9i, P = .04; and SNP 11, P = .04. The 2 other SNPs did not show evidence of significant association (SNP 9ii, P = .11, and SNP 9iii, P = .87). Strong evidence of association was found with haplotype analysis, with a positive association with one haplotype (P = .009) and a negative association with another haplotype (P = .007). Substantial linkage disequilibrium (P<.001) was detected between 4 of the 5 SNPs (SNPs 3,9i, 9ii, and 11).
This integrated approach of genetic linkage and positional association analyses implicates tau as a susceptibility gene for idiopathic PD.
A disabling impairment of higher-order language function can be seen in patients with Lewy body spectrum disorders such as Parkinson's disease (PD), Parkinson's disease dementia (PDD), and dementia with Lewy bodies (DLB). We focus on script comprehension in patients with Lewy body spectrum disorders. While scripts unfold sequentially, constituent events are thought to contain an internal organization. Executive dysfunction in patients with Lewy body spectrum disorders may interfere with comprehension of this internal structure. We examined 42 patients (30 non-demented PD and 12 mildly demented PDD/DLB patients) and 12 healthy seniors. We presented 22 scripts (e.g., “going fishing”), each consisting of six events. Pilot data from young controls provided the basis for organizing associated events into clusters and arranging them hierarchically into scripts. We measured accuracy and latency to judge the order of adjacent events in the same cluster versus adjacent events in different clusters. PDD/DLB patients were less accurate in their ordering judgments than PD patients and controls. Healthy seniors and PD patients were significantly faster to judge correctly the order of highly associated within-cluster event pairs relative to less closely associated different-cluster event pairs, while PDD/DLB patients did not consistently distinguish between these event-pair types. This relative insensitivity to the clustered-hierarchical organization of events was related to executive impairment and to frontal atrophy as measured by volumetric MRI. These findings extend prior work on script processing to patients with Lewy body spectrum disorders and highlight the potential impact of frontal/executive dysfunction on the daily lives of affected patients.
Parkinson's disease; Parkinson's disease dementia; Dementia with Lewy bodies; Frontal cortex; Executive function; Scripts; Organization; Discourse; Volumetric MRI
To estimate the frequency and correlates of involuntary emotional expression disorder (IEED) in Parkinson’s disease (PD) using the Center for Neurologic Study-Lability Scale (CNS-LS) and recently-proposed diagnostic criteria for IEED.
IEED is characterized by uncontrollable emotional episodes, typically unrelated to or in excess of the underlying mood, and occurring with minimal or no stimulus. IEED has been reported to occur in many neurological disorders and neurodegenerative diseases, but its prevalence and correlates in PD have not been well studied. Additionally, there is no published research using recently-proposed IEED diagnostic criteria in any population.
193 patients with idiopathic PD were assessed with a neuropsychiatric battery, including the CNS-LS and the 15-item Geriatric Depression Scale (GDS-15). A subset (N =100) was also administered a diagnostic interview by a blinded rater that applied criteria for both IEED and Diagnostic and Statistical Manual of Mental Disorders (DSM-IV-TR) depressive disorders.
Applying formal diagnostic criteria, 7.0% of patients were diagnosed with IEED, and an additional 7.0% had subsyndromal IEED symptoms. Applying recommended CNS-LS cutoff scores from other populations, either 42.5% (cutoff ≥13) or 16.6% (cutoff ≥17) screened positive for IEED. Depressive symptoms were associated with higher CNS-LS scores (B[SE] =0.27[.08], P =.001) but not with a diagnosis of IEED (odds ratio =1.1, [95% CI =1.0–1.3], P =.16). The CNS-LS had poor discriminant validity for an IEED diagnosis (AUC =.79, no cutoff value with sensitivity and specificity both >60%).
IEED and depression are overlapping but distinct disorders in PD. IEED symptoms may occur in up to 15% of PD patients, but a disorder occurs in only half of those, suggesting that often IEED symptoms are not clinically significant in this population. The CNS-LS does not appear to be a good screening instrument for IEED in PD, in part due to its high correlation with depressive symptoms.
Involuntary emotional expression disorder; Pseudobulbar affect; Emotional lability; Depression; Parkinson’s disease
Cognitive impairment occurs in the majority of Parkinson’s disease (PD) patients, but little is known about detection of mild cognitive impairment (MCI) in this population. We report on the frequency and characteristics of cognitive deficits in PD patients with intact global cognition based on Mini-Mental State Examination (MMSE) performance.
One hundred and six PD patients with normal age- and education-adjusted MMSE scores (mean [SD] score = 29.1 [1.1]) were administered standardized neuropsychological tests assessing memory, executive function, and attention. Impairment on a cognitive domain was a low score (i.e., ≥1.5 SD below the published normative mean) on at least two measures or tests (for memory and executive abilities) or a single measure (for attention).
Mild cognitive impairment was found in 29.2% of PD patients, with 17.9% demonstrating single domain and 11.3% multiple domain impairment. Memory and attention impairment were most common (15.1% and 17.0%, respectively), followed by executive impairment (8.5%). Depending on the measure of disease severity chosen, increasing age and disease severity, anti-anxiety medication use, and a suggestion for increasing severity of daytime sleepiness were independent predictors of cognitive impairment.
Cognitive deficits are common in PD patients with “normal” cognition based on MMSE performance, suggesting that MCI is under-recognized in clinical practice due to routine use of insensitive screening instruments. In contrast with some previous reports, early memory impairment may be as common as either executive or attentional deficits in PD. In addition, psychiatric medication use and daytime sleepiness may be reversible or treatable contributors to cognitive impairment.
Mild cognitive impairment; Parkinson’s disease; Mini-Mental State Examination; Neuropsychology
Though both psychosis and depression are common in Parkinson’s disease (PD), it is not clear if an association between the two disorders exists. One hundred and thirty PD patients were divided into four groups based on a comprehensive psychiatric assessment: (1) no depression or psychosis (47.7%); (2) psychosis only (16.2%); (3) depression only (26.2%); and (4) psychosis and depression (10.0%). Co-morbid psychosis and depression did not occur more frequently than expected by chance (P = .77). Psychosis was associated with dopamine agonist use (P = .02), depression with mild-cognitive impairment (P = .03), and their co-occurrence with higher daily levodopa dosages (P<.01). These results suggest that psychosis and depression in PD are distinct neurobehavioral disorders.
Parkinson’s disease; Depression; Psychosis; Co-morbidity
A range of impulse control disorders (ICDs) are reported to occur in Parkinson’s disease (PD). However, alterations in brain activity at rest and during risk taking occurring with ICDs in PD are not well understood.
We used both arterial spin labeling (ASL) perfusion fMRI to directly quantify resting cerebral blood flow (CBF) and blood oxygenation level dependent (BOLD) fMRI to measure neural responses to risk taking during performance on the Balloon Analogue Risk Task (BART).
18 PD patients, either with a diagnosis of one or more ICDs (N=9) or no lifetime ICD history (N=9), participated. BOLD fMRI data demonstrated that PD patients without an ICD activate the mesocorticolimbic pathway during risk taking. Compared with non-ICD patients, ICD patients demonstrated significantly diminished BOLD activity in the right ventral striatum during risk taking and significantly reduced resting CBF in the right ventral striatum.
ICDs in PD are associated with reduced right ventral striatal activity at rest and diminished striatal activation during risk taking, suggesting that a common neural mechanism may underlie ICDs in individuals with PD and those without PD. Thus, treatments for ICDs in non-PD patients warrant consideration in PD patients with ICDs.
Patients with Parkinson disease are increasingly recognized to suffer from non-motor symptoms in addition to motor symptoms. Many non-motor symptoms fluctuate in parallel with motor symptoms and in relationship to plasma levodopa levels. Though these symptoms are troublesome and result in reduced quality of life to patients and their caregivers, there has not been an objective method of recognizing and quantifying non-motor fluctuations (NMFs). This study sought to develop a patient-based instrument that would accurately capture the experience of patients with NMFs. Patient-based nominal group technique sessions, focus groups, and expert opinion were utilized in developing this questionnaire.
To apply a scaled, preference-based measure to the evaluation of health-related quality of life (HRQoL) in Parkinson's disease (PD); to evaluate the relationship between disease-specific rating scales and estimated HRQoL; and to identify predictors of diminished HRQoL.
Scaled, preference-based measures of HRQoL ("utilities") serve as indices of impact of disease, and can be used to generate quality-adjusted estimates of survival for health-economic evaluations. Evaluation of utilities for PD and their correlation with standard rating scales have been limited.
Utilities were generated using the Health Utilities Index Mark III (HUI-III) on consecutive patients attending a PD Clinic between October 2003 and June 2006. Disease severity, medical, surgical (subthalamic nucleus deep brain stimulation (STN-DBS)), and demographic information were used as model covariates. Predictors of HUI-III utility scores were evaluated using the Wilxocon rank-sum test and linear regression models.
68 men with a diagnosis of PD and a mean age of 74.0 (SD 7.4) were included in the data analysis. Mean HUI-III utility at first visit was 0.45 (SD 0.33). In multivariable models, UPDRS-II score (r2 = 0.56, P < 0.001) was highly predictive of HRQoL. UPDRS-III was a weaker, but still significant, predictor of utility scores, even after adjustment for UPDRS-II (P = 0.01).
Poor self-care in PD reflected by worsening UPDRS-II scores is strongly correlated with low generic HRQoL. HUI-III-based health utilities display convergent validity with the UPDRS-II. These findings highlight the importance of measures of independence as determinants of HRQoL in PD, and will facilitate the utilization of existing UPDRS data into economic analyses of PD therapies.
A range of psychiatric symptoms and cognitive deficits occur in Parkinson’s disease (PD), and symptom overlap and co-morbidity complicate the classification of non-motor symptoms. The objective of this study was to use analytic-based approaches to classify psychiatric and cognitive symptoms in PD.
Cross-sectional evaluation of a convenience sample of patients in specialty care.
Two outpatient movement disorders centers at the University of Pennsylvania and Philadelphia Veterans Affairs Medical Center.
177 patients with mild-moderate idiopathic PD and without significant global cognitive impairment.
Subjects were assessed with an extensive psychiatric, neuropsychological, and neurological battery. Latent class analysis (LCA) was used to statistically delineate group-level symptom profiles across measures of psychiatric and cognitive functioning. Predictors of class membership were also examined.
Results from the LCA indicated that a four-class solution best fit the data. 32.3% of the sample had good psychiatric and normal cognitive functioning, 17.5% had significant psychiatric co-morbidity but normal cognition, 26.0% had few psychiatric symptoms but had poorer cognitive functioning across a range of cognitive domains, and 24.3% had both significant psychiatric co-morbidity and poorer cognitive functioning. Age, disease severity, and medication use predicted class membership.
LCA delineates four classes of patients in mild-moderate PD, three of which experience significant non-motor impairments and comprise over two-thirds of patients. Neuropsychiatric symptoms and cognitive deficits follow distinct patterns in PD, and further study is needed to determine if these classes are generalizable, stable, predict function, quality of life and long-term outcomes, and are amenable to treatment at a class level.
Parkinson’s disease; neuropsychology; psychiatry; cognition; depression
To examine Montreal Cognitive Assessment (MoCA) performance in patients with Parkinson’s disease (PD) with “normal” global cognition according to Mini-Mental State Examination (MMSE) score.
A cross-sectional comparison of the MoCA and the MMSE.
Two movement disorders centers at the University of Pennsylvania and the Philadelphia Veterans Affairs Medical Center.
A convenience sample of 131 patients with idiopathic PD who were screened for cognitive and psychiatric complications.
Subjects were administered the MoCA and MMSE, and only subjects defined as having a normal age- and education-adjusted MMSE score were included in the analyses (N = 100). As previously recommended in patients without PD, a MoCA score less than 26 was used to indicate the presence of at least mild cognitive impairment (MCI).
Mean MMSE and MoCA scores ± standard deviation were 28.8 ± 1.1 and 24.9 ± 3.1, respectively. More than half (52.0%) of subjects with normal MMSE scores had cognitive impairment according to their MoCA score. Impairments were seen in numerous cognitive domains, including memory, visuospatial and executive abilities, attention, and language. Predictors of cognitive impairment on the MoCA using univariate analyses were male sex, older age, lower educational level, and greater disease severity; older age was the only predictor in a multivariate model.
Approximately half of patients with PD with a normal MMSE score have cognitive impairment based on the recommended MoCA cutoff score. These results suggest that MCI is common in PD and that the MoCA is a more sensitive instrument than the MMSE for its detection.
cognitive impairment; Parkinson’s disease; Mini-Mental State Examination; Montreal Cognitive Assessment; neuropsychology
Depression in Parkinson’s disease (dPD) remains under recognized and under treated. As patients’ beliefs may impact the reporting and treatment of depression, this study assessed the opinions of 38 dPD patients, approximately half with a self-reported poor response to antidepressant treatment, regarding the etiology and treatment of their depression using a semi-structured, audio-taped, qualitative interview. About half of the participants listed PD itself as a primary cause for their depressive symptoms, with most in this group citing psychosocial factors rather than PD-related neurobiological factors. Antidepressant therapy, psychotherapy, and self-initiated approaches were noted as preferred treatments for dPD. Many had concerns about antidepressant therapy, listing side-effects and medication dependency most frequently. About half raised concerns about psychotherapy with trust/discomfort, stigma, and transportation issues most frequently mentioned. This preliminary study suggests that many PD patients with clinically significant depressive symptoms attribute their depression to psychosocial factors and endorse nonpharmacologic treatment approaches.
Parkinson’s disease; depression; antidepressant; psychotherapy; qualitative interview
Recent studies have linked dopamine agonist (DA) usage with the development of impulse control disorders (ICDs) in Parkinson’s disease (PD). Little is known about optimal management strategies or the long-term outcomes of affected patients. To report on the clinical interventions and long-term outcomes of PD patients who developed an ICD after DA initiation. Subjects contacted by telephone for a follow-up interview after a mean time period of 29.2 months. They were administered a modified Minnesota Impulse Disorder Interview for compulsive buying, gambling, and sexuality, and also self-rated changes in their ICD symptomatology. Baseline and follow-up dopamine replacement therapy use was recorded and verified by chart review. Of 18 subjects, 15 (83.3%) participated in the follow-up interview. At follow-up, patients were receiving a significantly lower DA levodopa equivalent daily dosage (LEDD) (Z = -3.1, P = 0.002) and a higher daily levodopa dosage (Z = -1.9, P = 0.05), but a similar total LEDD dosage (Z = -0.47, P = 0.64) with no changes in Unified Parkinson’s Disease Rating Scale motor score (Z = -1.3, P = 0.19). As part of ICD management, 12 (80.0%) patients discontinued or significantly decreased DA treatment, all of whom experienced full or partial remission of ICD symptoms by self-report, and 10 (83.3%) of whom no longer met diagnostic criteria for an ICD. For PD patients who develop an ICD in the context of DA treatment, discontinuing or significantly decreasing DA exposure, even when offset by an increase in levodopa treatment, is associated with remission of or significant reduction in ICD behaviors without worsening in motor symptoms.
dopamine agonist; gambling; impulse control disorders; Parkinson’s disease
Parkinson’s disease (PD) is a chronic, disabling illness affecting primarily the elderly and is associated with a high prevalence of depression. Although these are known risk factors for suicidal and death ideation, little is known about the prevalence and correlates of such ideation in PD. A convenience sample of 116 outpatients with idiopathic PD at two movement disorders centers were administered a modified Paykel Scale for suicidal and death ideation, as well as an extensive psychiatric, neuropsychological, and neurological battery. Univariate and multivariate logistic regression models were used to determine the correlates of suicidal or death ideation. Current death ideation (28%) or suicide ideation (11%) were present in 30% of the sample, and 4% had a lifetime suicide attempt. On univariate logistic regression analysis, increasing severity of depression (odds ratio = 2.92, 95% CI 2.01-4.24, P < 0.001), impulse control disorder (ICD) behaviors sometime during PD (odds ratio = 6.08, 95% CI 1.90-19.49, P = 0.002), and psychosis (odds ratio = 2.45, 95% CI 1.05-5.69, P = 0.04) were associated with either ideation. On multivariate logistic regression analysis, only increasing severity of depressive symptoms (odds ratio = 2.76, 95% CI 1.88-4.07, P < 0.001) predicted suicidal or death ideation. In conclusion, active suicidal or death ideation occurs in up to one-third of PD patients. Comorbid psychiatric disorders, more than PD-related disease variables, are associated with this ideation, highlighting the need for a comprehensive approach to the clinical care of PD patients.
Parkinson’s disease; suicide; depression
To determine the frequency and correlates of impulse control disorders (ICDs) in Parkinson’s disease (PD).
An unstructured screening interview for ICDs (compulsive gambling, buying, and sexual behavior) followed by a telephone-administered structured interview for screen-positive patients.
Two university-affiliated movement disorders centers.
A convenience sample of 272 patients with idiopathic PD who were screened for psychiatric complications.
Main Outcome Measures
Presence of compulsive gambling, buying, or sexual behavior as assessed by the Minnesota Impulsive Disorders Interview.
Eighteen (6.6%) PD patients met criteria for an ICD at some point during the course of PD, including 11 (4.0%) with an active ICD. Compulsive gambling and compulsive sexual behavior were equally common. In a multivariate model, treatment with a dopamine agonist (P = .01) and a history of ICD symptomatology prior to PD onset (P = .02) predicted current ICD. There were no differences between the dopamine agonists in their association with ICDs (P = .21), and daily doses of dopamine agonists were higher in patients with an ICD than in dopamine agonist-treated patients without an ICD (P < .001).
PD patients treated with a dopamine agonist should be made aware of the risk of developing an ICD and monitored clinically. As dopamine agonists are increasing being used for other indications, future research should assess the dopamine agonist-associated risk for ICDs in other populations.
Depression and antidepressant use are common in Parkinson’s disease, but the benefit of selective serotonin reuptake inhibitor (SSRI) treatment in this population has not been established. The authors treated 14 Parkinson’s disease patients with major depression with escitalopram in an open-label study. Although treatment was well tolerated and correlated with a significant decrease in Inventory of Depressive Symptomatology score, response and remission rates were only 21% and 14%, respectively. However, half of the subjects met Clinical Global Impression-Improvement criteria for response. In Parkinson’s disease, either SSRIs may have limited antidepressant effects, or the use of existing depression diagnostic and rating instruments may be problematic.
The objective of this study was to compare the sensitivity, specificity, and diagnostic accuracy of the 15-item Geriatric Depression Scale (GDS-15) and the Hamilton Depression Rating Scale (HDRS) in patients with Parkinson disease (PD).
A convenience sample of 148 outpatients with idiopathic PD receiving specialty care completed the GDS-15 and were administered the HDRS and Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (SCID) depression module by a research psychiatrist or trained research assistant. Receiver-operating characteristic (ROC) curves were plotted for the GDS-15 and HDRS scores with a SCID diagnosis of a depressive disorder as the state variable.
Thirty-two subjects (22%) were diagnosed with a depressive disorder. The discriminant validity of the GDS-15 and HDRS were both high (ROC area under the curve: 0.92 and 0.91, respectively), with greatest dichotomization for the GDS-15 at a cutoff of 4/5 (87% accuracy, 88% sensitivity, 85% specificity) and the HDRS at a cutoff of 9/10 (83% accuracy, 88% sensitivity, 78% specificity).
The GDS-15 performs well as a screening instrument and in distinguishing depressed from nondepressed patients in PD. Its test characteristics are comparable to the HDRS. Because it is a brief instrument and can be self-administered, it is an excellent depression screening tool in this population.
Parkinson disease; depression; Geriatric Depression Scale
The purpose of this study was to compare the validity of the 15-item Geriatric Depression Scale (GDS-15) in nonelderly (<65 years), young-elderly (age, 65-75), and old-elderly (>75 years) patients with Parkinson’s disease (PD). 57 nonelderly, 88 young-elderly, and 81 old-elderly PD patients were administered the GDS-15 and the Structured Clinical Interview for DSM-IV depression module. Receiver-operating characteristic (ROC) curves were plotted for GDS-15 scores against a DSM-IV diagnosis of major or minor depression. The discriminant validity of the GDS-15 was high for nonelderly, young-elderly, and oldelderly subjects (ROC area under curve = 0.92, 0.91, and 0.95, respectively), with optimal dichotomization at a cut-off of 4/5 (85% sensitivity and 84% specificity in nonelderly; 89% sensitivity and 82% specificity in young-elderly) and 5/6 (90% sensitivity and 90% specificity in old-elderly). In conclusion, the GDS-15 has comparable validity in younger and older PD patients, suggesting its appropriateness as a depression screening instrument in PD patients of all ages.
Parkinson’s disease; depression; age; Geriatric Depression Scale
The objective of this study was to determine effect sizes for both antidepressant treatment and placebo for depression in Parkinson’s disease (PD), and to compare the findings with those reported in elderly depressed patients without PD. Recent reviews have concluded that there is little empiric evidence to support the use of antidepressants in PD; however, available data has not been analyzed to determine the effect size for antidepressant treatment in PD depression. A literature review identified antidepressant studies in PD. Suitable studies were analyzed using meta-analytic techniques, and effect sizes were compared with those from antidepressant studies in elderly patients without PD. Large effect sizes were found for both active treatment and placebo in PD, but there was no difference between the two groups. In contrast, active treatment was superior to placebo in depressed elderly patients without PD. In PD, increasing age and a diagnosis of major depression were associated with better treatment response. Results also suggest that newer antidepressants are well tolerated in PD. Despite the high prevalence of depression and antidepressant use in PD, controlled treatment research has been almost non-existent. Meta-analysis results suggest a large but nonspecific effect for depression treatment in PD. In addition, PD patients may benefit less from antidepressant treatment, particularly selective serotonin reuptake inhibitors, than do elderly patients without PD.
Parkinson’s disease; depression; antidepressive agent; treatment; effect size; meta-analysis
As no comprehensive assessment instrument for impulse control disorders (ICDs) in Parkinson’s disease (PD) exists, the aim of this study was to design and assess the psychometric properties of a self-administered screening questionnaire for ICDs and other compulsive behaviors in PD.
The Questionnaire for Impulsive-Compulsive Disorders in Parkinson’s Disease (QUIP) has 3 sections: Section 1 assesses four ICDs (involving gambling, sexual, buying, and eating behaviors), Section 2 other compulsive behaviors (punding, hobbyism and walkabout), and Section 3 compulsive medication use. For validation, a convenience sample of 157 PD patients at 4 movement disorders centers first completed the QUIP, and then was administered a diagnostic interview by a trained rater blinded to the QUIP results. A shortened instrument (QUIP-S) was then explored.
The discriminant validity of the QUIP was high for each disorder or behavior (receiver operating characteristic area under the curve [ROC AUC]: gambling=0.95, sexual behavior=0.97, buying=0.87, eating=0.88, punding=0.78, hobbyism=0.93, walkabout=0.79). On post hoc analysis, the QUIP-S ICD section had similar properties (ROC AUC: gambling=0.95, sexual behavior=0.96, buying=0.87, eating=0.88). When disorders/behaviors were combined, the sensitivity of the QUIP and QUIP-S to detect an individual with any disorder was 96% and 94%, respectively.
Scores on the QUIP appear to be valid as a self-assessment screening instrument for a range of ICDs and other compulsive behaviors that occur in PD, and a shortened version may perform as well as the full version. A positive screen should be followed by a comprehensive, clinical interview to determine the range and severity of symptoms, as well as need for clinical management.
Parkinson’s disease; impulse control disorders; dopamine dysregulation syndrome; punding; pathological gambling