帕金森病患者认知功能障碍临床分析

目的：通过对帕金森病患认知功能障碍及相关因素的评价、分析，探讨帕金森病患发生痴呆的可能机制。方法：采用简易精神状况检查表，对177例帕金森病患进行认知功能初步筛查，对其中可疑认知功能障碍进一步行神经心理学测验。结果：177例患中有33例（18.64%）可疑认知功能障碍，符合痴呆15例（8.47%）。经Logistic回归分析提示，发病年龄（OR=1.176)与UPDRS日常生活能力评分（OR=1.251)为发生痴呆症的危险因素，而病程和抑郁为非危险因素。结论：帕金森病患常合并认知功能障碍，早期主要表现为言语流畅性障碍、视空间障碍和记忆障碍，晚期则表现为智能改变和痴呆。神经心理学测验可国为全面、客观地反映患认知功能。     

帕金森病患者认知功能与脑电活动及脑影像学改变的相关性研究

目的研究帕金森病（Parkinsondisease,PD）患者认知功能、脑电活动及脑影像学的相关性。方法对70例PD患者及40例正常人进行中文版简易智能状态检查（MMSE）量表、BEAM频谱分析及脑影像学检查,对经MMSE初步测查后可疑认知功能障碍者进一步行成套神经心理学评估（FOM、RVR、DST、BD、BNT、HAMD）。结果PD痴呆组的神经心理学评估分值明显降低,痴呆组慢波（δ、θ频段）相对功率谱较非痴呆组明显增高（P〈0.01）,而快波（β1、β2频段）的相对功率谱显著降低（P〈0.05）;痴呆组额叶、颞叶的皮质萎缩及皮质下萎缩程度明显增加,且合并脑白质疏松症（LA）者明显高于非痴呆组;PD认知功能损害与额叶脑沟宽度、外侧裂宽度、三脑室宽度、脑室指数、前角指数及δ波功率值相关。结论神经心理学测验有利于发现PD患者的认知功能障碍,PD认知功能障碍与额颞叶皮质萎缩、皮质下机构萎缩程度、δ波功率及抑郁障碍密切相关,合并LA者痴呆发生率高。     

情绪对轻中度帕金森病患者认知功能的影响

目的探讨焦虑和抑郁情绪对轻中度帕金森病患者认知功能的影响。方法 71例原发性帕金森病患者,采用统一帕金森病评价量表(UPDRS)和Hoehn-Yahr分级评价病情严重程度、汉密尔顿焦虑量表(HAMA,14项)和汉密尔顿抑郁量表(HAMD,24项)评价焦虑和抑郁情绪、简易智能状态检查量表(MMSE)和蒙特利尔认知评价量表(Mo CA,北京版)评价认知功能,分析焦虑和抑郁情绪对认知功能的影响。结果 71例患者均为轻中度帕金森病患者,出现焦虑61例(85.92%)、抑郁55例(77.46%)、同时出现焦虑和抑郁52例(73.24%)。伴焦虑和抑郁患者UPDRS评分分别高于无焦虑(P=0.016)和无抑郁(P=0.000)患者,伴焦虑患者Mo CA评分低于无焦虑患者(P=0.042)。71例患者中49例(69.01%)出现认知功能障碍,其中轻度认知损害28例(39.44%)、痴呆21例(29.58%)。Logistic回归分析显示,仅焦虑是帕金森病患者认知功能障碍的独立危险影响(OR=10.816,95%CI:1.682~69.560;P=0.012)。结论伴焦虑或抑郁情绪的帕金森病患者病情更严重,存在焦虑的帕金森病患者认知功能障碍患病率更高、程度更严重。     

高同型半胱胺酸血症与帕金森病认知功能的相关性研究

目的探究高同型半胱胺酸血症与帕金森病认知功能相关性。方法选取我院收治的130例帕金森病患者作为试验组,同期的健康体检人员110例作为对照组,对影响认知功能的可能危险因素进行Logistic回归分析,并将轻度认知功能障碍患者、痴呆患者及健康人群血清高同型半胱胺酸含量进行对比。结果经Logisitc非条件回归分析可见,年龄、文化程度、吸烟、高血压、糖尿病、高密度脂蛋白、低密度脂蛋白、血清总胆固醇、血浆同型半胱氨酸为认知功能障碍的危险因素。对照组与帕金森非认知障碍组、帕金森认知障碍组的血浆同型半胱氨酸含量相比差异均具有统计学意义(t=3.45,P0.05;t=6.43,P0.05)。帕金森非认知功能障碍组与帕金森认知功能障碍组的血浆同型半胱氨酸含量相比差异具有统计学意义(t=5.23,P0.05)。结论帕金森病认知功能障碍患者同型半胱胺酸含量明显高于无认知功能障碍的帕金森病患者及健康人群,高同型半胱胺酸血症为帕金森病认知功能障碍的危险因素,可作为临床医师可靠的诊断依据。     

阿尔茨海默病患者的执行功能障碍

目的了解阿尔茨海默病(A lzhe im er d isease,AD)患者执行功能损害状况及对于生活能力的影响,探讨执行功能障碍与记忆等AD常见认知功能损害的相关性。方法运用神经心理学测验的方法对40例AD患者及30例轻度认知功能损害(m ild cogn itive impairm ent,MC I)患者进行执行功能、记忆及其他认知功能检查,同时进行生活能力评定。另外选择40名健康老人作对照。结果AD组的执行功能测验成绩均显著低于健康对照组(P<0.01),其中额叶功能评定量表(FAB)(5.29±2.47)分,执行性画钟作业(CLOX1)(4.63±3.56)分,Stroop测验错误次数(Stroop1)(14.17±8.99)分,词语流畅性测验(RVR)(17.56±10.51)分。除Stroop测验反应时间(Stroop2)外,MC I组的其他执行功能测验成绩显著低于健康对照组(P<0.05),其中FAB为(7.67±2.44)分,CLOX1为(7.86±3.78)分,Stroop1为(7.21±8.07)分,RVR为(30.86±8.38)分。用多元逐步回归方法分析不同认知功能对生活能力的影响,结果为反映执行功能的FAB测验成绩处于第一位,独立与操作性日常生活能力(IADL)相关(β=-0.778,t=-7.079,P<0.01)。各项执行功能测验与年龄相关性不明显(r=0.026~0.250,P>0.05),与简易精神状态量表(MMSE)、记忆测验成绩相关性好(r=0.438~0.786,P<0.01)。结论AD患者具有明显的执行功能障碍;在尚未到达痴呆水平的MC I阶段也可发现执行功能损害。执行功能和整体认知功能及记忆等认知域功能具有良好的相关性。AD患者的执行功能障碍是导致生活能力下降的重要因素。     

Hhcy对脑小血管病患者认知功能的影响

目的探讨高同型半胱氨酸血症(Hhcy)对脑小血管病(SVD)患者认知功能的影响。方法 142例SVD患者根据认知功能分为痴呆组、认知功能障碍非痴呆组、认知功能正常组,测定研究对象血浆同型半胱氨酸(Hcy)水平及MMSE、画钟测验评分。结果 (1)Hcy水平痴呆组明显高于认知功能障碍非痴呆组(P<0.05),认知功能障碍非痴呆组高于认知功能正常组。(2)Logistic回归分析得出Hcy水平升高是小血管病患者认知功能损害的独立危险因素。(3)Hhcy对MMSE总评分、定向功能、语言功能以及反应视空间功能、动作的计划性和执行功能画钟测验均有独立的危险性,其OR值分别为1.044、1.057、1.040、1.251。结论 Hcy水平升高是脑小血管病认知功能损伤的独立危险因素,对总体认知功能、定向功能、语言功能以及视空间功能、动作的计划性和执行功能有独立影响作用。     

帕金森病合并痴呆患者的认知运动障碍及影响因素

目的观察帕金森疾病合并痴呆患者的认知运动等功能障碍及影响因素。方法选取我院2014年6月至2015年10月期间收治的100例帕金森病合并痴呆患者。通过对患者评估运动功能量表(Webster量表)、简易智能评估(MMSE)量表、日常生活能力(ADL)量表和蒙特利尔认知评估(Mo CA)量表,评估帕金森病合并痴呆患者的运动功能、智力水平、日常生活能力及认知功能;并探究认知功能障碍与病程长短、发病年龄、性别、文化程度、运动功能的关系。结果 100例帕金森病痴呆患者的Webster量表评分、Mo CA评分、MMSE评分以及ADL评分与临界值相比,均存在异常。患者的病程、发病年龄、性别可能对患者的认知功能障碍无明显作用;患者的文化程度、运动功能水平与患者的认知功能障碍存在显著的联系,且均为保护因子(OR1)。结论帕金森病合并痴呆患者存在运动功能障碍、智力障碍、日常生活能力障碍等认知及其他功能障碍。患者的文化程度、运动功能与患者的认知功能障碍存在显著的联系,且均为保护因子。     

脑白质病变认知障碍的危险因素研究

目的研究缺血性脑白质病变患者认知功能障碍的发病率及相关危险因素。方法收集75例脑白质病变(white matter lesions,WML)患者的人口学资料和血管危险因素,并进行认知功能评定,将病例分为认知障碍组和对照组,2组对比研究,探讨WML患者认知障碍的可能危险因素。结果 75例患者中44例(58.7%)出现了不同程度的认知功能障碍。Logistic回归分析显示WML患者发生认知功能障碍与高血压(OR 4.050,95%CI 1.309～12.526)、糖尿病(OR 3.820,95%CI 1.103～13.231)和年龄(OR 1.133,95%CI 1.023～1.255)有关。结论较高比例WML患者可出现认知功能障碍,高血压、糖尿病和老龄与认知功能障碍的发生关系密切。     

帕金森病患者额叶认知功能和事件相关电位相关性研究

目的:探讨事件相关电位(P300)和额叶认知测试对帕金森病患者认知障碍评价的意义。方法:对31例非痴呆非抑郁帕金森病患者和25例年龄、性别、受教育程度相匹配的正常对照进行P300检测,同时采用词语流畅性、连线测验、Stroop字色干扰测验对病例组和对照组分别进行测试。结果:病例组与对照组比较:额叶认知功能评分较差,P300潜伏期延长(P<0.05),波幅下降;P300潜伏期与额叶认知功能障碍程度呈正相关。结论:非痴呆非抑郁帕金森病患者存在认知功能障碍。这种障碍可能是额叶功能受损后的表现。     

脑白质病变相关性轻度认知功能障碍患者神经心理学特征分析

目的观察脑白质病变(WML)对轻度认知功能损害(mild cognitive impairment,MCI)患者神经心理学的影响。方法 WML-MCI患者和健康对照者进行常规核磁共振及神经心理学检查,观察WML对MCI患者神经心理学的影响,并对其机制进行探讨。结果 WML-MCI组与对照组相比,高血压、糖尿病和冠心病比例明显增高;词语流畅性测验、积木测验和画钟测验评分均明显降低(P<0.05);而2组间MMSE、数字广度测验和词语延迟回忆测验评分无明显差异。结论 WML影响MCI患者的认知功能,主要表现为视空间及执行功能。血管危险因素是MCI发病的危险因素。     

Prevalence and characteristics of dementia in Parkinson disease: an 8-year prospective study

BACKGROUND: Few longitudinal studies of dementia in Parkinson disease (PD) have been reported, and the proportion of patients with PD who eventually develop dementia is unknown. OBJECTIVE: To examine the 8-year prevalence, characteristics, and risk factors of dementia in patients with PD. METHODS: Patients were recruited from an epidemiological study of PD in the county of Rogaland, Norway, using explicit criteria for PD. Subjects with cognitive impairment at disease onset were excluded. A semistructured caregiver-based interview, cognitive rating scales, and neuropsychological tests were used to diagnose dementia according to criteria from the Diagnostic and Statistical Manual of Mental Disorders, Revised Third Edition at baseline and 4 and 8 years later. A population-based sample of 3295 subjects in the municipality of Odense, Denmark, was used as a comparison group and examined at baseline and after 2 and 5 years. RESULTS: We included 224 patients with PD (116 women). At baseline, 51 patients (26%) had dementia. Fifty-five patients died, and 10 refused follow-up without their dementia status known. Forty-three and 28 new cases of dementia were identified at the 4- and 8-year evaluations, respectively. The 4-year prevalence of dementia in PD was nearly 3 times higher than in the non-PD group. The 8-year prevalence in PD was 78.2% (95% confidence interval [CI], 71.1-84.0). Risk factors for dementia were hallucinations before baseline (odds ratio [OR] = 3.1; 95% CI, 1.6-6.2) and akinetic-dominant or mixed tremor/akinetic PD (OR = 3.3; 95% CI, 1.2-8.5). CONCLUSIONS: More than three quarters of this representative PD cohort developed dementia during the 8-year study period. Early hallucinations and akinetic-dominant PD were associated with an increased risk of dementia.     

Cognitive impairment is common in Parkinson's disease without dementia in the early and middle stages in a Han Chinese cohort

BackgroundCognitive impairments have been reported to be common in Parkinson’s disease (PD) without dementia, which occur not only in the late stages of PD, but also in the early and middle stages. Until now, no reports on the profile of cognitive impairment in Chinese non-demented PD population have been published yet. Different ethnic groups should be assessed to improve evaluation of cognitive impairment in clinical practice. The aims of this study are to estimate the frequencies and profile of cognitive impairments and to explore the risk factors of cognitive impairments in Han Chinese non-demented PD patients at early and middle stages.MethodsEighty non-demented PD patients in early and middle stages and 86 healthy controls were invited to participate in this study. Neuropsychological batteries testing executive function, visuospatial function, memory and attention were evaluated. Cognitive impairments were defined as impaired performance in at least one cognitive domain.ResultsNeuropsychological batteries detected 30 cases with executive dysfunction, 27 cases with memory impairment, eight cases with visuospatial dysfunction and seven cases with attention impairment. As many as 48 cases (60%) of PD patients presented cognitive impairment. Logistic regression analysis indicated that education level and Hoehn &; Yahr stage were associated with cognitive impairment in PD.ConclusionsCognitive impairment is common in the early and middle stages of PD without dementia; executive function is the most common domain impaired in a Chinese PD population. Cognitive impairment might be predicted by lower education level and higher Hoehn and Yahr stage.     

洛文斯顿作业疗法认知评定量表在无痴呆型帕金森病患者中的应用价值

目的 探讨洛文斯顿作业疗法认知评定量表(LOTCA)在无痴呆型帕金森病(PD)患者中的应用价值.方法 采用简易精神状态检查(MMSE)量表及LOTCA对60例无痴呆型PD患者和50例对照者的认知功能进行检测,并对引起认知功能损害的相关因素进行分析.结果 采用MMSE评分时,仅2例(3.3%)无痴呆型PD患者出现认知功能损害;采用LOTCA评分时,23例(38.3%)无痴呆型PD患者出现认知功能损害,主要累及视运动组织功能和思维运作能力.单因素分析显示:年龄、起病年龄、抑郁症、运动障碍的严重程度及类型与PD患者认知功能损害有关;多因素Iogistic回归分析显示:年龄、抑郁、姿势不稳.步态异常(PICD)型运动障碍是认知功能损害的危险因素.结论 LOTCA量表适合无痴呆型PD患者认知功能的评定;老龄、抑郁状态及PIGD型运动功能障碍可能是影响无痴呆型PD患者的认知功能的危险因素.     

The morphological basis of mental dysfunction in Parkinson's disease

Mental dysfunction including dementia in Parkinson's disease (PD), the incidence of which averages 20-40%, is suggested to have six-fold lifetime risk compared to age-matched controls. It is caused by a variety of functional and pathological lesions ranging from damage to subcortical-cortical networks to cortical and limbic Lewy body and neuritic Alzheimer pathologies, the relationship and impact of which are still under discussion. Based on two consecutive autopsy series of PD, with prevalence of cognitive impairment of 33% to 35.7%, its essential morphological changes and their impact on the natural history (survival) are discussed. Whereas cortical Lewy body stages 5 and 6 without additional pathologies only rarely were associated with dementia, around 20% of demented PD cases were classified as dementia with Lewy bodies (DLB) with variable degrees of Alzheimer (AD) pathology, and around one third showed severe neuritic AD lesions which occurred in PD patients with later disease onset and significantly shorter survival. Frequent close relations in the severity between alpha-synuclein and tau-pathologies suggest synergistic reaction and common underlying pathogenesis of both lesions. Clinico-pathological studies in PD showed a significantly negative relation between cognitive impairment and neuritic AD lesions somewhat different from that in AD, suggesting that neuritic AD pathology, either alone or in combination with cortical and limbic Lewy bodies, are major causes of mental and cognitive dysfunction in PD.     

Risk of cognitive impairment or dementia in relatives of patients with Parkinson disease

BACKGROUND: The evidence for increased risk of dementia in relatives of patients with Parkinson disease (PD) remains conflicting. OBJECTIVE: To study the risk of cognitive impairment or dementia in first-degree relatives of patients with PD. Design, Setting, and PARTICIPANTS: We conducted a historical cohort study of 1019 first-degree relatives of 162 patients with PD and of 858 relatives of 147 matched controls representative of the population of Olmsted County, Minnesota. In addition, we studied 2716 first-degree relatives of 411 patients with PD referred to Mayo Clinic. MAIN OUTCOME MEASURES: We administered via telephone a cognitive test directly to relatives or a dementia questionnaire to proxies. For relatives reported by proxies to have dementia, we obtained copies of their medical records to confirm the diagnosis. We also obtained dementia information from a medical records-linkage system. RESULTS: In the overall population-based sample, the risk of cognitive impairment or dementia was increased in relatives of patients with PD compared with relatives of controls (hazard ratio, 1.37; 95% confidence interval, 1.03-1.81; P = .03) and was particularly increased in relatives of patients with onset of PD at age 66 years or younger (youngest tertile; hazard ratio, 1.73; 95% confidence interval, 1.21-2.46; P = .003). The findings were consistent in several sensitivity analyses. In the referral-based sample, the risk of cognitive impairment or dementia in relatives increased with younger age at onset of PD but did not vary by other clinical characteristics. CONCLUSION: Cognitive impairment or dementia may share familial susceptibility factors with PD (genetic or nongenetic).     

Functional brain imaging of cognitive dysfunction in Parkinson's disease

Multiple factors are involved in the development of cognitive impairment in Parkinson's disease (PD) and related disorders. Notably, several underlying factors, such as monoaminergic dysfunction, Lewy body pathology, Alzheimer disease-like pathology and cerebrovascular disease are implied in the PD pathophysiology of cognitive impairment. The mesocortical dopaminergic system is associated with executive functions which are frequently affected in PD and are influenced by local levodopa concentration, dopamine metabolism and baseline performance status. The ventral striatum and frontal cortex are associated with impulse control disorders reported in PD patients treated with dopamine replacement therapy. Cholinergic impairment in PD plays a cardinal role in the development of dementia. Acetylcholinesterase positron emission tomography demonstrates that posterior brain areas are related to cognitive decline in PD patients. Amyloid radiotracer illustrates that patients with PD with severe cognitive impairment were prone to accompanied cortical amyloid deposition. Metabolism/perfusion change associated with cognitive impairment in PD, so-called PD related cognitive pattern, is characterised by reduced frontoparietal activity and is an effective way to differentiate and monitor cognitive function of individual PD patients. Cognitive impairment in PD cannot be explained by a single mechanism and is entangled by multiple factors. Imaging studies can unravel each pathological domain, further shed light on the interrelation between different pathomechanisms, not only in PD but also in other dementia related disorders, and thereby integrate its interpretation to apply to therapeutics in individual patients.     

Long-term cognitive outcome of bilateral subthalamic deep brain stimulation in Parkinson’s disease

The effect of subthalamic deep brain stimulation (STN DBS) on cognition in Parkinson’s disease (PD) remains controversial, and it is unclear which factors are related to cognitive decline and dementia after STN DBS, especially over the long term. To this end, we analyzed the cognitive outcome of 103 non-demented patients with PD who were followed-up for at least 12 months after bilateral STN DBS surgery. Preoperatively, the patients were evaluated with the Unified Parkinson's Disease Rating Scale and neuropsychological tests. The rate of global cognitive decline and the incidence of dementia during follow-up for up to 7 years (mean 42.4 ± 24.5 months) were calculated, and preoperative clinical and neuropsychological factors associated with postoperative global cognitive decline or dementia were analyzed. The prevalence of mild cognitive impairment (MCI) and its relation to later cognitive decline or dementia were also evaluated. The annual decline in the mini–mental state examination score was 0.4 ± 1.7 with impaired attention and executive function and a higher levodopa equivalent dose at baseline being the predictors of a faster global cognitive decline after STN DBS. Dementia developed in 13 patients with an incidence rate of 35.7 per 1,000 person-years. Impaired executive function at baseline predicted dementia. At baseline, 63.1 % of the patients had PD-MCI, and these patients were more likely to develop dementia than those without PD-MCI. This study showed that dysfunctions in the frontostriatal circuitry at baseline were associated with a risk of subsequent global cognitive decline and dementia in patients with PD who underwent STN DBS. In addition, preoperative PD-MCI was a risk factor for dementia after STN DBS.     

Cognitive impairment in 873 patients with idiopathic Parkinson's disease

Background

Parkinson's disease (PD) is often accompanied by non-motor complications, such as dementia, depression, and psychotic symptoms, which worsen the prognosis and increase the personal and socioeconomic burden of disease. Prevalence estimates of these complications are quite variable and are lacking for the outpatient care sector.

Methods

As part of a larger, nationwide, cross-sectional epidemiological study in n = 315 neurological outpatient settings in Germany, this paper estimates the frequency of dementia and cognitive impairment in n = 873 outpatients meeting the UK Brain Bank criteria for idiopathic PD. Assessments were based on a clinical interview and neuropsychological assessments, including the Hoehn &; Yahr rating and Unified Parkinson's Disease Rating Scale (UPDRS). Cognitive impairment was assessed by the Mini-Mental State Exam (MMSE), Clock Drawing Test (CDT) and the Parkinson Neuropsychometric Dementia Assessment (PANDA) and the clinician's diagnosis of dementia was based on the diagnostic criteria of DSMIV.

Results

Using standardized cutoff scores, the prevalence of cognitive impairment in the study sample as measured by various methods was 17.5% by MMSE (≤ 24), 41.8% by CDT (≥ 3), 43.6% by PANDA (≤ 14), and 28.6% met the DSM-IV criteria for dementia. All estimates increased with age and PD severity. Gender was an inconsistent contributor while illness duration had no significant impact on cognition. Multiple regression analyses revealed PD severity to be the strongest predictor of dementia risk (OR = 4.3; 95% CI: 2.1–9.1), while neuropsychiatric syndromes had independent, although modest additional contributions (OR = 2.5, 95% CI: 1.6–3.8).

Conclusion

Estimates of cognitive impairment and dementia in PD patients are largely dependent on the diagnostic measure used. Using established clinical diagnostic standards for dementia the overall rate on routine outpatient neurological care is 28.6%, but using more sensitive neuropsychological measures, rates for cognitive impairment might be up to 2-fold higher. The MMSE revealed strikingly low sensitivity. Neuropsychiatric syndromes, in addition to PD severity and age, have an independent – although modest – additional contribution to patients' risk for cognitive impairment and dementia.     

A registry-based, case–control investigation of Parkinson''s disease with and without cognitive impairment

In approximately 40% of the patients, Parkinson's disease (PD) is complicated by cognitive impairment. The objective of this study was to evaluate the impact of cognitive impairment on disease severity and motor function in idiopathic PD patients. Forty-one PD patients with cognitive impairment (PD-CI) (Mini-Mental State Examination < or =24) and 41 PD patients without cognitive impairment (PD-Control) matched for age at onset and duration of the disease were examined using the Unified Parkinson's Disease Rating Scale (UPDRS). PD patients with cognitive impairment had overall poorer motor function, worse rigidity (both axial and limb) and bradykinesia, as well as worse performance in activities of daily living compared with matched PD patients without cognitive impairment. This could either be attributed to a direct effect of cognitive impairment on parkinsonian symptoms or to decreased compliance of patients during clinical examination. PD patients should be routinely and carefully screened for dementia and caregivers should be aware of the effect of dementia on PD.     

Cognitive predictors of dementia in Parkinson's disease: a community-based, 4-year longitudinal study

Although mild cognitive impairment and dementia are common and have important clinical consequences for patients with Parkinson's disease (PD) and their caregivers, it is still unclear whether cognitive symptoms may predict the development of dementia in PD patients. The objective of this study was to determine whether cognitive deficits in nondemented PD patients predicted the development of dementia 4 years later. A total of 76 nondemented PD patients from an epidemiological study of PD in the county of Rogaland, Norway, were assessed at baseline and 4 years later with neurological, psychiatric, and neuropsychological evaluations. Twenty-five (42%) new cases of dementia were diagnosed after 4 years. Time to complete the third card of the Stroop test was the only variable that was independently associated with dementia. The authors concluded that poor performance on a test sensitive to executive dysfunction predicted later development of dementia in PD patients. This finding may have important clinical implications as a marker of subsequent development of dementia.