[Show abstract][Hide abstract] ABSTRACT: Background
Diagnosing Parkinson's disease (PD) and tracking its progression may require the combination of reliable biomarkers. Among them, both serum uric acid (UA) and dopamine transporter (DaT) binding deserve more investigations.Aims of the studyWe aimed to investigate the relationship between serum UA levels and DaT availability in newly diagnosed, drug-naïve PD patients, by means of semiquantitative [(123) I]FP-CIT-SPECT.Methods
We recruited 52 newly diagnosed, drug-naïve PD patients, and performed serum UA dosage and [(123) I]FP-CIT-SPECT.ResultsPearson's correlation analysis showed that UA levels were significantly higher in patients with higher averaged, ipsilateral and contralateral DaT binding in caudate, putamen, and striatum.Conclusions
We showed, for the first time, by regional semiquantitative analysis of DaT binding in PD patients that UA levels significantly correlates with the severity of dopaminergic impairment in caudate, putamen, and striatum. This study broadens our knowledge on the importance of UA as a biomarker of PD.
[Show abstract][Hide abstract] ABSTRACT: Tremor dominant (TD) and akinetic-rigid type (ART) are two motor subtypes of Parkinson's disease associated with different disease progression and neurochemical/neuropathological features. The role of presynaptic nigrostriatal dopaminergic damage is still controversial, poorly explored, and only assessed in medicated patients. In this study, we investigated with FP-CIT SPECT the striatal dopamine transporter (DAT) availability in drug-naïve PD patients with ART and TD phenotypes. Fifty-one de novo, drug-naïve patients with PD underwent FP-CIT SPECT studies. Patients were evaluated with Unified Parkinson's Disease Rating Scale (UPDRS) part III and Hoehn and Yahr scale (H&Y) and divided into ART (24/51) and TD (27/51) according to UPDRS part III. ART and TD patients were not different with regard to age, gender, and disease duration. However, compared to TD, ART patients presented higher UPDRS part III (p = 0.01) and H&Y (p = 0.02) and lower DAT availability in affected and unaffected putamen (p = 0.008 and p = 0.007, respectively), whereas no differences were found in caudate. Moreover, in the whole group of patients, rigidity and bradykinesia, but not tremor scores of UPDRS part III were significantly related to FP-CIT binding in the putamen. These results suggest that in newly diagnosed drug-naïve PD patients DAT availability might be different between ART and TD in relation to different disease severity.
[Show abstract][Hide abstract] ABSTRACT: Background and purposeUric acid (UA) has been studied extensively as a valuable biomarker of Parkinson's disease (PD), but its relationship with non-motor symptoms (NMS) in de novo PD has been poorly investigated. Our aim was to evaluate the usefulness of baseline serum UA as a marker of NMS progression in newly diagnosed PD.Methods
Sixty-nine newly diagnosed PD patients were enrolled. At baseline, all patients completed the NMS questionnaire (NMSQuest), and serum UA levels were measured. After 2 years, the NMSQuest was completed again and patients were categorized into four groups: NMS improvement (domain involvement at baseline but not at 2-year follow-up visit), NMS absence (domain not involved at baseline or 2-year follow-up visits), NMS presence (domain involvement both at baseline and 2-year follow-up visits) and NMS worsening (domain not involved at baseline but involved at 2-year follow-up).Resultsanova with post hoc Bonferroni correction showed that patients with NMS absence presented significantly higher UA values than patients with NMS presence with regard to the attention/memory (P = 0.023), depression/anxiety (P = 0.028) and cardiovascular domains (P = 0.002), whilst no differences were found with regard to both the NMS improvement and worsening groups. In addition, multinomial regression analysis showed that the lowest tertile of NMS progression presented higher UA levels (P = 0.023; odds ratio 0.488) compared with patients with greater NMS progression.Conclusions
This is the first report of a relationship between serum UA and presence/progression of multiple NMS in de novo PD, providing additional evidence of the reliability of UA as a biomarker of PD and opening new insights on PD neuroprotection.
European Journal of Neurology 08/2014; · 4.16 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Background and purposeApathy may be either a symptom of major depression or a behavioral disturbance occurring in concomitance with depression or alone in Parkinson's disease (PD). The aim of the present study was to determine the progression of cognitive impairment in drug-naïve untreated PD patients with or without clinically significant apathy.Methods
Sixty-two PD patients with a disease duration <2 years and without history of present or past therapy with pro-dopaminergic agents were included and underwent the Apathy Evaluation Scale (S-AES), a clinical interview based on diagnostic criteria for apathy and a comprehensive neuropsychological battery to assess memory, frontal functions and visuospatial functions. Two years after the first assessment, all patients were re-evaluated on the S-AES, a clinical interview and neuropsychological tests.ResultsAccording to the cut-off value of the S-AES and diagnostic criteria for apathy, eight patients experienced apathy at both baseline and follow-up (A+A+), nine patients had apathy only at follow-up (A−A+), 37 patients never experienced apathy (A−A−) and eight patients showed apathy at the baseline only (A+A−). Cognitive performance significantly declined in all four groups. At both baseline and follow-up A+A+ performed worse than A−A− on visuospatial and frontal tests; A−A+ had lower scores than A−A− on the interference task of the Stroop test (IT-ST). Regression analysis showed that poor performance on the IT-ST at baseline was the only independent predictor of onset of apathy at follow-up.Conclusions
The results indicated a relationship between apathy and dysexecutive syndrome in early PD. Reduced scores on the IT-ST may predict development of apathy in PD patients.
European Journal of Neurology 05/2014; · 4.16 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Longitudinal studies on healthy participants have shown that subjective memory impairment (defined as subjective cognitive complaints with normal cognitive objective performance) might be a strong predictor of mild cognitive impairment (MCI). Parkinson disease (PD) also manifests cognitive disturbances, but whether subjective memory complaints may predict the development of MCI in PD has not yet been explored.
We prospectively screened newly diagnosed, untreated patients with PD in order to evaluate whether subjective memory complaints may predict development of MCI over a 2-year follow-up evaluation.
We enrolled 76 de novo untreated patients with PD. Of the 76 patients, 23 (30.3%) complained memory issues. Among the patients cognitively unimpaired at baseline, those with subjective complaints were more likely to develop MCI at follow-up. The regression model confirmed that presence of subjective memory complaints at baseline was an independent predictor of development of MCI at follow-up.
This is the first prospective study to explore the relationship between subjective and objective cognitive deficits in newly diagnosed, untreated patients. Our results provide preliminary evidence that subjective memory complaints might predict future development of MCI.
Journal of Geriatric Psychiatry and Neurology 04/2014; · 3.53 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Background
Low serum uric acid (UA) has been consistently shown to be associated with increased risk of PD, and to predict faster motor and cognitive decline in established PD. The aim of the present study is to evaluate the relationship between serum UA and non-motor symptoms (NMS) de novo PD.
Serum UA was measured in consecutively recruited, early drug-naïve PD patients. Exclusion criteria were: treatment with UA modifying drugs; current smoking status; metabolic or cardiac morbidity. All patients completed the NMS Questionnaire (NMSQuest). The relationship between UA levels and NMSQuest domains was explored by logistic regression, subsequently adjusted for age, gender, disease duration (months since reported motor onset) UPDRS part III, H&Y scale, and MMSE. Regression analysis studied the overall relationship between UA levels and total NMS score, and subsequently adjusted for age, gender, disease duration UPDRS part III, H&Y scale and MMSE.
Eighty PD patients were recruited. At logistic regression, higher UA levels were related to lower involvement of Attention/Memory (p=0.004), Cardiovascular (0.009) and Sleep (p=0.028) domains of NMSQuest. UA levels showed a significant negative correlation with total NMSQuest score at regression analysis (p=0.001; Adjusted R-squared=0.319).
The present study investigated, for the first time, the relation between NMSQuest and UA in de novo PD. Lower UA was related to higher NMSQuest total score and in particular to Attention/Memory, Cardiovascular and Sleep domains. Thus, UA seems to be a major candidate to be a valuable biomarker of such early features of PD as NMS.
Parkinsonism & Related Disorders 01/2014; · 3.27 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Background
We recently showed specific sex-related patterns of non motor symptoms (NMS) in early, drug-naïve PD patients. However, to date studies investigating gender-related effects of dopaminergic treatment on NMS in early PD are lacking.
In the present study, we first report a prospective assessment of gender-related differences in the spectrum of NMS before (baseline) and after starting dopaminergic therapy (2-year follow-up) in a large cohort of newly diagnosed PD patients. Differences in NMS frequency between baseline and follow-up were evaluated by McNemar test. Spearman's rank test was employed to explore interactions between NMS and drug treatment.
One-hundred and thirty four PD patients (86M and 48W) were included in the present study. At 2-year follow-up, Sadness/blues presented a significant percentage reduction as compared to baseline in both sexes, while Urgency, Daytime sleepiness, Weight change and Sex drive presented a significant percentage increase only in men. At follow up men complained of a greater number of NMS as compared to women. Occurrence of Weight change was related to therapy in both sexes. Male gender was found to be a risk factor for developing Dribbling and Nocturia, irrespective of therapy and clinical features.
In conclusion, our study showed that mood symptoms improved after the introduction of therapy in both sexes, while men appeared to be more prone to develop some NMS possibly linked to dopaminergic treatment.
Parkinsonism & Related Disorders 01/2014; · 3.27 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: 1)Detecting olfaction impairment may support the diagnosis of many ENT and Neurological diseases. The 40-item University of Pennsylvania Smell Identification test is one of the most frequently used identification test evaluating olfaction worldwide. 2)Smell identification tests can be significantly conditioned by age, gender and cultural background. Therefore, cultural adaptations and normative data are needed. 3)The 40-item University of Pennsylvania Smell Identification test was culturally adapted for Italian population and then administered with the help of a physician to 128 control subjects of different ages. 4)A correction grid for the 40-item University of Pennsylvania Smell Identification test raw scores was built according to age groups and gender. The cut-off value distinguishing between normal and pathological performances was fixed at 18.80, corresponding to the inner tolerance limit on the 5th centile. 5)The present data may implement the use of 40-item University of Pennsylvania Smell Identification test administered with the help of a physician in Italian population in both ENT and Neurology settings. This article is protected by copyright. All rights reserved.
Clinical otolaryngology: official journal of ENT-UK; official journal of Netherlands Society for Oto-Rhino-Laryngology & Cervico-Facial Surgery 12/2013; · 1.87 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Little is known about the anatomical progression over the body segments of extrapyramidal signs in Parkinson's disease (PD); furthermore a great unmet need is the availability of instruments able to detect disease progression, even in the early phase. The purpose of this study is to demonstrate that assessing topographical distribution of the cardinal motor features of PD may significantly improve the evaluation of disease progression in the early stages. Forty-four drug-naïve PD patients were included in the study. Presence or absence of bradykinesia, rest tremor and rigidity was derived from Unified Parkinson's disease rating scale part III (UPDRS-III) in five different anatomical segments: axial, right and left upper- and lower-limbs. Based on this approach, four new scores were computed evaluating the anatomical spread of the cardinal motor symptoms of PD on the five body segments over a 18-month follow-up period. The four new scores included: the Bradykinesia Segmental Score, the Tremor Segmental Score, the Rigidity Segmental Score, measuring the occurrence of each motor symptom in different segments and the Combined Segmental Score evaluating the occurrence of any motor symptom in different anatomical regions. Data were analyzed using a repeated measures analysis of variance. The Combined Segmental Score showed a significant progression over time whereas the Hoehn and Yahr and the UPDRS-III scores did not. We suggest that a simple approach evaluating the anatomical distribution of motor symptoms and their progression over the body segments may be a useful complement to the classical rating tools to assess progression in early PD.
Parkinsonism & Related Disorders 09/2013; · 3.27 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Gender differences in brain structure and function may lead to differences in the clinical expression of neurological diseases, including Parkinson's disease (PD). Few studies reported gender-related differences in the burden of non-motor symptoms (NMS) in treated PD patients, but this matter has not been previously explored in drug-naïve PD patients. This study is to assess gender differences in the prevalence of NMS in a large sample of early, drug-naïve PD patients compared with age and sex-matched healthy controls. Two hundred early, drug-naïve PD patients and ninety-three age and sex-matched healthy controls were included in the study. Frequency of NMS was evaluated by means of the Non-Motor Symptoms Questionnaire. The difference in gender distribution of NMS was evaluated with the χ (2) exact test; multiple comparisons were corrected with the Benjamini-Hochberg method. Male PD patients complained of problems having sex and taste/smelling difficulties significantly more frequently than female PD patients. Furthermore, men with PD complained more frequently of dribbling, sadness/blues, loss of interest, anxiety, acting during dreams, and taste/smelling difficulties as compared to healthy control men, while female PD patients reported more frequently loss of interest and anxiety as compared with healthy control women. This study shows specific sex-related patterns of NMS in drug-naïve PD. In contrast with previous data, female PD patients did not present higher prevalence of mood symptoms as compared to male PD patients. Comparison with healthy controls showed that some NMS classically present in premotor and early stage of disease (i.e., acting out during dreams, taste/smelling difficulties) are more frequent in male than in female patients.
Journal of Neurology 08/2013; · 3.58 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: BACKGROUND AND PURPOSE: Cognitive impairment is common in Parkinson's disease (PD), even in the early stages. We aimed to assess the relationship between insulin-like growth factor-1 (IGF-1) and cognitive functions in early, drug-naïve patients with PD. METHODS: Serum IGF-1 was measured in 65 early, drug-naïve patients with PD that underwent a complete neuropsychological battery at baseline and after 2 years. Linear regression analysis was used to evaluate the relationships between neuropsychological scores and IGF-1. Repeated-measures anova was applied to assess changes in neuropsychological variables over time. RESULTS: At baseline, IGF-1 levels were related to phonological fluency. At follow-up, IGF-1 levels were associated with the Rey auditory verbal learning test (RAVLT) - immediate and delayed recall, Frontal Assessment Battery, verbal span and Benton judgement of the line orientation test. Patients with low IGF-1 levels at baseline showed a significantly faster decline of performances than patients with high IGF-1 levels on immediate and delayed recall of the RAVLT and interference task of the Stroop test. CONCLUSIONS: Low serum IGF-1 levels are related to poor performance on executive tasks in early, drug-naïve patients with PD, and may predict poor performance on attention/executive and verbal memory tasks after a 2-year follow-up.
European Journal of Neurology 03/2013; · 4.16 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Much pre-clinical evidence show that insulin-like growth factor 1 (IGF-1) provides protection against loss of dopaminergic neurons. Recently, IGF-1 has been proposed as a possible biomarker for early diagnosis of Parkinson's disease (PD). We aimed to assess the relationship between serum IGF-1 levels and progression of motor symptoms in a cohort of drug-naïve PD patients. Serum IGF-1 was measured at baseline in 37 early, drug-naive PD patients; subsequently, patients were evaluated "on drug" by means of UPDRS-III, UPDRS dopa-resistant score and dopaminergic score at 12, 18 and 24 month follow-up. Repeated measures ANOVA was used both to evaluate progression of motor scores within time and differences between serum IGF-1 quartiles, age at onset and motor phenotype. Patients at the highest IGF-1 quartile were found to have significantly higher UPDRS-III (p < 0.001) and dopaminergic score (p < 0.001), as compared to patients at other quartiles. Mean serum IGF-1 level was moderately increased in PD as compared to healthy controls (p < 0.011). IGF-1 levels are related to those symptoms predominantly responsive to dopaminergic treatment. This is the first study to demonstrate a relationship between serum IGF-1 and progression of motor symptoms in the early stage of disease.
Journal of Neurology 02/2013; · 3.58 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The variability in the clinical phenotype of Parkinson's disease seems to suggest the existence of several subtypes of the disease. To test this hypothesis we performed a cluster analysis using data assessing both motor and non-motor symptoms in a large cohort of newly diagnosed untreated PD patients.
We collected data on demographic, motor, and the whole complex of non-motor symptoms from 100 consecutive newly diagnosed untreated outpatients. Statistical cluster analysis allowed the identification of different subgroups, which have been subsequently explored.
THE DATA DRIVEN APPROACH IDENTIFIED FOUR DISTINCT GROUPS OF PATIENTS, WE HAVE LABELED: 1) Benign Pure Motor; 2) Benign mixed Motor-Non-Motor; 3) Non-Motor Dominant; and 4) Motor Dominant.
Our results confirmed the existence of different subgroups of early PD patients. Cluster analysis revealed the presence of distinct subtypes of patients profiled according to the relevance of both motor and non-motor symptoms. Identification of such subtypes may have important implications for generating pathogenetic hypotheses and therapeutic strategies.
PLoS ONE 01/2013; 8(8):e70244. · 3.53 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: BACKGROUND: A relation between the side of motor onset and cognitive impairment in early PD has been reported, suggesting that the asymmetric degeneration affecting subcortical regions may play a pivotal role in lateralized cognitive function. However, evidences are controversial and all previous studies were performed on treated patients, though it is known that dopaminergic therapy can affect cognition in PD. METHODS: Sixty-nine early untreated PD patients underwent an extensive neuropsychological battery exploring memory, visuospatial and attention/executive functions. Patients were divided with respect of the side of onset (right vs. left) and further grouped according to motor phenotype (tremor vs. rigidity-bradykinesia). Multivariate analysis of variance has been carried out to compare clinical and neuropsychological data between subgroups. RESULTS: There were no differences in any neuropsychological task between right-sided and left-sided onset subgroups, irrespective of tremor dominant or rigid-bradykinetic phenotype. Age at onset was significantly higher in patients with any cognitive impairment as compared with patients without (66.7 ± 3.2 vs. 56.3 ± 6.8 years, p = 0.001). CONCLUSION: Side of motor onset is not a major determinant for developing lateralized cognitive deficits in newly diagnosed untreated PD patients.
Parkinsonism & Related Disorders 11/2012; · 3.27 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: BACKGROUND: Non-motor symptoms are very common among patients with Parkinson's disease since the earliest stage, but little is known about their progression and their relationship with dopaminergic replacement therapy. METHODS: We studied non-motor symptoms before and after 2 years from dopaminergic therapy introduction in ninety-one newly diagnosed previously untreated PD patients. RESULTS: At baseline, nearly all patients (97.8%) referred at least one non-motor symptom. At follow-up, only few non-motor symptoms significantly changed. Particularly, depression and concentration became less frequent, while weight change significantly increased after introduction of dopamine agonists. CONCLUSIONS: We reported for the first time a 2-year prospective study on non-motor symptoms before and after starting therapy in newly diagnosed PD patients. Even if non-motor symptoms are very frequent in early stage, they tend to remain stable during the early phase of disease, being only few non-motor symptoms affected from dopaminergic therapy and, specifically, by the use of dopamine agonists.
Journal of neurology, neurosurgery, and psychiatry 09/2012; · 4.87 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Epidermal growth factor (EGF) has been proposed as a candidate biomarker for cognitive impairment in Parkinson's disease (PD). We aimed to assess the relationship between serum EGF and cognitive functions in early, drug-naive PD patients and evaluate the predictive value of EGF on cognitive functions in a 2-year follow-up study. Serum EGF was measured in 65 early, drug-naive PD patients, that underwent a comprehensive neuropsychological battery. Motor symptoms were assessed by means of the Unified Parkinson's Disease Rating Scale, Part III (UPDRS-III). Neuropsychological evaluation was repeated after 2 years. Spearman's rank correlation was used to assess the relationship between serum EGF levels and neuropsychological variables. Linear regression analysis was used to evaluate the relationship between EGF and neuropsychological scores as well as other variables (age, gender, UPDRS-III, levodopa equivalent dose, and type of treatment at follow-up) potentially affecting cognitive performance. Variation over time in cognitive scores was analyzed using repeated-measures ANOVA. At baseline, EGF was the only significant variable associated with performance on semantic fluency (R (2) = 0.131; p = 0.005). EGF levels (p = 0.025), together with UPDRS-III (p = 0.009) and age (p = 0.011), were associated with performance on frontal assessment battery (R (2) = 0.260). At 2-year follow-up, EGF was the only significant variable to predict performance on semantic fluency (R (2) = 0.147; p = 0.025) and color naming task of Stroop color-word test (R (2) = 0.121; p = 0.044). Serum EGF levels are related to frontal and temporal cognitive functions in early, drug-naive PD patients and predict performance on frontal and posterior cognitive functions at 2-year follow-up. EGF is proposed as a potential serum biomarker for early cognitive impairment in PD.
Journal of Neurology 08/2012; · 3.58 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: BACKGROUND: Anxiety is a common non-motor symptom among patients with Parkinson's disease (PD). Although the etiology of anxiety in PD is likely to be multifactorial, a dysfunction in the dopaminergic system might be implicated in its pathogenesis. The aim of our study was to investigate a possible dopaminergic mechanism involved in anxiety in newly diagnosed never-medicated PD patients using SPECT and (123)I-FP-CIT as the dopamine transporter ligand. METHODS: Thirty-four newly diagnosed, untreated PD patients with asymmetric motor symptoms were included in the study: 17 patients with right- and 17 with left-motor onset, matched for age, disease duration and motor disability constituted the group. They were all evaluated for anxiety and depression and underwent an SPECT with (123)I-FP-CIT. Dopamine transporter (DAT) availability values for right and left caudate and putamen were calculated and compared between patients with and without anxiety. Regression analyses were also performed in order to correlate DAT availability with the severity of the anxiety symptoms. RESULTS: Comparison between PD patients with and those without anxiety revealed significant differences of DAT availability in all the examined regions except the right putamen. In the group of patients considered as a whole, a significant correlation was found between increased anxiety severity and decreased DAT availability in right caudate. CONCLUSIONS: We reported an association between nigrostriatal DAT availability deficits and anxiety symptoms in newly diagnosed, untreated PD patients. Our results suggest that hypofunction of the nigrostriatal dopaminergic system may represent one of the functional anomalies involved in anxiety in PD from the earliest stages of disease and irrespective of any therapy.
Parkinsonism & Related Disorders 07/2012; · 3.27 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Little is known about the relationship between cognitive dysfunctions and the non-motor complex in subjects with newly diagnosed untreated Parkinson's disease (PD). The aim of this study was to explore the association between non-motor symptoms (NMS) and cognitive dysfunctions in an incident cohort of de novo, drug-naive, PD patients. Sixty-six non-demented, early, untreated PD patients completed a semi-structured interview on NMS and a battery of neuropsychological tests that assess verbal memory, visuospatial abilities, and attention/executive functions. Scores were age- and education-corrected. Patients who failed at least two tests for each cognitive domain were diagnosed as having mild cognitive impairment (MCI). All but three (95.4%) PD patients complained of at least one NMS. A total of 37.8% was diagnosed with MCI. There was a relationship between sleep-NMS and cognitive dysfunctions. Specifically, both REM behavioral sleep disorders (RBD) and insomnia were associated with lower scores on several cognitive tests. Moreover, RBD was closely related to MCI. NMS and MCI are very common even in the early phase of PD, before patients are treated. Given the correlation between sleep disturbances and cognitive impairment, it is possible that sleep symptoms in PD patients might be considered as an early marker of dementia.
Journal of Neurology 02/2012; 259(9):1808-13. · 3.58 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: To characterize brain metabolic changes associated with mild cognitive impairment (MCI) in drug-naive patients with Parkinson disease (PD) using (18)F-fluorodeoxyglucose (FDG) and PET (FDG-PET).
This cross-sectional study included newly diagnosed patients with PD with MCI in single or multiple domain (PD-MCI; n =12) and without MCI (PD-nMCI; n =12), and healthy controls (n =12). The groups were matched for age. Moreover, the patient groups were matched for motor disability. All subjects underwent a FDG-PET study. Cerebral regional relative metabolic maps were compared in PD-MCI, PD-nMCI, and controls using regions of interest analysis (ROIs) and voxel-based analysis with statistical parametric mapping.
ROIs and voxel-based analyses revealed significant relative hypometabolism in the prefrontal, superior/inferior parietal, and associative occipital cortices as well as in the striatum in patients with PD-MCI relative to controls (p < 0.05) and to a lesser extent in patients with PD-nMCI. In contrast, patients with PD-nMCI did not show significant metabolic changes as compared to controls.
MCI in patients with PD is associated with cortical hypometabolism since the earliest stage, independent of therapy or motor disability. The early involvement of posterior cortical region, a pattern shared by advanced stages of PD-MCI and PD with dementia, could represent an early marker of dementia. The relevance of this pattern in predicting prodromal dementia has to be evaluated in longitudinal studies.