Intestinal histomorphological and molecular alterations in patients with Parkinson's disease

BACKGROUND AND PURPOSE

Changes in gut microbiota composition, enteric inflammation, impairments of the intestinal epithelial barrier and neuroplastic changes in the enteric nervous system have been reported in Parkinson's disease (PD) patients and could contribute to the onset of both neurological and gastrointestinal symptoms. However, their mutual interplay has rarely been investigated. This study evaluated, in an integrated manner, changes in faecal microbiota composition, morphofunctional alterations of colonic mucosal barrier and changes of inflammatory markers in blood and stools of PD patients.

METHODS

Nineteen PD patients and nineteen asymptomatic subjects were enrolled. Blood lipopolysaccharide binding protein (LBP, marker of altered intestinal permeability) and interleukin-1β (IL-1β) levels, as well as stool IL-1β and tumour necrosis factor (TNF) levels, were evaluated. Gut microbiota analysis was performed. Epithelial mucins, collagen fibres, claudin-1 and S100-positive glial cells as markers of an impairment of the intestinal barrier, mucosal remodelling and enteric glial activation were evaluated on colonic mucosal specimens collected during colonoscopy.

RESULTS

Faecal microbiota analysis revealed a significant difference in the α-diversity in PD patients compared to controls, while no differences were found in the β-diversity. Compared to controls, PD patients showed significant chenags in plasma LBP levels, as well as faecal TNF and IL-1β levels. The histological analysis showed a decrease in epithelial neutral mucins and claudin-1 expression and an increased expression of acidic mucins, collagen fibres and S100-positive glial cells.

CONCLUSIONS

Parkinson's disease patients are characterized by enteric inflammation and increased intestinal epithelial barrier permeability, as well as colonic mucosal barrier remodelling, associated with changes in gut microbiota composition.

Different Patterns of Locus Coeruleus MRI Alteration in Alzheimer's and Dementia with Lewy Bodies

BACKGROUND

The integrity of Locus Coeruleus can be evaluated in vivo using specific Magnetic Resonance Imaging sequences. While this nucleus has been shown to be degenerated both in post-mortem and in vivo studies in Alzheimer's Disease, for other neurodegenerative dementias such as Dementia with Lewy Bodies this has only been shown ex-vivo.

OBJECTIVE

To evaluate the integrity of the Locus Coeruleus through Magnetic Resonance Imaging in patients suffering from Dementia with Lewy Bodies and explore the possible differences with the Locus Coeruleus alterations occurring in Alzheimer's Dementia.

METHODS

Eleven patients with Dementia with Lewy Bodies and 35 with Alzheimer's Dementia were recruited and underwent Locus Coeruleus Magnetic Resonance Imaging, along with 52 cognitively intact, age-matched controls. Images were analyzed applying an already developed template-based approach; Locus Coeruleus signal was expressed through the Locus Coeruleus Contrast Ratio parameter, and a locoregional analysis was performed.

RESULTS

Both groups of patients showed significantly lower values of Locus Coeruleus Contrast Ratio when compared to controls. A different pattern of spatial involvement was found; patients affected by Dementia with Lewy bodies showed global and bilateral involvement of the Locus Coeruleus, whereas the alterations in Alzheimer's Dementia patients were more likely to be localized in the rostral part of the left nucleus.

CONCLUSIONS

Magnetic Resonance Imaging successfully detects widespread Locus Coeruleus degeneration in patients suffering from Dementia with Lewy Bodies. Further studies, in larger cohorts and in earlier stages of the disease, are needed to better disclose the potential diagnostic and prognostic role of this neuroradiological tool.

Qualitative evaluation of the Rey-Osterrieth Complex Figure Test in patients with progressive supranuclear palsy

Objective: In early stages of disease, the differential diagnosis between Parkinson's Disease (PD) and atypical parkinsonism, such as Progressive Supranuclear Palsy (PSP), could be challenging. Growing attention has recently been dedicated to investigating neuropsychological markers of degenerative parkinsonism. The Rey-Osterrieth Complex Figure Test (ROCFT) copy score was hypothesized able to differentiate PSP from PD. However, ROCFT is a drawing test requiring multiple cognitive abilities and it is still unknown which of them assumes an important role in PSP performance. Using a qualitative scoring system, we investigated which cognitive abilities underpin the PSP performance at the ROCFT copy trial. Moreover, we evaluated usefulness of the BQSS scores in discriminating PSP from PD. Methods: Thirty PSP-Richardson's Syndrome (PSP-RS) patients, 30 PD patients, and 30 healthy control (HC) comparable for age, education, and gender were enrolled. All subjects underwent a neuropsychological evaluation; ROCFT copy were evaluated with the 36-Point Score and with the Boston Qualitative Scoring System (BQSS). Results: PSP-RS patients performed worse in ROCFT 36-Point Score and in several BQSS scores compared to other groups. Most suitable scores discriminating PSP-RS from PD were "Perseveration" and "Vertical Expansion" of BQSS. A logistic regression model considering "Perseveration" and "Vertical Expansion" showed a diagnostic accuracy of 83,3% for PSP-RS condition. Conclusion: our findings showed that "Perseveration" and "Vertical Expansion" BQSS scores were useful in discriminating PSP-RS from PD. "Perseveration" and "Vertical Expansion" BQSS scores might be included in the cognitive evaluation along with quantitative scores when PSP diagnosis is considered.

Evaluation of iron overload in nigrosome 1 via quantitative susceptibility mapping as a progression biomarker in prodromal stages of synucleinopathies

Idiopathic rapid eye movement (REM) sleep behavior disorder (iRBD) is a prodromal stage of α-synucleinopathies, such as Parkinson's disease (PD), which are characterized by the loss of dopaminergic neurons in substantia nigra, associated with abnormal iron load. The assessment of presymptomatic biomarkers predicting the onset of neurodegenerative disorders is critical for monitoring early signs, screening patients for neuroprotective clinical trials and understanding the causal relationship between iron accumulation processes and disease development. Here, we used Quantitative Susceptibility Mapping (QSM) and 7T MRI to quantify iron deposition in Nigrosome 1 (N1) in early PD (ePD) patients, iRBD patients and healthy controls and investigated group differences and correlation with disease progression. We evaluated the radiological appearance of N1 and analyzed its iron content in 35 ePD, 30 iRBD patients and 14 healthy controls via T2*-weighted sequences and susceptibility (χ) maps. N1 regions of interest (ROIs) were manually drawn on control subjects and warped onto a study-specific template to obtain probabilistic N1 ROIs. For each subject the N1 with the highest mean χ was considered for statistical analysis. The appearance of N1 was rated pathological in 45% of iRBD patients. ePD patients showed increased N1 χ compared to iRBD patients and HC but no correlation with disease duration, indicating that iron load remains stable during the early stages of disease progression. Although no difference was reported in iron content between iRBD and HC, N1 χ in the iRBD group increases as the disease evolves. QSM can reveal temporal changes in N1 iron content and its quantification may represent a valuable presymptomatic biomarker to assess neurodegeneration in the prodromal stages of PD.

Morphometric imaging and quantitative susceptibility mapping as complementary tools in the diagnosis of parkinsonisms

Background and purpose

In the quest for in vivo diagnostic biomarkers to discriminate Parkinson's disease (PD) from progressive supranuclear palsy (PSP) and multiple system atrophy (MSA, mainly p phenotype), many advanced magnetic resonance imaging (MRI) techniques have been studied. Morphometric indices, such as the Magnetic Resonance Parkinsonism Index (MRPI), demonstrated high diagnostic value in the comparison between PD and PSP. The potential of quantitative susceptibility mapping (QSM) was hypothesized, as increased magnetic susceptibility (Δχ) was reported in the red nucleus (RN) and medial part of the substantia nigra (SNImed) of PSP patients and in the putamen of MSA patients. However, disease‐specific susceptibility values for relevant regions of interest are yet to be identified. The aims of the study were to evaluate the diagnostic potential of a multimodal MRI protocol combining morphometric and QSM imaging in patients with determined parkinsonisms and to explore its value in a population of undetermined cases.

Method

Patients with suspected degenerative parkinsonism underwent clinical evaluation, 3 T brain MRI and clinical follow‐up. The MRPI was manually calculated on T1‐weighted images. QSM maps were generated from 3D multi‐echo T2*‐weighted sequences.

Results

In determined cases the morphometric evaluation confirmed optimal diagnostic accuracy in the comparison between PD and PSP but failed to discriminate PD from MSA‐p. Significant nigral and extranigral differences were found with QSM. RN Δχ showed excellent diagnostic accuracy in the comparison between PD and PSP and good accuracy in the comparison of PD and MSA‐p. Optimal susceptibility cut‐off values of RN and SNImed were tested in undetermined cases in addition to MRPI.

Conclusions

A combined use of morphometric imaging and QSM could improve the diagnostic phase of degenerative parkinsonisms.

Negative DAT‐SPECT in old onset Parkinson's disease: an additional pitfall?

Background

Scans without evidence of dopaminergic deficit (SWEDDs) refer to patients clinically diagnosed with Parkinson's disease (PD), but showing normal findings on dopamine transporter single‐photon emission computed tomography (DAT‐SPECT). This entity remains highly debated, but recent findings suggesting that DAT‐SPECT does not reflect either nigral cell bodies or striatal fibers of dopaminergic nigrostriatal neurons could improve our understanding of SWEDDs. Notably, compensatory downregulation of DAT in the early stages of PD seems to be less efficient in older‐onset than in young‐onset patients.

Cases

We report eight patients with old‐onset clinical parkinsonism and a positive response to levodopa in which DAT‐SPECT was normal both visually and semiquantitatively. Two subjects demonstrated an abnormal scan when repeated later.

Conclusions

We suggest that old‐onset patients may truly have dopaminergic degeneration despite normal imaging results, presumably because they are diagnosed in the early stages confirming less efficient striatal compensatory strategies in old‐age onset PD.

Dissecting the Interplay Between Time of Dementia and Cognitive Profiles in Lewy Body Dementias

BACKGROUND

Dementia with Lewy bodies (DLB) and Parkinson's disease dementia (PDD) are differentiated by the time of onset of cognitive and motor symptoms ('1-year rule'). We explored the neuropsychological continuum of DLB and PDD subjects with different timing of dementia onset.

OBJECTIVE

Our aim was to compare the neuropsychological profile of DLB and PDD patients with different timing of dementia onset.

METHODS

Neuropsychological findings at the diagnosis of dementia of 66 PDD and 42 DLB patients were retrospectively compared. Patients with PDD were divided into three tertile subgroups according to the time interval between the onset of parkinsonism and dementia (N = 24, 2-4 years; N = 17, 5-7 years; N = 25 ≥8 years, respectively).

RESULTS

DLB patients performed worse on the Stroop and semantic fluency tests than PDD, even in comparison to PD with early dementia onset. No significant differences among PDD subgroups were reported.

CONCLUSION

Executive and semantic language tests could differentiate DLB and PD patients with earlier development of dementia relative to parkinsonism.

Statins in Parkinson's Disease: Influence on Motor Progression

BACKGROUND

It has been speculated that stains are neuroprotective and are associated with a reduced risk of Parkinson's disease (PD), but only a few studies have investigated the influence of statins on the progression of PD.

OBJECTIVE

To evaluate whether long-term statin use may affect motor progression in a large cohort of de novo patients with PD.

METHODS

We conducted a 4-year retrospective observational cohort study to assess patients with PD. The patients were consecutively recruited from a single tertiary center between January 2015 and January 2017. Information on motor function was obtained using the MDS-Unified Parkinson Disease Rating Scale (UPDRS)-III and all subjects were extensively characterized, including information about lifestyle habits, cardiovascular risk factors and cholesterol blood levels.

RESULTS

Of the 181 participants included in the study, 104 patients were evaluated for eligibility (42 patients were exposed to statin therapies and 62 were not treated with statins). They presented similar scores in UPDRS III at baseline but the statin users had a lower motor impairment at 4 years compared to non-user PD patients. Additionally, statin treatment resulted in slower progression of the rigidity score of UPDRS over 4 years. No other significant differences were observed between PD patients with and without statins.

CONCLUSION

Early PD patients with long-term statin usage showed lower motor deterioration after 4 years of disease duration compared with patients not taking statins at diagnosis, suggesting a possible influence of statins on disease progression in PD. Further investigation is warranted to understand the potential beneficial effects of statin treatment on clinical symptoms in PD.

Prevalence and Clinical Correlates of Comorbid Anxiety and Panic Disorders in Patients with Parkinson's Disease

Mood and anxiety disorders are the most common neuropsychiatric syndromes associated with Parkinson's disease (PD). The aim of our study was to estimate the prevalence of lifetime and current anxiety disorders in patients with Parkinson's Disease (PD), to explore possible distinctive neurological and psychiatric features associated with such comorbidity. One hundred patients were consecutively recruited at the Movement Disorders Section of the Neurological Outpatient Clinic of the University of Pisa. According to the MINI-Plus 5.0.0, 41 subjects were diagnosed with lifetime anxiety disorder (22 with panic disorder) and 26 were diagnosed with current anxiety disorders. Patients with anxiety disorders were more frequently characterized by psychiatric symptoms preceding PD, lifetime major depression and antidepressant treatments. They showed more anxious temperamental traits and scored higher at Parkinson Anxiety Scale (PAS) and persistent anxiety subscale. Current anxiety disorders were associated with more severe psychopathology, depressive symptomatology, and avoidant behavior. Among anxiety subtypes, patients with lifetime panic disorder showed higher rates of psychiatric symptoms before PD, lifetime unipolar depression, current psychiatric treatment, and a more severe psychopathology. Given the overall high impact of anxiety on patients' quality of life, clinicians should not underestimate the extent of different anxiety dimensions in PD.

Mild Cognitive Impairment in de novo Parkinson's Disease: Selective Attention Deficit as Early Sign of Neurocognitive Decay

Background: In the present study, we aimed to better investigate attention system profile of Parkinson's disease-Mild Cognitive Impairment (PD-MCI) patients and to determine if specific attentional deficits are associated with 123I-FP-CIT SPECT. Methods: A total of 44 de novo drug-naïve PD patients [(27) with normal cognition (PD-NC) and 17 with MCI (PD-MCI)], 23 MCI patients and 23 individuals with subjective cognitive impairment (SCI) were recruited at the Clinical Neurology Unit of Santa Chiara hospital (Pisa University Medical School, Italy). They were assessed by a wide neuropsychological battery, including Visual Search Test (VST) measuring selective attention. Performances among groups were compared by non-parametric tests (i.e., Kruskal-Wallis and Mann-Whitney, Bonferroni corrected). Further, Spearman's rank correlations were performed to explore the association between neuropsychological variables and 123I-FP-CIT SPECT data in PD subgroup. Results: PD-MCI patients performed worse on VST than patients with PD-NC (p = 0.002), patients with MCI and individuals with SCI (p < 0.001). The performance of PD-MCI patients on VST significantly correlated with caudate nucleus 123I-FP-CIT SPECT uptake (rho = 0.582, p < 0.05), whereas a negative correlation between such test and 123I-FP-CIT SPECT uptake in the left putamen (rho = -0.529, p < 0.05) was found in PD-NC patients. Conclusions: We suggest that selective attention deficit might be a trigger of cognitive decay in de novo PD-MCI patients. The VST should be routinely used to detect attentional deficits in hospital clinical practice, in the light of its closely association with dopamine depletion of basal ganglia in mildly impaired PD patients.

α-Synuclein Heteromers in Red Blood Cells of Alzheimer's Disease and Lewy Body Dementia Patients

BACKGROUND

Red blood cells (RBCs) contain the majority of α-synuclein (α-syn) in blood, representing an interesting model for studying the peripheral pathological alterations proved in neurodegeneration.

OBJECTIVE

The current study aimed to investigate the diagnostic value of total α-syn, amyloid-β (Aβ1-42), tau, and their heteroaggregates in RBCs of Lewy body dementia (LBD) and Alzheimer's disease (AD) patients compared to healthy controls (HC).

METHODS

By the use of enzyme-linked immunosorbent assays, RBCs concentrations of total α-syn, Aβ1-42, tau, and their heteroaggregates (α-syn/Aβ1-42 and α-syn/tau) were measured in 27 individuals with LBD (Parkinson's disease dementia, n = 17; dementia with Lewy bodies, n = 10), 51 individuals with AD (AD dementia, n = 37; prodromal AD, n = 14), and HC (n = 60).

RESULTS

The total α-syn and tau concentrations as well as α-syn/tau heterodimers were significantly lower in the LBD group and the AD group compared with HC, whereas α-syn/Aβ1-42 concentrations were significantly lower in the AD dementia group only. RBC α-syn/tau heterodimers had a higher diagnostic accuracy for differentiating patients with LBD versus HC (AUROC = 0.80).

CONCLUSION

RBC α-syn heteromers may be useful for differentiating between neurodegenerative dementias (LBD and AD) and HC. In particular, RBC α-syn/tau heterodimers have demonstrated good diagnostic accuracy for differentiating LBD from HC. However, they are not consistently different between LBD and AD. Our findings also suggest that α-syn, Aβ1-42, and tau interact in vivo to promote the aggregation and accumulation of each other.

Reduced oligodendrocyte exosome secretion in multiple system atrophy involves SNARE dysfunction

Transportation of key proteins via extracellular vesicles has been recently implicated in various neurodegenerative disorders, including Parkinson's disease, as a new mechanism of disease spreading and a new source of biomarkers. Extracellular vesicles likely to be derived from the brain can be isolated from peripheral blood and have been reported to contain higher levels of α-synuclein (α-syn) in Parkinson's disease patients. However, very little is known about extracellular vesicles in multiple system atrophy, a disease that, like Parkinson's disease, involves pathological α-syn aggregation, though the process is centred around oligodendrocytes in multiple system atrophy. In this study, a novel immunocapture technology was developed to isolate blood CNPase-positive, oligodendrocyte-derived enriched microvesicles (OEMVs), followed by fluorescent nanoparticle tracking analysis and assessment of α-syn levels contained within the OEMVs. The results demonstrated that the concentrations of OEMVs were significantly lower in multiple system atrophy patients, compared to Parkinson's disease patients and healthy control subjects. It is also noted that the population of OEMVs involved was mainly in the size range closer to that of exosomes, and that the average α-syn concentrations (per vesicle) contained in these OEMVs were not significantly different among the three groups. The phenomenon of reduced OEMVs was again observed in a transgenic mouse model of multiple system atrophy and in primary oligodendrocyte cultures, and the mechanism involved was likely related, at least in part, to an α-syn-mediated interference in the interaction between syntaxin 4 and VAMP2, leading to the dysfunction of the SNARE complex. These results suggest that reduced OEMVs could be an important mechanism related to pathological α-syn aggregation in oligodendrocytes, and the OEMVs found in peripheral blood could be further explored for their potential as multiple system atrophy biomarkers.

Association of MRI Measures With Disease Severity and Progression in Progressive Supranuclear Palsy

Objective: To verify the association of midbrain-based MRI measures as well as cortical volumes with disease core features and progression in patients with Progressive Supranuclear Palsy (PSP). Methods: Sixty-seven patients (52.2% with Richardson's syndrome) were included in the present analysis. Available midbrain-based MRI morphometric assessments as well as cortical lobar volumes were computed. Ocular, gait and postural involvement at the time of MRI was evaluated with the PSP rating scale. Specific milestones or death were used to estimate disease progression up to 72 months follow up. Hierarchical regression models and survival analysis were used for analyzing cross-sectional and longitudinal data, respectively. Results: Multivariate models showed vertical supranuclear gaze palsy was associated with smaller midbrain area (OR: 0.02, 95% CI 0.00-0.175, p = 0.006). Cox regression adjusted for age, disease duration, and phenotype demonstrated that lower midbrain area (HR: 0.122, 95% CI 0.030-0.493, p = 0.003) and diameter (HR: 0.313, 95% CI 0.112-0.878, p = 0.027), higher MR Parkinsonism Index (HR: 6.162, 95% CI 1.790-21.209, p = 0.004) and larger third ventricle width (HR: 2.755, 95% CI 1.068-7.108, p = 0.036) were associated with higher risk of dependency on wheelchair. Conclusions: Irrespective of disease features and other MRI parameters, reduced midbrain size is significantly associated with greater ocular motor dysfunction at the time of MRI and more rapid disease progression over follow up. This is the first comprehensive study to systematically assess the association of available midbrain-based MRI measures and cortical volumes with disease severity and progression in a large cohort of patients with PSP in a real-world setting.

Prevalence and impact of COVID-19 in Parkinson's disease: evidence from a multi-center survey in Tuscany region

Background

If Parkinson’s Disease (PD) may represent a risk factor for Coronavirus disease 2019 (COVID-19) is debated and there are few data on the direct and indirect effects of this pandemic in PD patients.

Objective

In the current study we evaluated the prevalence, mortality and case-fatality of COVID-19 in a PD cohort, also exploring possible risk factors. We also aimed to investigate the effect of lockdown on motor/non-motor symptoms in PD patients as well as their acceptability/accessibility to telemedicine.

Method

A case-controlled survey about COVID-19 and other clinical features in PD patients living in Tuscany was conducted. In non-COVID-19 PD patients motor/non-motor symptoms subjective worsening during the lockdown as well as feasibility of telemedicine were explored.

Results

Out of 740 PD patients interviewed, 7 (0.9%) were affected by COVID-19, with 0.13% mortality and 14% case-fatality. COVID-19 PD patients presented a higher presence of hypertension (p < 0.001) and diabetes (p = 0.049) compared to non-COVID-19. In non-COVID-19 PD population (n = 733) about 70% did not experience a subjective worsening of motor symptoms or mood, anxiety or insomnia. In our population 75.2% of patients was favorable to use technology to perform scheduled visits, however facilities for telemedicine were available only for 51.2% of cases.

Conclusion

A higher prevalence of COVID-19 respect to prevalence in Tuscany and Italy was found in the PD population. Hypertension and diabetes, as for general population, were identified as risk factors for COVID-19 in PD. PD patients did not experience a subjective worsening of symptoms during lockdown period and they were also favorable to telemedicine, albeit we reported a reduced availability to perform it.

Theory of mind in Parkinson's disease: evidences in drug-naïve patients and longitudinal effects of dopaminergic therapy

Theory of mind (ToM) is the ability to attribute mental states to one self and others and to understand that others have beliefs different from one's own. Different subcomponents of ToM have also been identified: cognitive and affective. Cognitive ToM refers to the capacity to infer others' beliefs and intentions, while affective ToM implies the ability to appreciate others' emotional states. The aim of this study was to explore ToM in drug-naïve Parkinson's disease (PD) patients and to investigate the effects of chronic dopaminergic therapy on different subcomponents of ToM during a 3 months and 1 year of follow-up. We examined 16 PD patients in three conditions: before (un-medicated) and after dopaminergic therapy (medicated 3 months: T1 and medicated 1 year: T2). We also compared our PD's ToM abilities with 11 healthy individuals. ToM was explored with 5 different tasks: Faux Pas Test, Picture Sequencing Task Capture Story, Emotion Attribution Task, Strange Stories Task, and Karolinska Directed Emotional Faces. Our study confirms that PD patients present deficits in cognitive components of ToM and preserved performances in the affective ones in early stages of disease. We also find a significant effect of dopaminergic therapy on ToM already after 3 months with a good persistency after 1 year of treatment.

SLC25A46 mutations in patients with Parkinson's Disease and optic atrophy

Mutations in the gene encoding the mitochondrial carrier protein SLC25A46 are known to cause optic atrophy associated with peripheral neuropathy and congenital pontocerebellar hypoplasia. We found novel biallelic SLC25A46 mutations (p.H137R, p.A401Sfs*17) in a patient with Parkinson's disease and optic atrophy. Screening of six unrelated patients with parkinsonism and optic atrophy allowed us to identify two additional mutations (p.A176V, p.K256R) in a second patient. All identified variants are predicted likely pathogenic and affect very conserved protein residues. These findings suggest for the first time a possible link between Parkinson's Disease and SLC25A46 mutations. Replication in additional studies is needed to conclusively prove this link.

Dopamine Transporter, Age, and Motor Complications in Parkinson's Disease: A Clinical and Single-Photon Emission Computed Tomography Study

BACKGROUND

Previous molecular imaging studies comparing dopamine function in vivo between early-onset PD and late-onset PD patients have shown contradictory results, presumably attributable to the aging-related decline in nigrostriatal function.

OBJECTIVES

(1) To investigate baseline dopamine transporter availability in early-onset PD (<55 years) and late-onset PD (>70 years) patients, z-scores values of putamen and caudate [¹²³ I]-ioflupane uptake were calculated using the respective age-matched controls in order to correct for early presynaptic compensatory mechanisms and age-related dopamine neuron loss; (2) to examine the associations of such baseline single-photon emission computed tomography measures with the emergence of late-disease motor complications.

METHODS

In this retrospective study, 105 de novo PD patients who underwent [¹²³ I]-ioflupane single-photon emission computed tomography at time of diagnosis were divided into three tertile groups according to age at disease onset (35 early-onset PD and 40 late-onset PD patients). Z-scores were compared between the two groups, and their predictive power for motor complications (during a mean follow-up of 7 years) was evaluated using Cox proportional hazard models.

RESULTS

Despite a less-severe motor phenotype, early-onset PD patients exhibited more reduced [¹²³ I]-ioflupane binding in the putamen and had a higher and earlier risk for developing motor complications than those with late-onset PD. Lower [¹²³ I]-Ioflupane uptake in the putamen and caudate increased the risk of motor complications.

CONCLUSIONS

Our findings indicate that a lower dopamine transporter binding in early-onset PD predicts the later development of motor complications, but it is not related to severity of motor symptoms, suggesting age-related differences in striatal compensatory mechanisms in PD. © 2020 International Parkinson and Movement Disorder Society.

Midbrain MRI assessments in progressive supranuclear palsy subtypes

OBJECTIVES

To explore the role of the available midbrain-based MRI morphometric assessments in (1) differentiating among progressive supranuclear palsy (PSP) subtypes (PSP Richardson's syndrome (PSP-RS), PSP with predominant parkinsonism (PSP-P) and the other variant syndromes of PSP (vPSP)), and (2) supporting the diagnosis of PSP subtypes compared with Parkinson's disease (PD) and healthy controls (HC).

METHODS

Seventy-eight patients with PSP (38 PSP-RS, 21 PSP-P and 19 vPSP), 35 PD and 38 HC were included in the present analysis. Available midbrain-based MRI morphometric assessments were calculated for all participants.

RESULTS

Current MRI midbrain-based assessments do not display an adequate sensitivity and specificity profile in differentiating PSP subtypes. On the other hand, we confirmed MR Parkinsonism Index (MRPI) and pons area to midbrain area ratio (P/M) have adequate diagnostic value to support PSP-RS clinical diagnosis compared with both PD and HC, but low sensitivity and specificity profile in differentiating PSP-P from PD as well as from HC. The same measures show acceptable sensitivity and specificity profile in supporting clinical diagnosis of vPSP versus HC but not versus PD. Similar findings were detected for the newer MRPI and P/M versions.

CONCLUSIONS

Further studies are warranted to identify neuroimaging biomarkers supporting the clinical phenotypic categorisation of patients with PSP. MRPI and P/M have diagnostic value in supporting the clinical diagnosis of PSP-RS.

CLASSIFICATION OF EVIDENCE

This study provides class III evidence that available MRI midbrain-based assessments do not have diagnostic value in differentiating the Movement Disorder Society PSP subtypes.

Validation of the Italian version of the PSP Quality of Life questionnaire

BACKGROUND

Progressive supranuclear palsy (PSP) is a rare rapidly progressive, neurodegenerative disease characterized by falls and ocular movement disturbances. The use of health-related quality of life (HR-QoL) measures allows assessing changes in health status induced by therapeutic interventions or disease progress in neurodegenerative diseases. The PSP-QoL is a 45-item, self-administered questionnaire designed to evaluate HR-QoL in PSP.

METHODS AND RESULTS

Here, the PSP-QoL was translated into Italian and validated in 190 PSP (96 women and 94 men; mean age ± standard deviation, 72 ± 6.5; mean disease duration, 4.2 ± 2.3) patients diagnosed according to the Movement Disorder Society criteria and recruited in 16 third level movement disorders centers participating in the Neurecanet project. The mean PSP-QoL total score was 77.8 ± 37 (physical subscore, 46.5 ± 18.7; mental subscore, 33.6 ± 19.2). The internal consistency was high (Cronbach's alpha = 0.954); corrected item-total correlation was > 0.40 for the majority of items. The significant and moderate correlation of the PSP-QoL with other HR-QoL measures as well as with motor and disability assessments indicated adequate convergent validity of the scale. Gender and geographic location presented a significant impact on the PSP-QoL in our sample with women and patients from the South of Italy scoring higher than their counterparts.

CONCLUSION

In conclusion, the Italian version of the PSP-QoL is an easy, reliable and valid tool for assessment of HR-QoL in PSP.

Validation of the Italian version of carers' quality-of-life questionnaire for parkinsonism (PQoL Carer) in progressive supranuclear palsy

Progressive supranuclear palsy (PSP) is a rare, rapidly progressive, neurodegenerative disease characterized by falls and ocular movement disturbances. Caring for a partner or relative who suffers from PSP entails a strenuous and demanding task, usually lasting for years that affects carers' everyday life routines and emotional and social well-being. The 26-item Parkinsonism Carers QoL (PQoL Carer) is a self-administered, concise instrument evaluating the quality of life of caregivers of patients with atypical parkinsonism (both PSP and multiple system atrophy). Here, the PQoL Carer was translated into Italian and validated in 162 carers of PSP patients (54.3% women; mean age (standard deviation), 62.4 (15.4)) diagnosed according to the Movement Disorder Society criteria and recruited in 16 third-level movement disorders centers participating in the Neurecanet project. The mean PQoL total score was 40.66 ± 19.46. The internal consistency was excellent (Cronbach's alpha = 0.941); corrected item-total correlation was > 0.40 for all the items. A correlation with other health-related quality of life measures as well as with behavioral assessments was shown suggesting adequate convergent validity of the scale. PQoL also correlated with patients' severity of disease. The discriminant validity of the scale was evidenced by its capacity to differentiate between carers with varying levels of self-reported health (p < 0.001). In conclusion, the Italian version of the PQoL Carer is an easy, consistent, and valid tool for the assessment of the quality of life in carers of PSP patients.

Freezing of gait and dementia in parkinsonism: A retrospective case-control study

OBJECTIVES

To support the cognitive model of Freezing of Gait (FoG) we investigated FoG in a cohort of patients with Dementia with Lewy Bodies (DLB).

MATERIALS AND METHODS

We assessed FoG frequency in 19 DLB patients compared to 19 control PD patients within 2 years from symptom onset and with at least 5 years follow-up. The two groups were matched by age and motor presentation at onset, severity of parkinsonism and disease duration. The presence and severity of FoG was identified as those with a score of 1 or greater on subitem 14 of the Unified Parkinson's Disease Rating Scale Part II  (UPDRS II).

RESULTS

At T0, 68.4% DLB and 10.5% PD patients experienced FoG ≥1. The prevalence of FoG increased with disease progression (94.7% DLB and 47.3% PD subjects had FoG ≥1 at T5). DLB also showed a more severe FoG (FoG ≥2) than PD (21% vs. 0% at T0 and 52.6% vs. 10.5% at T5), consistently with previous studies reporting FoG prevalence in DLB.

CONCLUSION

This is the first study looking specifically at FoG in DLB, identifying it as a frequent and early feature of DLB and emphasizing the crucial role of cognitive impairment in the occurrence of this mysterious phenomenon.

Social Cognition and Oxytocin in Huntington's Disease: New Insights

This study is aimed at relating social cognition in Huntington's Disease (HD) to plasma levels of the social hormone oxytocin (OT). Indeed, HD patients commonly display reduced social skills and OT is involved in bonding behavior and improved recognition of facial emotions. Twelve mild-symptomatic HD patients (stage II Shoulson &amp; Fahn) and 11 gender/age matched controls (healthy controls, HC), without concurrent psychiatric disorders, were investigated at baseline (T₀) for OT plasma levels and social cognition through an extensive battery of neuropsychological tests. Social cognition was also re-examined after two years (T1) in 8 of the 12 patients. Results showed a trend for reduced T₀-OT levels in HD vs. HC, mean ± stardard deviation: 6.5 ± 2.4 vs. 9.9 ± 7.2 pg/mL, without reaching statistical significance. At T₀, patients showed significantly lower performances than controls at the "Faux-Pas" and "Strange Stories" tests (p < 0.05; p < 0.01); a reduced perception of visual emotions (p < 0.01) and verbal stimuli (p < 0.01) was also reported, involving anger, fear, and sadness (p < 0.05; p < 0.01). Additionally, in the HD population, OT concentrations positively correlated with T1-performances at Neutral\Faux-Pas test (p < 0.05), whereas the cognitive Montreal Cognitive Assessment (MoCA) and Mini Mental State Examination (MMSE) scores positively correlated with psychosocial perception at the "Strange Stories" and Karolinska Directed Emotional Faces (KDEF) tests (p < 0.05). This study, despite its limitations, supports correlations between OT and HD social cognition, suggesting a possible therapeutic use of this hormone. More subjects and additional body tissues/fluids, such as cerebrospinal fluid, should be investigated to confirm this hypothesis.

α-Synuclein Heterocomplexes with β-Amyloid Are Increased in Red Blood Cells of Parkinson's Disease Patients and Correlate with Disease Severity

Neurodegenerative disorders (NDs) are characterized by abnormal accumulation/misfolding of specific proteins, primarily α-synuclein (α-syn), β-amyloid1-42 (Aβ1-42) and tau, in both brain and peripheral tissues. In addition to oligomers, the role of the interactions of α-syn with Aβ or tau has gradually emerged. Nevertheless, despite intensive research, NDs have no accepted peripheral markers for biochemical diagnosis. In this respect, Red Blood Cells (RBCs) are emerging as a valid peripheral model for the study of aging-related pathologies. Herein, a small cohort (N = 28) of patients affected by Parkinson's disease (PD) and age-matched controls were enrolled to detect the content of α-syn (total and oligomeric), Aβ1-42 and tau (total and phosphorylated) in RBCs. Moreover, the presence of α-syn association with tau and Aβ1-42 was explored by co-immunoprecipitation/western blotting in the same cells, and quantitatively confirmed by immunoenzymatic assays. For the first time, PD patients were demonstrated to exhibit α-syn heterocomplexes with Aβ1-42 and tau in peripheral tissues; interestingly, α-syn-Aβ1-42 concentrations were increased in PD subjects with respect to healthy controls (HC), and directly correlated with disease severity and motor deficits. Moreover, total-α-syn levels were decreased in PD subjects and inversely related to their motor deficits. Finally, an increase of oligomeric-α-syn and phosphorylated-tau was observed in RBCs of the enrolled patients. The combination of three parameters (total-α-syn, phosphorylated-tau and α-syn-Aβ1-42 concentrations) provided the best fitting predictive index for discriminating PD patients from controls. Nevertheless further investigations should be required, overall, these data suggest α-syn hetero-aggregates in RBCs as a putative tool for the diagnosis of PD.

Semiautomated Evaluation of the Primary Motor Cortex in Patients with Amyotrophic Lateral Sclerosis at 3T

BACKGROUND AND PURPOSE

Amyotrophic lateral sclerosis is a neurodegenerative disease involving the upper and lower motor neurons. In amyotrophic lateral sclerosis, pathologic changes in the primary motor cortex include Betz cell depletion and the presence of reactive iron-loaded microglia, detectable on 7T MR images as atrophy and T2*-hypointensity. Our purposes were the following: 1) to investigate the signal hypointensity-to-thickness ratio of the primary motor cortex as a radiologic marker of upper motor neuron involvement in amyotrophic lateral sclerosis with a semiautomated method at 3T, 2) to compare 3T and 7T results, and 3) to evaluate whether semiautomated measurement outperforms visual image assessment.

MATERIALS AND METHODS

We investigated 27 patients and 13 healthy subjects at 3T, and 19 patients and 18 healthy subjects at 7T, performing a high-resolution 3D multiecho T2*-weighted sequence targeting the primary motor cortex. The signal hypointensity-to-thickness ratio of the primary motor cortex was calculated with a semiautomated method depicting signal intensity profiles of the cortex. Images were also visually classified as "pathologic" or "nonpathologic" based on the primary motor cortex signal intensity and thickness.

RESULTS

The signal hypointensity-to-thickness ratio of the primary motor cortex was greater in patients than in controls (P < .001), and it correlated with upper motor neuron impairment in patients (ρ = 0.57, P < .001). The diagnostic accuracy of the signal hypointensity-to-thickness ratio was high at 3T (area under the curve = 0.89) and even higher at 7T (area under the curve = 0.94). The sensitivity of the semiautomated method (0.81) outperformed the sensitivity of the visual assessment (0.56-0.63) at 3T.

CONCLUSIONS

The signal hypointensity-to-thickness ratio of the primary motor cortex calculated with a semiautomated method is suggested as a radiologic marker of upper motor neuron burden in patients with amyotrophic lateral sclerosis. This semiautomated method may be useful for improving the subjective radiologic evaluation of upper motor neuron pathology in patients suspected of having amyotrophic lateral sclerosis.

Gait dynamics in Pisa syndrome and Camptocormia: The role of stride length and hip kinematics

This is an observational cross-sectional study evaluating gait dynamics in patients with Parkinson's Disease (PD) and severe postural deformities, PD without axial deviations and healthy subjects. Ten PS individuals with Pisa syndrome (PS) and nine subjects with Camptocormia (CC) performed 3-D Gait Analysis and were evaluated with walking and balance scales. Correlations with clinical and functional scales were investigated. Spatio-temporal and kinematic data were compared to ten PD subjects without postural deformities (PP) and ten healthy matched individuals (CG). Data obtained showed decreased walking velocity, stride and step length in PP, PS and CC groups compared to controls. The correlation analysis showed that stride and step length were associated with reduced functional abilities and disease severity in PS and CC groups. Kinematic data revealed marked reduction in range of movements (ROMs) at all lower-extremity joints in PS group. While, in CC group the main differences were pronounced in hip and knee joints. PS and CC groups presented a more pronounced reduction in hip articular excursion compared to PP subjects, revealing an increased hip flexion pattern during gait cycle. Moreover, the increased hip and knee flexion pattern adversely affected functional performance during walking tests. Results obtained provide evidence that step length, along with stride length, can be proposed as simple and clear indicators of disease severity and reduced functional abilities. The reduction of ROMs at hip joint represented an important mechanism contributing to decreased walking velocity, balance impairment and reduced gait performance in PD patients with postural deformities.

Nigral involvement in atypical parkinsonisms: evidence from a pilot study with ultra-high field MRI

Ten healthy subjects (HS) and 15 patients with atypical parkinsonisms underwent 7-T susceptibility-weighted-imaging MR to evaluate substantia nigra (SN). All HS were judged "normal". Twelve out of 15 patients exhibited bilateral abnormal SN while three patients with corticobasal degeneration (CBD) showed bilateral normal aspect of SN. Anatomical changes of SN at 7 T occur in multiple system atrophy and progressive supranuclear palsy as previously reported in Parkinson's disease. Preserved SN in CBD confirms the pathological heterogeneity of this disease.

High-Resolution 7T MR Imaging of the Motor Cortex in Amyotrophic Lateral Sclerosis

BACKGROUND AND PURPOSE

Amyotrophic lateral sclerosis is a progressive motor neuron disorder that involves degeneration of both upper and lower motor neurons. In patients with amyotrophic lateral sclerosis, pathologic studies and ex vivo high-resolution MR imaging at ultra-high field strength revealed the co-localization of iron and activated microglia distributed in the deep layers of the primary motor cortex. The aims of the study were to measure the cortical thickness and evaluate the distribution of iron-related signal changes in the primary motor cortex of patients with amyotrophic lateral sclerosis as possible in vivo biomarkers of upper motor neuron impairment.

MATERIALS AND METHODS

Twenty-two patients with definite amyotrophic lateral sclerosis and 14 healthy subjects underwent a high-resolution 2D multiecho gradient-recalled sequence targeted on the primary motor cortex by using a 7T scanner. Image analysis consisted of the visual evaluation and quantitative measurement of signal intensity and cortical thickness of the primary motor cortex in patients and controls. Qualitative and quantitative MR imaging parameters were correlated with electrophysiologic and laboratory data and with clinical scores.

RESULTS

Ultra-high field MR imaging revealed atrophy and signal hypointensity in the deep layers of the primary motor cortex of patients with amyotrophic lateral sclerosis with a diagnostic accuracy of 71%. Signal hypointensity of the deep layers of the primary motor cortex correlated with upper motor neuron impairment (r = -0.47; P < .001) and with disease progression rate (r = -0.60; P = .009).

CONCLUSIONS

The combined high spatial resolution and sensitivity to paramagnetic substances of 7T MR imaging demonstrate in vivo signal changes of the cerebral motor cortex that resemble the distribution of activated microglia within the cortex of patients with amyotrophic lateral sclerosis. Cortical thinning and signal hypointensity of the deep layers of the primary motor cortex could constitute a marker of upper motor neuron impairment in patients with amyotrophic lateral sclerosis.

Serotonergic antidepressant drugs and L-dopa-induced dyskinesias in Parkinson's disease

BACKGROUND

Serotonergic system is believed to play a role in levodopa-induced-dyskinesias pathogenesis, and serotonin transporter has been evaluated as potential target.

AIM OF THE STUDY

To retrospectively investigate the potential effect of selective serotonin reuptake inhibitors (SSRIs) during dopaminergic treatment, in the development of dyskinesias in patients with Parkinson's disease (PD).

METHODS

One hundred and thirty-five consecutive patients with PD, with 10-year follow-up since diagnosis. Age at PD onset, duration of levodopa treatment, maximum daily dose, and SSRIs exposure were collected. Risk, latency, and severity of dyskinesias were evaluated comparing patients with and without SSRIs exposure.

RESULTS

Forty-nine patients received SSRIs for a variable period, 86 were never treated; no significant difference between the groups was observed (P = 0.897) in the prevalence of dyskinesias. Considering latency between PD diagnosis and dyskinesias onset, patients exposed to SSRIs developed dyskinesias later (6.48 ± 1.99 vs 5.70 ± 1.89 years, P = 0.020). The median dyskinesia severity score was 0 in the exposed group vs 1 in non-exposed patients (P = 0.025). Multivariate analysis demonstrated SSRIs exposure as the only independent predictor, protecting from severe dyskinesia.

CONCLUSIONS

Use of SSRIs in patients with PD did not protect from dyskinesias; however, exposure may delay the onset and reduce the severity, confirming modulation of the serotonergic system as possible antidyskinetic strategy.

Comparison of 3T and 7T susceptibility-weighted angiography of the substantia nigra in diagnosing Parkinson disease

BACKGROUND AND PURPOSE

Standard neuroimaging fails in defining the anatomy of the substantia nigra and has a marginal role in the diagnosis of Parkinson disease. Recently 7T MR target imaging of the substantia nigra has been useful in diagnosing Parkinson disease. We performed a comparative study to evaluate whether susceptibility-weighted angiography can diagnose Parkinson disease with a 3T scanner.

MATERIALS AND METHODS

Fourteen patients with Parkinson disease and 13 healthy subjects underwent MR imaging examination at 3T and 7T by using susceptibility-weighted angiography. Two expert blinded observers and 1 neuroradiology fellow evaluated the 3T and 7T images of the sample to identify substantia nigra abnormalities indicative of Parkinson disease. Diagnostic accuracy and intra- and interobserver agreement were calculated separately for 3T and 7T acquisitions.

RESULTS

Susceptibility-weighted angiography 7T MR imaging can diagnose Parkinson disease with a mean sensitivity of 93%, specificity of 100%, and diagnostic accuracy of 96%. 3T MR imaging diagnosed Parkinson disease with a mean sensitivity of 79%, specificity of 94%, and diagnostic accuracy of 86%. Intraobserver and interobserver agreement was excellent at 7T. At 3T, intraobserver agreement was excellent for experts, and interobserver agreement ranged between good and excellent. The less expert reader obtained a diagnostic accuracy of 89% at 3T.

CONCLUSIONS

Susceptibility-weighted angiography images obtained at 3T and 7T differentiate controls from patients with Parkinson disease with a higher diagnostic accuracy at 7T. The capability of 3T in diagnosing Parkinson disease might encourage its use in clinical practice. The use of the more accurate 7T should be supported by a dedicated cost-effectiveness study.

MR imaging of the substantia nigra at 7 T enables diagnosis of Parkinson disease

PURPOSE

To evaluate the anatomy of the substantia nigra (SN) in healthy subjects by performing 7-T magnetic resonance (MR) imaging of the SN, and to prospectively define the accuracy of 7-T MR imaging in distinguishing Parkinson disease (PD) patients from healthy subjects on an individual basis.

MATERIALS AND METHODS

The 7-T MR imaging protocol was approved by the Italian Ministry of Health and by the local competent ethics committee. SN anatomy was described ex vivo on a gross brain specimen by using highly resolved proton-density (spin-echo proton density) and gradient-recalled-echo (GRE) images, and in vivo in eight healthy subjects (mean age, 40.1 years) by using GRE three-dimensional multiecho susceptibility-weighted images. After training on appearance of SN in eight healthy subjects, the SN anatomy was evaluated twice by two blinded observers in 13 healthy subjects (mean age, 54.7 years) and in 17 PD patients (mean age, 56.9 years). Deviations from normal SN appearance were described and indicated as abnormal, and both diagnostic accuracy and intra- and interobserver agreement for diagnosis of PD with 7-T MR imaging were calculated.

RESULTS

Three-dimensional multiecho susceptibility-weighted 7-T MR imaging reveals a three-layered organization of the SN allowing readers to distinguish pars compacta ventralis and dorsalis from pars reticulata. The abnormal architecture of the SN allowed a discrimination between PD patients and healthy subjects with sensitivity and specificity of 100% and 96.2% (range, 92.3%-100%), respectively. Intraobserver agreement (κ = 1) and interobserver agreement (κ = 0.932) were excellent.

CONCLUSION

MR imaging at 7-T allows a precise characterization of the SN and visualization of its inner organization. Three-dimensional multiecho susceptibility-weighted images can be used to accurately differentiate healthy subjects from PD patients, which provides a novel diagnostic opportunity.

The relationship between motor symptom lateralization and cognitive performance in newly diagnosed drug-naïve patients with Parkinson's disease

The side of motor symptom predominance may influence cognitive performance in patients with Parkinson's disease (PD): PD patients with right-side motor symptom predominance typically present difficulties in tasks of language and verbal memory, whereas PD patients with left-side motor symptom predominance typically present difficulties in visuospatial tasks. The current study aimed at investigating the relationship between motor symptom lateralization and cognitive performance in PD patients without the possible confounding effect of dopaminergic drugs, which may enhance or impair cognition on the basis of assessed function and disease stage. From the initial sample of 137 consecutive newly diagnosed drug-naïve (de novo) PD patients, clinical follow-ups and neurological examinations identified 108 right-handed patients with a unilateral motor presentation or a clear motor asymmetry (59 right-PD: 54.6%; 49 left-PD: 45.4%). Any cognitive difference emerged between right-PD patients and left-PD patients at this disease stage. Scores of lateralized motor impairment severity correlated with some cognitive performances: Right motor impairment correlated with a measure of set shifting (Trail Making Test B-A), and left motor impairment correlated with phonemic fluency and tasks with visuospatial material (Colored Progressive Matrices of Raven, Rey-Osterrieth Complex Figure Copy and Immediate Recall). Findings of the current study supported the conclusion that the side of clinical motor predominance scarcely influences cognition in the early untreated stages of PD, suggesting that cognitive differences between subgroups of lateralized PD patients probably may appear in more advanced disease stages.

Mild affective symptoms in de novo Parkinson's disease patients: relationship with dopaminergic dysfunction

BACKGROUND AND PURPOSE

The investigation of the relationship between affective symptoms and dopamine transporter (DAT) density provided conflicting data in both Parkinson's disease (PD) and non-PD patients. However, the potential interference of psychoactive as well as anti-parkinsonian drugs on DAT density should be taken into account.

OBJECTIVE

To investigate the relationship between affective symptoms and pre-synaptic dopaminergic function in de novo PD patients.

METHODS

Forty-four de novo PD consecutive outpatients were recruited, and the severity of anxious symptoms was evaluated with the Hamilton Anxiety Rating Scale (HAM-A), the severity of depressive symptoms with the Hamilton Depression Scale (HAM-D) and the Beck Depression Inventory (BDI). Six patients had a formal diagnosis of depression. All patients performed (123) I-FP-CIT SPECT, and semi-quantitative striatal indices were calculated.

RESULTS

Disease severity, as measured by Unified Parkinson's Disease Rating Scale (UPDRSIII), was inversely correlated with bilateral striatal indices. Bilateral striatal uptake was significantly positively correlated with HAM-D (r.329; r.423, respectively, right and left), BDI (r.377; r.360, respectively, right and left) and HAM-A (r.338; r.340, respectively, right and left). After controlling for age, disease duration and severity, and Mini Mental State Examination (MMSE), no significant reduction in r-values was observed (P < 0.05).

CONCLUSION

Our data support the existence of a relationship between depressive and anxious symptoms and the striatal (123) I-FP-CIT uptake. The finding of an increased DAT density associated with mild affective symptoms could be due to the lack of compensatory mechanisms usually present in early PD, and/or it might have a pathogenic role in affective symptoms by reducing the dopaminergic tone in the synaptic cleft.

[¹²³I]FP-CIT single photon emission computed tomography findings in drug-induced Parkinsonism

Drug-induced parkinsonism (DIP) in patients treated with antipsychotic drugs is considered a form of post-synaptic parkinsonism, caused by D2-receptor blockade. Recent studies, however, carried out on small and heterogeneous patient samples, have shown that DIP may be associated with [(123)I]FP-CIT single photon emission computed tomography (SPECT) abnormalities, which are markers of dopamine nigrostriatal terminal defect. In the present study, outpatients fulfilling the DSM-IV criteria for schizophrenia and treated with antipsychotics for at least 6 months, were enrolled in order to estimate the prevalence of DIP and, among patients with DIP, the prevalence of [(123)I]FP-CIT SPECT abnormalities. Socio-demographic and clinical variables associated with the presence of DIP and SPECT abnormalities were also assessed. DIP was diagnosed in 149 out of 448 patients with schizophrenia (33%). Age, use of long-acting antipsychotics and a positive family history of parkinsonism were the only demographic variables significantly associated with the development of DIP. Neuroimaging abnormalities were found in 41 of 97 patients who agreed to undergo [(123)I]FP-CIT SPECT (42%). Only age differentiated this group of patients from those with normal imaging. These preliminary findings suggest that D2-receptor blockade may coexist with a dopamine nigrostriatal terminal defect, as assessed by [(123)I]FP-CIT SPECT abnormalities, in a relevant proportion of DIP patients. Longitudinal studies should be designed with the aim of improving our understanding of the mechanisms of pre-synaptic abnormalities in DIP patients and identifying specific treatment strategies.

Mild cognitive impairment and cognitive-motor relationships in newly diagnosed drug-naive patients with Parkinson's disease

BACKGROUND AND AIMS

(1) To establish the prevalence of mild cognitive impairment (MCI) in newly diagnosed drug-naive patients with Parkinson's disease adopting recently proposed and more conservative preliminary research criteria. (2) To investigate the relation between cognitive performances, MCI and motor dysfunction.

METHODS

132 consecutive newly diagnosed drug-naive PD patients and 100 healthy controls (HCs) underwent a neuropsychological evaluation covering different cognitive domains. Moreover, on the basis of the Unified Parkinson's Disease Rating Scale II/III, different motor scores were calculated and patients were classified in motor subtypes. 11 patients were excluded from the analysis during clinical follow-up which was continued at least 3 years from the diagnosis; therefore, the final sample included 121 patients.

RESULTS

MCI prevalence was higher in PD (14.8%) patients than in HCs (7.0%). PD patients reported lower cognitive performances than HCs in several cognitive domains; HCs also outperformed cognitively preserved PD patients in tasks of episodic verbal memory and in a screening task of executive functions. MCI-PD patients presented a more severe bradykinesia score than non-MCI PD patients and patients mainly characterised by tremor had better performances in some cognitive domains, and specific cognitive-motor relationships emerged.

CONCLUSIONS

Although the adoption of more conservative diagnostic criteria identified a lower MCI prevalence, we found evidence that newly diagnosed drug-naive PD patients present a higher risk of MCI in comparison with HCs. Axial symptoms and bradykinesia represent risk factors for MCI in PD patients and a classification of PD patients that highlights the presence/absence of tremor, as proposed in this study, is probably better tailored for the early stages of PD than classifications proposed for more advanced PD stages.