Asymmetry Of Motor Symptoms Research Articles

Correlation between dopaminergic and metabolic asymmetry in Lewy body disease – A dual-imaging study

IntroductionThe a-Synuclein Origin and Connectome (SOC) model of Lewy body diseases postulates that a-syuclein will be asymmetrically distributed in some patients with Lewy body diseases, potentially leading to asymmetric neuronal dysfunction and symptoms. MethodsWe included two patient groups: 19 non-demented Parkinson's disease (nPD) patients with [18F]FDG PET and motor symptoms assessed by UPDRS-III, and 65 Lewy body dementia (LBD) patients with [18F]FDG PET and dopamine radioisotope imaging. Asymmetry indices were calculated for [18F]FDG PET by including the cortex for each hemisphere, for dopamine radioisotope imaging by including the putamen and caudate separately, and for motor symptoms by using the difference between right-left UPDRS-III score. Correlations between these asymmetry indices were explored to test the predictions of the SOC model. To identify cases with a more typical LBD imaging profile, we calculated a Cingulate Island Sign (CIS) index on the [18F]FDG PET image. ResultsWe found a significant correlation between cortical interhemispheric [18F]FDG asymmetry and motor-symptom asymmetry in nPD patients (r = 0.62, P = 0.004). In patients with LBD, we found a significant correlation between cortical interhemispheric [18F]FDG asymmetry and dopamine transporter asymmetry in the caudate (r = 0.37, P = 0.0019), but not in the putamen (r = 0.15, P = 0.22). We observed that the correlation in the caudate was stronger in LBD subjects with the highest CIS index, i.e., with more typical LBD imaging profiles. ConclusionOur study partly supports the SOC model, but further investigations are needed – ideally of de novo, non-demented PD patients.

Gait asymmetry and symptom laterality in Parkinson’s disease: two of a kind?

BackgroundThe laterality of motor symptoms is considered a key feature of Parkinson’s disease (PD). Here, we investigated whether gait and turning asymmetry coincided with symptom laterality as determined by the MDS-UPRDS part III and whether it was increased compared to healthy controls (HC).MethodsWe analyzed the asymmetry of gait and turning with and without a cognitive dual task (DT) using motion capture systems and wearable sensors in 97 PD patients mostly from Hoehn & Yahr stage II and III and 36 age-matched HC. We also assessed motor symptom asymmetry using the bilateral sub-items of the MDS-UPDRS-III. Finally, we examined the strength of the association between gait asymmetry and symptom laterality.ResultsParticipants with PD had increased gait but not more turning asymmetry compared to HC (p < 0.05). Only 53.7% of patients had a shorter step length on the more affected body side as determined by the MDS-UPDRS-III. Also, 54% took more time and 29% more steps during turns toward the more affected side. The degree of asymmetry in the different domains did not correlate with each other and was not influenced by DT-load.ConclusionsWe found a striking mismatch between the side and the degree of asymmetry in different motor domains, i.e., in gait, turning, and distal symptom severity in individuals with PD. We speculate that motor execution in different body parts relies on different neural control mechanisms. Our findings warrant further investigation to understand the complexity of gait asymmetry in PD.

Moderating effects of uric acid and sex on cognition and psychiatric symptoms in asymmetric Parkinson’s disease

BackgroundNon-motor symptoms are an important early feature of Parkinson’s disease (PD), encompassing a variety of cognitive and psychiatric symptoms that seem to manifest differently depending on motor symptom asymmetry. Different factors, such as uric acid (UA) and sex, seem to influence cognitive and psychiatric expression in PD, however their interplay remains to be better understood.MethodsParticipants taking part in the Parkinson’s Progression Marker Initiative were studied based on the side of motor symptom asymmetry and sex. Three-way interaction modeling was used to examine the moderating effects of sex and UA on cognitive functions and psychiatric symptoms.ResultsSignificant three-way interactions were highlighted at 1-year follow-up between motor symptom asymmetry, UA and sex for immediate and long-term memory in female patients exhibiting predominantly left-sided motor symptoms, and for processing speed and sleepiness in female patients exhibiting predominantly right-sided motor symptoms. No significant interactions were observed for male patients. Moreover, female patients exhibiting predominantly right-sided motor symptoms demonstrated lower serum UA concentrations and had overall better outcomes, while male patients with predominantly right-sided motor symptoms demonstrated particularly poor outcomes.ConclusionsThese findings suggest that in the earliest stages of the disease, UA and sex moderate cognitive functions and psychiatric symptoms differently depending on motor asymmetry, holding important clinical implications for symptom management in patients.

Association between hearing sensitivity and dopamine transporter availability in Parkinson's disease.

In a previous study, we observed: (i) significant hearing function impairment, assessed with pure tone audiometry and distortion product otoacoustic emissions, in patients with Parkinson's disease, compared with a matched control group, and (ii) lateralization of the hearing dysfunction, worse on the side affected by more pronounced Parkinson's disease motor symptoms. This study investigates the association between the basal ganglia dopamine transporter availability and the hearing function in Parkinson's disease patients, focusing also on the lateralization of both dysfunctions, with respect to that of the motor symptoms, and introducing a further distinction between patients with left-sided and right-sided predominant motor symptoms. Patients with right-handed Parkinson's disease with a recent estimation of 123I-FP-CIT striatal uptake were audiologically tested with pure tone audiometry and distortion product otoacoustic emissions. Thirty-nine patients were included in the study. A statistically significant association was found, in the left-side predominant group only, between the distortion product otoacoustic emission levels and the contralateral dopamine transporter availability, and between the hearing threshold and the dopamine transporter availability difference between the ipsi- and the contralateral sides. The hearing impairment lateralization correlated to the motor symptom asymmetry was found significant only in the left-side predominant patients. The association between hearing function and basal ganglia dopamine transporter availability supports the hypothesis that the peripheral hearing function decline associated with dopamine depletion is involved in Parkinson's disease development, with a significant difference between patients with left- and right-sided predominant motor symptoms. These findings also suggest that peripheral hearing function evaluation and its lateralization could be key elements for subtyping the disease.

Motor Symptom Asymmetry Predicts Cognitive and Neuropsychiatric Profile Following Deep Brain Stimulation of the Subthalamic Nucleus in Parkinson's Disease: a 5-Year Longitudinal Study.

Risk factors (e.g., motor symptom asymmetry) for short- and long-term cognitive and neuropsychiatric symptoms following deep brain stimulation (DBS) of the subthalamic nucleus (STN) in patients with Parkinson's disease have yet to be fully identified. The objectives of the present study were to determine whether motor symptom asymmetry in Parkinson's disease is one such risk factor and to identify predictors of subnormal cognitive decline. A total of 26 patients receiving STN-DBS (13 with left-sided motor symptoms and 13 with right-sided ones) underwent follow-up neuropsychological, depression and apathy assessments over a 5-year period. Nonparametric intergroup comparisons were performed on raw scores, as well as Cox regression analyses on standardized Mattis Dementia Rating Scale scores. Compared with patients who had predominantly left-sided symptoms, right-sided patients scored higher on both apathy (at 3months and 36months) and depressive symptoms (at 6months and 12months) and scored lower on global cognitive efficiency (at 36months and 60months). Survival analyses revealed that only right-sided patients had subnormal standardized dementia scores, which were negatively associated with the number of perseverations in the Wisconsin Card Scoring Test. Right-sided motor symptoms are a risk factor for more severe short- and long-term cognitive and neuropsychiatric symptoms following STN-DBS, confirming literature findings on left hemispheric vulnerability.

Mapping Cholinergic Synaptic Loss in Parkinson's Disease: An [18F]FEOBV PET Case-Control Study.

Cholinergic degeneration is strongly associated with cognitive decline in patients with Parkinson's disease (PD) but may also cause motor symptoms and olfactory dysfunction. Regional differences are striking and may reflect different PD related symptoms and disease progression patterns. To map and quantify the regional cerebral cholinergic alterations in non-demented PD patients. We included 15 non-demented PD patients in early-moderate disease stage and 15 age- and sex-matched healthy controls for [18F]FEOBV positron emission tomography imaging. We quantitated regional variations using VOI-based analyses which were supported by a vertex-wise cluster analysis. Correlations between imaging data and clinical and neuropsychological data were explored. We found significantly decreased [18F]FEOBV uptake in global neocortex (38%, p = 0.0002). The most severe reductions were seen in occipital and posterior temporo-parietal regions (p < 0.0001). The vertex-wise cluster analysis corroborated these findings. All subcortical structures showed modest non-significant reductions. Motor symptoms (postural instability and gait difficulty) and cognition (executive function and composite z-score) correlated with regional [18F]FEOBV uptake (thalamus and cingulate cortex/insula/hippocampus, respectively), but the correlations were not statistically significant after multiple comparison correction. A strong correlation was found between interhemispheric [18F]FEOBV asymmetry, and motor symptom asymmetry of the extremities (r = 0.84, p = 0.0001). Cortical cholinergic degeneration is prominent in non-demented PD patients, but more subtle in subcortical structures. Regional differences suggest uneven involvement of cholinergic nuclei in the brain and may represent a window to follow disease progression. The correlation between asymmetric motor symptoms and neocortical [18F]FEOBV asymmetry indicates that unilateral cholinergic degeneration parallels ipsilateral dopaminergic degeneration.

Biomarkers and non-motor symptoms as a function of motor symptom asymmetry in early Parkinson's disease

IntroductionThe longitudinal trajectories of cognitive-neuropsychiatric symptoms from the early stages of Parkinson's disease, as a function of motor symptom asymmetry at the onset of the disease, remain to be fully explored. Moreover, the relationship to biomarkers warrants further investigation. MethodologyNon-motor and biospecimen data from 413 patients with Parkinson's disease, dissociating predominantly left-sided motor symptoms patients (n = 179), predominantly right-sided motor symptoms patients (n = 234), and matched healthy controls (n = 196), were extracted from the Parkinson's Progression Marker Initiative database during a 3-Year follow-up. Non-parametric and conservative corrections for multivariate comparisons were carried out on neuropsychiatric and biomarker data. ResultsA decline for global cognitive efficiency scores in predominantly right-sided motor symptoms patients was observed, whereas depressive and anxiety symptoms were greater overtime for predominantly left-sided motor symptoms patients. Biomarker analysis revealed that predominantly right-sided patients expressed decreased levels of total-tau and phospho-tau over time, while left-sided patients didn't differ from healthy controls. ConclusionFrom the early course of the disease, the existence of different clinical phenotypes is proposed, associated to emerging evidences of distinct pathological pathways and a left-hemispheric vulnerability for cognitive decline.

Motor symptom asymmetry predicts non-motor outcome and quality of life following STN DBS in Parkinson's disease

Risk factors for long-term non-motor symptoms and quality of life following subthalamic nucleus deep brain stimulation (STN DBS) have not yet been fully identified. In the present study, we investigated the impact of motor symptom asymmetry in Parkinson’s disease. Data were extracted for 52 patients with Parkinson’s disease (half with predominantly left-sided motor symptoms and half with predominantly right-sided ones) who underwent bilateral STN and a matched healthy control group. Performances for cognitive tests, apathy and depression symptoms, as well as quality-of-life questionnaires at 12 months post-DBS were compared with a pre-DBS baseline. Results indicated a deterioration in cognitive performance post-DBS in patients with predominantly left-sided motor symptoms. Performances of patients with predominantly right-sided motor symptoms were maintained, except for a verbal executive task. These differential effects had an impact on patients’ quality of life. The results highlight the existence of two distinct cognitive profiles of Parkinson’s disease, depending on motor symptom asymmetry. This asymmetry is a potential risk factor for non-motor adverse effects following STN DBS.

Factors Contributing to the Severity and Laterality of Pisa Syndrome in Parkinson's Disease.

Objective: Pisa syndrome (PS) is a disabling postural deformity in Parkinson’s disease (PD). We aimed to elucidate clinical factors determining the severity and laterality of PS in PD.Methods: In 54 PD patients with PS, we measured the clinical factors that are previously known to contribute to the occurrence of PS as follows: asymmetry of motor symptoms for the evaluation of asymmetric basal ganglia dysfunction, the degree and direction of subjective visual vertical (SVV) tilt for the misperception of body verticality, the canal paresis for unilateral peripheral vestibulopathy, and the tonic electromyographic (EMG) hyperactivity of paraspinal muscles for dystonia. Multivariable linear and logistic regression analyses were conducted to identify the clinical factors associated with the degree of truncal tilt, for the quantification of the severity of PS, and PS tilting to the less affected side, respectively.Results: The multivariable linear regression analyses revealed that the larger degree of SVV tilt (β = 0.29, SE = 0.10, p = 0.005), right-sided SVV tilt (β = 2.32, SE = 0.82, p = 0.007), and higher Hoehn and Yahr (HY) stage (β = 4.01, SE = 1.29, p = 0.003) significantly increased the severity of PS. In the multivariable logistic regression analyses, greater asymmetry of motor symptoms [odds ratio (OR) = 2.01, 95% CI = 1.34–3.49] was significantly associated with PS tilting to the less affected side, while right-sided SVV tilt (OR = 0.02, 95% CI = 0.001–0.21), unilateral canal paresis (OR = 0.06, 95% CI = 0.003–0.79), and higher HY stage (OR = 0.04, 95% CI = 0.002–0.46) were associated with PS tilting to the more affected side.Conclusion: Misperception of verticality, asymmetric basal ganglia dysfunction, unilateral peripheral vestibulopathy, and motor disability are the clinical factors associated with the severity and laterality of PS in patients with PD.

The Association Between Clinical Characteristics and Motor Symptom Laterality in Patients With Parkinson's Disease.

Background and Purpose: The unilateral onset and persistent asymmetry of motor symptoms are important characteristics of Parkinson's disease (PD). By using scales and wearable sensors, this study explored whether motor symptom laterality could affect non-motor symptom and gait performance.Methods: A total of 130 right-handed patients with PD were enrolled in our study and were divided into two groups according to the side of predominant motor symptom presentation by using the Unified Parkinson's Disease Rating Scale part III. We measured the non-motor symptoms with the Non-motor symptoms Scale, sleep quality with the Parkinson's Disease Sleep Scale and Pittsburgh sleep quality index, cognitive function with the Mini-mental State Examination and Montreal Cognitive Assessment, quality of life with the Parkinson's Disease Questionnaire-39, and the severity of anxiety and depression with the Hamilton Anxiety Scale and Hamilton Depression Scale, respectively. All participants underwent the instrumented stand and walk test, and gait data were collected using a set of JiBuEn gait analysis system.Results: We observed that left-dominant symptom PD patients (LPD) were associated with a greater impairment of sleep quality than right-dominant symptom PD patients (RPD). We found no difference between LPD and RPD in terms of gait performance. However, compared with the severe asymmetry RPD patients (RPD-S), severe asymmetry LPD patients (LPD-S) showed a shorter stride length and decreased range of motion of hip joints.Conclusions: In this study, LPD was associated with a more severe sleep-related dysfunction than RPD. In addition, LPD-S exhibited more gait impairments than RPD-S. Considering that motor symptom laterality may affect the non-motor symptom and gait performance, it should be taken into account when evaluating and treating PD patients.

Motor asymmetry related cerebral perfusion patterns in Parkinson's disease: An arterial spin labeling study.

Persisting asymmetry of motor symptoms are characteristic of Parkinson's disease (PD). We investigated the possible lateralized effects on regional cerebral blood flow (CBF), CBF‐connectivity, and laterality index (LI) among PD subtypes using arterial spin labeling (ASL). Forty‐four left‐sided symptom dominance patients (PDL), forty‐eight right‐sided symptom dominance patients (PDR), and forty‐five matched HCs were included. Group comparisons were performed for the regional normalized CBF, CBF‐connectivity and LI of basal ganglia (BA) subregions. The PDL patients had lower CBF in right calcarine sulcus and right supramarginal gyrus compared to the PDR and the HC subjects. Regional perfusion alterations seemed more extensive in the PDL than in the PDR group. In the PDL, correlations were identified between right thalamus and motor severity, between right fusiform gyrus and global cognitive performance. None of correlations survived after multiple comparisons correction. The significantly altered CBF‐connectivity among the three groups included: unilateral putamen, unilateral globus pallidus, and right thalamus. LI score in the putamen was significantly different among groups. Motor‐symptom laterality in PD may exhibit asymmetric regional and interregional abnormalities of CBF properties, particularly in PDL patients. This preliminary study underlines the necessity of classifying PD subgroups based on asymmetric motor symptoms and the potential application of CBF properties underlying neuropathology in PD.

Parkinson\u2019s disease laterality: a 11C-PE2I PET imaging study

Asymmetry of striatal dopaminergic deficits and motor symptoms is a typical characteristic of idiopathic Parkinson’s disease (PD). This study aims to characterise the trend of asymmetry in moderate-stage PD. We performed a 19-month longitudinal study in 27 patients with PET-CT imaging and appropriate clinical assessments. 11C-PE2I non-displaceable binding potential (BPND) was calculated bilaterally for the striatum at baseline and follow-up to estimate the in vivo density of striatal dopamine transporters (DAT). Changes in striatal 11C-PE2I BPND over time were more prominent in the ipsilateral as compared to contralateral side. Changes in MDS-UPDRS-III (motor component of the Movement Disorders Society Unified PD Rating Scale) were not different between the clinically most and least affected body sides. Our data support that the asymmetry in striatal dopaminergic degeneration becomes less prominent in moderate-stage PD. In contrast, during the above period, the asymmetry of motor symptoms was maintained between the clinically most and least affected body sides.

Motor symptom asymmetry in Parkinson's disease predicts emotional outcome following subthalamic nucleus deep brain stimulation

The objective of this study was to explore the brain modifications associated with vocal emotion (i.e., emotional prosody) processing deficits in patients with Parkinson’s disease after deep brain stimulation of the subthalamic nucleus, and the impact of motor asymmetry on these deficits. We therefore conducted 18-fluorodeoxyglucose positron emission tomography scans of 29 patients with left- or right-sided motor symptoms of Parkinson’s disease before and after surgery, and correlated changes in their glucose metabolism with modified performances on the recognition of emotional prosody. Results were also compared with those of a matched healthy control group. Patients with more left-sided motor symptoms exhibited a deficit in vocal emotion recognition for neutral, anger, happiness and sadness in the preoperative condition that was normalized postoperatively. Patients with more right-sided motor symptoms performed comparably to controls in the preoperative condition, but differed significantly on fear postoperatively. At the metabolic level, the improvement observed among patients with left-sided motor symptoms was correlated with metabolic modifications in a right-lateralized network known to be involved in emotional prosody, while the behavioral worsening observed among patients with right-sided motor symptoms was correlated with metabolic modifications in the left parahippocampal gyrus and right cerebellum. We suggest that surgery has a differential impact on emotional processing according to motor symptom lateralization, and interpret these results as reflecting the (de)synchronization of the limbic loop in the postoperative condition.

Asymmetry of Periodic Leg Movements in Sleep (PLMS) in Parkinson's Disease.

Periodic limb movements in sleep (PLMS) are repetitive movements usually of the legs strongly associated with Restless-legs syndrome (RLS), which appear more frequently in males, older age and other sleep disturbances, such as sleep-disordered breathing (SDB). Patients with Parkinson's disease (PD) suffer from various sleep disturbances including REM sleep behavior disorder, RLS and PLMS. Although a dopaminergic pathophysiology of PLMS is discussed, no systematic data on PLMS side-to-side distribution in PD and its correlation with asymmetry of motor symptoms are available. This study aimed at elucidating PLMS asymmetry in correlation to that of motor symptoms in PD compared to SDB and RLS. Cross-sectional, retrospective analysis of two polysomnography (PSG) recordings per patient scoring PLMS separately for both legs. Of 105 patients (44 PD, 44 age- and sex-matched SDB and 17 RLS patients) PLMS measures (number of PLM, PLM-Index, PLM-arousal index) showed significant side-to-side differences in all disease entities in both PSGs (P < 0.001; Wilcoxon rank test). PLM-Index asymmetry (PLM-I difference of >5/h between both sides) was observed less frequently in PD (34% of patients) compared to RLS (77% , P < 0.05) and SDB (59% , P < 0.05; χ2 test). In asymmetric PD patients, predominant side of PLMS was more stable than in SDB and RLS comparing the two PSGs, but we did not detect an agreement between PLMS predominant side with that of motor symptoms in PD patients. Only the minority of PD patients shows asymmetric PLMS distribution with relatively high night-to-night stability but no correlation with motor symptom asymmetry.

The influence of motor asymmetry on cognitive functions in Parkinson's disease

The asymmetry of motor symptoms in Parkinson's disease (PD) reflects the asymmetry of the degenerative process and death of nigrostriatal dopaminergic neurons in the substantia nigra, which is confirmed by the data of functional neuroimaging. This review discusses a possible effect of the asymmetry of substantia nigra lesions on other PD symptoms, primarily neuropsychological functions. The authors summarize the data obtained in a comparative analysis of cognitive impairments in PD patients with right-sided and left-sided predominance of motor symptoms. The association between the asymmetry of motor and cognitive symptoms indicates the variability of the profile of cognitive impairments in PD, as well as an important modulating role of subcortical structures on neuropsychological functions traditionally referred to as cortical. The effect of lateralization of symptoms on cognitive function should be considered when evaluating and treating PD patients.

An investigation of asymmetric reduction in dopamine transporter density in patients with Parkinson's disease.

Asymmetric motor symptoms and the contralateral side of dopaminergic deficits are commonly observed in patients with Parkinson's disease. The laterality of the specific binding ratio (SBR) for dopamine transporter single-photon emission computed tomography may be useful for estimation of reduced dopamine transporter density in striatum of patients with Parkinson's disease. SBR with Southampton method (S-SBR) is widely used to evaluate in our country, but the results occasionally contradict with that of motor symptoms or visual evaluation in clinical practice, thus preventing a confident diagnosis. We reported dopamine transporter evaluation with distance-weighted histogram (DWH). We hypothesized that the SBR calculated using DWH (DWH-SBR) may also be useful to evaluate the laterality. The purpose of this study was to investigate the laterality of the SBR versus the asymmetry of motor symptoms, and versus visual evaluation. In total, 100 adult patients with Parkinson's disease were enrolled in our study. The symptom-affected side, the visual-affected side, and the lower SBR side were evaluated. The evaluation was performed in a blinded manner. Correlations between the Hoehn and Yahr scale (HY scale) and both the SBRs were also investigated. Concordance of lower DWH-SBR side for visual-affected side was significantly higher (99.0%) than it of lower S-SBR side (86.0%, P < 0.01). The HY scale was significantly related to both lower S-SBR and DWH-SBR (P < 0.01). The DWH method might minimize the disagreement of laterality between the SBR and visual evaluation, and be useful for making a confident diagnosis in patients with Parkinson's disease.

Differential diagnosis of Parkinson Disease and Corticobasal Degeneration (disease course and progression)

The objective of our research was the description of the differential diagnostic features of Corticobasal Degeneration and Parkinson Disease in order to improve the diagnosis and the differential diagnosis of these diseases. Corticobasal Degeneration was characterized by marked asymmetry of motor symptoms, malignant progression and the lack of therapeutic effect of dopaminergic medications. Parkinson Disease was characterized by an asymmetry of motor symptoms, benign progression and efficacy of dopaminergic medications.

Hemispheric specialization of the basal ganglia during vocal emotion decoding: Evidence from asymmetric Parkinson's disease and 18FDG PET

The possible hemispheric specialization of the basal ganglia during emotional prosody (i.e., vocal emotion) processing has still to be elucidated. Coupled with affective measures and neuroimaging, Parkinson's disease offers a unique opportunity to study this question, on account of its characteristically asymmetric striatal dysfunction, which translates into predominantly contralateral motor symptoms. We investigated the cerebral metabolic bases of emotional prosody recognition in patients with Parkinson's disease with left- versus right-lateralized motor symptoms, postulating that patients with greater right hemispheric brain dysfunction have a specific impairment that correlates with the metabolic modification of a brain network known to be involved in emotional prosody. A total of 38 patients performed a validated emotional prosody recognition task and underwent a resting-state F-18 fluorodeoxyglucose PET scan, as well as clinical, motor, neuropsychological, and psychiatric assessments. Patients’ performances were compared with those of 45 healthy controls. As expected, vocal emotion recognition was significantly poorer among patients with left-sided motor symptoms than among both right-sided patients and controls. There was no significant difference between right-sided patients and controls. This effect was observed for both the total score and the happiness subscore. Interestingly, regressions showed that the greater the emotional misattribution, the greater the patients’ age and asymmetric motor symptom severity. Finally, at the metabolic level, positive correlations were found between the happiness recognition subscore and the metabolism of the right orbitofrontal cortex in patients with left-sided motor symptoms. A right orbitofrontal-basal ganglia coupling seems to be specifically involved in the vocal emotion recognition deficit observed in Parkinson's disease. The asymmetry of motor symptoms is thus an important clinical factor, in that it may influence the presence or severity of affective disorders in Parkinson's disease.

Pisa Syndrome in Parkinson\u2019s Disease: Pathogenic Roles of Verticality Perception Deficits

We elucidated whether verticality misperception is associated with the generation of Pisa syndrome (PS) in patients with Parkinson’s disease (PD). To examine the heterogenous influence of verticality perception, we also identified the characteristics distinguishing between PD patients with PS who tilted toward the deviation of perceived verticality and those who did not. Subjective visual vertical (SVV) testing was performed in 54 PD patients with PS and 36 without PS to measure verticality perception. Other potential risk factors for PS were evaluated by assessing the asymmetry of motor symptoms, EMG activities of paraspinal muscles, bithermal caloric tests, back pain history, and Berg Balance Scale. Abnormal SVV (odds ratio (OR) 18.40, p = 0.006), postural imbalance (OR 0.71, p = 0.046), and unilateral EMG hyperactivity of paraspinal muscles (OR 39.62, p = 0.027) were independent contributors to PS. In subgroup analysis, EMG hyperactivity of paraspinal muscles contralateral to the leaning side and postural imbalance were associated with PD patients with PS who tilted toward the SVV deviation, whereas back pain was more frequent in those who did not. Verticality misperception is a potent risk factor for PS in PD and contributes differentially to PS depending on the congruence between its direction and PS direction, indicating distinct pathogenic roles.

Adenosine A1 receptors measured with 11 C-MPDX PET in early Parkinson's disease.

Adenosine A1 receptors (A1 Rs) interact negatively with dopamine D1 receptors (D1 Rs) in neurons of the basal ganglia's direct pathway, while adenosine A2A receptors (A2A Rs) negatively interact with dopamine D2 receptors (D2 Rs) in indirect-pathway neurons. The aim of this study was to investigate the cerebral density of A1 Rs in Parkinson's disease (PD) in its early stages, using PET scans with the radioligand 8-dicyclopropylmethyl-1-11 C-methyl-3-propylxanthine (11 C-MPDX). We studied 10 drug-naïve patients with early PD. Each patient was also examined for dopamine transporters (DATs) and D2 Rs by PET using 11 C-2-β-carbomethoxy-3-β-(4-fluorophenyl)-tropane (11 C-CFT) and 11 C-raclopride (11 C-RAC), respectively. Ten elderly, healthy volunteers were recruited as controls for 11 C-MPDX PET scanning and eight elderly volunteers were recruited as controls for 11 C-CFT and 11 C-RAC PET scanning. The PET scans revealed a decrease in the uptake ratio index (URI) of 11 C-CFT and an increase in the URI of 11 C-RAC in patients. In the temporal lobe, the binding potential for 11 C-MPDX was higher in the patient group than in healthy subjects, but not in the other regions examined, including the striatum. In patients, we observed motor-symptom asymmetry and a relationship between parkinsonism and the striatal density of DATs, but not A1 R density. In the putamen of early PD, asymmetrical down-regulation of A2A Rs is likely a compensatory mechanism in response to a decrease in dopamine. However, our study suggests that A1 Rs are unaltered in the putamen of early PD.