Clinical features, disease progression, and nuclear imaging in ATXN2-related parkinsonism in a longitudinal cohort.

BACKGROUND: Spinocerebellar ataxia 2 (SCA2) with a low range of CAG repeat expansion of ATXN2 gene can present with predominant or isolated parkinsonism that closely resembles Parkinson's disease (PD). This study is aimed at comparing clinical features, disease progression, and nuclear imaging between ATXN2-related parkinsonism (ATXN2-P) and PD. METHODS: Three hundred and seventy-seven clinically diagnosed PD with family history were screened by multiplex ligation-dependent probe amplification, whole-exome sequencing or target sequencing, and dynamic mutation testing of 10 SCA subtypes. The baseline and longitudinal clinical features as well as the dual-tracer positron emission tomography (PET) imaging were compared between ATXN2-P and genetically undefined familial PD (GU-fPD). RESULTS: Fifteen ATXN2-P patients from 7 families and 50 randomly selected GU-fPD patients were evaluated. Significantly less resting tremor and more symmetric signs were observed in ATXN2-P than GU-fPD. No significant difference was found in motor progression and duration from onset to occurrence of fluctuation, dyskinesia, and recurrent falls between the two groups. Cognitive impairment and rapid-eye-movement sleep behavior disorder were more common in ATXN2-P. During follow-up, olfaction was relatively spared, and no obvious progression of cognition dysfunction evaluated by Mini-Mental State Examination scores was found in ATXN2-P. PET results of ATXN2-P demonstrated a symmetric, diffuse, and homogenous dopamine transporter loss of bilateral striatum and a glucose metabolism pattern inconsistent with that in PD. CONCLUSIONS: Symmetric motor signs and unique nuclear imaging might be the clues to distinguish ATXN2-P from GU-fPD.

The genetic spectrum of a cohort of patients clinically diagnosed as Parkinson's disease in mainland China.

So far, over 20 causative genes of monogenic Parkinson's disease (PD) have been identified. Some causative genes of non-parkinsonian entities may also manifest with parkinsonism mimicking PD. This study aimed to investigate the genetic characteristics of clinically diagnosed PD with early onset age or family history. A total of 832 patients initially diagnosed with PD were enrolled, of which, 636 were classified into the early-onset group and 196 were classified into the familial late-onset group. The genetic testing included the multiplex ligation-dependent probe amplification and next generation sequencing (target sequencing or whole-exome sequencing). The dynamic variants of spinocerebellar ataxia were tested in probands with family history. In the early-onset group, 30.03% of patients (191/636) harbored pathogenic/likely pathogenic (P/LP) variants in known PD-related genes (CHCHD2, DJ-1, GBA (heterozygous), LRRK2, PINK1, PRKN, PLA2G6, SNCA and VPS35). Variants in PRKN were the most prevalent, accounting for 15.72% of the early-onset patients, followed by GBA (10.22%), and PLA2G6 (1.89%). And 2.52% (16/636) had P/LP variants in causative genes of other diseases (ATXN3, ATXN2, GCH1, TH, MAPT, GBA (homozygous)). In the familial late-onset group, 8.67% of patients (17/196) carried P/LP variants in known PD-related genes (GBA (heterozygous), HTRA2, SNCA) and 2.04% (4/196) had P/LP variants in other genes (ATXN2, PSEN1, DCTN1). Heterozygous GBA variants (7.14%) were the most common genetic cause found in familial late-onset patients. Genetic testing is of vital importance in differential diagnosis especially in early-onset and familial PD. Our findings may also provide some clues to the nomenclature of genetic movement disorders.

Autosomal dominant Parkinson's disease caused by the recently identified LRRK2 N1437D mutation in a Chinese family: Clinical features, imaging findings, and functional impact.

INTRODUCTION: Mutations in leucine-rich repeat kinase 2 (LRRK2) are the most common genetic cause of autosomal dominantly inherited Parkinson's disease (PD). Recently, a novel pathogenic variant (N1437D; c.4309A > G; NM_98578) in the LRRK2 gene has been identified in three Chinese families with PD. In this study, we describe a Chinese family with autosomal dominant PD that segregated with the N1437D mutation. A detailed clinical and neuroimaging characterization of the affected family members is reported. We also sought to investigate the functional mechanisms by which the detected mutation could cause PD. METHODS: We characterized the clinical and imaging phenotype of a Chinese pedigree with autosomal dominant PD. We searched for a disease-causing mutation by targeted sequencing and multiple ligation-dependent probe amplification. The functional impact of the mutation was investigated in terms of LRRK2 kinase activity, guanosine triphosphate (GTP) binding, and guanosine triphosphatase (GTPase) activity. RESULTS: The disease was found to co-segregate with the LRRK2 N1437D mutation. Patients in the pedigree exhibited typical parkinsonism (age at onset: 54.0 ± 5.9 years). One affected family member - who had evidence of abnormal tau accumulation in the occipital lobe on tau PET imaging - developed PD dementia at follow-up. The mutation markedly increased LRRK2 kinase activity and promoted GTP binding, without affecting GTPase activity. CONCLUSIONS: This study describes the functional impact of a recently identified LRRK2 mutation, N1437D, that causes autosomal dominant PD in the Chinese population. Further research is necessary to investigate the contribution of this mutation to PD in multiple Asian populations.

Dopaminergic Dysfunction and Glucose Metabolism Characteristics in Parkin-Induced Early-Onset Parkinson's Disease Compared to Genetically Undetermined Early-Onset Parkinson's Disease.

While early-onset Parkinson's disease (EOPD) caused by mutations in the parkin gene (PRKN) tends to have a relatively benign course compared to genetically undetermined (GU)-EOPD, the exact underlying mechanisms remain elusive. We aimed to search for the differences between PRKN-EOPD and GU-EOPD by dopamine transporter (DAT) and glucose metabolism positron-emission-tomography (PET) imaging. Twelve patients with PRKN-EOPD and 16 with GU-EOPD who accepted both 11C-2b-carbomethoxy-3b-(4-trimethylstannylphenyl) tropane (11C-CFT) and 18F-fluorodeoxyglucose PET were enrolled. The 11C-CFT uptake was analyzed on both regional and voxel levels, whereas glucose metabolism was assessed in a voxel-wise fashion. Correlations between DAT and glucose metabolism imaging, DAT imaging and clinical severity, as well as glucose metabolism imaging and clinical severity were explored. Both clinical symptoms and DAT-binding patterns in the posterior putamen were highly symmetrical in patients with PRKN-EOPD, and dopaminergic dysfunction in the ipsilateral putamen was severer in patients with PRKN-EOPD than GU-EOPD. Meanwhile, the DAT binding was associated with the severity of motor dysfunction in  patients with GU-EOPD only. Patients with PRKN-EOPD showed increased glucose metabolism in the contralateral medial frontal gyrus (supplementary motor area (SMA)), contralateral substantia nigra, contralateral thalamus, and contralateral cerebellum. Notably, glucose metabolic activity in the contralateral medial frontal gyrus was inversely associated with regional DAT binding in the bilateral putamen. Patients with PRKN-EOPD showed enhanced metabolic connectivity within the bilateral putamen, ipsilateral paracentral and precentral lobules, and the ipsilateral SMA. Collectively, compared to GU-EOPD, PRKN-EOPD is characterized by symmetrical, more severe dopaminergic dysfunction and relative increased glucose metabolism. Meanwhile, SMA with elevated glucose metabolism and enhanced connectivity may act as compensatory mechanisms in PRKN-EOPD. Supplementary Information: The online version contains supplementary material available at 10.1007/s43657-022-00077-8.

18 F-Florzolotau Positron Emission Tomography Imaging of Tau Pathology in the Living Brains of Patients with Corticobasal Syndrome.

BACKGROUND: Recent development in tau-sensitive tracers has sparkled significant interest in tracking tauopathies using positron emission tomography (PET) biomarkers. However, the ability of 18 F-florzolotau PET imaging to topographically characterize tau pathology in corticobasal syndrome (CBS) remains unclear. Further, the question as to whether disease-level differences exist with other neurodegenerative tauopathies is still unanswered. OBJECTIVE: To analyze the topographical patterns of tau pathology in the living brains of patients with CBS using 18 F-florzolotau PET imaging and to examine whether differences with other tauopathies exist. METHODS: 18 F-florzolotau PET imaging was performed in 20 consecutive patients with CBS, 20 cognitively healthy controls (HCs), 20 patients with Alzheimer's disease (AD), and 16 patients with progressive supranuclear palsy-Richardson's syndrome (PSP-RS). Cerebrospinal fluid (CSF) levels of ß-amyloid biomarkers were quantified in all patients with CBS. 18 F-florzolotau uptake was quantitatively assessed using standardized uptake value ratios. RESULTS: Of the 20 patients with CBS, 19 (95%) were negative for CSF biomarkers of amyloid pathology; of them, three had negative 18 F-florzolotau PET findings. Compared with HCs, patients with CBS showed increased 18 F-florzolotau signals in both cortical and subcortical regions. In addition, patients with CBS were characterized by higher tracer retentions in subcortical regions compared with those with AD and showed a trend toward higher signals in cortical areas compared with PSP-RS. An asymmetric pattern of 18 F-florzolotau uptake was associated with an asymmetry of motor severity in patients with CBS. CONCLUSIONS: In vivo 18 F-florzolotau PET imaging holds promise for distinguishing CBS in the spectrum of neurodegenerative tauopathies. © 2023 International Parkinson and Movement Disorder Society.

PDQ-8: A Simplified and Effective Tool Measuring Life Quality in Progressive Supranuclear Palsy.

BACKGROUND: The self-reported quality of life (QoL) should be carefully listened to in progressive supranuclear palsy (PSP) from the patient-centered perspective. However, there was still a lack of short QoL measurement tool in atypical parkinsonism. OBJECTIVE: We aimed to test whether the short Parkinson's Disease Questionnaire-8 (PDQ-8) was effective in assessing QoL in PSP, comparing with Progressive Supranuclear Palsy Quality of Life Scale (PSP-QoL) and Parkinson's Disease Questionnaire-39 (PDQ-39). METHODS: 132 patients with clinical diagnosed PSP, including PSP-Richardson syndrome (RS) subtype (n = 71) and PSP-non-RS subtype (n = 61) were recruited for clinical evaluation including QoL assessment. The detailed QoL profiles and possibility of using PDQ-8 were systemically analyzed. The determinants to the QoL were then calculated by multivariate linear regression analysis. RESULTS: The PSP-QoL total score summary index (SI) was 22.8 (10.1, 41.1), while the PDQ-8 and PDQ-39 total SI score were 28.1 (12.5, 46.9) and 29.5 (15.4, 49.4). Mobility, activities of daily life, cognition and communication were the main affected QoL subdomains (median SI: 40.0, 31.3, 25.0 and 25.0 respectively). PSP-RS subtype showed more severe damage physically (p<0.001) and mentally (p = 0.002) compared to other subtypes. More importantly, the strong relevance of PDQ-8 and recommended PSP QoL tools were confirmed (p<0.001). In addition, disease severity, depression and daytime sleepiness were proved to be critical determinants for QoL in PSP. CONCLUSIONS: PDQ-8 could be an easy, reliable, and valid tool to evaluate QoL in patients with PSP. Besides motor symptoms, more attention should be paid to non-motor impairment such as depression in PSP.

18F-Florzolotau PET imaging captures the distribution patterns and regional vulnerability of tau pathology in progressive supranuclear palsy.

PURPOSE: Human post mortem studies have described the topographical patterns of tau pathology in progressive supranuclear palsy (PSP). Recent advances in tau PET tracers are expected to herald the next era of PSP investigation for early detection of tau pathology in living brains. This study aimed to investigate whether 18F-Florzolotau PET imaging may capture the distribution patterns and regional vulnerability of tau pathology in PSP, and to devise a novel image-based staging system. METHODS: The study cohort consisted of 148 consecutive patients with PSP who had undergone 18F-Florzolotau PET imaging. The PSP rating scale (PSPrs) was used to measure disease severity. Similarities and differences of tau deposition among different clinical phenotypes were examined at the regional and voxel levels. An 18F-Florzolotau pathological staging system was devised according to the scheme originally developed for post mortem data. In light of conditional probabilities for the sequence of events, an 18F-Florzolotau modified staging system by integrating clusters at the regional level was further developed. The ability of 18F-Florzolotau staging systems to reflect disease severity in terms of PSPrs score was assessed by analysis of variance. RESULTS: The distribution patterns of 18F-Florzolotau accumulation in living brains of PSP showed a remarkable similarity to those reported in post mortem studies, with the binding intensity being markedly higher in Richardson's syndrome. Moreover, 18F-Florzolotau PET imaging allowed detecting regional vulnerability and tracking tau accumulation in an earlier fashion compared with post mortem immunostaining. The 18F-Florzolotau staging systems were positively correlated with clinical severity as reflected by PSPrs scores. CONCLUSIONS: 18F-Florzolotau PET imaging can effectively capture the distribution patterns and regional vulnerability of tau pathology in PSP. The 18F-Florzolotau modified staging system holds promise for early tracking of tau deposition in living brains.

Striatal dopaminergic lesions contributed to the disease severity in progressive supranuclear palsy.

Background: Reduced dopamine transporter (DAT) binding in the striatum has been reported in patients with progressive supranuclear palsy (PSP). However, the relationship between striatal dopaminergic lesions and the disease severity of PSP remains to be explored. Objective: To investigate the contributions of striatal dopaminergic lesions to the disease severity of PSP. Methods: One hundred patients with clinically diagnosed PSP were consecutively enrolled in this study. The disease severity was systemically assessed using the PSP rating scale (PSPrs), and the dopaminergic lesions were assessed using the 11C-N-2-carbomethoxy-3-(4-fluorophenyl)-tropane positron emission tomography (11C-CFT PET) imaging. To explore the correlations between striatal DAT bindings and the disease severity, both the region-wise and voxel-wise analysis were adopted. Partial correlations and multiple linear regressions were performed to investigate the contribution of striatal dopaminergic lesions to the disease severity in PSP. Results: Sixty-three patients of PSP with Richardson's syndrome (PSP-RS) and 37 patients with PSP-non-RS were finally included. The disease severity in PSP-RS was much heavier than that in the PSP-non-RS. The DAT bindings in the caudate and anterior putamen correlated significantly with the PSPrs total scores, mainly in the domains of history, mentation, bulbar, and ocular motor symptoms. The striatal DAT bindings (caudate) contributed significantly to the disease severity of PSP, independent of the motor, cognition, emotion and behavioral dysfunctions. Conclusion: Our study highlighted the independent contribution of striatal dopaminergic lesions to the disease severity in PSP.

Serum metabolomic characterization of PLA2G6-associated dystonia-parkinsonism: A case-control biomarker study.

Introduction: Phospholipase A2 Group VI (PLA2G6), encoding calcium-independent phospholipase A2, has been isolated as the gene responsible for an autosomal recessive form of early-onset Parkinson's disease (namely, PARK14). Compared to idiopathic Parkinson's disease (iPD), PARK14 has several atypical clinical features. PARK14 has an earlier age at onset and is more likely to develop levodopa-induced dyskinesia. In iPD, serum metabolomics has observed alterations in several metabolic pathways that are related to disease status and clinical manifestations. This study aims to describe the serum metabolomics features of patients with PARK14. Design: This case-control biomarker study tested nine patients diagnosed with PARK14. Eight age and sex-matched healthy subjects were recruited as controls. To evaluate the influence of single heterozygous mutation, we enrolled eight healthy one-degree family members of patients with PARK14, two patients diagnosed with early-onset Parkinson's disease (EOPD) who had only a single heterozygous PLA2G6 mutation, and one patient with EOPD without any known pathogenic mutation. Methods: The diagnosis of PARK14 was made according to the diagnostic criteria for Parkinson's disease (PD) and confirmed by genetic testing. To study the serum metabolic features, we analyzed participants' serum using UHPLC-QTOF/MS analysis, a well-established technology. Results: We quantified 50 compounds of metabolites from the serum of all the study subjects. Metabolites alterations in serum had good predictive accuracy for PARK14 diagnosis (AUC 0.903) and advanced stage in PARK14 (AUC 0.944). Of the 24 metabolites that changed significantly in patients' serum, eight related to lipid metabolism. Oleic acid and xanthine were associated with MMSE scores. Xanthine, L-histidine, and phenol correlated with UPDRS-III scores. Oleic acid and 1-oleoyl-L-alpha-lysophosphatidic acid could also predict the subclass of the more advanced stage in the PLA2G6 Group in ROC models. Conclusion: The significantly altered metabolites can be used to differentiate PLA2G6 pathogenic mutations and predict disease severity. Patients with PLA2G6 mutations had elevated lipid compounds in C18:1 and C16:0 groups. The alteration of lipid metabolism might be the key intermediate process in PLA2G6-related disease that needs further investigation.

18 F-Florzolotau Tau Positron Emission Tomography Imaging in Patients with Multiple System Atrophy-Parkinsonian Subtype.

BACKGROUND: Anecdotal evidence suggests that patients diagnosed with the parkinsonian subtype of multiple system atrophy (MSA-P) may show uptake of the second-generation tau positron emission tomography (PET) tracer 18 F-Florzolotau (previously known as 18 F-APN-1607) in the putamen. OBJECTIVES: This study systematically investigated the localization and magnitude of 18 F-Florzolotau uptake in a relatively large cohort of patients with MSA-P. METHODS: 18 F-Florzolotau PET imaging was performed in 31 patients with MSA-P, 24 patients with Parkinson's disease (PD), and 20 age-matched healthy controls. 18 F-Florzolotau signal in the striatum was analyzed by visual inspection and classified as either positive or negative. Regional 18 F-Florzolotau binding was also expressed as standardized uptake value ratio (SUVR) to assess whether it was associated with core symptoms of MSA-P after adjustment for potential confounders. RESULTS: By visual inspection and semiquantitative SUVR comparisons, patients with MSA-P showed elevated 18 F-Florzolotau uptake in the putamen, globus pallidus, and dentate-a finding that was not observed in PD. This increased signal was significantly associated with the core symptoms of MSA-P. In addition, patients with MSA-P with cerebellar ataxia showed an elevated 18 F-Florzolotau uptake in the cerebellar dentate. CONCLUSIONS: 18 F-Florzolotau tau PET imaging findings may reflect the clinical severity of MSA-P and can potentially discriminate between this condition and PD. © 2022 International Parkinson and Movement Disorder Society.

Dopamine transporter imaging in progressive supranuclear palsy: Severe but nonspecific to subtypes.

BACKGROUND: Previous studies with a limited sample size suggested more severe dopaminergic transporter (DAT) lesions in the striatum of progressive supranuclear palsy (PSP) than those in Parkinson's disease (PD) and multiple system atrophy-parkinsonism (MSA-P). However, few studies had taken various subtypes of PSP into consideration, making the reanalysis of DAT imaging in larger PSP cohort with various subtypes in need. OBJECTIVES: To compare the dopaminergic lesion patterns of PSP with MSA-P and PD, and to explore the specific striatal subregional patterns of different PSP subtypes. METHODS: 11 C-CFT positron emission tomography (PET) imaging was conducted in 83 PSP patients consisting of different subtypes, 61 patients with PD, 41 patients with MSA-P, and 43 healthy volunteers. Demographic and clinical data were compared by the chi-squared test or one-way analysis of variance. A generalized linear model was used to examine intergroup differences in tracer uptake values after adjusting for age, disease duration, and disease severity. Areas under the receiver operating characteristic curve were calculated to assess the diagnostic accuracy of subregional DAT binding patterns. RESULTS: The patients with PSP presented more severe DAT loss in the striatum than in PD and MSA-P, especially in caudate. In PSP, the subregional lesion was still more severe in putamen than in caudate, similar to that in PD and MSA-P. Among detailed subtypes, no significant difference was detected. CONCLUSION: The dopaminergic lesions were more severe in PSP, and no difference was detected among subtypes.

Comparison of comfort and complications of Implantable Venous Access Port (IVAP) with ultrasound guided Internal Jugular Vein (IJV) and Axillary Vein/Subclavian Vein (AxV/SCV) puncture in breast cancer patients: a randomized controlled study.

BACKGROUND: Axillary vein/subclavian vein (AxV/SCV) and Internal jugular vein (IJV) are commonly used for implantable venous access port (IVAP) implantation in breast cancer patients for chemotherapy. Previous research focused on comparison of complications while patient comfort was ignored. This study aims to compare patient comfort, surgery duration and complications of IVAP implantation between IJV and AxV/SCV approaches. METHODS: Two hundred forty-eight breast cancer patients were enrolled in this randomized controlled study from August 2020 to June 2021. Patients scheduled to undergo IVAP implantation were randomly and equally assigned to receive central venous catheters with either AxV /SCV or IJV approaches. All patients received comfort assessment using a comfort scale table at day 1, day 2 and day 7 after implantation. Patient comfort, procedure time of operation as well as early complications were compared. RESULTS: Patient comfort was significantly better in the AxV/SCV group than that of IJV group in day 1 (P < 0.001), day 2 (P < 0.001) and day 7(P = 0.023). Procedure duration in AxV/SCV group was slightly but significantly shorter than IJV group (27.14 ± 3.29 mins vs 28.92 ± 2.54 mins, P < 0.001). More early complications occurred in AxV/SCV group than IJV group (11/124 vs 2/124, P = 0.019). No difference of complications of artery puncture, pneumothorax or subcutaneous hematoma between these two groups but significantly more catheter misplacement in AxV/SCV group than IJV group (6/124 vs 0/124, P = 0.029). Absolutely total risk of complications was rather low in both groups (8.87% in AxV/SCV group and 1.61% in IJV group). CONCLUSIONS: Our study indicates that patients with AxV/SCV puncture have higher comfort levels than IJV puncture. AxV/SCV puncture has shorter procedure duration but higher risk of early complications, especially catheter misplacement. Both these two approaches have rather low risk of complications. Consequently, our study provides an alternative choice for breast cancer patients to reach better comfort.

The Frontal and Cerebellar Metabolism Related to Cognitive Dysfunction in Multiple System Atrophy.

BACKGROUND: Cognitive dysfunctions have been reported in multiple system atrophy (MSA). However the underlying mechanisms remain to be elucidated. This study aimed to explore the possible cerebral metabolism associated with domain-specific cognitive performances in MSA. METHODS: A total of 84 patients were diagnosed as probable or possible MSA, comprised of 27 patients as MSA with predominant parkinsonism (MSA-P) and 57 patients as MSA with predominant cerebellar ataxia (MSA-C). The comprehensive neuropsychological tests and 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET) imaging were performed. Z-score was calculated to non-dimensionalize and unify indicators of different tests in the domains of executive function, attention, language, memory, and visuospatial function. Correlations between specific Z-score and cerebral 18F-FDG uptake were analyzed using statistical parametric mapping. The cognition-related metabolic differences between patients with MSA-P and MSA-C were analyzed using the post-hoc test. RESULTS: Z-scores of the domains including attention, executive function, and language correlated positively with the metabolism in the superior/inferior frontal gyrus and cerebellum, but negatively with that in the insula and fusiform gyrus (p < 0.001). No significant differences in neuropsychological performances and frontal metabolism were found between patients with MSA-P and MSA-C. Only lower metabolism in the cerebellum was observed in MSA-C. CONCLUSION: Metabolic changes in the frontal lobe and cerebellum may participate in the cognitive impairments of patients with MSA. Nevertheless, cognitive and corresponding metabolic differences between the two subtypes of MSA still need more exploration.

In Vivo 18 F-APN-1607 Tau Positron Emission Tomography Imaging in MAPT Mutations: Cross-Sectional and Longitudinal Findings.

BACKGROUND: Frontotemporal lobar degeneration with tauopathy caused by MAPT (microtubule-associated protein tau) mutations is a highly heterogenous disorder. The ability to visualize and longitudinally monitor tau deposits may be beneficial to understand disease pathophysiology and predict clinical trajectories. OBJECTIVE: The aim of this study was to investigate the cross-sectional and longitudinal 18 F-APN-1607 positron emission tomography/computed tomography (PET/CT) imaging findings in MAPT mutation carriers. METHODS: Seven carriers of MAPT mutations (six within exon 10 and one outside of exon 10) and 15 healthy control subjects were included. All participants underwent 18 F-APN-1607 PET/CT at baseline. Three carriers of exon 10 mutations received follow-up 18 F-APN-1607 PET/CT scans. Standardized uptake value ratio (SUVR) maps were obtained using the cerebellar gray matter as the reference region. SUVR values observed in MAPT mutation carriers were normalized to data from healthy control subjects. A regional SUVR z score ≥ 2 was used as the criterion to define positive 18 F-APN-1607 PET/CT findings. RESULTS: Although the seven study patients had heterogenous clinical phenotypes, all showed a significant 18 F-APN-1607 uptake characterized by high-contrast signals. However, the anatomical localization of tau deposits differed in patients with distinct clinical symptoms. Follow-up imaging data, which were available for three patients, demonstrated worsening trends in patterns of tau accumulation over time, which were paralleled by a significant clinical deterioration. CONCLUSIONS: Our data represent a promising step in understanding the usefulness of 18 F-APN-1607 PET/CT imaging for detecting tau accumulation in MAPT mutation carriers. Our preliminary follow-up data also suggest the potential value of 18 F-APN-1607 PET/CT for monitoring the longitudinal trajectories of frontotemporal lobar degeneration caused by MAPT mutations. © 2021 International Parkinson and Movement Disorder Society.

Associations of sleep disorders with cerebrospinal fluid α-synuclein in prodromal and early Parkinson's disease.

OBJECTIVES: Our aim is to investigate the associations of sleep disorders with cerebrospinal fluid (CSF) α-synuclein (α-syn) in healthy controls (HCs), and patients with prodromal and early Parkinson's disease (PD). METHODS: We included a total of 575 individuals, consisting of 360 PD individuals, 46 prodromal PD individuals, and 169 HCs. Multiple linear regression models and linear mixed-effects models were used to investigate the associations of sleep disorders with baseline and longitudinal CSF α-syn. Associations between the change rates of sleep disorders and CSF α-syn were further investigated via multiple linear regression models. RESULTS: In PD, probable Rapid-eye-movement sleep Behavior Disorder (pRBD) (ß = - 0.1199; P = 0.0444) and RBD sub-items, such as aggressive dreams (ß = - 0.1652; P = 0.0072) and hurting bed partner (ß = - 0.2468; P = 0.0010), contributed to lower CSF α-syn. The association between aggressive dreams and lower CSF α-syn further survived Bonferroni correction (P < 0.0036). In prodromal PD, dream-enacting (a specific RBD behavior) was significantly associated with decreased CSF α-syn during the follow-up (ß = - 0.0124; P = 0.0237). HCs with daytime sleepiness when inactive-sitting in public places (ß = - 0.0033; P = 0.0135) showed decreased CSF α-syn. Furthermore, increased possibilities of daytime sleepiness when sitting and reading contributed to a greater decrease of CSF α-syn in HCs (ß = - 196.8779; P = 0.0433). CONCLUSIONS: Sleep disorders were associated with decreased CSF α-syn. Sleep management may be important for disease monitoring and preventing the progression of α-syn pathology.

Disease progression in Parkinson's disease patients with subjective cognitive complaint.

OBJECTIVE: Little is known about the disease progression of Parkinson's disease patients with subjective cognitive complaint (PD-SCC). This longitudinal cohort study aims to compare the progression of clinical features and quality of life (QoL) in PD patients with normal cognition (NC), SCC, and mild cognitive impairment (MCI). METHODS: A total of 383 PD patients were enrolled, including 189 PD-NC patients, 59 PD-SCC patients, and 135 PD-MCI patients, with 1-7 years of follow-up. Linear mixed models were applied to evaluate longitudinal changes in motor symptoms, nonmotor features (cognitive impairment, depression, and excessive daytime sleepiness), and QoL in PD. RESULTS: At baseline, PD-SCC patients had lower Beck Depression Inventory (BDI) scores and Parkinson's Disease Questionnaire-39 (PDQ-39) scores than PD-NC patients (all p < 0.05). Longitudinal analyses revealed that the PD-SCC group exhibited faster progression in terms of BDI scores (p = 0.042) and PDQ-39 scores (p = 0.035) than the PD-NC group. The PD-MCI group exhibited faster progression rates in the Epworth Sleepiness Scale scores (p = 0.001) and PDQ-39 scores (p = 0.005) than the PD-NC group. In addition, the PD-SCC group exhibited a greater reduction in attention (Trail Making Test Part A, p = 0.047) and executive function (Stroop Color-Word Test, p = 0.037) than the PD-NC group. INTERPRETATION: PD-SCC patients exhibited faster deterioration of depression and QoL than PD-NC patients, and SCC may be an indicator of initial attention and executive function decline in PD. Our findings provided a more accurate prognosis in PD-SCC patients.

Clinical Utility of 18 F-APN-1607 Tau PET Imaging in Patients with Progressive Supranuclear Palsy.

BACKGROUND: 18 F-APN-1607 is a novel tau PET tracer characterized by high binding affinity for 3- and 4-repeat tau deposits. Whether 18 F-APN-1607 PET imaging is clinically useful in PSP remains unclear. OBJECTIVES: The objective of this study was to investigate the clinical utility of 18 F-APN-1607 PET in the diagnosis, differential diagnosis, and assessment of disease severity in patients with PSP. METHODS: We enrolled 3 groups consisting of patients with PSP (n = 20), patients with α-synucleinopathies (MSA with predominant parkinsonism, n = 7; PD, n = 10), and age- and sex-matched healthy controls (n = 13). The binding patterns of 18 F-APN-1607 in PET/CT imaging were investigated. Regional standardized uptake ratios were compared across groups and examined in relation to their utility in the differential diagnosis of PSP versus α-synucleinopathies. Finally, the relationships between clinical severity scores and 18 F-APN-1607 uptake were investigated after adjustment for age, sex, and disease duration. RESULTS: Compared with healthy controls, patients with PSP showed increased 18 F-APN-1607 binding in several subcortical regions, including the striatum, putamen, globus pallidus, thalamus, subthalamic nucleus, midbrain, tegmentum, substantia nigra, pontine base, red nucleus, raphe nuclei, and locus coeruleus. We identified specific regions that were capable of distinguishing PSP from α-synucleinopathies. The severity of PSP was positively correlated with the amount of 18 F-APN-1607 uptake in the subthalamic nucleus, midbrain, substantia nigra, red nucleus, pontine base, and raphe nuclei. CONCLUSIONS: 18 F-APN-1607 PET imaging holds promise for the diagnosis, differential diagnosis, and assessment of disease severity in patients with PSP. © 2021 International Parkinson and Movement Disorder Society.

Cerebral Metabolism Related to Cognitive Impairments in Multiple System Atrophy.

Objective: We aimed to characterize the cognitive profiles in multiple system atrophy (MSA) and explore the cerebral metabolism related to the cognitive decline in MSA using 18F-fluorodeoxyglucose (18F-FDG) Positron Emission Tomography (PET). Methods: In this study, 105 MSA patients were included for cognitive assessment and 84 of them were enrolled for 18F-FDG PET analysis. The comprehensive neuropsychological tests covered five main domains including execution, attention, memory, language, and visuospatial function. The cognitive statuses were classified to MSA with normal cognition (MSA-NC) and MSA with cognitive impairment (MSA-CI), including dementia (MSA-D), and mild cognitive impairment (MSA-MCI). With 18F-FDG PET imaging, the cerebral metabolism differences among different cognitive statuses were analyzed using statistical parametric mapping and post-hoc analysis. Results: Among 84 MSA patients, 52 patients were found with MSA-CI, including 36 patients as MSA-MCI and 16 patients as MSA-D. In detail, the cognitive impairments were observed in all the five domains, primarily in attention, executive function and memory. In 18F-FDG PET imaging, MSA-D and MSA-MCI patients exhibited hypometabolism in left middle and superior frontal lobe compared with MSA-NC (p < 0.001). The normalized regional cerebral metabolic rate of glucose (rCMRglc) in left middle frontal lobe showed relative accuracy in discriminating MSA-CI and MSA-NC [areas under the curve (AUC) = 0.750; 95%CI = 0.6391-0.8609]. Conclusions: Cognitive impairments were not rare in MSA, and the hypometabolism in frontal lobe may contribute to such impairments.

Neuroprotection of Exendin-4 by Enhanced Autophagy in a Parkinsonian Rat Model of α-Synucleinopathy.

Glucagon-like peptide-1 (GLP-1) receptor stimulation ameliorates parkinsonian motor and non-motor deficits in both experimental animals and patients; however, the disease-modifying mechanisms of GLP-1 receptor activation have remained unknown. The present study investigated whether exendin-4 (a GLP-1 analogue) can rescue motor deficits and exert disease-modifying effects in a parkinsonian rat model of α-synucleinopathy. This model was established by unilaterally injecting AAV-9-A53T-α-synuclein into the right substantia nigra pars compacta, followed by 4 or 8 weeks of twice-daily intraperitoneal injections of exendin-4 (5 µg/kg/day) starting at 2 weeks after AAV-9-A53T-α-synuclein injections. Positron emission tomography/computed tomography (PET/CT) scanning and immunostaining established that treatment with exendin-4 attenuated tyrosine-hydroxylase-positive neuronal loss and terminal denervation and mitigated the decrease in expression of vesicular monoamine transporter 2 within the nigrostriatal dopaminergic systems of rats injected with AAV-9-A53T-α-synuclein. It also mitigated the parkinsonian motor deficits assessed in behavioral tests. Furthermore, through both in vivo and in vitro models of Parkinson's disease, we showed that exendin-4 promoted autophagy and mediated degradation of pathological α-synuclein, the effects of which were counteracted by 3-methyladenine or chloroquine, the autophagic inhibitors. Additionally, exendin-4 attenuated dysregulation of the PI3K/Akt/mTOR pathway in rats injected with AAV-9-A53T-α-synuclein. Taken together, our results demonstrate that exendin-4 treatment relieved behavioral deficits, dopaminergic degeneration, and pathological α-synuclein aggregation in a parkinsonian rat model of α-synucleinopathy and that these effects were mediated by enhanced autophagy via inhibiting the PI3K/Akt/mTOR pathway. In light of the safety and tolerance of exendin-4 administration, our results suggest that exendin-4 may represent a promising disease-modifying treatment for Parkinson's disease.