Objective: To investigate the effects of balance exercise and brisk walking on nonmotor and motor symptoms, balance and gait functions, walking capacity, and balance confidence in Parkinson disease (PD) at posttraining and 6-month follow-up.
Design: Two-arm, assessor-blinded randomized controlled trial SETTING: University research laboratory and the community PARTICIPANTS: Ninety-nine eligible individuals with mild-to-moderate PD INTERVENTIONS: Participants were randomized to balance and brisk walking group (B&B, n=49) or active control group (n=50). B&B received ten 90-minute sessions of balance exercises and brisk walking supervised by physical therapists for 6 months (week 1-6: weekly, week 7-26: monthly), whereas control practiced whole-body flexibility and upper limb strength exercise at same dosage (180 min/wk).
Background: Major intracerebral hemorrhage (ICH) trials have largely been unable to demonstrate therapeutic benefit in improving functional outcomes. This may be partly due to the heterogeneity of ICH outcomes based on their location, where a small strategic ICH could be debilitating, thus confounding therapeutic effects. We aimed to determine the ideal hematoma volume cutoff for different ICH locations in predicting ICH outcomes.
View Article and Find Full Text PDFBackground: Leucine-rich repeat kinase 2 (LRRK2) mutation is a common genetic risk factor of Parkinson's disease (PD). Presynaptic dysfunction is an early pathogenic event associated with dopamine (DA) dysregulation in striatum of the brain. DA uptake activity of DA uptake transporter (DAT) affects synaptic plasticity and motor and non-motor behavior.
View Article and Find Full Text PDFBackground: Intracerebral hemorrhage (ICH) survivors are at high risk for recurrent stroke and cardiovascular events. Blood pressure (BP) control represents the most potent intervention to lower these risks, but optimal treatment targets in this patient population remain unknown. We sought to determine whether survivors of ICH achieving more intensive BP control than current guideline recommendations (systolic BP <130 mmHg and diastolic BP <80 mmHg) were at lower risk of major adverse cardiovascular and cerebrovascular events and mortality.
View Article and Find Full Text PDFParkinson's disease (PD) is characterized by dopaminergic neurodegeneration in nigrostriatal and cortical brain regions associated with pathogenic α-synuclein (αSyn) aggregate/oligomer accumulation. LRRK2 hyperactivity is a disease-modifying therapeutic target in PD. However, LRRK2 inhibition may be associated with peripheral effects, albeit with unclear clinical consequences.
View Article and Find Full Text PDFSynaptogyrin-3 (SYNGR3) is a synaptic vesicular membrane protein. Amongst four homologues (SYNGR1 to 4), SYNGR1 and 3 are especially abundant in the brain. SYNGR3 interacts with the dopamine transporter (DAT) to facilitate dopamine (DA) uptake and synaptic DA turnover in dopaminergic transmission.
View Article and Find Full Text PDFBackground Survivors of intracranial hemorrhage (ICH) are at increased risk for major adverse cardiovascular and cerebrovascular events (MACCE), in the form of recurrent stroke and myocardial Infarction. We investigated whether long-term blood pressure (BP) variability represents a risk factor for MACCE after ICH, independent of average BP. Methods and Results We analyzed data from prospective ICH cohort studies at Massachusetts General Hospital and the University of Hong Kong.
View Article and Find Full Text PDFMutations in the leucine-rich repeat kinase 2 gene (LRRK2) are one of the most frequent genetic causes of both familial and sporadic Parkinson's disease (PD). Mounting evidence has demonstrated pathological similarities between LRRK2-associated PD (LRRK2-PD) and sporadic PD, suggesting that LRRK2 is a potential disease modulator and a therapeutic target in PD. LRRK2 mutant knock-in (KI) mouse models display subtle alterations in pathological aspects that mirror early-stage PD, including increased susceptibility of nigrostriatal neurotransmission, development of motor and non-motor symptoms, mitochondrial and autophagy-lysosomal defects and synucleinopathies.
View Article and Find Full Text PDFMutations in leucine-rich repeat kinase 2 (LRRK2) and glucocerebrosidase (GBA) represent two most common genetic causes of Parkinson's disease (PD). Both genes are important in the autophagic-lysosomal pathway (ALP), defects of which are associated with α-synuclein (α-syn) accumulation. LRRK2 regulates macroautophagy via activation of the mitogen activated protein kinase/extracellular signal regulated protein kinase (MAPK/ERK) kinase (MEK) and the calcium-dependent adenosine monophosphate (AMP)-activated protein kinase (AMPK) pathways.
View Article and Find Full Text PDFParkinson's psychosis (PDP) describes a spectrum of symptoms that may arise in Parkinson's disease (PD) including visual hallucinations (VH). Imaging studies investigating the neural correlates of PDP have been inconsistent in their findings, due to differences in study design and limitations of scale. Here we use empirical Bayes harmonisation to pool together structural imaging data from multiple research groups into a large-scale mega-analysis, allowing us to identify cortical regions and networks involved in VH and their relation to receptor binding.
View Article and Find Full Text PDFIdentifying rare variants that contribute to complex diseases is challenging because of the low statistical power in current tests comparing cases with controls. Here, we propose a novel and powerful rare variants association test based on the deviation of the observed mutation burden of a gene in cases from a baseline predicted by a weighted recursive truncated negative-binomial regression (RUNNER) on genomic features available from public data. Simulation studies show that RUNNER is substantially more powerful than state-of-the-art rare variant association tests and has reasonable type 1 error rates even for stratified populations or in small samples.
View Article and Find Full Text PDFBackground Survivors of intracerebral hemorrhage (ICH) are at high risk for recurrent stroke, which is associated with blood pressure control. Because most recurrent stroke events occur within 12 to 18 months of the index ICH, rapid blood pressure control is likely to be crucial. We investigated the frequency and prognostic impact of uncontrolled short-term hypertension after ICH.
View Article and Find Full Text PDFAutophagy
January 2021
Autophagy
October 2021
Mitochondrial dysfunction causes energy deficiency and nigrostriatal neurodegeneration which is integral to the pathogenesis of Parkinson disease (PD). Clearance of defective mitochondria involves fission and ubiquitin-dependent degradation via mitophagy to maintain energy homeostasis. We hypothesize that LRRK2 (leucine-rich repeat kinase 2) mutation disrupts mitochondrial turnover causing accumulation of defective mitochondria in aging brain.
View Article and Find Full Text PDFBackground: Parkinson's disease (PD) is characterized by dopaminergic neuronal loss in the substantia nigra pars compacta and intracellular inclusions called Lewy bodies (LB). During the course of disease, misfolded α-synuclein, the major constituent of LB, spreads to different regions of the brain in a prion-like fashion, giving rise to successive non-motor and motor symptoms. Etiology is likely multifactorial, and involves interplay among aging, genetic susceptibility and environmental factors.
View Article and Find Full Text PDFParkinson disease (PD) is an age-related neurodegenerative disorder associated with misfolded SNCA/α-synuclein accumulation in brain. Impaired catabolism of SNCA potentiates formation of its toxic oligomers. (leucine-rich repeat kinase-2) mutations predispose to familial and sporadic PD.
View Article and Find Full Text PDFMutations that activate the LRRK2 (leucine-rich repeat protein kinase 2) protein kinase predispose to Parkinson's disease, suggesting that LRRK2 inhibitors might have therapeutic benefit. Recent work has revealed that LRRK2 phosphorylates a subgroup of 14 Rab proteins, including Rab10, at a specific residue located at the centre of its effector-binding switch-II motif. In the present study, we analyse the selectivity and sensitivity of polyclonal and monoclonal phospho-specific antibodies raised against nine different LRRK2-phosphorylated Rab proteins (Rab3A/3B/3C/3D, Rab5A/5B/5C, Rab8A/8B, Rab10, Rab12, Rab29[T71], Rab29[S72], Rab35 and Rab43).
View Article and Find Full Text PDFThe clinical diagnosis of neurodegenerative disorders based on phenotype is difficult in heterogeneous conditions with overlapping symptoms. It does not take into account the disease etiology or the highly variable clinical course even amongst patients diagnosed with the same disorder. The advent of next generation sequencing (NGS) has allowed for a system-wide, unbiased approach to identify all gene variants in the genome simultaneously.
View Article and Find Full Text PDFGenetic variants are implicated in the development of amyotrophic lateral sclerosis (ALS), but it is unclear whether the burden of rare variants in ALS genes has an effect on survival. We performed whole genome sequencing on 8 familial ALS (FALS) patients with superoxide dismutase 1 (SOD1) mutation and whole exome sequencing on 46 sporadic ALS (SALS) patients living in Hong Kong and found that 67% had at least 1 rare variant in the exons of 40 ALS genes; 22% had 2 or more. Patients with 2 or more rare variants had lower probability of survival than patients with 0 or 1 variant (p = 0.
View Article and Find Full Text PDFBackground: Antiplatelet resumption in patients who developed intracerebral hemorrhage (ICH) while on antiplatelet therapy (antiplatelet-related ICH) represents an important medical dilemma. We aimed to study the long-term cardiovascular outcomes of antiplatelet-related ICH survivors, and the risk of recurrent ICH with antiplatelet resumption.
Methods: This was an observational study of 109 antiplatelet-related ICH survivors.
Objective: In patients with TIA and ischemic stroke, we validated the total small vessel disease (SVD) score by determining its prognostic value for recurrent stroke.
Methods: Two independent prospective studies were conducted, one comprising predominantly Caucasian patients with TIA/ischemic stroke (Oxford Vascular Study [OXVASC]) and one predominantly Chinese patients with ischemic stroke (University of Hong Kong [HKU]). Cerebral MRI was performed and assessed for lacunes, microbleeds, white matter hyperintensities (WMH), and perivascular spaces (PVS).
Aging, genetics and environmental toxicity are important etiological factors in Parkinson's disease (PD). However, its pathogenesis remains unclear. A major obstacle is the lack of an appropriate experimental model which incorporates genetic susceptibility, aging and prolonged environmental toxicity.
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