Kyoungwon Baik

• clinical professor at Korea University

Background and purpose The co‐occurrence of amyloid‐β pathology in Parkinson's disease (PD) is common; however, the role of amyloid‐β deposition in motor prognosis remains elusive. This study aimed to investigate the association between striatal amyloid deposition, motor complications and motor prognosis in patients with PD. Methods Ninety‐six pat...

BACKGROUND As the percentage of the older population increases, the percentage of people with Parkinson’s disease (PD) also increases. People with PD experience a range of non-motor symptoms, including pain, constipation, dysphagia, sleep disturbances, and fatigue. Because PD is a chronic disease that requires lifelong management, people with PD ne...

Background As the percentage of the older population increases, it is accompanied by an increase in the prevalence of Parkinson disease (PD). People with PD experience a range of nonmotor symptoms, including pain, constipation, dysphagia, sleep disturbances, and fatigue. Improving self-care is necessary for people with PD because it is a chronic di...

Background and purpose Olfactory dysfunction or dysautonomia is one of the earliest prodromal nonmotor symptoms of Parkinson’s disease (PD). We aimed to investigate whether PD patients with dysautonomia and hyposmia at the de novo stage present different prognoses regarding PD dementia (PDD) conversion, motor complication development, and change in...

Background and Purpose Although dementia with Lewy bodies (DLB) is the second most common cause of neurodegenerative dementia, its clinical prevalence is low. We developed a short and easy-to-complete DLB screening questionnaire (DLBSQ) to raise diagnostic sensitivity in routine clinical settings. Methods A total of 501 participants were retrospec...

Background The pre‐clinical stage of dementia, mild cognitive impairment (MCI) carries various pathological pathways and respective prognoses. The two foremost causes of MCI and dementia that have been identified through autopsy diagnoses are Amyloid plaques and Lewy body, commonly referred to as Alzheimer’s disease (AD) and Lewy body disease (LBD)...

Background Diagnostic value of dopamine transporter (DAT) imaging and electroencephalography (EEG) biomarkers in Dementia with Lewy bodies (DLB) is well studied, but their relationships with clinical symptoms in DLB are not elusive. We investigated the association between DAT imaging and EEG biomarkers and clinical characteristics of DLB. Method W...

Background Early screening and prevention of dementia are widely discussed and studied in the current healthcare paradigm. However, about 70 percent of dementia diagnoses are categorized into Alzheimer’s disease (AD), neglecting the presence and influence of Lewy body. The present study aims to distinguish Alzheimer’s disease dementia (pure AD) and...

Background Although mixed pathologies are common in Alzheimer’s disease (AD) and dementia with Lewy bodies (DLB), effects of β‐amyloid and dopaminergic depletion on brain perfusion and clinical features have not been elucidated. Method In 99 patients with cognitive impairment due to AD and/or DLB and 32 control participants, ¹⁸ F‐Florbetaben (FBB)...

Background Minor hallucinations (mHs) and well‐structured major hallucinations (MHs) are common symptoms of Parkinson's disease (PD) psychosis. Objectives To investigate the resting‐state networks (RSNs) in patients with PD without hallucinations (PD‐nH), with mH (PD‐mH), and with MH (PD‐MH). Methods A total of 73 patients with PD were enrolled (...

Background and Objectives Neuropsychiatric symptoms (NPS) are closely associated with cognitive decline in patients with Parkinson’s disease (PD). We investigated which profiles of NPS are associated with the risk of dementia in PD with mild cognitive impairment (PD-MCI). Methods We retrospectively assessed 338 patients with PD-MCI from a single t...

Introduction Concomitant amyloid pathology is not uncommon and contributes to the clinical characteristics of Lewy body disease (LBD). We investigated the effect of amyloid on striatal ¹⁸ F-FP-CIT uptake patterns in LBD, including Parkinson's disease (PD) and dementia with Lewy bodies. Methods We enrolled 125 patients with LBD who underwent ¹⁸ F-f...

Nigrostriatal dopaminergic degeneration is a pathological hallmark of dementia with Lewy bodies (DLB). To identify the subregional dopamine transporter (DAT) uptake patterns that improve the diagnostic accuracy of DLB, we analyzed N-(3-[18F] fluoropropyl)-2β-carbomethoxy-3β-(4-iodophenyl)-nortropane (FP-CIT) PET in 51 patients with DLB, in 36 patie...

Background and purpose: This study aimed to determine the neuropsychological differences between patients with early-stage Alzheimer's disease (AD) and dementia with Lewy bodies (DLB) with a Clinical Dementia Rating (CDR) score of ≤1. Methods: We examined 168 patients with AD (126 with CDR score=0.5, 42 with CDR score=1) and 169 patients with DL...

Background: Dihydropyridines (DHPs) may have neuroprotective effects against Parkinson's disease (PD). Objective: This study investigated the effects of DHPs on nigrostriatal dopaminergic denervation and longitudinal motor and cognitive outcomes in PD. Methods: We classified 476 patients with drug-naive PD who had undergone dopamine transporte...

Background and purpose: To determine the imaging characteristics and cutoff value of 18F-florapronol (FC119S) quantitative analysis for detecting β-amyloid positivity and Alzheimer's disease (AD), we compared the findings of FC119S and 18F-florbetaben (FBB) positron- emission tomography (PET) in patients with cognitive impairment. Methods: We pr...

Background and purpose: We aimed to determine the effect of demographic factors on cortical thickness and brain glucose metabolism in healthy aging subjects. Methods: The following tests were performed on 71 subjects with normal cognition: neurological examination, 3-tesla magnetic resonance imaging, 18F-fluorodeoxyglucose positron-emission tomo...

Background: Cholesterol is vital in neuronal function; however, the influence of cholesterol levels on parkinsonism is unclear. To investigate the relationship between baseline total cholesterol (TC) levels, dopamine loss, and motor symptoms in drug-naïve Parkinson's disease (PD). Methods: This cross-sectional study enrolled 447 drug-naïve patie...

As existence of alpha synucleniopathy could affect progression of cognitive impairment in Alzheimer’s disease (AD), it’s very important to differentiate comorbidity of alpha synucleniopathy in AD to predict progression. To develop affordable EEG‐based discriminating machine‐learning(ML) algorithm for existence of alpha synucleniopathy, we explore d...

Background: Concomitant amyloid pathology contributes to the clinical heterogeneity of Lewy body diseases (LBDs). Objective: The objective of this study was to investigate the pattern and effect of amyloid accumulation on cognitive dysfunction in Parkinson's disease (PD) and dementia with Lewy bodies (DLB). Methods: We retrospectively assessed...

Neuromelanin (NM)-sensitive MRI using a magnetization transfer (MT)-prepared T1-weighted sequence has been suggested as a tool to visualize NM contents in the brain. In this study, a new NM-sensitive imaging method, sandwichNM, is proposed by utilizing the incidental MT effects of spatial saturation RF pulses in order to generate consistent high-qu...

We evaluated the patterns of quantitative electroencephalography (EEG) in patients with Alzheimer’s disease (AD), Lewy body disease (LBD), and mixed disease. Sixteen patients with AD, 38 with LBD, 20 with mixed disease, and 17 control participants were recruited and underwent EEG. The theta/alpha ratio and theta/beta ratio were measured. The relati...

Coexisting Alzheimer’s disease (AD) pathology is common in Parkinson’s disease (PD). However, the implications of genetic risk scores (GRS) for AD have not been elucidated in PD. In 413 de novo PD and 195 healthy controls from the Parkinson’s Progression Marker Initiative database, the effects of GRS for AD (GRS-AD) and PD (GRS-PD) on the risk of P...

Introduction This study investigated the relationship between white matter hyperintensities (WMHs), nigrostriatal dopamine deficits, and cognitive decline in patients with drug-naïve early-stage Parkinson's disease (PD). Method This cross-sectional study enrolled 309 non-demented patients with de novo PD who underwent [¹⁸F] N-(3-fluoropropyl)-2β-c...

Objective: This study aimed to determine the pattern of 18 F-fluorodeoxyglucose positron emission tomography (FDG-PET) related to postmortem Lewy body disease (LBD) pathology in clinical Alzheimer's disease (AD). Methods: FDG-PET scans were analyzed in 62 autopsy-confirmed patients and 110 controls in the Alzheimer's Disease Neuroimaging Initiat...

Background Premorbid educational attainment is a well-known proxy of reserve, not only with regard to cognition, but also to motor symptoms. Objective In the present study, we investigated the relationship between educational attainment and long-term motor prognosis in patients with Parkinson’s disease (PD). Methods We analyzed 466 patients with...

Background Focused ultrasound (FUS)-mediated blood–brain barrier (BBB) opening has shown efficacy in removal of amyloid plaque and improvement of cognitive functions in preclinical studies, but this is rarely reported in clinical studies. This study was conducted to evaluate the safety, feasibility and potential benefits of repeated extensive BBB o...

Background Although levodopa-induced dyskinesia-relevant white matter change has been evaluated, it is uncertain whether these changes may reflect the underlying predisposing conditions leading to the development of levodopa-induced dyskinesia.Objective To elucidate the role of white matter connectivity networks in the development of levodopa-induc...

Objectives To investigate the association between cognitive function at baseline and the progression of motor disability in Parkinson’s disease (PD). Methods We consecutively enrolled 257 drug-naïve patients with early-stage PD (follow-up > 2 years) who underwent a detailed neuropsychological test at initial assessment. Factor analysis was conduct...

Background: This study is aimed at investigating the safety and tolerability of the intra-arterial administration of autologous bone marrow-derived mesenchymal stem cells (BM-MSCs) in patients with multiple system atrophy- (MSA-) cerebellar type (MSA-C). Methods: This was a single-center, open-label phase I clinical trial in patients with MSA-C....

Background Neuropsychiatric symptoms (NPS) are the most common non-motor symptom in Parkinson’s disease (PD). Objective To investigate the association between the burden of NPS and motor prognosis in patients with PD. Methods We enrolled 329 drug-naïve patients with PD, who was non-demented and followed-up≥2 years after their first visit to the c...

Background and Objective To investigate whether dipeptidyl peptidase-4 inhibitors (DPP-4i) have beneficial effects on amyloid aggregation and longitudinal cognitive outcome in diabetic Alzheimer disease–related cognitive impairment (ADCI). Methods We retrospectively reviewed 282 patients with ADCI with positive 18F-florbetaben amyloid PETimages...

The pons is one of the earliest affected regions in patients with synucleinopathies. We aimed to investigate the diagnostic value of measuring pontine damage using diffusion tensor imaging (DTI) in these patients. We enrolled 49 patients with Parkinson's disease (PD), 16 patients with idiopathic rapid eye movement sleep behavior disorder (iRBD), 23...

Background Small vessel disease (SVD) magnetic resonance imaging (MRI) markers including deep and periventricular white matter hyperintensities (PWMH), lacunes, and microbleeds are frequently observed in Alzheimer’s disease (AD) and Lewy body disease (LBD), but their implication has not been clearly elucidated. Objective To investigate the implica...

To evaluate the implication of ¹⁸ F-fluorodeoxyglucose (FDG)- and dopamine transporter (DAT)-positron emission tomography (PET) in the diagnosis and clinical symptoms of dementia with Lewy bodies (DLB), 55 DLB patients and 49 controls underwent neuropsychological evaluation and FDG-, DAT-, and ¹⁸ F-Florbetaben (FBB) PET. DAT- and FDG-uptake and FDG...

Background: White matter hyperintensities, prevalent in patients with Parkinson's disease (PD), significantly affect parkinsonian motor symptoms. The objective of this study was to investigate the relationship between white matter hyperintensities and nigrostriatal dopamine depletion and their interaction or mediating effects on motor symptoms in...

The role of apolipoprotein E4 (APOE4) in the risk of Alzheimer's disease (AD) and Lewy body disease (LBD), and their relationship with β-amyloid deposition and cognitive dysfunction, remain unclear. Using amyloid and dopamine transporter imaging, we enrolled 126 controls and 208 patients with typical AD (pure AD and Lewy body variant of AD), AD wit...

Introduction: Lewy body-related pathology is commonly observed at autopsy in individuals with dementia, but in vivo biomarkers for α-synucleinopathy are lacking. Methods: Baseline cerebrospinal fluid (CSF) biomarkers, polygenic risk score (PRS) for Parkinson's disease (PRS-PD) and Alzheimer's disease (PRS-AD), longitudinal cognitive scores, and...

Serum uric acid, a natural antioxidant, may have a protective effect on the progression of Alzheimer's disease (AD). To investigate the effect of serum uric acid on longitudinal cognitive and brain metabolic changes, we utilized data on baseline serum uric acid levels, APOE genotyping, and longitudinal cognitive scores from the Alzheimer's Disease...

Dipeptidyl peptidase 4 (DPP4) inhibitors are widely used hypoglycaemic agents and improve glucose metabolism by enhancing the bioavailability of active glucagon-like peptide-1. In this study, we hypothesized that treatment with DPP4 inhibitors may have beneficial effects on nigrostriatal dopamine and longitudinal motor performance in diabetic patie...

Objective We evaluated disruption of the white matter (WM) network related with Alzheimer's disease (AD) and Lewy body disease (LBD), which includes Parkinson's disease and dementia with Lewy bodies. Methods We consecutively recruited 37 controls and 77 patients with AD‐related cognitive impairment (ADCI) and/or LBD‐related cognitive impairment (L...

Background To investigate the relationship between temporalis muscle thickness (TMT) at baseline as a surrogate marker for sarcopenia and long-term motor outcomes in patients with Parkinson’s disease (PD). Methods We enrolled 249 patients with drug-naïve early-stage PD (119 males and 130 females, follow-up > 3 years). Baseline TMT of each patient...

We investigated the efficacy of donepezil for mild cognitive impairment in Parkinson’s disease (PD-MCI). This was a prospective, non-randomized, open-label, two-arm study. Eighty PD-MCI patients were assigned to either a treatment or control group. The treatment group received donepezil for 48 weeks. The primary outcome measures were the Korean ver...

Background The different effects of white matter hyperintensity (WMH) severity and WMH-associated microstructural connectivity on cognition in the early stages of Parkinson’s disease (PD) have not been investigated. Objective To investigate the differential effect of WMH severity and WMH-associated microstructural connectivity on cognition in earl...

This study aimed to compare the patterns of β-amyloid deposition between patients with early-stage Alzheimer's disease (AD) with mild parkinsonism and those without parkinsonism. Sixty-one patients with early-stage AD (Clinical Dementia Rating [CDR], 0.5 or 1) who underwent ¹⁸F-florbetaben (¹⁸F-FBB) PET scans were enrolled. We performed comparative...

Background The relationship among amyloid-β (Aβ) deposition on amyloid positron emission tomography (PET), cortical metabolism on ¹⁸F-fluoro-2-deoxy-D-glucose (FDG)-PET, and clinical diagnosis has not been elucidated for both Alzheimer’s disease (AD) and Lewy body disease (LBD). Objective We investigated the patterns of cerebral metabolism accordi...

Objectives To determine whether vascular parkinsonism (VaP) patients with visually normal dopamine transporter (DAT) scans have presynaptic dopaminergic depletion. Methods We enrolled 23 VaP patients who had parkinsonism, relevant diffuse subcortical white matter hyperintensities (WMH), and visually normal DAT scans, 23 Parkinson's disease (PD) pa...

Background We investigated the effects of apolipoprotein E e4 allele ( APOE4 ) on the risk of Alzheimer’s disease (AD) and/or Lewy body disease (LBD), cerebral amyloid deposition, and cognitive dysfunction. Method We consecutively recruited 131 control subjects and 208 (110 non‐demented and 98 demented) patients with AD and/or LBD. Patients were c...

Objectives To investigate the potential of using changes in the plasma levels of trimethylamine N-oxide (TMAO), a gut microbiota-derived metabolite, as a biomarker in early Parkinson's disease (PD). Methods Plasma TMAO levels were measured in 85 patients with drug-naïve early-stage PD and 20 healthy controls. A linear mixed model was used to asses...

Background: The role of APOE4 in the risk of Alzheimer’s disease, Lewy body disease, and their mixed diseases have not been evaluated in antemortem patients. Also, the APOE4 effect on β-amyloid deposition and cognition, with consideration of both Alzheimer’s and Lewy body diseases, remains unclear. We aimed to determine the APOE4 effects on the ris...

Objective: To investigate the role of motor cerebellar connectivity in future development of freezing of gait, because it is a complex network disorder in Parkinson's disease (PD). Methods: We recruited 26 de novo patients with PD who experienced freezing of gait within 5 years from magnetic resonance imaging acquisition (vulnerable PD group), 6...

Background: This study aimed to investigate the safety and tolerability of the intra-arterial administration of autologous bone marrow-derived mesenchymal stem cells (BM-MSCs) in patients with multiple system atrophy (MSA)-cerebellar type (MSA-C). Methods: This was a single-center, open-label phase I clinical trial in patients with MSA-C. A three-s...

Objectives To investigate which baseline neuropsychological profile predicts the risk of developing dementia in early-stage Parkinson’s disease (PD). Methods We retrospectively reviewed detailed medical records of 350 drug-naïve patients with early-stage PD (follow-up > 3 years), who underwent a detailed neuropsychological test at initial assessme...

Objective As a major antioxidant, uric acid (UA) is known to be associated with the clinical progression of Parkinson’s disease (PD). This study investigated whether baseline UA levels are associated with the risk for levodopa‐induced dyskinesia (LID) in PD in a sex‐dependent manner. Methods We enrolled 152 patients with de novo PD (78 males and 7...

Objective: To investigate whether the burden of white matter hyperintensities (WMHs) is associated with the risk of developing levodopa-induced dyskinesia (LID) in Parkinson's disease (PD). Methods: According to the Clinical Research Center for Dementia of South Korea WMH visual rating scale, 336 patients with drug-naïve early stage PD (follow-u...

Objective: To investigate the relationship between the serum urate (UA) levels and patterns of striatal dopamine depletion in patients with de novo Parkinson's disease (PD). Methods: We enrolled 167 de novo PD patients who underwent 18 F-fluorinated N-3-fluoropropyl-2-beta-carboxymethoxy-3-beta-(4-iodophenyl) nortropane positron emission tomogra...

Hyposmia is common in Alzheimer's dementia (AD) and Parkinson's disease dementia (PDD). We evaluated the pattern of olfactory functional connectivity (FC) in AD and PDD to uncover neural correlates that are related to olfactory dysfunction. This study enrolled 57 patients with AD and PDD and 25 control subjects. Using a seed-based approach, we comp...

Background Neuropsychiatric symptoms impact the patients’ quality of life and caregivers’ burdens in Parkinson’s disease (PD). We aimed to investigate the effects of striatal dopaminergic depletion and brain atrophy on the neuropsychiatric symptoms of patients with PD. Methods Two hundred and seven patients with de novo drug-naïve PD underwent dop...

A 43-year-old male presented with daytime sleepiness at work and indifferent behavior like never before. Two weeks prior to hospital admission, he had episodic memory loss with well preserved remote memory. Brain MRI showed a dural arteriovenous fistula (DAVF) in the right lateral transverse sinus with a bilateral thalamic venous infarction. Cerebr...

Parkinson's disease (PD) is characterized by degenerative changes of nigral dopamine neurons, resulting in the dopaminergic denervation of the striatum. Resting state networks studies have demonstrated that dopamine modulates distinct network connectivity patterns in both a linear and a nonlinear fashion, but quantitative analyses of dopamine-depen...