Association between migraine and the risk of vascular dementia: A nationwide longitudinal study in South Korea

OBJECTIVE

We aimed to examine the potential association between migraine and vascular dementia (VaD) using a nationwide population database.

BACKGROUND

Migraine and VaD showed similar structural and functional changes in pathophysiology process and shared common risk factors, However, whether migraine prevalence increases VaD incidence remains controversial.

METHODS

This retrospective population-based cohort study used the medical records from the Korean National Health Insurance System database. Migraine (G43) was defined by using the Tenth Revision of the International Classification of Diseases code. More than two migraine diagnoses at least 3 months apart were defined as "chronic migraine". Cox proportional hazards model estimated hazard ratios (HRs) of VaD for group comparisons.

RESULTS

We included 212,836 patients with migraine and 5,863,348 individuals without migraine. During 10 years of follow-up, 3,914 (1.8%) and 60,258 (1.0%) patients with and without migraine, respectively, were newly diagnosed with VaD. After adjustment, patients with migraine showed a 1.21-fold higher risk of VaD than those without migraine (HR = 1.21; 95% confidence interval (CI): 1.17-1.25). Patients with chronic migraine showed a higher cumulative incidence of VaD than those with episodic migraine. The adjusted HR for the VaD incidence with migraine was higher in: (1) patients aged <65 years; (2) women; (3) patients without hypertension, diabetes, or atrial fibrillation; and (4) non-smokers.

CONCLUSION

Migraine is associated with an increased risk of VaD, particularly in chronic migraine patients. Incidence of VaD in the setting of migraine may have distinct pathophysiology from that of VaD with traditional cardiovascular risks.

The association between migraine and Parkinson's disease: a nationwide cohort study

OBJECTIVES

Clinical studies have suggested an association between migraine and the occurrence of Parkinson's disease (PD). However, it is unknown whether migraine affects PD risk. We aimed to investigate the incidence of PD in patients with migraine and to determine the risk factors affecting the association between migraine and PD incidence.

METHODS

Using the Korean National Health Insurance System database (2002-2019), we enrolled all Koreans aged ≥40 years who participated in the national health screening program in 2009. International Classification of Diseases (10th revision) diagnostic codes and Rare Incurable Diseases System diagnostic codes were used to define patients with migraine (within 12 months of enrollment) and newly diagnosed PD.

RESULTS

We included 214,193 patients with migraine and 5,879,711 individuals without migraine. During 9.1 years of follow-up (55,435,626 person-years), 1,973 (0.92%) and 30,664 (0.52%) individuals with and without migraine, respectively, were newly diagnosed with PD. Following covariate adjustment, patients with migraine showed a 1.35-fold higher PD risk than individuals without migraine. The incidence of PD was not significantly different between patients with migraine with aura and those without aura. In males with migraine, underlying dyslipidemia increased the risk of PD (p=0.012). In contrast, among females with migraine, younger age (<65 years) increased the risk of PD (p=0.038).

CONCLUSIONS

Patients with migraine were more likely to develop PD than individuals without migraine. Preventive management of underlying comorbidities and chronic migraine may affect the incidence of PD in these patients. Future prospective randomized clinical trials are warranted to clarify this association.

Image-based Gait Spatiotemporal Parameters Estimation using a Single Camera and CNN-Transformer Hybrid Network

Vision-based gait analysis can play an important role in the remote and continuous monitoring of the elderly's health conditions. However, most vision-based approaches compute gait spatiotemporal parameters using human pose information and provide average parameters. This study aimed to propose a straightforward method for stride-by-stride gait spatiotemporal parameters estimation. A total of 160 elderly individuals participated in this study. Data were gathered with a GAITRite system and a mobile camera simultaneously. Three deep learning networks were trained with a few RGB frames as input and a continuous 1D signal containing both spatial and temporal gait parameters as output. The trained networks estimated the stride lengths with correlations of 0.938 and more and detected gait events with F1-scores of 0.914 and more.Clinical relevance- The proposed method showed excellent agreements with the GAITRite system in analyzing spatiotemporal gait parameters. Our approach can be applied to monitor the elderly's health conditions based on their gait parameters for early diagnosis of diseases, proper treatment, and timely intervention.

Association between migraine and Alzheimer's disease: a nationwide cohort study

Background and objective

Migraine is a common chronic neurological disease characterized by pulsating headaches, photophobia, phonophobia, nausea, and vomiting. The prevalence of dementia in individuals aged over 65 years in Korea is more than 10%, and Alzheimer's disease (AD) dementia accounts for most cases. Although these two neurological diseases account for a large portion of the medical burden in Korea, few studies have examined the relationship between the two diseases. Therefore, this study investigated the incidence and risk of AD in patients with migraines.

Methods

We retrospectively collected nationwide data from a national health insurance claims database governed by Korea's National Health Insurance Service. Among Koreans in the 2009 record, patients with migraine were identified according to the International Classification of Diseases, 10th revision (ICD-10) code G43. First, we screened the database for participants aged over 40 years. Individuals diagnosed with migraine at least twice over more than 3 months in a year were considered to have chronic migraine in this study. Further, all participants with an AD diagnosis (ICD-10 code: Alzheimer's disease F00, G30) were investigated for AD dementia development. The primary endpoint was AD development.

Results

The overall incidence of AD dementia was higher in individuals with a history of migraine than in those with no migraine history (8.0 per 1,000 person-years vs. 4.1 per 1,000 person-years). The risk of AD dementia was higher in individuals diagnosed with migraine (hazard ratio = 1.37 [95% confidence interval, 1.35-1.39]) than in the control group after adjustments for age and sex. Individuals with chronic migraine had a higher incidence of AD dementia than those with episodic migraine. Younger age (<65 years old) was associated with an increased risk of AD dementia compared to older age (≥65  years old). Higher body mass index (BMI) (≥25 kg/m²) was also associated with an increased risk of AD dementia compared to lower BMI (<25 kg/m²) (p < 0.001).

Conclusion

Our results suggest that individuals with a migraine history are more susceptible to AD than those without a migraine history. Additionally, these associations were more significant in younger and obese individuals with migraine than in individuals without migraine.

Nigrosome 1 visibility and its association with nigrostriatal dopaminergic loss in Parkinson's disease

BACKGROUND

Nigrosome 1 (NG1), a small cluster of dopaminergic cells in the substantia nigra and visible in the susceptibility map weighted MR image (SMwI), is severely affected in Parkinson's disease (PD). However, the degree of nigrostriatal degeneration according to the visibility of NG1 has not yet been well elucidated.

METHODS

We consecutively recruited 138 PD and 78 non-neurodegenerative disease (non-ND) patients, who underwent both ¹⁸ F-FP-CIT PET and SMwI. Three neurologists and one radiologist evaluated the visibility of NG1 in SMwI. The participants were thereby grouped into the visible, intermediate, and non-visible groups. Nigrostriatal dopaminergic input was calculated using the specific binding ratio (SBR) of the ¹⁸ F-FP-CIT PET. We determined the threshold of regional SBR for discriminating NG1 visibility and the probability for NG1 visibility according to regional SBR.

RESULTS

Visual rating of NG1 showed excellent interobserver agreements as well as high sensitivity and specificity to differentiate the PD group from the non-ND group. NG1 was visible in seven patients (5.1%) in the PD group, who had relatively short disease duration or less severe loss of striatal dopamine. The threshold of putaminal SBR reduction on the more affected side for the disappearance of NG1 was 45.5%, and the probability for NG1 visibility dropped to 50% after the reduction of putaminal SBR to 41% from the normal mean.

CONCLUSIONS

Almost half loss of nigrostriatal dopaminergic input is required to dissipate the hyperintensity of NG1 on SMwI, suggesting its utility in diagnosing PD only after the onset of the motor symptoms.

Dynamic network model reveals distinct tau spreading patterns in early- and late-onset Alzheimer disease

BACKGROUND

The clinical features of Alzheimer's disease (AD) vary substantially depending on whether the onset of cognitive deficits is early or late. The amount and distribution patterns of tau pathology are thought to play a key role in the clinical characteristics of AD, which spreads throughout the large-scale brain network. Here, we describe the differences between tau-spreading processes in early- and late-onset symptomatic individuals on the AD spectrum.

METHODS

We divided 74 cognitively unimpaired (CU) and 68 cognitively impaired (CI) patients receiving 18F-flortaucipir positron emission tomography scans into two groups by age and age at onset. Members of each group were arranged in a pseudo-longitudinal order based on baseline tau pathology severity, and potential interregional tau-spreading pathways were defined following the order using longitudinal tau uptake. We detected a multilayer community structure through consecutive tau-spreading networks to identify spatio-temporal changes in the propagation hubs.

RESULTS

In each group, ordered tau-spreading networks revealed the stage-dependent dynamics of tau propagation, supporting distinct tau accumulation patterns. In the young CU/early-onset CI group, tau appears to spread through a combination of three independent communities with partially overlapped territories, whose specific driving regions were the basal temporal regions, left medial and lateral temporal regions, and left parietal regions. For the old CU/late-onset CI group, however, continuation of major communities occurs in line with the appearance of hub regions in the order of bilateral entorhinal cortices, parahippocampal and fusiform gyri, and lateral temporal regions.

CONCLUSION

Longitudinal tau propagation depicts distinct spreading pathways of the early- and late-onset AD spectrum characterized by the specific location and appearance period of several hub regions that dominantly provide tau.

Movement Disorders Associated With Cerebral Artery Stenosis: A Nationwide Study

Background

Studies of secondary movement disorder (MD) caused by cerebrovascular diseases have primarily focused on post-stroke MD. However, MD can also result from cerebral artery stenosis (CAS) without clinical manifestations of stroke. In this study, we aimed to investigate the clinical characteristics of MD associated with CAS.

Materials and Methods

A nationwide multicenter retrospective analysis was performed based on the data from patients with CAS-associated MDs from 16 MD specialized clinics in South Korea, available between January 1999 and September 2019. CAS was defined as the >50% luminal stenosis of the major cerebral arteries. The association between MD and CAS was determined by MD specialists using pre-defined clinical criteria. The collected clinical information included baseline demographics, features of MD, characteristics of CAS, treatment, and MD outcomes. Statistical analyses were performed to identify factors associated with the MD outcomes.

Results

The data from a total of 81 patients with CAS-associated MD were analyzed. The mean age of MD onset was 60.5 ± 19.7 years. Chorea was the most common MD (57%), followed by tremor/limb-shaking, myoclonus, and dystonia. Atherosclerosis was the most common etiology of CAS (78%), with the remaining cases attributed to moyamoya disease (MMD). Relative to patients with atherosclerosis, those with MMD developed MD at a younger age (p < 0.001) and had a more chronic mode of onset (p = 0.001) and less acute ischemic lesion (p = 0.021). Eight patients who underwent surgical treatment for CAS showed positive outcomes. Patients with acute MD onset had a better outcome than those with subacute-to-chronic MD onset (p = 0.008).

Conclusions

This study highlights the spectrum of CAS-associated with MD across the country. A progressive, age-dependent functional neuronal modulation in the basal ganglia due to CAS may underlie this condition.

Annual Trends in the Incidence and Prevalence of Alzheimer's Disease in South Korea: A Nationwide Cohort Study

Despite recent studies suggesting a declining incidence and prevalence of dementia on a global scale, epidemiologic results with respect to Alzheimer's disease (AD) are lacking due to the methodological limitations inherent to conducting large-scale cohort investigations of this topic. The aim of the current study was to investigate the incidence and prevalence of AD in Korea. We conducted a secondary analysis within the National Health Insurance System (NHIS) database, a unique resource that reports medical information for the entire Korean population. AD diagnoses as well as evaluations of vascular risks were defined based on International Statistical Classification of Diseases (ICD-10) codes along with prescription records. The cut-off age for diagnosing AD was defined as the age of the patient's highest Youden index. In this study, the incidence and prevalence of AD in the Korean population aged 40 years or older showed an overall increase between 2006 and 2015. Although both older and younger age groups showed an increase in the incidence and prevalence of AD, the highest increase was observed in older age groups. Based on the highest Youden's index value (sensitivity + specificity – 1), the cut-off value for the diagnosis of AD was 69 years with an area under the curve (AUC) of 0.92. We found that the incidence of AD was higher in individuals with underlying vascular risks. However, in recent years, the prevalence of AD was conversely found to be lower in individuals with hypertension or dyslipidemia. Despite efforts toward reducing the number of AD cases through educational, policy, and various public health and preventive medicine interventions, the incidence and prevalence of AD continues to grow in Korea. Efforts aimed at early diagnosis and the modification of underlying risks may be critical to reducing the socioeconomic burden of AD.

Reliability and Validity of the Subjective Cognitive Complaints Questionnaire for Parkinson’s Disease (SCCQ-PD)

Background and Purpose

Subjective cognitive complaints (SCCs) are gaining attention as a self-perceived symptom for cognitive impairment in patients with Parkinson’s disease (PD), but there are few suitable tools for assessing SCCs in PD. This study aimed to develop and validate a questionnaire for assessing SCCs in PD, called the Subjective Cognitive Complaints Questionnaire for Parkinson’s Disease (SCCQ-PD).

Methods

The SCCQ-PD consists of 12 yes/no questions on subjective cognitive function, and the questionnaire was completed by patients with PD (score-P) and their caregivers (score-C). The cognitive function of patients was examined using comprehensive neuropsychological tests.

Results

This study included 73 patients (38 cognitively normal, 25 with mild cognitive impairment [MCI], and 10 demented) and their caregivers. Score-P and score-C had excellent reliability (Kuder-Richardson formula 20 coefficients of 0.893 and 0.931, respectively), and the scores exhibited a strong intercorrelation. Both score-P and score-C were negatively correlated with cognitive performance, and both were excellent in discriminating demented patients from those with normal cognition or MCI (areas under the receiver operating characteristic curve of 0.83 and 0.88, respectively).

Conclusions

The SCCQ-PD is a reliable tool for assessing SCCs in patients with PD. SCCs measured using the SCCQ-PD are correlated with objective cognitive decline and useful for discriminating demented patients from nondemented patients.

Temporal trajectory of biofluid markers in Parkinson's disease

Full dynamics of biofluid biomarkers have been unknown in patients with Parkinson’s disease (PD). Using data from 396 PD patients and 182 controls in the Parkinson's Progression Markers Initiative (PPMI) database, we estimated long-term temporal trajectories of CSF α-synuclein (α-syn), amyloid-β (Aβ), total tau (t-tau), phosphorylated tau (p-tau) and serum neurofilament light chain (NfL) by integrating function between the baseline levels and annual changes. At baseline, PD patients showed lower CSF α-syn, Aβ, t-tau and p-tau levels than those of the controls. In all PD patients, CSF α-syn and Aβ decreased in a negative exponential pattern before the onset of motor symptoms, whereas CSF t-tau and p-tau, and serum NfL increased. Patients with cognitive impairment exhibited faster decline of Aβ and α-syn and faster rise of t-tau, p-tau and NfL, when compared to those without. Similarly, low Aβ group showed earlier decline of α-syn, faster rise of t-tau, p-tau and NfL, and faster decline of cognitive performances, when compared to high Aβ group. Our results suggest that longitudinal changes in biomarkers can be influenced by cognitive impairment and Aβ burden at baseline. PD patients with Aβ pathology may be associated with early appearance of α-synuclein pathology, rapid progression of axonal degeneration and neurodegeneration, and consequently greater cognitive decline.

Risks and Prognoses of Alzheimer's Disease and Vascular Dementia in Patients With Insomnia: A Nationwide Population-Based Study

This study aimed to investigate the risk and prognosis of Alzheimer's disease (AD) and vascular dementia (VaD) in patients with insomnia using the National Health Insurance Service database covering the entire population of the Republic of Korea from 2007 to 2014. In total, 2,796,871 patients aged 40 years or older with insomnia were enrolled, and 5,593,742 controls were matched using a Greedy digit match algorithm. Mortality and the rate of admission to a long-term care facility were estimated using multivariable Cox analysis. Of all patients with insomnia, 138,270 (4.94%) and 26,706 (0.96%) were newly diagnosed with AD and VaD, respectively. The incidence rate ratios for AD and VaD were 1.73 and 2.10, respectively, in patients with insomnia compared with those without. Higher mortality rates and long-term care facility admission rates were also observed in patients with dementia in the insomnia group. Known cardiovascular risk factors showed interactions with the effects of insomnia on the risk of AD and VaD. However, the effects of insomnia on the incidence of AD and VaD were consistent between the groups with and without cardiovascular risk factors. Insomnia is a medically modifiable and policy-accessible risk factor and prognostic marker of AD and VaD.

Association between physical activity and conversion from mild cognitive impairment to dementia

Background

Physical activity has been suggested to prevent the conversion of mild cognitive impairment (MCI) to dementia in patients. We investigated the association between the continuance and regularity of physical activity and the risk of developing dementia in patients with MCI.

Methods

We analyzed 6-year followed up data for 247,149 individuals in the National Health Insurance Service (NHIS) cohort of Korea who were enrolled between January 1, 2009, and December 31, 2015. The patients were divided into four groups: those who did not engage in physical activity consistently (Never-PA group), those who initiated physical activity (Initiation-PA group), those who ceased physical activity (Withdrawal-PA group), and those who performed physical activity consistently (Maintenance-PA group). We also divided the patients into two groups: those who engaged in physical activity irregularly (Irregular-PA) and those who undertook physical activity regularly (Regular-PA).

Results

When the risk for the Never-PA group was set as the benchmark (ref = 1), the Maintenance-PA group had the lowest incidence of dementia of the Alzheimer type (DAT) compared to the other groups (HR = 0.82, 95% CI 0.79–0.86). The DAT risk of the Initiation-PA group (HR = 0.89, 95% CI 0.85–0.93) was lower than the Never-PA group. In addition, compared to the Irregular-PA group, the Regular-PA group had a 15% reduced risk for developing DAT.

Conclusions

Although no causal inference could be made, continued regular physical activity in patients with MCI is associated with a protective effect against developing DAT. Moreover, ceasing physical activity could halt this protective effect.

Supplementary information

Supplementary information accompanies this paper at 10.1186/s13195-020-00707-1.

Effect of APOE ε4 genotype on amyloid-β and tau accumulation in Alzheimer's disease

Background

To assess the effects of apolipoprotein E (ApoE) ε4 genotype on amyloid-β (Aβ) and tau burden and their longitudinal changes in Alzheimer’s disease (AD) spectrum.

Methods

Among 272 individuals who underwent PET scans (¹⁸F-florbetaben for Aβ and ¹⁸F-flortaucipir for tau) and ApoE genotyping, 187 individuals completed 2-year follow-up PET scans. After correcting for the partial volume effect, we compared the standardized uptake value ratio (SUVR) for Aβ and tau burden between the ε4+ and ε4− groups. By using a linear mixed-effect model, we measured changes in SUVR in the ApoE ε4+ and ε4− groups.

Results

The ε4+ group showed greater baseline Aβ burden in the diffuse cortical regions and greater tau burden in the lateral, and medial temporal, cingulate, and insula cortices. Tau accumulation rate was higher in the parietal, occipital, lateral, and medial temporal cortices in the ε4+ group. In Aβ+ individuals, baseline tau burden was greater in the medial temporal cortex, while Aβ burden was conversely greater in the ε4− group. Tau accumulation rate was higher in the ε4+ group in a small region in the lateral temporal cortex. The effect of ApoE ε4 on enhanced tau accumulation persisted even after adjusting for the global cortical Aβ burden.

Conclusions

Progressive tau accumulation may be more prominent in ε4 carriers, particularly in the medial and lateral temporal cortices. ApoE ε4 allele has differential effects on the Aβ burden depending on the existing amyloidosis and may enhance vulnerability to progressive tau accumulation in the AD spectrum independent of Aβ.

Supplementary information

Supplementary information accompanies this paper at 10.1186/s13195-020-00710-6.

Principal components of tau positron emission tomography and longitudinal tau accumulation in Alzheimer's disease

Background

We aimed to investigate the clinical correlates of principal components (PCs) of tau positron emission tomography (PET) and their predictability for longitudinal changes in tau accumulation in Alzheimer’s disease (AD).

Methods

We enrolled 272 participants who underwent two PET scans [¹⁸F-flortaucipir for tau and ¹⁸F-florbetaben for amyloid-β (Aβ)], brain magnetic resonance imaging, and neuropsychological tests as baseline assessments. Among them, 187 participants underwent the same follow-up assessments after an average of 2 years. Using Aβ-positive AD dementia-specific PCs obtained from the baseline scans of 56 Aβ-positive patients with AD dementia, we determined the expression of the first two PCs (PC1 and PC2) in all participants. We assessed the correlation of PC expression with baseline clinical characteristics and tau accumulation rates. Moreover, we investigated the predictability of PCs for the longitudinal tau accumulation in training and test sets.

Results

PC1 corresponded to the tau distribution pattern in AD, while the two PC2 extremes reflected the parietal or temporal predominance of tau distribution. PC1 expression increased with tau burden and decreased with cognitive impairment, while PC2 expression decreased with advanced age and visuospatial and attention function deterioration. The tau accumulation rate was positively correlated with PC1 expression (greater tau burden) and negatively correlated with PC2 expression (temporal predominance). A regression model using both PCs could predict longitudinal changes in the tau burden (intraclass correlation coefficient = 0.775, R² = 0.456 in test set).

Conclusions

PC analysis of tau PET could be useful for evaluating disease progression, characterizing the tau distribution pattern, and predicting longitudinal tau accumulation.

Effect of A/T/N imaging biomarkers on impaired odor identification in Alzheimer's disease

Odor identification ability may serve as an important diagnostic biomarker in Alzheimer’s disease (AD). The aim of the study is to investigate the contribution of A/T/N neuroimaging biomarkers to impaired odor identification ability in the Alzheimer’s disease spectrum. In 127 participants, we compared A/T/N neuroimaging biomarkers between normosmia and hyposmia groups, and performed correlation analysis between the biomarkers and Cross-Cultural Smell Identification Test (CCSIT) scores. Additionally, path analysis for odor identification ability was performed using cognitive function as a mediator. In between-group comparison, individuals with hyposmia showed higher frequency of amyloid-β (Aβ) positivity, and lower neuropsychological test performance than those with normosmia. After correction for covariates including total cognition scores, there was no difference in the Aβ or tau burden between the normosmia and hyposmia groups, and no correlation between CCSIT scores and Aβ or tau burden. Meanwhile, cortical volumes in the lateral and medial temporal cortices were smaller in the hyposmia group and decreased with the worsening of CCSIT scores. Path analysis showed that only neurodegeneration had a direct effect on odor identification, while Aβ and tau burden contributed to odor identification with the mediation of cognition. In the Alzheimer’s disease spectrum, impaired odor identification ability may be attributable to neurodegeneration rather than the direct effect of Aβ or tau burden.

Temporal trajectories of in vivo tau and amyloid-β accumulation in Alzheimer's disease

PURPOSE

To investigate the temporal trajectories of tau and amyloid-β (Aβ) accumulation in Alzheimer's disease (AD) by using the longitudinal positron emission tomography (PET) study.

METHODS

A total of 132 participants, who were healthy volunteers or recruited in our memory disorder clinic, completed longitudinal ¹⁸F-flortaucipir and ¹⁸F-florbetaben PET studies with a mean follow-up time of 2 years. Referencing baseline data from 57 Aβ-negative cognitively unimpaired individuals, Z-scores and their annual changes were calculated with the global cortical or regional standardized uptake value ratios measured at baseline and follow-up after correcting for partial volume effect. The temporal trajectories of tau and Aβ burden as a function of time were obtained based on the spline models from the annual changes and baseline Z-score data.

RESULTS

Tau burden first emerged in the Braak's stage I-II regions, followed by stage III-IV regions, and finally in the stage V-VI regions. Time intervals between two time points at which Z-score curves rose above 2 were 17.3 years for the stages I-II and III-IV and 15.2 years for the stages III-IV and V-VI. Rise in the tau curve for stages I-II preceded that for global cortical Aβ, while the rise in global cortical Aβ curve preceded that for global cortical tau. Aβ accumulation rate was attenuated during the surge in tau burden in the global cortex and reached a plateau.

CONCLUSION

Sequential appearance of Aβ and tau accumulation supports a hypothetical dynamic biomarker model and Braak's hierarchical tau spreading model in AD.

Customized FreeSurfer-based brain atlas for diffeomorphic anatomical registration through exponentiated lie algebra tool

OBJECTIVE

Digital brain template and atlas designed for a specific group provide advantages for the analysis and interpretation of neuroimaging data, but require a significant workload for development. We developed a simple method to create customized brain atlas for diffeomorphic anatomical registration through exponentiated lie algebra (DARTEL) tool using FreeSurfer-generated volume-of-interest (FSVOI) images and validated.

METHODS

¹⁸F-florbetaben positron emission tomography (PET) and magnetic resonance (MR) imaging data were obtained from 248 participants of Alzheimer's disease spectrum (from cognitively normal to Alzheimer's disease dementia). To create a customized atlas, MR images of 84 amyloid-negative controls were first processed with FreeSurfer to obtain individual FSVOI and with DARTEL tool to create DARTEL template. Individual FSVOI images were spatially normalized, and each voxel was then labelled with a VOI label with maximum probability. Using these template and atlas, all images were normalized, and the regional standardized uptake value ratios (SUVR) were measured.

RESULTS

¹⁸F-florbetaben SUVR values measured with customized atlas showed excellent one-to-one correlation with SUVR measured with individual FSVOI in all regions, and thereby showed almost identical between-group comparison results and outperformed the classic methods.

CONCLUSIONS

Customized FreeSurfer-based brain atlas for DARTEL tool is easy to create and useful for the analysis of PET and MR images with high adaptability and reliability for broad research purposes.

18F-AV-1451 binds to motor-related subcortical gray and white matter in corticobasal syndrome

OBJECTIVE

To investigate tau distribution in patients with corticobasal syndrome (CBS) using ¹⁸F-AV-1451 PET.

METHODS

Six consecutively recruited patients with CBS and 20 age-matched healthy controls underwent 2 PET scans with ¹⁸F-AV-1451 (for tau) and ¹⁸F-florbetaben (for β-amyloid). We compared standardized uptake value ratio maps of the ¹⁸F-AV-1451 PET images between the patients with CBS and controls.

RESULTS

Compared to controls, patients with CBS exhibited asymmetrically increased ¹⁸F-AV-1451 binding in the putamen, globus pallidus, and thalamus contralateral to the clinically more affected side and in the ipsilateral globus pallidus and dentate nucleus. Voxel-based comparison additionally showed asymmetrically increased ¹⁸F-AV-1451 binding in the focal regions of the precentral gray and white matter and in the midbrain, predominantly in the contralateral side. ¹⁸F-AV-1451 binding in the precentral white matter correlated with motor severity.

CONCLUSIONS

¹⁸F-AV-1451 asymmetrically binds to motor-related subcortical gray and white matter structures in patients with CBS. This pattern corresponds to tau pathology distribution in postmortem studies, and motor deficit in patients with CBS may be associated with tau accumulation predominantly in the subcortical white matter underlying the motor cortex, leading to disruptions in motor-related networks.

A Patient with Recurrent Dyskinesia and Hyperpyrexia Syndrome

Dyskinesia hyperpyrexia syndrome is a rare medical emergency in Parkinson's disease. It is characterized by continuous dyskinesia associated with hyperthermia, rhabdomyolysis, and alteration of the mental state. We present the case of a 74-year-old woman who presented with recurrent dyskinesia hyperpyrexia syndrome. Although some provocation factors and clinical manifestations seem to be shared with parkinsonism hyperpyrexia syndrome, a clear distinction in management should be considered.

Dural Arteriovenous Fistula Manifested as Rapid Progressive Dementia Successfully Treated by Endovascular Embolization Only

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. Cerebral angiography confirmed a right transverse sigmoid dural arteriovenous fistula with a feeding artery of the right occipital artery and left posterior meningeal artery. The DAVF was completely eliminated through multiple endovascular interventions. Recently, endovascular treatment has become one of the main therapeutic options to obliterate a fistulous site, which has led to a rapid diagnostic approach and management of DAVFs with high curative rates. We report a rare case of posterior fossa located at a dural arteriovenous fistula that caused rapid progressive dementia and was successfully eliminated through only endovascular treatment.

Presence or absence of lipopolysaccharide O antigens affects type III secretion by Pseudomonas aeruginosa

Pseudomonas aeruginosa is one of the major causative agents of mortality and morbidity in hospitalized patients due to a multiplicity of virulence factors associated with both chronic and acute infections. Acute P. aeruginosa infection is primarily mediated by planktonic bacteria expressing the type III secretion system (TTSS), a surface-attached needle-like complex that injects cytotoxins directly into eukaryotic cells, causing cellular damage. Lipopolysaccharide (LPS) is the principal surface-associated virulence factor of P. aeruginosa. This molecule is known to undergo structural modification (primarily alterations in the A- and B-band O antigen) in response to changes in the mode of life (e.g., from biofilm to planktonic). Given that LPS exhibits structural plasticity, we hypothesized that the presence of LPS lacking O antigen would facilitate eukaryotic intoxication and that a correlation between the LPS O-antigen serotype and TTSS-mediated cytotoxicity would exist. Therefore, strain PAO1 (A+ B+ O-antigen serotype) and isogenic mutants with specific O-antigen defects (A+ B-, A- B+, and A- B-) were examined for TTSS expression and cytotoxicity. A strong association existed in vitro between the absence of the large, structured B-band O antigen and increased cytotoxicity of these strains. In vivo, all three LPS mutant strains demonstrated significantly increased lung injury compared to PAO1. Clinical strains lacking the B-band O antigen also demonstrated increased TTSS secretion. These results suggest the existence of a cooperative association between LPS O-antigen structure and the TTSS in both laboratory and clinical isolates of P. aeruginosa.

Metabolism of dimethyl-4,4'-dimethoxy-5,6,5',6'-dimethylene dioxybiphenyl-2,2'-dicarboxylate (DDB) by human liver microsomes: characterization of metabolic pathways and of cytochrome P450 isoforms involved

Metabolic fate of DDB and identification of P450 isozymes involved in the metabolism of DDB were investigated in human liver microsomes. DDB was rapidly metabolized to five different metabolites, and the structures of each metabolite were characterized based on UV, mass, and NMR spectral analyses. The major metabolic pathways of DDB in human liver microsomes were identified as O-demethylation of the carboxymethyl moiety (M4) and demethylenation of the methylenedioxyphenyl group (M2). The intramolecular lactonization between the hydroxyl group at the C6 and carboxymethyl group at the C2' of M2 resulted in the generation of M5, which was either hydrolyzed to its hydrolyzed derivative (M1) or further metabolized to the O-demethylated derivative (M3). The interconversion of M1, M2, and M5 took place nonenzymatically depending on the solvent condition. M5 was predominantly detected at the acidic condition, whereas M1 was preferentially detected at the basic environment. Cytochrome P450 (P450) isoform(s) involved in the metabolism of DDB was identified using several in vitro approaches. Chemical inhibition using isoform-selective P450 inhibitors, correlation of DDB metabolites formation with several isoform-specific P450 activities in a panel of liver microsomes, metabolism by microsomes derived from P450 cDNA-expressed B-lymphoblastoid cells, and immunoinhibition by isoform-specific anti-P450 antibodies collectively indicated that CYP1A2, CYP2C9, and CYP3A4 are responsible for the metabolism of DDB. O-Dealkylation of the carboxymethyl group was preferentially catalyzed by CYP1A2, whereas demethylenation of the methylenedioxyphenyl moiety was catalyzed by CYP3A4 and CYP2C9.

Antitumor activity and nephrotoxicity of a novel platinum complex, [1,3-bis(diphenylphosphino)propane](trans-1-dach)platinum(I I) dinitrate

We have developed a new class of platinum complex [Pt(trans-l-dach)(1,3-bis(phosphino)propane)] dinitrate (KHPC-001) with potent antitumor activity and low nephrotoxicity, confirmed in vitro and compared in vivo with cisplatin, KHPC-001 or cisplatin was intraperitoneally injected on days 1, 5, and 9 into P388-bearing mice and the antitumor effects were compared. In vitro cytotoxicity, Pt accumulation, and DNA cross-link index were measured in P388 and LLC-PK1 cells after treatment with KHPC-001 or cisplatin. Twenty mg/kg (below one-tenth of LD50) of KHPC-001 had stronger antitumor effects than 2 mg/kg (about one-fifth of LD50) of cisplatin and cured 2 out of 6 mice without any toxicity. While the cytotoxicity of KHPC-001 and cisplatin were similar on P388 mouse leukemia cells, this new compound was much less cytotoxic to a kidney-derived line, LLC-PK1. This lower toxicity on the kidney cells was based on its low accumulation, causing less DNA crosslinking. KHPC-001 is a unique third-generation platinum complex with potent antitumor activity and low nephrotoxicity.