Ventral Anterior Cingulate Atrophy as a Predisposing Factor for Transient Global Amnesia.

Background and Purpose: This study aimed to evaluate the brain magnetic resonance imaging (MRI) of patients with acute transient global amnesia (TGA) using volumetric analysis to verify whether the brains of TGA patients have pre-existing structural abnormalities. Methods: We evaluated the brain MRI data from 87 TGA patients and 20 age- and sex-matched control subjects. We included brain MRIs obtained from TGA patients within 72 hours of symptom onset to verify the pre-existence of structural change. For voxel-based morphometric analyses, statistical parametric mapping was employed to analyze the structural differences between patients with TGA and control subjects. Results: TGA patients exhibited significant volume reductions in the bilateral ventral anterior cingulate cortices (corrected p<0.05). Conclusions: TGA patients might have pre-existing structural changes in bilateral ventral anterior cingulate cortices prior to TGA attacks.

Efficacy and safety of oxiracetam in patients with vascular cognitive impairment: A multicenter, randomized, double-blinded, placebo-controlled, phase IV clinical trial.

BACKGROUND: Oxiracetam may have a modest effect on preventing cognitive decline. Exercise can also enhance cognitive function. This trial aims to investigate the effect of oxiracetam on post-stroke cognitive impairment and explore whether this effect is modified by exercise. Furthermore, the mechanisms that mediate this effect will be investigated through a neural network analysis. METHODS: This is a multicenter, randomized, double-blind, placebo-controlled phase IV trial. Patients who complained of cognitive decline 3 months after stroke and had a high risk of cognitive decline were eligible. Patients were randomly assigned to receive either 800 mg of oxiracetam or placebo twice daily for 36 weeks. After randomization, a predetermined exercise protocol was provided to each participant, and the degree of physical activity was assessed using wrist actigraphy at 4, 12, 24, and 36 weeks. Resting-state functional MRI was obtained in baseline and 36-week follow-up. Co-primary endpoints are changes in the Mini-Mental State Examination and Clinical Dementia Rating-Sum of Boxes. Secondary endpoints include changes in the NINDS-CSN VCIHS-Neuropsychology Protocol, Euro QoL, patient's global assessment, and functional network connectivity. If there is a significant difference in physical activity between the two groups, the interaction effect between physical activity and the treatment group will be examined. A total of 500 patients were enrolled from February 2018, and the last patient's final follow-up was completed in September 2022. CONCLUSION: This trial is meaningful not only to prove the efficacy of oxiracetam, but also evaluate whether exercise can modify the effects of medication and how cognitive function can be restored. Trial registrationhttp://cris.nih.go.kr (KCT0005137).

Predictors of long-term medication adherence in stroke survivors: A multicentre, prospective, longitudinal study.

BACKGROUND: Although the optimal use of prescribed medications for stroke survivors is critical for preventing secondary stroke, longitudinal observations of the natural course of medication persistence and adherence in Korean stroke survivors are rare. Furthermore, studies are needed to identify strong predictors influencing medication adherence and to determine whether these predictors change over time. AIMS AND OBJECTIVES: To evaluate the longitudinal medication persistence and adherence at 3 months and 1 year after discharge in all stroke patients and to identify predictors of long-term medication adherence in patients who can self-medicate. DESIGN: A multicentre, prospective, longitudinal descriptive study. METHODS: A total of 600 consecutive ischaemic stroke patients were recruited from three stroke centres across Korea, from 1 September, 2017 to 28 February, 2019. Various factors related to medication adherence suggested by the World Health Organisation were investigated through face-to-face interviews at each centre during hospitalisation. Medication persistence and adherence were assessed at 3 months and 1 year after discharge using the eight-item Morisky Medication Adherence Scale through telephone interviews. RESULTS: Of 537 survivors at 3 months, 526 (98.0%) were persistent and 472 (89.7%) were adherent. Of 493 survivors at 1 year, 477 (96.8%) were persistent and 392 (82.2%) were adherent. Medication belief, income and health literacy were statistically significant predictors of three-month medication adherence, which predicted one-year medication adherence with older age and low income. CONCLUSIONS: Among Korean stroke survivors, three-month and one-year medication persistence and adherence were relatively good. Medication beliefs and three-month medication adherence were important and modifiable factors predicting three-month adherence and one-year adherence, respectively. RELEVANCE TO CLINICAL PRACTICE: To increase long-term adherence to medication, various strategies are needed to improve beliefs about medication, taking into account the patient's age and level of knowledge. These interventions need to be initiated during hospitalisation to form early medication habits after discharge.

Comparison of Factors Associated With Direct Versus Transferred-in Admission to Government-Designated Regional Centers Between Acute Ischemic Stroke and Myocardial Infarction in Korea.

BACKGROUND: There has been no comparison of the determinants of admission route between acute ischemic stroke (AIS) and acute myocardial infarction (AMI). We examined whether factors associated with direct versus transferred-in admission to regional cardiocerebrovascular centers (RCVCs) differed between AIS and AMI. METHODS: Using a nationwide RCVC registry, we identified consecutive patients presenting with AMI and AIS between July 2016 and December 2018. We explored factors associated with direct admission to RCVCs in patients with AIS and AMI and examined whether those associations differed between AIS and AMI, including interaction terms between each factor and disease type in multivariable models. To explore the influence of emergency medical service (EMS) paramedics on hospital selection, stratified analyses according to use of EMS were also performed. RESULTS: Among the 17,897 and 8,927 AIS and AMI patients, 66.6% and 48.2% were directly admitted to RCVCs, respectively. Multivariable analysis showed that previous coronary heart disease, prehospital awareness, higher education level, and EMS use increased the odds of direct admission to RCVCs, but the odds ratio (OR) was different between AIS and AMI (for the first 3 factors, AMI > AIS; for EMS use, AMI < AIS). EMS use was the single most important factor for both AIS and AMI (OR, 4.72 vs. 3.90). Hypertension and hyperlipidemia increased, while living alone decreased the odds of direct admission only in AMI; additionally, age (65-74 years), previous stroke, and presentation during non-working hours increased the odds only in AIS. EMS use weakened the associations between direct admission and most factors in both AIS and AMI. CONCLUSIONS: Various patient factors were differentially associated with direct admission to RCVCs between AIS and AMI. Public education for symptom awareness and use of EMS is essential in optimizing the transportation and hospitalization of patients with AMI and AIS.

Executive Summary of the 2021 International Conference of Korean Dementia Association: A Report From the Academic Committee of the Korean Dementia Association.

Recently, aducanumab, a beta amyloid targeted immunotherapy, has been approved by the US Food and Drug Administration for the treatment of Alzheimer's dementia (AD). Although many questions need to be answered, this approval provides a promising hope for the development of AD drugs that could be supported by new biomarkers such as blood-based ones and composite neuropsychological tests that can confirm pathologic changes in early stages of AD. It is important to elucidate the complexity of AD which is known to be associated with other factors such as vascular etiologies and neuro-inflammation. Through the second international conference of the Korean Dementia Association (KDA), researchers from all over the world have participated in the exchange of opinions with KDA members on the most up-to-date topics. The Academic Committee of the KDA summarizes lectures to provide the depth of the conference as well as discussions. This will be an important milestone to widen the latest knowledge in the research of AD's diagnosis, therapeutics, pathogenesis that can lead to the establishment of future directions.

Comparisons of Prehospital Delay and Related Factors Between Acute Ischemic Stroke and Acute Myocardial Infarction.

Background Prehospital delay is an important contributor to poor outcomes in both acute ischemic stroke (AIS) and acute myocardial infarction (AMI). We aimed to compare the prehospital delay and related factors between AIS and AMI. Methods and Results We identified patients with AIS and AMI who were admitted to the 11 Korean Regional Cardiocerebrovascular Centers via the emergency room between July 2016 and December 2018. Delayed arrival was defined as a prehospital delay of >3 hours, and the generalized linear mixed-effects model was applied to explore the effects of potential predictors on delayed arrival. This study included 17 895 and 8322 patients with AIS and AMI, respectively. The median value of prehospital delay was 6.05 hours in AIS and 3.00 hours in AMI. The use of emergency medical services was the key determinant of delayed arrival in both groups. Previous history, 1-person household, weekday presentation, and interhospital transfer had higher odds of delayed arrival in both groups. Age and sex had no or minimal effects on delayed arrival in AIS; however, age and female sex were associated with higher odds of delayed arrival in AMI. More severe symptoms had lower odds of delayed arrival in AIS, whereas no significant effect was observed in AMI. Off-hour presentation had higher and prehospital awareness had lower odds of delayed arrival; however, the magnitude of their effects differed quantitatively between AIS and AMI. Conclusions The effects of some nonmodifiable and modifiable factors on prehospital delay differed between AIS and AMI. A differentiated strategy might be required to reduce prehospital delay.

A rare case of aquaporin-4-antibody-positive neuromyelitis optica associated with bladder cancer.

BACKGROUND: Paraneoplastic neurological syndrome, a heterogeneous disorder affecting the neurological function, is associated with different types of systemic cancer but rarely with bladder cancer. CASE REPORT: We report the case of a 54-year-old woman presenting with longitudinally extensive transverse myelitis and optic neuritis (neuromyelitis optica) detected on neurological examination and magnetic resonance imaging of both the brain and spine. As a result, the patient initiated treatment with intravenous steroids for five days. In agreement with the diagnosis, the clinical condition was associated with serum positivity for aquaporin-4 antibodies. Subsequent abdominopelvic computed tomography and biopsy of the mass confirmed urothelial carcinoma, and a radical cystectomy was performed. Immunotherapy was maintained, and the patient showed progressive clinical improvement with total recovery of visual acuity and leg strength three and five months after surgery, respectively. No recurrence was observed during the post-surgery follow-up period of two years. CONCLUSION: Case reports on paraneoplastic syndrome associated with cancer increases the knowledge on this topic, especially on rare presentations. Our findings further support that early diagnosis of various paraneoplastic symptoms is critical for patient´s treatment and prognosis.

Hydrocephalus in a Patient with Alzheimer's Disease.

BACKGROUND: Normal pressure hydrocephalus (NPH) is an etiology of dementia that is reversible following cerebrospinal fluid shunt placement, however, surgical intervention not always clinically effective and the respons to shunt therapy is poorly understood. Furthermore, NPH is a source of comorbidity in diseases with neurodegenerative pathology, such as Alzheimer's disease (AD). CASE REPORT: A 61-year-old woman presented to the neurology clinic with progressive gait difficulties and cognitive impairment over five years. Nine years after ventriculoperitoneal (VP) shunt treatment, the patient began to experience frequent falls. There was no improvement in clinical symptoms after the alteration of valve pressure on the VP shunt. An 18F-florbetaben amyloid positron emission tomography scan showed increased diffusion uptake over the bilateral cortices, precuneus, and posterior cingulate cortex. CONCLUSIONS: The patient of NPH was unresponsive to shunt therapy due to the development of AD.

Decreased Metabolism in the Posterior Medial Network with Concomitantly Increased Metabolism in the Anterior Temporal Network During Transient Global Amnesia.

Perturbation of corticohippocampal circuits is a key step in the pathogenesis of transient global amnesia. We evaluated the spatial distribution of altered cerebral metabolism to determine the location of the corticohippocampal circuits perturbed during the acute stage of transient global amnesia. A consecutive series of 12 patients with transient global amnesia who underwent 18F-fluorodeoxyglucose positron emission tomography within 3 days after symptom onset was identified. We used statistical parametric mapping with two contrasts to identify regions of decreased and increased brain metabolism in transient global amnesia patients compared with 25 age-matched controls. Transient global amnesia patients showed hypometabolic clusters in the left temporal and bilateral parieto-occipital regions that belong to the posterior medial network as well as, hypermetabolic clusters in the bilateral inferior frontal regions that belong to the anterior temporal network. The posterior medial and anterior temporal networks are the two main corticohippocampal circuits involved in memory-guided behavior. Decreased metabolism in the posterior medial network might explain the impairment of episodic memory observed during the acute stage of transient global amnesia. Concomitant increased metabolism within the anterior temporal network might occur as a compensatory mechanism.

Oligomeric forms of amyloid-ß protein in plasma as a potential blood-based biomarker for Alzheimer's disease.

BACKGROUND: Soluble amyloid-ß (Aß) oligomers are the major toxic substances associated with the pathology of Alzheimer's disease (AD). The ability to measure Aß oligomer levels in the blood would provide simple and minimally invasive tools for AD diagnostics. In the present study, the recently developed Multimer Detection System (MDS) for AD, a new enzyme-linked immunosorbent assay for measuring Aß oligomers selectively, was used to detect Aß oligomers in the plasma of patients with AD and healthy control individuals. METHODS: Twenty-four patients with AD and 37 cognitively normal control individuals underwent extensive clinical evaluations as follows: blood sampling; detailed neuropsychological tests; brain magnetic resonance imaging; cerebrospinal fluid (CSF) measurement of Aß42, phosphorylated tau protein (pTau), and total tau protein (tTau); and 11C-Pittsburgh compound B (PIB) positron emission tomography. Pearson's correlation analyses between the estimations of Aß oligomer levels by MDS and other conventional AD biomarkers (CSF Aß42, pTau, and tTau, as well as PIB standardized uptake value ratio [PIB SUVR]) were conducted. ROC analyses were used to compare the diagnostic performance of each biomarker. RESULTS: The plasma levels of Aß oligomers by MDS were higher in patients with AD than in normal control individuals, and they correlated well with conventional AD biomarkers (levels of Aß oligomers by MDS vs. CSF Aß42, r = -0.443; PIB SUVR, r = 0.430; CSF pTau, r = 0.530; CSF tTau, r = 0.604). The sensitivity and specificity of detecting plasma Aß oligomers by MDS for differentiating AD from the normal controls were 78.3% and 86.5%, respectively. The AUC for plasma Aß oligomers by MDS was 0.844, which was not significantly different from the AUC of other biomarkers (p = 0.250). CONCLUSIONS: Plasma levels of Aß oligomers could be assessed using MDS, which might be a simple, noninvasive, and accessible assay for evaluating brain amyloid deposition related to AD pathology.

Transient Global Amnesia Deteriorates the Network Efficiency of the Theta Band.

Acute perturbation of the hippocampus, one of the connector hubs in the brain, is a key step in the pathophysiological cascade of transient global amnesia (TGA). We tested the hypothesis that network efficiency, meaning the efficiency of information exchange over a network, is impaired during the acute stage of TGA. Graph theoretical analysis was applied to resting-state EEG data collected from 21 patients with TGA. The EEG data were obtained twice, once during the acute stage (< 24 hours after symptom onset) and once during the resolved stage (> 2 months after symptom onset) of TGA. Characteristic path lengths and clustering coefficients of functional networks constructed using phase-locking values were computed and normalized as a function of the degree in the delta, theta, alpha, beta 1, beta 2 and gamma frequency bands of the EEG. We investigated whether the normalized characteristic path length (nCPL) and normalized clustering coefficients (nCC) differed significantly between the acute and resolved stages of TGA at each frequency band using the Wilcoxon signed-rank test. For networks where the nCPL or nCC differed significantly between the two stages, we also evaluated changes in the connections of the brain networks. During the acute stage of TGA, the nCPL of the theta band networks with mean degrees of 8, 8.5, 9 and 9.5 significantly increased (P < 0.05). During the acute stage, the lost edges for these networks were mostly found between the anterior (frontal and anterior temporal) and posterior (parieto-occipital and posterior temporal) brain regions, whereas newly developed edges were primarily found between the left and right frontotemporal regions. The nCC of the theta band with a mean degree of 5.5 significantly decreased during the acute stage (P < 0.05). Our results indicate that TGA deteriorates the network efficiency of the theta frequency band. This effect might be related to the desynchronization between the anterior and posterior brain areas.

Analysis of Cerebrospinal Fluid and [11C]PIB PET Biomarkers for Alzheimer's Disease with Updated Protocols.

BACKGROUND: Recently, a Korean research group suggested a consensus protocol, based on the Alzheimer's Disease Neuroimaging Initiative study protocol but with modifications for minimizing the confounding factors, for the evaluation of cerebrospinal fluid (CSF) biomarkers. OBJECTIVE: Here, we analyzed fluid and imaging biomarkers of Alzheimer's disease (AD) in Korean population. We used the updated protocol to propose a more accurate CSF biomarker value for the diagnosis of AD. METHODS: Twenty-seven patients with AD and 30 cognitively normal controls (NC) were enrolled. CSF was collected from 55 subjects (patients with AD = 26, NC = 29) following the Korea consensus protocol. CSF biomarkers were measured using the INNO-BIA AlzBio3 immunoassay, and Pittsburgh compound B (PIB) positron emission tomography (PET) scans were also performed. RESULTS: The cutoff values of CSF amyloid beta 1-42 (Aß42), total tau (t-Tau), and phosphorylated tau (p-Tau) proteins were 357.1 pg/ml, 83.35 pg/ml, and 38.00 pg/ml, respectively. The cutoff values of CSF t-Tau/Aß42 and p-Tau/Aß42 ratio- were 0.210 (sensitivity 100%, specificity 86.21%) and 0.1350 (sensitivity 88.46%, specificity of 92.86%). The concordance rate with PIB-PET was higher using the CSF t-Tau/Aß42 ratio (κ= 0.849, CI 0.71-0.99) than CSF Aß42 alone (κ= 0.703, CI 0.51-0.89). CONCLUSIONS: Here, we improved controversial factors associated with the previous CSF study protocol and suggested a new cutoff value for the diagnosis of AD. Our results showed good diagnostic performance for differentiation of AD. Thus, we expect our findings could be a cornerstone in the establishment and clinical application of biomarkers for AD diagnosis.

Neurosyphilis Mimicking Creutzfeldt-Jakob Disease.

BACKGROUND: As rapidly progressive dementia (RPD), general paresis and Creutzfeldt-Jakob disease (CJD) may have overlapping clinical presentation due to a wide variety of clinical manifestations. CASE REPORT: A 57-year-old man presented with rapid progressive cognitive decline, behavioral change, ataxic gait, tremor and pyramidal signs for 3 months. In addition to these multiple systemic involvements, positive result for the cerebrospinal fluid (CSF) 14-3-3 protein tentatively diagnosed him as probable CJD. However, due to increased serum rapid plasma reagin, venereal disease research laboratory, and fluorescent treponemal antibody-absorption reactivity in CSF, the final diagnosis was changed to general paresis. CONCLUSIONS: A patient with RPD needs to be carefully considered for differential diagnosis, among a long list of diseases. It is important to rule out CJD, which is the most frequent in RPD and is a fatal disease with no cure. Diagnostic criteria or marker of CJD, such as 14-3-3 protein, may be inconclusive, and a typical pattern in diffusion-weighted imaging is important to rule out other reversible diseases.

Increased DJ-1 in urine exosome of Korean males with Parkinson's disease.

Parkinson's disease (PD) is a difficult disease to diagnose although it is the second most common neurodegenerative disease. Recent studies show that exosome isolated from urine contains LRRK2 or DJ-1, proteins whose mutations cause PD. To investigate a potential use for urine exosomes as a tool for PD diagnosis, we compared levels of LRRK2, α-synuclein, and DJ-1 in urine exosomes isolated from Korean PD patients and non-PD controls. LRRK2 and DJ-1, but not α-synuclein, were detected in the urine exosome samples, as reported previously. We initially could not detect any significant difference in these protein levels between the patient and the control groups. However, when age, disease duration, L-dopa daily dose, and gender were considered as analytical parameters, LRRK2 and DJ-1 protein levels showed clear gender-dependent differences. In addition, DJ-1 level was significantly higher (1.7-fold) in male patients with PD than that in male non-PD controls and increased in an age-dependent manner in male patients with PD. Our observation might provide a clue to lead to a novel biomarker for PD diagnosis, at least in males.