Alterations of Structural Network Efficiency in Early-Onset and Late-Onset Alzheimer’s Disease

Background@#and Purpose Early- and late-onset Alzheimer’s disease (EOAD and LOAD, respectively) share the same neuropathological hallmarks of amyloid and neurofibrillary tangles but have distinct cognitive features. We compared structural brain connectivity between the EOAD and LOAD groups using structural network efficiency and evaluated the association of structural network efficiency with the cognitive profile and pathological markers of Alzheimer’s disease (AD). @*Methods@#The structural brain connectivity networks of 80 AD patients (47 with EOAD and 33 with LOAD) and 57 healthy controls were reconstructed using diffusion-tensor imaging.Graph-theoretic indices were calculated and intergroup differences were evaluated. Correlations between network parameters and neuropsychological test results were analyzed. The correlations of the amyloid and tau burdens with network parameters were evaluated for the patients and controls. @*Results@#Compared with the age-matched control group, the EOAD patients had increased global path length and decreased global efficiency, averaged local efficiency, and averaged clustering coefficient. In contrast, no significant differences were found in the LOAD patients. Locally, the EOAD patients showed decreases in local efficiency and the clustering coefficient over a wide area compared with the control group, whereas LOAD patients showed such decreases only within a limited area. Changes in network parameters were significantly correlated with multiple cognitive domains in EOAD patients, but only with Clinical Dementia Rating Sum-of-Boxes scores in LOAD patients. Finally, the tau burden was correlated with changes in network parameters in AD signature areas in both patient groups, while there was no correlation with the amyloid burden. @*Conclusions@#The impairment of structural network efficiency and its effects on cognition may differ between EOAD and LOAD.

Stroke in Women: A Review Focused on Epidemiology, Risk Factors, and Outcomes / 대한뇌졸중학회지

Stroke is a particularly important issue for women. Women account for over half of all persons who experienced a stroke. The lifetime risk of stroke is higher in women than in men. In addition, women have worse stroke outcomes than men. Several risk factors have a higher association with stroke in women than in men, and women-specific risk factors that men do not have should be considered. This focused review highlights recent findings in stroke epidemiology, risk factors, and outcomes in women.

Relationships between ¹⁸F-THK5351 Retention and Language Functions in Primary Progressive Aphasia

BACKGROUND AND PURPOSE: There are three distinct subtypes of primary progressive aphasia (PPA): the nonfluent/agrammatic variant (nfvPPA), the semantic variant (svPPA), and the logopenic variant (lvPPA). We sought to characterize the pattern of [¹⁸F]-THK5351 retention across all three subtypes and determine the topography of [¹⁸F]-THK5351 retention correlated with each neurolinguistic score. METHODS: We enrolled 50 participants, comprising 13 PPA patients (3 nfvPPA, 5 svPPA, and 5 lvPPA) and 37 subjects with normal cognition (NC) who underwent 3.0-tesla magnetic resonance imaging, [¹⁸F]-THK5351 positron-emission tomography scans, and detailed neuropsychological tests. The PPA patients additionally participated in extensive neurolinguistic tests. Voxel-wise and region-of-interest-based analyses were performed to analyze [¹⁸F]-THK5351 retention. RESULTS: The nfvPPA patients exhibited higher [¹⁸F]-THK5351 retention in the the left inferior frontal and precentral gyri. In svPPA patients, [¹⁸F]-THK5351 retention was elevated in the anteroinferior and lateral temporal cortices compared to the NC group (left>right). The lvPPA patients exhibited predominant [¹⁸F]-THK5351 retention in the inferior parietal, lateral temporal, and dorsolateral prefrontal cortices, and the precuneus (left>right). [¹⁸F]-THK5351 retention in the left inferior frontal area was associated with lower fluency scores. Comprehension was correlated with [¹⁸F]-THK5351 retention in the left temporal cortices. Repetition was associated with [¹⁸F]-THK5351 retention in the left inferior parietal and posterior temporal areas, while naming difficulty was correlated with retention in the left fusiform and temporal cortices. CONCLUSIONS: The pattern of [¹⁸F]-THK5351 retention was well matched with clinical and radiological findings for each PPA subtype, in agreement with the anatomical and functional location of each language domain.

Current Status and Issues of Acute Stroke Management in Korea: Results of a Nationwide Acute Stroke Care Hospital Survey

BACKGROUND: Burden of acute stroke management is increasing according to aging population and advances in the therapeutic time window. However, reduction of resident numbers by the national policy in addition to the underlying low medical charge and reward gradually leaded to a lower rate of application to neurology department. METHODS: We conducted a nationwide survey from May 29, 2017 through July 11, 2017 to evaluate the real-world working conditions and issues of acute stroke management by stroke neurologists in Korea. Of 100 candidates of stroke professors/specialists, a total of 81 physicians participated the survey comprising 40 questionnaires. RESULTS: Stroke care physicians were suffering from heavy work load of inpatient care, outpatient clinic due to shortage of manpower for caring acute stroke. There were only three hospitals (3.7%) where neurologists independently take lead an endovascular therapy. About 43% of the participants were involving in primary duty for acute stroke management stroke, majority of whom (65.7%) were on by themselves. Participants pointed out that the biggest drawbacks were manpower shortage due to lack of residents, and numerous frequencies of primary duty. Approximately 80% of the participants forecasted a dismal future for stroke field. CONCLUSIONS: With the growing incidence of stroke, there is an emerging need for increasing number of neurologists due to contemporary grave shortage of stroke neurologists. It is necessary to investigate the effective demand forecasting for stroke neurologists for the strategy to improve an unmet quality of stroke care with the awareness and help of government.

Congenital Nystagmus in Turner Syndrome

No abstract available.

Ischemic Stroke Caused by Spontaneous Subclavian Artery Dissection

No abstract available.

¹⁸F-THK5351 PET Imaging in Nonfluent-Agrammatic Variant Primary Progressive Aphasia

BACKGROUND AND PURPOSE: To analyze 18F-THK5351 positron emission tomography (PET) scans of patients with clinically diagnosed nonfluent/agrammatic variant primary progressive aphasia (navPPA). METHODS: Thirty-one participants, including those with Alzheimer's disease (AD, n=13), navPPA (n=3), and those with normal control (NC, n=15) who completed 3 Tesla magnetic resonance imaging, 18F-THK5351 PET scans, and detailed neuropsychological tests, were included. Voxel-based and region of interest (ROI)-based analyses were performed to evaluate retention of 18F-THK5351 in navPPA patients. RESULTS: In ROI-based analysis, patients with navPPA had higher levels of THK retention in the Broca's area, bilateral inferior frontal lobes, bilateral precentral gyri, and bilateral basal ganglia. Patients with navPPA showed higher levels of THK retention in bilateral frontal lobes (mainly left side) compared than NC in voxel-wise analysis. CONCLUSIONS: In our study, THK retention in navPPA patients was mainly distributed at the frontal region which was well correlated with functional-radiological distribution of navPPA. Our results suggest that tau PET imaging could be a supportive tool for diagnosis of navPPA in combination with a clinical history.

Late-onset non-thymomatous myasthenia gravis: Comparison with early-onset and very late-onset myasthenia gravis

Objective: To identify the clinical characteristics of patients with myasthenia gravis (MG) according to age at onset. Methods: We retrospectively recruited 227 non-thymomatous MG patients with adult onset who had been followed up for more than one year. The patients were classified based on the age of symptom onset as “early-onset MG” (EOMG,18–50 years; N=135), “late-onset MG” (LOMG, 50–64 years; N=53), and “very late-onset MG” (VLOMG, 65 years; N=39). Clinical features and serological findings were compared between these groups. Results: LOMG patients showed more frequent ocular MG (55%) and less frequent thymic hyperplasia (9%) compared to EOMG patients (31% and 38%; p=0.006 and p<0.001, respectively), and no female preponderance compared to VLOMG patients (female, 49% vs.77%; p=0.014). However, there were no significant differences between VLOMG and EOMG patients, except for more frequent thymic hyperplasia (p<0.001) in EOMG patients. When analyzing female patients only, less frequent secondary generalization (10%) were additionally found in LOMG patients, compared to EOMG (47%, p= 0.008) and VLOMG (59%, p=0.004) patients. Anti-acetylcholine receptor antibody (HR, 5.48; 95% CI, 1.73–17.37; p=0.004) was independently associated with secondary generalization in female EOMG patients. Conclusion: Our study suggests that LOMG patients, especially female, were characterized by frequent ocular MG and less frequent secondary generalization, distinguished from EOMG and VLOMG patients. Further large epidemiologic studies in Korea are needed to determine the characteristics of MG patients according to the age at onset and gender.

Sex differences in large artery atherosclerotic stroke, a Korean study

Background & Objective: Sex differences in cerebral atherosclerosis and subsequent stroke have not been thoroughly investigated and conflicting data exist. The aim of this study was to investigate sex differences in the risk factors and distribution of large artery atherosclerotic stroke in a Korean population. Methods: We included consecutive acute ischemic stroke patients with symptomatic extracranial atherosclerosis (ECAS) or intracranial atherosclerosis (ICAS) based on brain and vascular imaging who presented at our hospital between January 2011 and December 2015. We then compared risk factor profiles and the proportion of symptomatic ECAS and ICAS between men and women. Results: Eight hundred and forty four patients were enrolled during the study period. The proportion of ECAS in men was notably higher than in women (19.4% in men vs. 9.3% in women; p < 0.001). A multiple regression analysis showed that male gender was a factor favoring ECAS (vs. ICAS, odds ratio [OR], 3.554; 95% confidence interval [CI], 2.175-5.808; p < 0.001). Age (OR, 1.051; 95% CI, 1.031-1.072; p = 0.001) and hyperlipidemia (OR, 2.330; 95% CI, 1.538-3.529; p < 0.001) were also factors favoring ECAS. However, after stratification by sex, the association was only significant in men. Conclusions: There is a sex difference in the distribution of atherosclerotic stroke. Sex may be an effect modifier of the association between atherosclerotic risk factors and atherosclerotic distribution.

Recent advances in ischemic stroke management

There have been recent advances in the hyperacute treatment and secondary prevention of ischemic stroke. Thrombolysis with intravenous tissue plasminogen activator has been approved for a 3 to 4.5 hour time window, but the recent controversy over the optimal dose has not been resolved. Five endovascular trials published in 2015 have shown dramatically positive results. Regarding secondary prevention of ischemic stroke, a study suggesting the beneficial effect of a short course of dual antiplatelet therapy has been published. Non-vitamin K antagonist oral anticoagulation agents have been approved for stroke prevention in non-valvular atrial fibrillation. Here, we review these recent advances in ischemic stroke management.