Digital Biomarkers for Alzheimer’s Disease

There is a growing interest in developing new biomarkers using digital devices. The primary purpose of digital biomarkers is to obtain features based on multi-dimensional data such as multiple data sources from various digital devices and time-series data reflecting temporal changes. Therefore, digital biomarkers can be used to measure the behavioral patterns of individuals in their daily lives in contrast to traditional biomarkers that reflect specific time points in clinical or laboratory settings. However, there are still several limitations including validation and interpretation. This article reviews the potential of digital biomarkers, explores previous studies on digital phenotypes related to Alzheimer’s disease, and discusses the future challenges of implementing digital biomarkers in the medical field.

A Comparison of Speech Features between Mild Cognitive Impairment and Healthy Aging Groups

Background@#and Purpose: Language dysfunction is a symptom common to patients with Alzheimer's disease (AD). Speech feature analysis may be a patient-friendly screening test for early-stage AD. We aimed to investigate the speech features of amnestic mild cognitive impairment (aMCI) compared to normal controls (NCs). @*Methods@#Spoken responses to test questions were recorded with a microphone placed 15 cm in front of each participant. Speech samples delivered in response to four spoken test prompts (free speech test, Mini-Mental State Examination [MMSE], picture description test, and sentence repetition test) were obtained from 98 patients with aMCI and 139 NCs.Each recording was transcribed, with speech features noted. The frequency of the ten speech features assessed was evaluated to compare speech abilities between the test groups. @*Results@#Among the ten speech features, the frequency of pauses (p=0.001) and mumbles (p=0.001) were significantly higher in patients with aMCI than in NCs. Moreover, MMSE score was found to negatively correlate with the frequency of pauses (r=−0.441, p<0.001) and mumbles (r=−0.341, p<0.001). @*Conclusions@#Frequent pauses and mumbles reflect cognitive decline in aMCI patients in episodic and semantic memory tests. Speech feature analysis may prove to be a speech-based biomarker for screening early-stage cognitive impairment.

Visuospatial Dysfunction in Patients With the Right Vestibular Neuritis / 대한평형의학회지

Acute vestibular neuritis (VN) is characterized by acute/subacute vertigo with spontaneous nystagmus and unilateral loss of semicircular canal function. Vestibular system in human is represented in the brain bilaterally with functional asymmetries of the right hemispheric dominance in the right handers. Spatial working memory entails the ability to keep spatial information active in working memory over a short period of time which is also known as the right hemispheric dominance. Three patients (patient 1, 32-year-old female; patient 2, 18-year-old male; patient 3, 63-year-old male) suffered from acute onset of severe vertigo, nausea and vomiting. Patients 1 and 2's examination revealed VN on the right side showing spontaneous left beating nystagmus and impaired vestibular ocular reflex on the right side in video head-impulse and caloric tests. Patient 3's finding was fit for VN on the left side. We also evaluated visuospatial memory function with the block design test in these 3 VN patients which discovered lower scores in patients 1 and 2 and the average level in patient 3 compare to those of healthy controls. Follow-up block design test after resolved symptoms showed within normal range in both patients. Our cases suggest that the patients with unilateral peripheral vestibulopathy may have an asymmetrical effect on the higher vestibular cognitive function. The right VN can be associated with transient visuospatial memory dysfunction. These findings add the evidence of significant right hemispheric dominance for vestibular and visuospatial structures in the right-handed subjects, and of predominant dysfunction in the hemisphere ipsilateral to the peripheral lesion side.

Artificial Neural Network: Understanding the Basic Concepts without Mathematics

Machine learning is where a machine (i.e., computer) determines for itself how input data is processed and predicts outcomes when provided with new data. An artificial neural network is a machine learning algorithm based on the concept of a human neuron. The purpose of this review is to explain the fundamental concepts of artificial neural networks.

Numerical Considerations of the Neurologist in Korea for Appropriate Management of Dementia

As the number of dementia patients increases due to rapid aging, the burden of dementia becomes a big social problem. In response to this, various policies have been introduced in Korea. In particular, as the new policy of national responsibility for dementia care has been implemented in 2017, detailed plans for improving health care and long-term care support for dementia patients and their caregivers have been introduced. The most important thing in carrying out the comprehensive government plan will be securing sufficient the professional health and social care workforce. However, the number of neurologists to play an important role in the management of dementia will be more and more insufficient. Therefore, the need to supply an adequate number of neurologists in Korea should be discussed.

Altered Function of Ventrolateral Prefrontal Cortex in Adolescents with Peer Verbal Abuse History

OBJECTIVE: Previous studies showing the association of exposure to peer (PeVA) and parental verbal abuse in childhood with structural alterations in the young adult brain suggest functional changes in adolescence. In this functional MRI study, we investigated the effects of exposure to PeVA, during elementary and middle school periods, on brain response to emotional words, in high school students. METHODS: An emotional Stroop task consisting of swear, negative, positive, and neutral words was performed during functional MRI scan for 23 subjects who were divided into low- and high exposure groups to PeVA. RESULTS: High-PeVA group had a higher depression score, greater left ventrolateral prefrontal cortex (VLPFC) activity, and higher left VLPFC-left hippocampus connectivity in swear word conditions. The VLPFC activity and left VLPFC-left hippocampus connectivity was negatively related to the severity of anxiety and depressive symptoms, respectively. CONCLUSION: These preliminary findings support the hypothesis that exposure to PeVA, during childhood, is an aversive stimulus associated with meaningful functional change in emotional regulation network, showing hypersensitivity to swear words, at middle adolescence.

The Psychometric Properties of the Korean Version of the Verbal Abuse Questionnaire in University Students

OBJECTIVE: The aim of the present study was to examine the psychometric properties of the Korean Verbal Abuse Questionnaire (K-VAQ) that consists of 15 items related with life-time verbal aggression exposure. METHODS: A total of 5814 university students who agreed to take part in the study completed the K-VAQ, the Korean version of the Life Event CheckList (LEC-K) and Impact of Event Scale-Revised (K-IES-R). Internal consistency was checked by using item-total item correlation and Cronbach's alpha coefficient. Exploratory and confirmatory factor analyses were performed, and convergent and concurrent validity levels were examined. Finally, a cluster analysis was conducted to verify the validity of the cutoff point of the K-VAQ. RESULTS: The Cronbach's alpha correlation coefficient was 0.9. The K-VAQ showed a single factor structure which explained 55.34% of the total variance. The K-VAQ was significantly associated with the LEC-K (r=0.24) and K-IES-R (r=0.28), indicating good convergent validity and concurrent validity. The cluster analysis provided four clusters of trauma experiences: high, moderate, low, and minimal, with K-VAQ ranges of 43-81, 20-42, 7-19, and 0-6, respectively. In a further investigation, a K-VAQ score of 40 was found to be the appropriate cutoff point to delineate the highly verbally abused group, as used in the previous studies. A sum of 36.5% of the highly verbally abused group reported to show substantial symptoms of PTSD (K-IES-R score >22). CONCLUSION: The present findings suggest that the K-VAQ has good psychometric properties for assessing verbal aggression among the Korean population.

Caudate Volume Change in Transient Global Amnesia Patients; Voxel-Based Morphometric Study

BACKGROUND: Transient global amnesia (TGA) is characterized by a severe disturbance of memory, lasting less than a day, and complete resolution. However, some authors have suggested the occurrence of permanent memory impairment in such cases. In this study, we investigated whether the gray-matter structure suffers degeneration in TGA, based on the assumption that TGA attacks appear to be related to underlying permanent pathology. METHODS: T1-weighted magnetic resonance imaging data for 20 TGA and 55 normal subjects were analyzed. The gray-matter volume was measured using voxel-based morphometry. The subjects also completed the Seoul Neuropsychological Screening Battery (SNSB). RESULTS: The gray-matter volume was reduced in the left superior frontal gyrus, right precentral gyrus, right superior frontal gyrus, left caudate nucleus, left precentral gyrus, left post central gyrus, and both putamens. The SNSB revealed the presence of selective neuropsychological dysfunctions after clinical recovery. Most of the cases exhibited attention deficit, and difficulties in copying of the Rey-Osterrieth Complex Figure, and in the Seoul verbal learning test. CONCLUSIONS: Left caudate nucleus atrophy could explain the attention deficit and memory impairment experienced in these TGA patients. Many patients with TGA have neuropsychological dysfunctions even after they appear to be clinically improved.

Reversible Splenial Lesion in a Patient With Acute Alcohol Intoxication

No abstract available.

Comparison of Protein Expression in Normal Myometrium and Uterine Leiomyoma Using Two-Dimensional Gel Electrophoresis in Korean Women / 대한산부인과학회잡지

OBJECTIVE: Comparison of protein expression by two-dimensional gel electrophoresis (2-DE) in normal myometrium and uterine leiomyoma in Korean women. METHODS: Normal myometrium and uterine leiomyoma tissues were solubilized with 2-DE buffer and the first dimension of PROTEAN IEF CELL, isoelectric focusing (IEF), was performed using pH4-8 linear IPG strips of 17 cm. And then running 12% sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS- PAGE) and sliver stain. Scanned image analyzed using PDQuest 2-D softwareTM. Protein spot spectrum was identified by assisted laser desorption/ionization-time of fighting (MALDI-TOF) and the protein mass spectrums identification were performed by searching protein databases of Swiss-prot/TrEMBL, Mascot and MS-FIT. RESULTS: In this study, we found 17 up-regulated proteins (phosphate carrier protein, 60 kDa heat shock protein, acidic calcium-independent, glutathione transferase omega, chloride intracellular channel 4, Ras-related protein Rab-11B, phosphatidylinositol transfer protein alpha isoform, type II keratin subunit protein, Cofilin 2 isoform 1, transgelin, ATP carrier protein, alpha-catenin homolog, parkinson disease 2, apo-cellular retinoic acid binding protein II, osteoglycin preproprotein, proteasome activator subunit 1 isoform, Unnamed protein) and 7 down-regulated proteins (Serum amyloid P component, annexin IV, alpha 1 actin precursor, hypoxanthine-guanine phosphoribosyltransferase, tumor necrosis factor receptor superfamily member EDAR precursor, peroxiredoxin 2, translation elongation factor EF-Tu precursor) between myometrium and leiomyoma. CONCLUSION: 2-DE offer total protein expression between normal myometrium and uterine leiomyoma, and searching of differently expressed protein for the diagnostic markers of leiomyoma.