Coping with Dementia in the Middle of the COVID-19 Pandemic

Multiple neurological complications have been associated with the coronavirus disease-19 (COVID-19), which is caused by severe acute respiratory syndrome coronavirus 2. This is a narrative review to gather information on all aspects of COVID-19 in elderly patients with cognitive impairment. First, the following three mechanisms have been proposed to underlie the neurological complications associated with COVID-19: 1) direct invasion, 2) immune and inflammatory reaction, and 3) hypoxic brain damage by COVID-19. Next, because the elderly dementia patient population is particularly vulnerable to COVID-19, we discussed risk factors and difficulties associated with cognitive disorders in this vulnerable population. We also reviewed the effects of the patient living environment in COVID-19 cases that required intensive care unit (ICU) care. Furthermore, we analyzed the impact of stringent social restrictions and COVID-19 pandemic-mediated policies on dementia patients and care providers. Finally, we provided the following strategies for working with elderly dementia patients: general preventive methods; dementia care at home and nursing facilities according to the activities of daily living and dementia characteristics; ICU care after COVID-19 infection; and public health care system and government response. We propose that longitudinal follow-up studies are needed to fully examine COVID-19 associated neurological complications, such as dementia, and the efficacy of telemedicine/telehealth care programs.

Multimodal Assessment of Neural Substrates in Computerized Cognitive Training: A Preliminary Study

BACKGROUND AND PURPOSE: Several studies have validated the clinical efficacy of computerized cognitive training applications. However, few studies have investigated the neural substrates of these training applications using simultaneous multimodal neuroimaging modalities. We aimed to determine the effectiveness of computerized cognitive training and corresponding neural substrates through a multimodal approach. METHODS: Ten patients with mild cognitive impairment (MCI), six patients with subjective memory impairment (SMI), and 10 normal controls received custom-developed computerized cognitive training in the memory clinic of a university hospital. All of the participants completed 24 sessions of computerized cognitive training, each lasting 40 minutes and performed twice weekly. They were assessed using neuropsychological tests (both computerized and conventional), electroencephalography, fluorodeoxyglucose positron-emission tomography (FDG-PET), volumetric magnetic resonance imaging (MRI), and diffusion-tensor imaging (DTI) at pre- and posttraining. RESULTS: The patients with MCI exhibited significant improvements in the trail-making test–black & white-B, and memory domain of the computerized cognitive assessment. Subjects with normal cognition exhibited significant improvements in scores in the language and attention-/psychomotor-speed domains. There were no significant changes in subjects with SMI. In the pre- and posttraining evaluations of the MCI group, FDG-PET showed focal activation in the left anterior insula and anterior cingulate after training. Volumetric MRI showed a focal increase in the cortical thickness in the rostral anterior cingulate. DTI revealed increased fractional anisotropy in several regions, including the anterior cingulate. CONCLUSIONS: The anterior cingulate and anterior insula, which are parts of the salience network, may be substrates for the improvements in cognitive function induced by computerized cognitive training.

Re-standardization of the Korean- Instrumental Activities of Daily Living (K-IADL): Clinical Usefulness for Various Neurodegenerative Diseases

BACKGROUND AND PURPOSE: Evaluating instrumental activities of daily living (IADL) is an important part of procedure to diagnose dementia. The Korean-Instrumental Activities of Daily Living (K-IADL) has been used extensively in Korea. However, its cut-off score has not been reformulated since 2002. The purpose of this study was to yield a new optimal cut-off score for the K-IADL and confirm the validity of this new cut-off score with various dementia groups. METHODS: We retrospectively collected a total of 2,347 patients' K-IADL data from 6 general hospitals in Korea. These patients had mild cognitive impairment (MCI) or dementia with various etiologies for cognitive impairment. We also recruited a normal control group (n=254) from the community. Korean-Mini Mental State Examination, Short version of the Geriatric Depression Scale, Clinical Dementia Rating, and Global Deterioration Scale were administered to all participants. Caregivers completed K-IADL and Barthel Index. RESULTS: K-IADL scores were significantly different among dementia subgroups, but not significantly different among MCI subgroups. Based on internal consistency, correlations with other scales, and factor analysis, K-IADL showed excellent reliability and validity. The new optimal cut-off score to diagnose dementia was 0.40, which gave a sensitivity of 0.901 and a specificity of 0.916. Positive predictive value for dementia using the new cut-off score was 94.2% for Alzheimer's disease, 100% for vascular dementia, and 84% for Parkinson's disease. CONCLUSIONS: Our results illustrate that the new K-IADL cut-off score of 0.40 is reliable and valid for screening impairments of daily functioning resulting from various etiologies.

A Comparison of Five Types of Trail Making Test in Korean Elderly

BACKGROUND AND PURPOSE: Previously developed Korean versions of the Trail Making Test (TMT) that replaced the English in part B, has been unsuccessful in Korea. The current study identifies the type of TMT tasks from the among multiple TMT versions, which practically and accurately detects the stage of cognitive decline. METHODS: We applied five TMT versions, which include the original TMT, TMT-Korean letter (TMT-KL), TMT-Korean consonant (TMT-KC), TMT-black and white (TMT-B&W), and TMT-square and circle (TMT-S&C). A total of 168 participants were enrolled: 42 cognitively normal controls (NC), 72 patients with mild cognitive impairment (MCI), and 54 patients with Alzheimer's disease (AD). Two sets of TMT (set "A" including TMT, TMT-KL and TMT-B&W, and set "B" including TMT, TMT-KC, and TMT-S&C) were randomly administered to subjects within the contact of a fixed neuropsychological battery. RESULTS: The completion times of TMT-B and TMT-B&W successfully distinguished NC from MCI and AD. TMT-B&W also showed a high correlation with other neuropsychological tests, and correlated well with the original TMT. The other TMT were frequently not successfully completed, nor could they differentiate the clinical groups. CONCLUSIONS: Among the five TMT tasks, the original TMT and the TMT-B&W appeared to be most sensitive to the degree of cognitive impairment. TMT-B&W showed a pattern consistent with the original TMT; thus, this measure may be optimal in Korean older adults, where familiarity with the English alphabet is questionable.

Representational Neglect in Left Anterior Cerebral Artery Infarction

We report a patient with a left anterior cerebral artery (ACA) infarct showing representational neglect. Representational neglect is some form of neglect to areas of imagined space. We believe that the description of our case gives further information about neglect syndrome and the functional asymmetry of the cerebral hemispheres because these observations are rare.

A Case with Viral Encephalitis presenting a Dissociations in the Retrograde Amnesia

We describe a case of anterograde and retrograde amnesia resulting from probable herpes simplex encephalitis. In retrograde amnesia, dissociations not only between episodic and semantic memories, but also between semantic memories for personal and public things were observed. We postulated, using FDG-PET, that the former was caused by mesial temporal lesions, based on `multiple trace theory', and the latter, by bilateral lateral temporal lesions, which were probably related to the retrieval of semantic memory, especially for public things.

Neuropsychology and PET Findings of Corticobasal Degeneration

BACKGROUND: Corticobasal degeneration (CBD) is a rare neurodegenerative disorder involving the cortical and subcortical areas enabling it to cause abnormalities of both cognition and movement. In some reports, CBD has been known to develop variable degrees of intellectual, memory and language impairment. However, detailed neuropsychological assessments of CBD up to now have been few. We conducted a detailed neuropsychological investigation and FDG-PET to delineate the pattern of neuropsychological dysfunction of CBD and to correlate neuropsychological dysfunction with FDG-PET findings. METHODS: All 6 patients (5; right handedness, 1; left handedness) were diagnosed with CBD using clinical criteria. All the patients underwent detailed neuropsychological and brain FDG-PET tests. RESULTS: Neuropsychological tests showed multiple cognitive dysfunctions with moderate memory impairment. FDG-PET scans showed asymmetric decreased metabolism in bilateral fronoto-temporo-parietal cortical and subcortical areas. The extent of asymmetricity was greater on the subcortical than cortical areas. Unlike previous reports, the medial temporal and fronto-parietal metabolisms were similarly depressed. CONCLUSIONS: All CBD patients displayed prominent deficits on mostly cognitive domains. FDG-PET may explain the relation between cognitive dysfunctions and cortical hypometabolism and help differentiate CBD with other dementing disorders.

Subtypes and Their Clinical Characteristics of Mild Cognitive Impairment (MCI): Cross Sectional Study

BACKGROUND: Mild cognitive impairment (MCI) represents a transitional state between the cognitive changes of normal aging and very early dementia. Recently, the published MCI classification in `The Current Concepts in MCI Conference' suggested subtypes of MCI (amnestic, single nonmemory domain, multiple domains slightly impared) based on recognized heterogeneity. The purpose of this study was to ascertain the existence of subtypes of MCI and investigate their relative prevalence and clinical characteristics. METHODS: We recruited the MCI patients according to the consensus criteria of MCI. We classified them into 3 subtypes of MCI by our working criteria based on the definitions of MCI subtypes and then calculated their respective prevalence. We described their various clinical variables including demographic features, symptoms on the first visit, neuroimaging findings, and the genotype of apolipoprotein E. RESULTS: Sixty patients (36 females and 24 males) were enrolled as MCI and analyzed. The prevalence of each subtype (amnestic, single nonmemory domain, multiple domains slightly impared) were 13 (21.67%), 24 (40.0%), and 23 (38.33%) respectively, suggesting the most prevalent type was the single nonmemory domain type. MCI cases with subcortical vascular features were 18 (11 single nonmemory domain and 7 multiple domains slightly impaired). The ApoE epsilon4 carriers were about 50% of tested patients. CONCLUSIONS: We ascertained the existence of MCI subtypes and investigated their prevalence and various clinical features. In evaluation of MCI patients, we should keep the notion of heterogeneity and subclassification in mind.