Incidence and Risk Factors of Osteonecrosis of the Femoral Head after Cephalomedullary Nailing for Pertrochanteric Fractures: Observational Single-Center Study.

Background: The objective of this study was to investigate the incidence of osteonecrosis of the femoral head (ONFH) after cephalomedullary nailing in elderly patients with pertrochanteric fractures and to analyze the risk factors related to ONFH. Methods: A total of 689 consecutive patients with cephalomedullary nailing for pertrochanteric fractures at our hospital were recruited. Of these, 368 patients who met the inclusion criteria were finally enrolled. ONFH after cephalomedullary nailing was identified by reviewing patients' electronic charts and serial radiographs. The ONFH group was then compared with the non-ONFH group. Results: ONFH was identified in 9 of 368 patients (2.4%). The time to diagnosis of ONFH averaged 23.8 months (range, 5-54 months) after index surgery. The mean age, body mass index, and bone mineral density (T-score in femur neck) were 84.1 ± 7.1 years, 23.7 ± 3.6 kg/m2, and -3.1 ± 0.7 kg/m2, respectively. The times from injury to surgery, from admission to surgery, and operation time averaged 4.2 ± 2.7 days, 3.6 ± 2.6 days, and 87.2 ± 30.0 minutes, respectively. Among 9 patients, 3 underwent conversion arthroplasty. The ONFH group had advanced age (p = 0.029), more basicervical fracture components (p = 0.002), and inadequate reduction (p = 0.045) compared to the non-ONFH group. On multivariate analysis, advanced age (odds ratio [OR], 1.61;, p = 0.022), basicervical fracture components (OR, 24.58; p = 0.001), and inadequate reduction (OR, 4.11; p = 0.039) were identified as risk factors of ONFH. Conclusions: Although ONFH is relatively rare after cephalomedullary nailing for pertrochanteric fractures in elderly patients, its risk may increase with advanced age, basicervical fracture components, and inadequate reduction. Therefore, in patients with these risk factors, meticulous and longer follow-up is needed even after bone union.

Simultaneous reduction and fixation using an anatomical suprapectineal quadrilateral surface plate through modified Stoppa approach in superomedially displaced acetabular fractures.

Treatment of superomedially displaced acetabular fractures including a quadrilateral surface (QLS) is challenging. We present a surgical technique using an anatomical suprapectineal QLS plate through the modified Stoppa approach and report the availability of this plate to treat this fracture type along with the surgical outcomes. Sixteen consecutive patients (14 men and 2 women) who underwent surgical treatment using an anatomical suprapectineal QLS plate through a modified Stoppa approach for superomedially displaced acetabular fractures between June 2018 and June 2020, were enrolled retrospectively. These fractures included 11 both-column fractures and 5 anterior-column and posterior hemitransverse fractures, which were confirmed on preoperative 3-dimensional computed tomography. Surgical outcomes were clinically assessed using the Postel Merle d'Aubigné (PMA) score and visual analog scale (VAS) score at the final follow-up, and radiological evaluations were performed immediately after the operation and at the final follow-up. For comparative analysis, 23 patients who underwent internal fixation with the conventional reconstruction plate through modified ilioinguinal approach between February 2010 and May 2018, were selected. This control group was composed of 18 both-column fractures and 5 anterior-column and posterior hemitransverse fractures. The follow-up period was at least 1 year in all patients. The mean operation time and blood loss was 109 min, and 853 ml, respectively, whereas 236 min, and 1843 ml in control group. Anatomical reduction was achieved in 14 (87.5%) patients, while imperfect reduction was achieved in the remaining 2 patients. At the final follow-up, radiographic grades were excellent, fair, and poor in 14 patients (87.5%), one, and one, respectively. The mean PMA score was 16.1 (range 13-18) and the mean VAS score was 1.0 (range 0-3). No secondary reduction loss or implant loosening was observed. However, 2 patients underwent conversion to total hip arthroplasty (THA) due to post-traumatic arthritis and subsequent joint pain. No other complications were observed. In the comparative analysis, radiological outcome showed a significant relationship with the conversion to THA (p = 0.013). Shorter operation time and less blood loss were significantly observed in the QLS plate fixation group through the modified Stoppa approach compared with the conventional reconstruction plate fixation group through modified ilioinguinal approach (p < 0.001, respectively). Simultaneous reduction and fixation using an anatomical suprapectineal QLS plate through the modified Stoppa approach may be a viable technique in superomedially displaced acetabular fractures along with shorter operation time and less blood loss.

Analysis of the Incidence and Risk Factors of Postoperative Delirium in Patients With Degenerative Cervical Myelopathy.

OBJECTIVE: The purpose of this study is to analyze various risk factors that can cause postoperative delirium (POD) in degenerative cervical myelopathy (DCM) patients, which may affect normal recovery and outcomes after surgery, and to help deal with them in advance and to take a medical approach. METHODS: A total of 148 patients aged 60 years or older who underwent laminoplasty or anterior cervical discectomy and fusion (ACDF) for DCM from 2008 to 2015 were included in this study. Incidence and multiple risk factors for development of POD were analyzed. RESULTS: POD occurred in 24 patients (16.2%). Among the 148 patients, 78 received laminoplasty, of whom 19 patients (24%) experienced delirium; the other 70 patients underwent ACDF, of whom 5 patients (7.1%) experienced delirium. History of Parkinson disease (odds ratio [OR], 178.242; p = 0.015), potassium level (OR, 3.764; p = 0.031), and surgical approach of laminoplasty over ACDF (OR, 8.538; p = 0.008) were found to be significant risk factors in a multivariate analysis. Age (OR, 1.056; p = 0.04) and potassium level (OR, 3.217; p = 0.04) were significant risk factors in the laminoplasty group. CONCLUSION: The findings of this study suggest that the incidence and risk factors for POD may vary in patients with DCM. It is necessary to understand multiple factors that affect the development of POD.

Implementation of a Skull-Conformal Phased Array for Transcranial Focused Ultrasound Therapy.

OBJECTIVE: To implement a skull-conformal phased array for ultrasound-guided transcranial focused ultrasound therapy with improved patient comfort. METHODS: Using patient-specific computed tomography and MRI neuroimaging data, tightly-conforming helmet scaffolds were designed computationally. The helmet scaffolds were designed to hold reusable transducer modules at near-normal incidence in an optimal configuration for the treatment location(s) of interest. Numerical simulations of trans-skull ultrasound propagation were performed to evaluate different conformal array designs and to compare with hemispherical arrays similar to those employed clinically. A 4096-element phased array was constructed by 3D printing a helmet scaffold optimised for an ex vivo human skullcap, and its performance was evaluated via benchtop and in vivo experiments. RESULTS: Acoustic field measurements confirmed the system's ability to focus through human skull bone using simulation-based transcranial aberration corrections. Preliminary in vivo testing demonstrated safe trans-human skull blood-brain barrier (BBB) opening in rodents. CONCLUSION: Patient-specific conformal ultrasound phased arrays appear to be a feasible and safe approach for conducting transcranial BBB opening procedures. SIGNIFICANCE: Skull-conformal phased arrays stand to improve patient comfort and have the potential to accelerate the adoption of transcranial FUS therapy by improving access to the technology.

Network Analysis of Language Disorganization in Patients with Schizophrenia.

Language disorganization, an objective component of formal thought process abnormality, has been regarded as a core symptom of schizophrenia from an evolutionary psychopathology perspective. However, to the best of our knowledge, the network structure of language disorganization has rarely been examined in patients with schizophrenia. Thus, our preliminary study aimed to evaluate the network structure using the Clinical Language Disorder Rating Scale (CLANG) in 167 inpatients with schizophrenia. All 17 of the CLANG items were considered to be ordered categorical variables ranging from 0 to 3. Our results indicated that disclosure failure, excess syntactic constraints, abnormal prosody, and aprosodic speech rank among the top five central domains within the network structure. We deemed that disclosure failure and prosody problems are the most important symptoms of language disorder in schizophrenia. Thus, reduced top-down processing of linguistic information may be a core neurobiological underpinning of language disorganization in schizophrenia. Further studies controlling for the potential effects of confounding factors (i.e., duration of illness) on network analyses of language disorder and formal thought disorder are warranted in patients with schizophrenia.

Factors Associated with Burnout among Healthcare Workers during an Outbreak of MERS.

OBJECTIVE: Although healthcare workers (HCWs) experienced significant stress during the 2015 outbreak of Middle East Respiratory Syndrome (MERS), the factors associated with this stress remain unknown. Thus, the present study assessed burnout among HCWs during the MERS outbreak to identify the influential factors involved in this process. METHODS: This study was a retrospective chart review of the psychological tests and questionnaires completed by 171 hospital employees from two general hospitals that treated MERS patients. The tests included the Oldenburg Burnout Inventory, Positive Resources Test, the questionnaires assessed exposure to the MERS outbreak event and perceptions about MERS. RESULTS: Of the 171 HCWs, 112 (65.5%) experienced disengagement and 136 (79.5%) suffered from exhaustion. Disengagement was associated with lower levels of purpose and hope, a higher perception of job risk, and exposure to the media. Exhaustion was associated with lower levels of purpose and hope, a higher perception of little control of the infection, a higher perception of job risk, prior experience related to infections, and being female. CONCLUSION: Our results revealed the risk and protective factors associated with burnout among HCWs during an outbreak of MERS. These findings should be considered when determining interventional strategies aimed at ameliorating burnout among HCWs.

Factors associated with quality of life in patients with depression: A nationwide population-based study.

BACKGROUND: Depression, one of the most costly and common mental disorders, is reported to be associated with lower quality of life (QoL) in several studies. Improved understanding of the associated factors with QoL is necessary to optimize long-term outcomes and reduce disability in patients with depression. Therefore, the aim of this study was to identify factors that are associated with lower QoL among patients with depression. METHODS: The study was based on the Korea National Health and Nutrition Examination Survey, a cross-sectional health examination, years 2008 to 2014. The final analyzed sample consisted of a total of 1,502 study subjects who had been diagnosed by clinicians as having depression. A multivariate logistic regression model was performed to exam the association between the clinical characteristics (age, sex, demographic and health-related characteristics) and QoL. Analysis of covariance was also used to analyze EQ-5D according to mental health. RESULTS: Older age, lower level of education, lower income, worse subjective perception of health, unemployment, obesity and mental health struggles were found to be significantly associated with low QoL in depressive individuals after adjustment for multiple covariates. CONCLUSIONS: This study has outlined grounding data in identifying patients who are at risk of QoL impairment. Policy makers should direct their interests to these individuals and provide appropriate management.

Psychometric Properties of the Korean Version of the Clinical Language Disorder Rating Scale (CLANG).

OBJECTIVE: Our study aimed to measure inter-rater and test-retest reliability, concurrent and convergent validity, and factor solutions of the Korean version of the Clinical Language Disorder Rating Scale (CLANG). METHODS: The Korean version of the CLANG for assessing thought, language, and communication, the Brief Psychiatric Rating Scale, Young Mania Rating Scale, and Calgary Depression Scale for Schizophrenia were used to evaluate language disorder, formal thought disorder, positive and negative symptoms, manic symptoms, and depressive symptoms, respectively, in 167 hospitalized patients with schizophrenia. The factor solution was obtained by the direct oblimin method. A receiver operating characteristic curve was used to find the optimal cut-off score for discriminating schizophrenia patients with and without disorganized speech. RESULTS: Inter-rater reliability was considered moderate (intraclass coefficient=0.67, F=3.30, p=0.04), and test-retest reliability was considered high (r=0.94, p＜0.001). Five factors, namely, pragmatics, disclosure, production, prosody, and association, were identified. An optimal cut-off score of 7 points with 84.5% sensitivity and 81.7% specificity was proposed for distinguishing schizophrenia patients with and without disorganized speech. CONCLUSION: Our findings suggest that the Korean version of the CLANG is a promising tool for evaluating language disorder in patients with schizophrenia.

The Effect of Choline Acetyltransferase Genotype on Donepezil Treatment Response in Patients with Alzheimer's Disease.

OBJECTIVE: We examined the difference in responses to donepezil between carriers and non-carriers of the A allele at the +4 position of the choline acetyltransferase (ChAT) gene in Koreans. METHODS: Patients who met the criteria for probable Alzheimer's disease (AD) (n=199) were recruited. Among these, 145 completed the 12-week follow-up evaluation and 135 completed the 26-week scheduled course. Differences and changes in the Korean version of the mini-mental state examination (MMSE-KC) score, Korean version of the Consortium to Establish a Registry for Alzheimer's Disease Neuropsychological Assessment Battery (CERAD-K[N]) wordlist subtest score (WSS), CERAD-K(N) total score (TS), and the Korean version of geriatric depression scale (GDS-K) score between baseline and 12 weeks or 26 weeks were assessed by the Student's t-test. RESULTS: At 12 weeks, the changes in the MMSE-KC score, CERAD-K(N) WSS, and CERAD-K(N) TS from baseline were not significant between ChAT A allele carriers and non-carriers; however, at 26 weeks, these changes were significantly larger in ChAT A allele carriers than in non-carriers (p=0.02 for MMSE-KC and p=0.03 for CERAD-K(N) WSS respectively). CONCLUSION: Our findings in this study suggested that presence of the A allele at the +4 position of ChAT might positively influence the treatment effect of donepezil in the early stages of AD in Koreans.

Reliability and validity of the Korean version of the Scale for the Assessment of Thought, Language, and Communication.

BACKGROUND: Our study aimed to assess the inter-rater and test-retest reliability, as well as concurrent and convergent validity, of the Korean version of the Scale for the Assessment of Thought, Language, and Communication (TLC scale). METHODS: The factor solutions and psychometric properties of the Korean version of the TLC scale were evaluated among 167 schizophrenia inpatients (study subjects) at two sites in South Korea. Using Pearson's correlation, the concurrent and convergent validities of each of the factor solutions were represented by the correlations with the scores on the Clinical Language Disorder Rating Scale, Brief Psychiatric Rating Scale, Young Mania Rating Scale, and Calgary Depression Scale. Using receiver operating characteristics curves, the optimal cut-off score for the Korean version of the TLC scale to distinguish between study subjects with and without disorganized speech, was identified. RESULTS: The results showed that the Korean version of the TLC scale has a three-factor solution: fluent disorganization, speech emptiness, and speech peculiarity. In addition, the interrater reliability of the Korean version of the TLC scale was moderately good (intraclass correlation coefficient = 0.51) and its test-retest reliability was very good (Pearson's correlation coefficient = 0.94). For detecting the current presence of disorganized speech, the optimal cut-off total score on the TLC scale was proposed to be 8 points (sensitivity = 88.1%; specificity = 82.9%). LIMITATIONS: Psychometric tools covering cognitive functions were not used in our study. CONCLUSIONS: The Korean version of the TLC scale is a promising psychometric method for examining formal thought disorder (FTD) and disorganized speech in schizophrenia patients.

Progressive decrease of N-acetylaspartate to total creatine ratio in the pregenual anterior cingulate cortex in patients with major depressive disorder: longitudinal 1H-MR spectroscopy study.

BACKGROUND: Longitudinal metabolic changes of total choline (tCho), creatine+phosphocreatine (total creatine, tCr), and N-acetylaspartate (NAA) in the pregenual anterior cingulate cortex (pACC) of patients with major depressive disorder (MDD) have not been well evaluated. PURPOSE: To evaluate the longitudinal changes of the metabolic levels of tCho, tCr, and NAA in the pACC of MDD patients and normal controls with the use of Single-voxel (1)HMRS. MATERIAL AND METHODS: Single-voxel (1)HMRS was acquired in the pACC of 21 female patients with MDD and 26 age- and gender-matched controls. Follow-up scans were acquired in 10 patients with MDD and 15 controls after 9-10 months from baseline scans. Absolute concentrations of tCho, tCr, and NAA, and the ratios of NAA/tCr and tCho/tCr were calculated and compared between and within groups. RESULTS: The patient group showed slightly improved clinical symptoms, as measured by Beck's Depression Inventory (P=0.035), after treatment with antidepressants. Comparison of baseline scans between the groups showed no differences in any of the absolute metabolite concentrations or ratios. The NAA/tCr ratio in the pACC of patients with MDD showed a significant decrease in the follow-up scan (P=0.032), and the NAA/tCr ratio of the baseline scan showed logarithmic negative association with illness duration (P=0.024). CONCLUSION: A progressive decrease in the NAA/tCr ratio in the pACC of patients with MDD was demonstrated and the decrease in this ratio was at the highest rate in the early period after illness onset. These findings indicate the neuronal degeneration and dysfunction of the pACC, and the importance of early clinical intervention in female patients with MDD.

Spatiotemporal Segregation of Neural Response to Auditory Stimulation: An fMRI Study Using Independent Component Analysis and Frequency-Domain Analysis.

Although auditory processing has been widely studied with conventional parametric methods, there have been a limited number of independent component analysis (ICA) applications in this area. The purpose of this study was to examine spatiotemporal behavior of brain networks in response to passive auditory stimulation using ICA. Continuous broadband noise was presented binaurally to 19 subjects with normal hearing. ICA was performed to segregate spatial networks, which were subsequently classified according to their temporal relation to the stimulus using power spectrum analysis. Classification of separated networks resulted in 3 stimulus-activated, 9 stimulus-deactivated, 2 stimulus-neutral (stimulus-dependent but not correlated with the stimulation timing), and 2 stimulus-unrelated (fluctuations that did not follow the stimulus cycles) components. As a result of such classification, spatiotemporal subdivisions were observed in a number of cortical structures, namely auditory, cingulate, and sensorimotor cortices, where parts of the same cortical network responded to the stimulus with different temporal patterns. The majority of the classified networks seemed to comprise subparts of the known resting-state networks (RSNs); however, they displayed different temporal behavior in response to the auditory stimulus, indicating stimulus-dependent temporal segregation of RSNs. Only one of nine deactivated networks coincided with the "classic" default-mode network, suggesting the existence of a stimulus-dependent default-mode network, different from that commonly accepted.

Brain volumetry in Parkinson's disease with and without dementia: where are the differences?

BACKGROUND: Cognitive dysfunction is well documented in Parkinson's disease (PD). However, association between regional brain volume change and cognitive decline of PD is uncertain. PURPOSE: To compare regional brain volume difference between PD without dementia (PDND) and PD with dementia (PDD). MATERIAL AND METHODS: We enrolled 16 normal controls (mean ± SD: 69.5 ± 6.31) and 32 sex-, age-matched patients with PD (16 PDND and 16 PDD patients with Hoehn & Yahr stage II or III). Cognitive function was assessed using mini-mental status examination (MMSE). Intracranial volume (ICV) and the hippocampal volumes were manually measured using magnetic resonance imaging (MRI). Regional gray/white matter volume changes were analyzed using voxel-based morphometry. RESULTS: Age, ICV, volume of gray matter volume (GMV), white matter, and hippocampi did not differ among the three groups. The regional GMV of PDD was significantly decreased in the areas of right middle frontal gyrus, short insular gyri, superior temporal gyri; both precuneus compared to PDND (uncorrected P < 0.001). In the partial correlation analysis (controlled for age, sex, ICV), regional GMV of PD was positively correlated with MMSE score in the areas of short insular gyri, right circular insular sulcus, right calcarine sulcus, left superior temporal gyrus (planum porale), and left inferior precentral sulcus (uncorrected P < 0.001). CONCLUSION: We suggest that the volume loss of hippocampus may not be a finding in developing of PDD while variation of the regional volume of the frontal, insular cortex, superior temporal gyri, and precuneus lobes may be a phenomenon of PDD.

Clonazepam quiets tinnitus: a randomised crossover study with Ginkgo biloba.

OBJECTIVE: To assess the effect of Ginkgo biloba and clonazepam, a γ-aminobutyric acid (GABA)-receptor agonist, upon tinnitus. METHODS: This was an open-label, randomised, crossover study. 27 men and 11 women (aged 16-80 (mean 58)) with tinnitus for more than 2 months were enrolled. Participants were randomised to either clonazepam or G biloba for the first 3 weeks. For the next 2 weeks of washout no medication was taken. For the final 3 weeks, subjects were given the other drug. The initial dose of clonazepam and G biloba was one tablet daily (clonazepam 0.5 mg; G biloba 40 mg). Subjects were instructed to increase the dose by one tablet every 3 days to a maximum of four tablets daily until they perceived a satisfactory decrease in tinnitus loudness or intolerable side effects. Tinnitus was assessed with pitch and loudness matching, tinnitus handicap inventory, and visual analogue scales of loudness, duration and annoyance. RESULTS: Comparing before and after each drug, clonazepam significantly improved tinnitus loudness (74% of subjects), duration (63%), annoyance (79%), and tinnitus handicap inventory score (61%), whereas the G biloba showed no significant differences on any of these measures. CONCLUSION: Clonazepam is effective in treating tinnitus; G biloba is ineffective.

The effects of perfectionism on academic achievement in medical students.

PURPOSE: The purpose of this study was to explore the differential effects of multi-dimensional perfectionism on academic achievement, depression, engagement, and burnout in medical students. Also, the mediating effects of engagement on perfectionism and academic achievement, as well as the effects of burnout on perfectionism and depression, were examined. METHODS: Two hundred eight medical students participated, and 167 students completed questionnaires, including the Frost Multi-dimensional Perfectionism Scale (FMPS), Hewitt & Flett Multi-dimensional Perfectionism Scale (HFMPS), Beck Depression Inventory (BDI), Schaufeli Engagement Scale (SES), and Malslach Burnout Inventory-General Survey (MBI-GS). Academic achievement was measured as the grade point average (GPA) of the previous semester. Data were analyzed by correlation analyses, independent t-tests, and Structural Equation Model (SEM) for path analysis. RESULTS: Adaptive perfectionism (personal standard, self-oriented perfectionism) was associated with GPA (r=0.164, p<0.05; r=0.173, p<0.05) and engagement (r=0.394, p<0.01; r=0.449, p<0.01), and maladaptive perfectionism (parental criticism, concern over mistakes, socially prescribed perfectionism) was associated with depression (r=0.208, p<0.01; r=0.254, p<0.01; r=0.234, p<0.01) and burnout (r=0.218, p<0.01; r=0.236, p<0.01; r=0.280, p<0.01). Engagement had mediating effects on adaptive perfectionism and GPA, and burnout had mediating effects on maladaptive perfectionism and depression. Students who experienced academic failure had lower engagement than those who did not. CONCLUSION: This study demonstrates that academic achievement and emotional difficulties such as depression are determined by adaptive and maladaptive perfectionism, respectively, in medical students.

Validation of hippocampal volumes measured using a manual method and two automated methods (FreeSurfer and IBASPM) in chronic major depressive disorder.

INTRODUCTION: To validate the usefulness of the packages available for automated hippocampal volumetry, we measured hippocampal volumes using one manual and two recently developed automated volumetric methods. METHODS: The study included T1-weighted magnetic resonance imaging (MRI) of 21 patients with chronic major depressive disorder (MDD) and 20 normal controls. Using coronal turbo field echo (TFE) MRI with a slice thickness of 1.3 mm, the hippocampal volumes were measured using three methods: manual volumetry, surface-based parcellation using FreeSurfer, and individual atlas-based volumetry using IBASPM. In addition, the intracranial cavity volume (ICV) was measured manually. RESULTS: The absolute left hippocampal volume of the patients with MDD measured using all three methods was significantly smaller than the left hippocampal volume of the normal controls (manual P = 0.029, FreeSurfer P = 0.035, IBASPM P = 0.018). After controlling for the ICV, except for the right hippocampal volume measured using FreeSurfer, both measured hippocampal volumes of the patients with MDD were significantly smaller than the measured hippocampal volumes of the normal controls (right manual P = 0.019, IBASPM P = 0.012; left manual P = 0.003, FreeSurfer P = 0.010, IBASPM P = 0.002),. In the intrarater reliability test, the intraclass correlation coefficients (ICCs) were all excellent (manual right 0.947, left 0.934; FreeSurfer right 1.000, left 1.000; IBASPM right 1.000, left 1.000). In the test of agreement between the volumetric methods, the ICCs were right 0.846 and left 0.848 (manual and FreeSurfer), and right 0.654 and left 0.717 (manual and IBASPM). CONCLUSION: The automated hippocampal volumetric methods showed good agreement with manual hippocampal volumetry, but the volume measured using FreeSurfer was 35% larger and the agreement was questionable with IBASPM. Although the automated methods could detect hippocampal atrophy in the patients with MDD, the results indicate that manual hippocampal volumetry is still the gold standard, while the automated volumetric methods need to be improved.

Development of sound measurement systems for auditory functional magnetic resonance imaging.

Auditory functional magnetic resonance imaging (fMRI) requires quantification of sound stimuli in the magnetic environment and adequate isolation of background noise. We report the development of two novel sound measurement systems that accurately measure the sound intensity inside the ear, which can simultaneously provide the similar or greater amount of scanner- noise protection than ear-muffs. First, we placed a 2.6 x 2.6-mm microphone in an insert phone that was connected to a headphone [microphone-integrated, foam-tipped insert-phone with a headphone (MIHP)]. This attenuated scanner noise by 37.8+/-4.6 dB, a level better than the reference amount obtained using earmuffs. The nonmetallic optical microphone was integrated with a headphone [optical microphone in a headphone (OMHP)] and it effectively detected the change of sound intensity caused by variable compression on the cushions of the headphone. Wearing the OMHP reduced the noise by 28.5+/-5.9 dB and did not affect echoplanar magnetic resonance images. We also performed an auditory fMRI study using the MIHP system and presented increase in the auditory cortical activation following 10-dB increment in the intensity of sound stimulation. These two newly developed sound measurement systems successfully achieved the accurate quantification of sound stimuli with maintaining the similar level of noise protection of wearing earmuffs in the auditory fMRI experiment.

The prevalence of dementia in older people in an urban population of Korea: the Seoul study.

OBJECTIVES: To estimate prevalence of dementia and its subtypes in older people in Seoul, a metropolitan area of Korea, and compare these findings with estimates reported for other populations. DESIGN: The study employed a two-stage design for case identification. Initially, the Mini-Mental State Examination in the Korean version (MMSE-KC) of the Consortium to Establish a Registry for Alzheimer's Disease (CERAD) assessment packet was administered to all participants. Two hundred seventeen persons sampled from three levels of performance on MMSE-KC underwent the second-stage clinical evaluation based on the Korean Version of the CERAD assessment packet. SETTING: The study was conducted in an urban community setting. PARTICIPANTS: Six hundred forty-three persons aged 65 and over participated in the study. MEASUREMENTS: Dementia was defined using the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition diagnostic features of dementia. RESULTS: Dementia prevalence ranged from 2.6% in persons aged 65 to 69 to 32.6% in persons aged 85 and older. Age-standardized prevalence was 8.2% for dementia, 5.4% for Alzheimer's disease, and 2.0% for vascular dementia. The prevalence estimates, which excluded very mild cases (clinical dementia rating index 0.5), were approximately 5.3% for dementia and 4.3% for Alzheimer's disease. CONCLUSION: The prevalence of dementia in older people in Seoul appears to be somewhat lower than in rural areas of Korea. Considering the difficulties involved in establishing a diagnostic threshold for dementia, actual differences in dementia prevalence between Asian populations are probably minimal.