An increasing population of dementia patients produces substantial societal impacts. We assessed the prevalence of mild cognitive impairment (MCI) and all-cause dementia, including very mild dementia (VMD), in Taiwan. In a nationwide population-based cross-sectional survey, participants were selected by computerized random sampling from all 19 Taiwan counties and were enrolled between December 2011 and March 2013. Cases were identified through in-person interviews based on the National Institute on Aging-Alzheimer’s Association clinical criteria. Demographic data and histories involving mental status and function in daily living were collected. The principal objective assessments were the Taiwanese Mental Status Examination and Clinical Dementia Rating. In all, 10,432 people aged 65 years or older (mean age 76.2±6.7, 52.3% women) were interviewed. The age-adjusted prevalence of all-cause dementia was 8.04% (95% CI 7.47–8.61), including a 3.25% (95% CI 2.89–3.61) prevalence of VMD; that of MCI was 18.76% (95% CI 17.91–19.61). Women had a higher prevalence than men of both all-cause dementia (9.71% vs. 6.36%) and MCI (21.63% vs. 15.57%). MCI affects a considerable portion of the population aged 65 and above in Taiwan. The inclusion of VMD yields dementia prevalence rates higher than those previously reported from Taiwan. Old age, female gender, and a low educational level are significant associated factors.

Objective To examine whether plasma neurofilament light chain (NfL) levels were associated with motor and cognitive progression in Parkinson disease (PD). Methods This prospective follow-up study enrolled 178 participants, including 116 with PD, 22 with multiple system atrophy (MSA), and 40 healthy controls. We measured plasma NfL levels with electrochemiluminescence immunoassay. Patients with PD received evaluations of motor and cognition at baseline and at a mean follow-up interval of 3 years. Changes in the Unified Parkinson9s Disease Rating Scale (UPDRS) part III motor score and Mini-Mental State Examination score were used to assess motor and cognition progression. Results Plasma NfL levels were significantly higher in the MSA group than in the PD and healthy groups (35.8 ± 6.2, 17.6 ± 2.8, and 10.6 ± 2.3 pg/mL, respectively, p < 0.001). In the PD group, NfL levels were significantly elevated in patients with advanced Hoehn-Yahr stage and patients with dementia (p < 0.001). NfL levels were modestly correlated with UPDRS part III scores (r = 0.42, 95% confidence interval 0.46–0.56, p < 0.001). After a mean follow-up of 3.4 ± 1.2 years, a Cox regression analysis adjusted for age, sex, disease duration, and baseline motor or cognitive status showed that higher baseline NfL levels were associated with higher risks for either motor or cognition progression (p = 0.029 and p = 0.015, respectively). Conclusions Plasma NfL levels correlated with disease severity and progression in terms of both motor and cognitive functions in PD. Classification of evidence This study provides Class III evidence that plasma NfL level distinguishes PD from MSA and is a surrogate biomarker for PD progression.

The purpose of this paper is to integrate the technologies of radio frequency identification, global positioning system, global system for mobile communications, and geographic information system (GIS) to construct a stray prevention system for elderly persons suffering from dementia without interfering with their activities of daily livings. We also aim to improve the passive and manpowered way of searching the missing patient with the help of the information technology. Our system provides four monitoring schemes, including indoor residence monitoring, outdoor activity area monitoring, emergency rescue, and remote monitoring modes, and we have developed a service platform to implement these monitoring schemes. The platform consists of a web service server, a database server, a message controller server, and a health-GIS (H-GIS) server. Family members or volunteer workers can identify the real-time positions of missing elderly using mobile phone, PDA, Notebook PC, and various mobile devices through the service platform. System performance and reliability is analyzed. Experiments performed on four different time slots, from three locations, through three mobile telecommunication companies show that the overall transaction time is 34 s and the average deviation of the geographical location is about 8 m. A questionnaire surveyed by 11 users show that eight users are satisfied with the system stability and 10 users would like to carry the locating device themselves, or recommend it to their family members

The 42 amino acid form of amyloid-β (Aβ ₄₂ ) plays a key role in the pathogenesis of Alzheimer’s disease (AD) and is a core biomarker for the diagnosis of AD. Numerous studies have shown that cerebrospinal fluid (CSF) Aβ ₄₂ concentrations are decreased in AD, when measured by enzyme-linked immunosorbent assay (ELISA) and other conventional immunoassays. While most studies report no change in plasma Aβ ₄₂ , independent studies using the immunomagnetic reduction (IMR) technique report an increase in plasma Aβ ₄₂ levels in AD. To confirm the opposite changes of Aβ ₄₂ levels in CSF and plasma for AD, we assayed the levels of Aβ ₄₂ in plasma of subjects with known CSF Aβ ₄₂ levels. In total 43 controls and 63 AD patients were selected at two sites: the VU University Medical Center ( n = 55) and Sahlgrenska University Hospital ( n = 51). IMR and ELISA were applied to assay Aβ ₄₂ in plasma and CSF, respectively. We found a moderately negative correlation between plasma and CSF Aβ ₄₂ levels in AD patients ( r = –0.352), and a weakly positive correlation in controls ( r = 0.186). These findings further corroborate that there are opposite changes of Aβ ₄₂ levels in CSF and plasma in AD. The possible causes for the negative correlation are discussed by taken assay technologies, Aβ ₄₂ transport from brain to peripheral blood, and sample matrix into account.

Objective α-Synuclein is critical to the pathogenesis of Parkinson’s disease (PD). Few studies examined the plasma levels of α-synuclein due to the exceptionally low level of α-synuclein in plasma compared with cerebrospinal fluid. We aimed to investigate plasma α-synuclein in patients with PD of different disease severity. Methods There were total 114 participants, including 80 patients with PD and 34 controls, in the study. Participants received a complete evaluation of motor and non-motor symptoms, including cognitive function. We applied immunomagnetic reduction-based immunoassay to measure plasma levels of α-synuclein. Results Plasma levels of α-synuclein were significantly higher in patients with PD compared with controls (median: 1.56 pg/mL, 95% CI 1.02 to 1.98 pg/mL vs 0.02 pg/mL, 95% CI 0.01 to 0.03 pg/mL; p<0.0001). Although there was a significant increase in plasma α-synuclein levels in PD patients with a higher Hoehn-Yahr (H-Y) stage, there was no correlation with motor symptom severity, as assessed by Unified Parkinson’s Disease Rating Scale part III scores, after confounders (age, gender, and disease duration) were taken into account. However, plasma α-synuclein levels were significantly higher in PD patients with dementia (PDD) than in PD patients with mild cognitive impairment (PD-MCI) or normal cognition (0.42 pg/mL, (95% CI 0.25 to 0.93) for PD with normal cognition; 1.29 pg/mL (95% CI 0.76 to 1.93) for PD-MCI and 4.09 pg/mL (95% CI 1.99 to 6.19) for PDD, p<0.01) and were negatively correlated with Mini-Mental State Examination scores (R²-adjusted=0.3004, p<0.001), even after confounder adjustment. Conclusions Our data suggest that plasma α-synuclein level correlates with cognitive decline but not motor severity in patients with PD. Plasma α-synuclein could serve as a surrogate biomarker for patients at risk of cognitive decline.

Identification of subjects at the early stages of Alzheimer’s disease (AD) is fundamental for drug development and possible intervention or prevention of cognitive decline. The concept of mild cognitive impairment (MCI) evolved during the past two decades to define subjects at the transitional stage between normal aging and dementia. Evidence from cross-sectional and longitudinal studies has shown that MCI is associated with an increased risk of positive AD biomarkers and an increased annual conversion rate of 5%–17% to AD. The presence of AD biomarkers in subjects with MCI was associated with an even higher risk of progression to dementia. However, earlier clinical trials for pharmacotherapy in subjects with MCI were disappointing. To extend the spectrum of AD to an earlier stage before MCI, subjective cognitive decline (SCD) was introduced and was defined as self-reported cognitive decline before the deficits could be detected by cognitive tests. Subjects with SCD have an increased risk of underlying AD pathology. However, SCD can also develop secondary to other heterogeneous etiologies, including other neurodegenerative and psychiatric diseases, personality traits, physical conditions, and medication use. Several clinical and biomarker features were proposed to predict risk of conversion to AD in subjects with SCD. Further longitudinal studies are needed to support the validity of these high-risk features.