A systematic review of atypical Alzheimer's disease including behavioural and psychological symptoms.

Alzheimer's disease (AD) is the commonest cause of dementia, characterized by the clinical presentation of progressive anterograde episodic memory impairment. However, atypical presentation of patients is increasingly recognized. These atypical AD include logopenic aphasia, behavioural variant AD, posterior cortical atrophy, and corticobasal syndrome. These atypical AD are more common in patients with young onset AD before the age of 65 years old. Since medical needs (including the behavioural and psychological symptoms of dementia) of atypical AD patients could be different from typical AD patients, it is important for clinicians to be aware of these atypical forms of AD. In addition, disease modifying treatment may be available in the future. This review aims at providing an update on various important subtypes of atypical AD including behavioural and psychological symptoms.

Prevalence of hyperphagia in Alzheimer's disease: a meta-analysis.

BACKGROUND: Unlike other behavioural and psychological symptoms of dementia, hyperphagia is less recognized among patients with Alzheimer's disease (AD). The prevalence of hyperphagia varies among studies, but there has been no systematic review or meta-analysis. METHODS: An extensive search on the literature on hyperphagia in AD published between 1 January 1980 and 30 October 2017 was conducted. Data on the prevalence were retrieved. Meta-analysis with a random effect model was performed to determine the pooled estimate of prevalence. Meta-regression analysis was performed based on study characteristics, population demographics, or condition information. RESULTS: Results from 20 studies were extracted. Twenty-six reported cases of hyperphagia were identified. The mean age of onset was 70.7 ± 8.9 years, with a male predominance (68.4%). Hyperphagia occurred in all stages of AD. Only eight studies reported the prevalence of hyperphagia. Meta-analysis showed a pooled prevalence of hyperphagia of 18.6%. Publication bias may have been present. Meta-regression showed that ethnicity accounted for the variance among studies (coefficient: -1.247 (95% confidence interval: -1.978 to -0.516), R2 analogue: 0.77, P < 0.001). CONCLUSIONS: Hyperphagia occurs in all stages of AD. In this meta-analysis of eight published studies, the prevalence of hyperphagia was 18.6%. In view of the possible publication bias, a large-scale study on hyperphagia is recommended in the future.

Chinese patients with Lewy body dementia had shorter survival and developed complications earlier than those with Alzheimer's disease.

INTRODUCTION: Alzheimer's disease (AD) and Lewy body dementia (LBD) are two common forms of dementia. There are still controversies regarding whether LBD patients have a worse clinical course than AD patients. METHODS: We retrospectively reviewed all biomarkers that supported AD and LBD patients presenting to the Memory Clinic of Queen Mary Hospital, Hong Kong, between 1 January 2008 and 30 December 2016. Diagnoses of AD and LBD were supported by clinical diagnostic criteria and biomarkers. LBD patients included those with dementia with Lewy bodies (DLB) and Parkinson's disease dementia (PDD). Baseline demographics, presenting clinical features, degree of cognitive impairment and specified clinical outcomes were compared. RESULTS: We recruited 31 AD and 25 LBD patients (18 DLB, 7 PDD). When measured from disease onset, LBD patients were noted to have shorter overall survival (p = 0.02) with earlier occurrence of falls (p < 0.001), dysphagia (p < 0.001), pneumonia (p = 0.01), pressure injuries (p = 0.003) and institutionalisation (p = 0.03) than AD patients. Cox regression analyses showed that LBD predicted falls (hazard ratio [HR] 5.86, 95% confidence interval [CI] 2.29-15.01, p < 0.001), dysphagia (HR 10.06, 95% CI 2.50-40.44, p = 0.001), pressure injuries (HR 17.39, 95% CI 1.51-200.10, p = 0.02), institutionalisation (HR 2.72, 95% CI 1.12-6.60, p = 0.03) and death (HR 2.96, 95% CI 1.18-7.42, p = 0.02). CONCLUSION: LBD patients had shorter overall survival with earlier occurrence of pre-specified long-term events compared with AD patients. LBD also independently predicted pre-specified long-term events.

Novel presenilin 1 mutation (p.F386I) in a Chinese family with early-onset Alzheimer's disease.

Autosomal dominant familial Alzheimer's disease accounts for 0.5% of all Alzheimer's disease. A familial Alzheimer's disease Chinese family, with 7 affected family members, underwent PSEN1 screening in 3 affected family members. A heterozygous novel missense mutation in the PSEN1 gene c.1156T>A, altering phenylalanine to isoleucine at codon 386, was identified. Because the change occurred in conserved domains of this gene and cosegregated with affected family members, this change may have a mutagenic and probably pathogenic effect.