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.

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.