Basic Science and Pathogenesis.

Background: Excessive daytime sleepiness is a common and early symptom of Alzheimer's disease (AD). The subcortical wake-promoting neurons in the lateral hypothalamic area, tuberomammillary nucleus (TMN), and locus coeruleus synchronize to maintain wakefulness/arousal. Although significant neuronal decline occurs in wake-promoting regions, the TMN histaminergic neurons remain relatively more intact than orexinergic and nor-adrenergic neurons.

Basic Science and Pathogenesis.

Background: Common and rare variants in SORL1 have been associated with increased risk of Alzheimer's disease (AD). Since 2019, we have run an international collaborative research initiative to ascertain a Peruvian cohort for Alzheimer's disease and other related dementias for genetic studies (PeADI).

Method: A Peruvian family (4 AD cases and two mild cognitive impairment (MCI) cases) was recruited through the PeADI study.

Basic Science and Pathogenesis.

Background: Lewy body disease (LBD) is a neurodegenerative condition marked by the accumulation of neuronal alpha-synuclein, leading to both Parkinson's disease and Lewy body dementia. It is regarded as the second most common neurodegenerative disease associated with aging. However, there is limited knowledge of LBD prevalence in the general population, particularly among non-whites.

Basic Science and Pathogenesis.

Background: Clinicopathological studies suggest a role of minor cerebrovascular changes in the cognitive decline of individuals with a low neurodegenerative burden. However, it remains unclear whether small vascular brain lesions can impact cognition in middle aging individuals. Additionally, recent clinicopathological studies have shown that even a low Alzheimer's disease (AD) neuropathological burden can significantly impact neuropsychiatric function.

Basic Science and Pathogenesis.

Background: The study of dementia and its differences between the sexes is widely investigated, mainly in Alzheimer's disease. However, most studies on dementia are not carried out in a multiethnic population. Here we analyze demographic data, clinical symptoms, and neuropathological characteristics of a large mixed Brazilian sample.