Alzheimer's Early Neurofibrillary Tangles Linked to Sleep Disturbances

A study published in the Journal of Alzheimer's Disease from researchers at the University of California, San Francisco (UCSF) and the University of São Paulo demonstrated that the earliest stages of brain atrophy associated with Alzheimer's are linked to neuropsychiatric symptoms including anxiety, depression, loss of appetite, and sleep disturbances, reports Sleep Review . They suggest the findings could support earlier Alzheimer's diagnosis and provide a valuable biomarker in the development of therapies. "The discovery that the biological basis for these symptoms is the early Alzheimer's pathology itself was quite surprising," says UCSF's Lea Grinberg. "It suggests these people with neuropsychiatric symptoms are not at risk of developing Alzheimer's disease — they already have it." The investigators examined the brains of 1,092 seemingly healthy adults older than 50 in São Paulo, ultimately focusing on 455 brains with either no signs of degeneration or a range of Alzheimer's-related pathology. In persons whose brainstems exhibited the very earliest stages of neurofibrillary (NF) tangles but lacked memory changes, relatives and caregivers reported increased rates of one or more neuropsychiatric symptoms including agitation, anxiety, appetite changes, depression, and sleep disturbances, but no perceived memory problems. Greater NF buildup in the brainstem was associated with increased odds of agitation. Later stages in which NF accumulation reached the brain's outer cortex were accompanied by dementia-like delusions and Alzheimer's-associated cognitive and memory decline.