People with dementia often struggle to judge time correctly. This problem, called time estimation issues, affects how they sense how long things last or when events happen. It makes daily life harder because they might think a short task took hours or forget how much time has passed since lunch.
In Alzheimer’s disease, one big challenge is estimating when symptoms will start. Harmful proteins called amyloid build up in the brain quietly for up to 20 years before confusion or memory loss shows up. Doctors now use a simple brain scan called an amyloid PET scan along with the person’s age to guess how far along the disease is and how many years until real problems begin. For example, if someone hits a key buildup point at age 50, it might take nearly 20 years for symptoms. But if it happens at age 80, symptoms could come in less than 10 years. Older brains often have other damage too, so less buildup is needed to cause trouble. This scan method gives a strong prediction, with results matching real diagnoses closely.
Other types of dementia change how people feel time passing with sounds or events. Folks with Alzheimer’s or frontotemporal dementia have trouble noticing small changes in how long a sound lasts. They might think a quick noise dragged on or miss when it ends. People with certain language-related dementias guess sound lengths wrong based on what the sound is, like overestimating nature noises or underestimating voices. These issues tie to damage in brain areas that handle senses and feelings.
Early clues of these time problems can appear before full dementia hits. Someone might repeat stories because they forgot they told them already, mix up time of day, or get lost in places they know well. Families notice this during gatherings when conversations confuse them or they pull away from talks.
New tools help spot these issues faster. Brain wave tests called EEGs use computer programs to check patterns and tell dementia types apart by looking at time-based brain activity. Slow waves in the front of the brain signal trouble in both Alzheimer’s and frontotemporal dementia, but Alzheimer’s spreads wider.
These time estimation problems come from deep brain changes that start years ahead. Spotting them early with scans or tests lets doctors plan better care.
Sources
https://medicine.washu.edu/news/time-until-dementia-symptoms-appear-can-be-estimated-via-brain-scan/
https://academic.oup.com/braincomms/advance-article/doi/10.1093/braincomms/fcaf496/8407400
https://www.fau.edu/newsdesk/articles/ai-eeg-decodes-dementia-type
https://www.bangkokhospital.com/en/bangkok-bone-brain/content/3m-memory-moving_multiple_sclerosis
https://www.medcentral.com/neurology/dementia/amyloid-pet-values-may-predict-dementia-risk-years-before-symptoms
https://www.trinityhealthmichigan.org/blog-articles/spotting-signs
