Researchers from the Center for Brain Research at the Indian Institute of Science (IISc) have studied the behavioural and physiological changes in the brains of persons showing early signs of dementia to understand and aid early diagnosis. They aimed to understand the neurocognitive changes, which involve both the brain's thinking processes and the physical structure of the brain itself, in individuals showing early signs of cognitive decline.
Dementia is a term used to describe a variety of brain disorders that result in a long-term and often gradual decrease in the ability to think and remember. It eventually leads to memory loss, further mental decline, and, ultimately, the inability to carry out daily activities. Alzheimer's disease is the most common form of dementia. Symptoms often start with mild forgetfulness, confusion over words, and getting lost in familiar places. As the condition progresses, it can cause severe cognitive decline, impacting judgment, language, problem-solving, and even mood or behaviour. For many families, dementia significantly affects their loved ones and presents various challenges in caregiving.
Research has shown that the changes in the brain that lead to dementia or Alzheimer's disease start a long time before any symptoms come to light. Recently, scientists have been keenly interested in a condition called "Subjective Cognitive Decline" (SCD). Individuals with SCD experience a sense of memory loss or cognitive difficulty, even though standard tests show their mental functions to be normal. A subset of this condition called "SCD plus" criteria is believed to have a higher chance of developing more serious memory problems in the future, such as Mild Cognitive Impairment (MCI) and, ultimately, Alzheimer’s Disease (AD). Understanding this condition and identifying it early may help doctors and scientists delay the onset or progression of such diseases.
The researchers selected 188 participants from Srinivaspura Aging, Neuro Senescence, and COGnition (SANSCOG) and Tata Longitudinal Study of Aging (TLSA) split into different study groups. These participants were all older adults above the age of 59. Among them, 94 participants satisfied the criteria for SCD-plus. The other 94 participants were matched as closely as possible to the SCD-plus group in terms of age, gender, and level of education but did not fit the SCD-plus criteria.
Participants were asked questions about their overall health, mood, diet, smoking habits, exercise routines, and social networks. The researchers also used several tests, such as memory tasks to measure how well people could remember words, faces, or short lists of people’s names and language tasks that checked how easily people could come up with words, such as naming items in a category or quickly listing words that start with a certain letter. By comparing the scores, the researchers could see who might be struggling in areas that could signal early Alzheimer’s.
A smaller number of these participants underwent brain scans. The brain regions the researchers focused on included areas known to be involved in memory and language skills. Specifically, they looked at the volumes (or sizes) of certain brain regions, such as the cerebellar cortex (which, among other things, helps in language processing) and the inferior occipital cortex (which can help in recognizing faces).
The study discovered that individuals in the SCD-plus group performed worse on certain memory and language tasks compared to healthy individuals. Tasks including remembering details, recognizing familiar faces, and generating words beginning with certain letters became more challenging for the SCD-plus participants.
Furthermore, brain scans revealed that individuals in the SCD-plus group had smaller volumes in specific areas of the brain, such as the left cerebellar cortex and the right inferior occipital cortex, which are associated with language processing and facial recognition, respectively. The study also found that individuals with SCD-plus had higher levels of depression, higher LDL (high cholesterol), and less healthy lifestyles.
Even though the findings need more investigation over time, this study offers a valuable snapshot of how memory complaints and certain risk factors can overlap with subtle brain changes. By knowing the warning signs, healthcare professionals and researchers can develop earlier and more targeted interventions. Early detection means patients could benefit from lifestyle changes, medications, or therapies aimed at maintaining brain health for as long as possible. This study highlights the importance of monitoring self-reported memory issues within the elderly population, as they might be the first sign of something more serious developing.
This research news was partly generated using artificial intelligence and edited by an editor at Research Matters