## 1 Introduction  
Recent advancements in medical sciences and healthcare technologies have led to remarkable progress in improved disease detection, early diagnosis, better therapeutic interventions, and enhanced patient outcomes. These innovations have significantly contributed to increased global life expectancy and better quality of life. As a result, the world is experiencing a significant demographic shift, with the proportion of elderly individuals in the global population steadily rising. According to the World Health Organization (WHO), the number of individuals aged 60 years and older is expected to rise from 1 billion in 2020 to 2.1 billion by 2050 [1]. This surge in the elderly population is accompanied by an increased prevalence of age-related illnesses, particularly AD, which has emerged as one of the most prevalent and debilitating neurodegenerative disorders worldwide. Alzheimer's disease is the most common form of dementia worldwide, accounting for approximately 60-80% of cases [2]. It is also recognized as a leading cause of disability and dependence among older adults. It is estimated that more than 55 million people globally are living with dementia, a number expected to rise to 78 million by 2030 and 139 million by 2050, largely driven by population aging [3]. As of 2025, Alzheimer's disease affects nearly 7.2 million adults aged 65 and older in the United States with projections indicating it will nearly double to 13 million by 2050. Beyond its clinical progression, the disease imposes a heavy emotional burden on families and caregivers, while generating substantial healthcare and societal costs. Among older adults, Alzheimer's is the fifth leading cause of death preceded only by heart disease, cancer, stroke, and chronic lower respiratory conditions underscoring its significance as a major public health concern [4]. It is a progressive, irreversible brain disorder characterized by memory loss, cognitive dysfunction, reasoning, language, problem-solving abilities, and behavioral changes, which gradually impair a person's ability to perform everyday tasks. As it advances, patients often require full-time care and medical support, placing an enormous emotional and economic burden on families and healthcare systems. The exact cause of AD still remains unknown. Factors like growing older, family history, level of education, and daily habits are known to play a role. In addition, several brain-related conditions can contribute to the development of dementia symptoms [5]. The disease often begins with subtle symptoms such as difficulty recalling recent events and gradually advances to severe memory loss, disorientation, and loss of speech and motor skills. Pathologically, AD is linked to the accumulation of amyloid-beta plaques and tau neurofibrillary tangles in the brain. These protein aggregates are believed to interfere with neuron-to-neuron communication and trigger inflammation and cell death [6]. It initially begins in the entorhinal cortex and hippocampus, critical regions for memory and learning, and subsequently spreads to the cerebral cortex, affecting language, judgment, social behavior, and motor functions [7]. These changes lead to a gradual decline in cognitive function and behavioral disturbances. Diagnosing Alzheimer's in its early stages remains a significant challenge in clinical practice. In its initial stages, symptoms include mild memory loss, difficulty in recalling recent events, confusion, challenges in completing familiar tasks, language disturbances, and mood or personality changes. These symptoms can be subtle and are often mistaken for normal aging or other forms of dementia, resulting in many cases remaining undiagnosed until the disease has significantly progressed, and irreversible brain damage has already occurred. As the disease progresses, these symptoms worsen, severely impairing daily functioning and quality of life.