THADOMAL SHAHANI ENGINEERING COLLEGE
All About Alzheimer’s
Alzheimer’s Disease (AD) is the most widespread chronic neurodegenerative disease severely affecting the thinking and cognitive abilities of the person. It is considered the leading cause of Dementia and may account for 60-70% of Dementia cases. The rising number of patients year by year depicts the prevalence of this disease among late of old age. Approximately 5.7 million people are living with AD in the USA alone. At the same time, more than 40 million are affected globally, and this figure is estimated to cross 100 million by 2050 with a subsequent increase in the social and financial burden.
AD is a slowly progressive disease that begins as short-term memory loss, followed by disorientation, impaired judgment, language disturbances, mood swings, and behavioral changes (e.g., irritability, depression). These symptoms arise due to a decrease in neuronal brain cells and are linked with high morbidity and mortality rate in the elderly. AD is a multifactorial disease believed to be caused by a combination of abnormal cellular/molecular processing, genetics, lifestyle, and many other environmental factors that affect the brain over time. Nonetheless, age is considered the most significant risk factor for AD; the older you grow, the chances of getting diseased by Alzheimer’s increases but Alzheimer’s is not an inevitable part of aging. The AD can be classified into the early-onset AD (EOAD) and late-onset AD (LOAD) based on the age of onset, while familial AD (FAD) and sporadic AD (SAD) on the grounds of heritability and genetics.
The pathways and mechanisms leading to Alzheimer’s are still unclear, but two significant hallmarks exist since the discovery of the disease drives the current research. These co-pathological indicators are the accumulation of extracellular senile plaques caused by aggregation of ꞵ-amyloid peptides and formation of intracellular neurofibrillary tangles (NFT) containing hyperphosphorylated tau proteins in affected neurons. Other complex pathways include deficiency in cholinergic neurotransmission and oxidative and inflammatory pathways. Shrinkage of the hippocampus and entorhinal cortex regions is apparent from MRI scans of AD patients’ brains compared to normal brains.
Figure 1:- Comparison between the pathology of a healthy brain and a diseased brain
Why is Alzheimer’s Disease a rising concern for us?
Alzheimer’s is difficult to diagnose, and only surety can be provided after performing a postmortem of the brain of the diseased person. AD exhibits complex mechanisms that are not understood completely, leading to drug development lag and failure. The currently available drugs act only on the symptoms related to memory, thinking, language, judgment and do not have the proper ability to affect the advancement of AD. Our leading explanation for the onset of Alzheimer’s, the Amyloid Cascade hypothesis, is now decades old. Still, no new drug has been approved by the FDA since 2003, and there are no approved Disease Modifying Treatments (DMT) for this neurodegenerative disease; hence, Alzheimer’s remains incurable. More than 200 research projects have failed in the last decade or were abandoned despite many long and expensive trials. The development of Multi-target drugs instead of one drug one target (ODOTs) is the primary area of research at the current time.
AD being a fatal, progressive neurodegenerative disorder with multiple complications, there is a need for superior drug therapies with minimal side-effects is of utmost importance for a better future of the present and upcoming generations.