Alzheimer

Alzheimer, commonly referred to as Alzheimer's disease, is a progressive neurodegenerative disorder and the most common cause of dementia. It is named after Alois Alzheimer, who first described the condition in 1906. The disease is characterized by the accumulation of beta-amyloid plaques and neurofibrillary tangles in the brain, leading to neuronal loss and brain atrophy.

Early symptoms typically include worsening short-term memory, difficulty learning new information, and confusion. As the disease advances, language difficulties, impaired executive function, disorientation, and changes in mood or behavior occur. In later stages, individuals lose the ability to perform daily activities and rely on others for care.

Pathologically, amyloid plaques and tau tangles are hallmark features. Risk factors include increasing age, family history, and genetic variations such as mutations in APP, PSEN1, PSEN2 in early-onset forms, and the APOE ε4 allele in sporadic cases. Modifiable risk factors include cardiovascular disease, diabetes, obesity, physical inactivity, and smoking.

Diagnosis relies on clinical assessment and cognitive testing, supported by brain imaging (MRI or CT) to rule out other causes, and, when available, biomarkers such as CSF levels of beta-amyloid and tau or amyloid/tau PET imaging.

There is no cure. Treatments focus on symptom management and preserving function. Cholinesterase inhibitors (donepezil, rivastigmine, galantamine) are used in mild to moderate stages, and memantine may be added in moderate to severe stages. Nonpharmacologic approaches, including cognitive stimulation, physical activity, sleep management, nutrition, and caregiver support, are integral. Treatments targeting disease progression are an area of active research; some anti-amyloid therapies have shown mixed results.

Alzheimer's disease typically progresses over several years, with survival after diagnosis varying widely. The condition has substantial societal impact due to care needs and caregiver burden. Early detection and management of vascular and other risk factors are emphasized in public health strategies.