Alzheimer's Disease

Alzheimer's Disease (AD), also referred to simply as Alzheimer's, is a chronic neurodegenerative disease that usually starts slowly and progressively worsens over time. It is the cause of 60–70% of cases of dementia. The most common early symptom is difficulty in remembering recent events. As the disease advances, symptoms can include problems with language, disorientation (including easily getting lost), mood swings, loss of motivation, not managing self-care, and behavioral issues. As a person's condition declines, they often withdraw from family and society. Gradually, bodily functions are lost, ultimately leading to death. Although the speed of progression can vary, the typical life expectancy following diagnosis is three to nine years.

The cause of Alzheimer's disease is poorly understood. About 70% of the risk is believed to be genetic with many genes usually involved. Other risk factors include a history of head injuries, depression, or hypertension. The disease process is associated with plaques and tangles in the brain. A probable diagnosis is based on the history of the illness and cognitive testing with medical imaging and blood tests to rule out other possible causes. Initial symptoms are often mistaken for normal aging. Examination of brain tissue is needed for a definite diagnosis. Mental and physical exercise, and avoiding obesity may decrease the risk of AD; however, evidence to support these recommendations is not strong.

There is no cure for Alzheimer's disease; available treatments offer relatively small symptomatic benefit but remain palliative in nature. Current treatments can help with some of the symptoms of Alzheimer's disease, but do not stop the progression of the disease. Management of the disease is primarily supportive in nature, focusing on helping the person manage symptoms and maintain a level of independence. Caregiving is also an important aspect of management, often provided by family members or professional caregivers.

Symptoms and Stages

Alzheimer's disease is characterized by loss of neurons and synapses in the cerebral cortex and certain subcortical regions. This loss results in gross atrophy of the affected regions, including degeneration in the temporal lobe and parietal lobe, and parts of the frontal cortex and cingulate gyrus. Disease progression is divided into four stages, with progressive patterns of cognitive and functional impairments.

Early Stage

In the early stage of Alzheimer's, the person may exhibit mild confusion and trouble remembering names or recent events. As the disease progresses, problems with short-term memory increase.

Moderate Stage

The moderate stage is marked by further cognitive decline, including difficulty with language (aphasia), coordination (apraxia), and recognizing family and friends (agnosia). Behavioral and psychological symptoms of dementia are also common at this stage and can include wandering, agitation, and aggression.

Advanced Stage

In the advanced stage, the person is unable to perform daily activities and becomes completely dependent on caregivers. Communication becomes severely limited, and physical abilities decline, leading to bedridden state and, eventually, death typically from an external cause such as infection.

Causes and Risk Factors

The exact cause of Alzheimer's disease is still not fully understood, but it is believed to be a combination of genetic, environmental, and lifestyle factors. The presence of amyloid plaques and neurofibrillary tangles in the brain are key hallmarks of the disease.

Diagnosis

Diagnosis of Alzheimer's disease is based on clinical assessment, including a detailed medical history, physical examination, neurological examination, and cognitive testing. Brain imaging techniques, such as magnetic resonance imaging (MRI) or computed tomography (CT), can be used to rule out other conditions.

Treatment and Management

There is no cure for Alzheimer's disease, but treatments are available to help manage symptoms. Medications such as cholinesterase inhibitors and memantine may help with cognitive symptoms. Supportive care, including physical therapy, occupational therapy, and speech therapy, can help manage other symptoms and improve quality of life.

Prevention

While there is no guaranteed way to prevent Alzheimer's disease, certain lifestyle choices, such as regular physical activity, a healthy diet, and cognitive training, may help reduce the risk.