Article Originally written by Ganesh Lamichhane , MBBS TU , 13th batch (Janaki Medical College )
Alzheimer’s disease is named after Dr. Alzheimer. In 1906, Dr. Alzheimer noticed changes in the brain tissue of a lady who died of an unusual mental illness. Her symptoms included memory loss, language problem and unpredictable behavior. After she died he examined her brain and found many abnormal clump (amyloid plaques) and tangled bundles of fibers (neuro fibrillary tangles). The plaques and tangles in brain are still considered as some of the main features of Alzheimer disease.
Alzheimer disease, also referred simply as Alzheimer’s is chronic neurodegenerative diseases that usually start slowly and worsens over time. It is the cause of 60-70% of causes of dementia. Thus Alzheimer’s is a type of dementia that causes problems with memory, thinking and behavior. The most common early symptoms is difficulty in remembering recent event (short term memory loss). As the disease advances the symptoms gets worsen over time, become severe enough to interfere with daily tests. Later symptoms can include problem with language, disorientation, mood swings, loss of motivations and behavioral issue. As a person’s condition worsens, he/she tries to get isolated from the community. Gradually body functions are lost, ultimately leading to death. As per the experts, more than 5.5 million Americans are considered to have Alzheimer’s.
Alzheimer’s disease is currently ranked as the sixth leading cause of death in the united states, however recent estimates indicates that the disease may rank third ; just behind the heart disease and cancer, as the cause of death of older people.
It has been found that 60-70% of dementia are due to Alzheimer’s. Dementia is the loss of cognitive functioning, thinking, remembering, reasoning and behavioral abilities to such an extent that it interferes with a person’s daily life and activities.
Early sign of dementia include
-Memory problems, especially in remembering recent events.
-Increase in confusion.
-Personality and behavioral change.
-Loss of ability for daily activities.
Stages of dementia
1. Re illness
2. Very mild sign of cognitive decline
3. Signs of decline go from very mild to mild
4. Moderate cognitive decline
5. Moderately severe sign of cognitive decline
6. Severe dementia
NOTE- many people have trouble with memory but it doesn’t mean that they have Alzheimer’s.
The cause of Alzheimer’s is not fully understood but the clinical, laboratory and epidemiological findings suggest that several factors play pathogenic role as listed below.
-Several genes are involved.
– Amyloidal precursor proteins (chromosome no- 21)
– Resenilin 1 and 2 (chromosome no 14 & 1)
– Apolipo protein E
– α 2 macroglobulin may be involved in clearance of amyloid protein
b.Acquired (environmental factors)
– Toxic substances like aluminum
– Reduced nerve growth factor and diminishing repair
– Impairment of calcium dependent potassium channel in neurons
– Repeated head injury
– Free radical injury
– Some vascular disease
Histological hallmarks of Alzheimer’s disease
A) Atrophy of brain
B) Intranuclear neuro-fibrillary tangles
C) Intracellular neurotic plaques
D) Amyloid angiopathy
E) Hirano bodies
Comparison of normal and Alzheimer’s brain is shown below:
Symptoms of Alzheimer’s disease
A) Memory loss that disrupts daily life
– forget recently learned information, dates and events.
– asks the same information repeatedly.
B) Challenges in planning or solving problems
-may have trouble in following a familiar recipe or keeping track of monthly bill
-difficulty in concentration
C) Difficulty in completing familiar tasks at home, work or leisure .
D) Confusion related to their present situations and passage of time.
E) Problems in understanding the visual images.
F) Language problems
-may stuck in the middle of conversations and have no idea how to continue or may repeat the same.
-have problem in finding the correct word
G) Poor judgments
Alzheimer’s disease is usually diagnosed based on person’s behavior and medical history. Following points can be considered-
- Know about the behaviors of patient from family
- Conduct memory tests
- Perform brain scans like MRI , PET.
It is important to note that the disease can be definitely diagnosed only after death by linking clinical measures with an examination of brain tissue in an autopsy.
Alzheimer’s is complex, and is unlikely that drug or intervention will successfully treat it. Current approaches focus on helping the patient to maintain mental functions, manage behaviors and slow down the symptoms of disease. Most medicines work best in early stage of disease.
– Medications called cholinesterase inhibitors are prescribed for mild to moderate Alzheimer’s disease. These drugs may help reduce some symptoms and help control some behavioral symptoms
– A medication known as Namenda (memantine), an N-methyl D-aspartate (NMDA) antagonist, is prescribed to treat moderate to severe Alzheimer’s disease.