Alzheimer Disease

WHAT IS IT?

TREATMENTS

Alzheimer's is a progressive type of dementia that affects memory, thinking, and behavior serious enough to interfere with daily life.
Accounts for 60-70% of dementia cases among older adults.
Affects 5-10% of the population greater than 65 years of age and 40% age 85 years and older.

CAUSATIVE FACTORS

Brain proteins fail to function normally which form plaques and tangles leading to damaged neurons, and loss of connection and communication.

MOLECULAR AND GENETIC DETAILS

PATHOPHYSIOLOGIC ETIOLOGY

Formation of amyloid plaques and neurofibrillary tangles in the cortex and hippocampus which lead to progressive neuron loss

Plaques: Beta amyloid fragment clusters together forming amyloid plaques which disrupt cell-to-cell communication.

Tangles: Tau proteins form neurofibrillary tangles which disrupt the transport system.

COMMON FINDINGS

DIAGNOSTIC TESTS

RISK FACTORS

Age

E4 allele

Neurodegeneration and decreased cognition including loss of memory, facial recognition, language capability, recall, loss of judgement, and personality alterations.

Definitive diagnosis occurs postmortem with direct examination of the brain.

Diagnosis of exclusion

Down Syndrome

Sex

Mild cognitive impairment

Past head trauma

Lifestyle and heart health

Medications temporarily affect disease severity and progression

Two types of drugs to treat cognitive symptoms: Cholinesterase inhibitors and Memantine (Namenda)

Gene causing Alzheimer's is located on chromosome 21. This gene is present in 3 copies in trisomy 21, which leads to amyloid deposition and the occurance of Alzheimer Disease in individuals with down syndrome.

Individuals with one copy of e4 allele are 2-5x more likely to develop Alzheimers and those with two copies are 5-10x more likely to develop Alzheimers. Europeans and Japanese are at highest risk of having this allele.

Family history and genetics

Risk doubles with affected first degree relative

Autosomal dominant in 10% of cases

Genetically heterogenous disorder

Explained on attached sheet with pictures. (It is a little complicated to be explaining in concept map.)