Alzheimer’s Disease

By: Ryan Triplett

Alzheimer’s

• The deterioration of intellectual capabilities, memory, judgment, and personality to the extent that daily functioning and quality of life are seriously impaired.

• Generally occurs in the elderly impairing brain function, which can lead to dementia.

• Named for German neurologist Alois Alzheimer in 1907.

Statistics

• 4 million or more cases in U.S.• 100,000 die each year.• 4th major leading cause of

death in U.S.• 65 or older when symptoms

can begin

Clinical Features

• Loss of short-term memory and ability to create memories

• Concentration on past• Loss of time• Communication diminishes• Personality changes• Delusions• Become immobilized and uncomprehending• Death due to respiratory failure• 65 and up disease lasts 8-20 years• 65 and down disease lasts 5-10 years disease more

rapid

Histological Analysis3 distinctive neuropathological features

1. Devastating losses of synapses and neurons within hippocampus and entorhinal cortex.

2. Dense spherical structures, called senile plaques (SP), prevalent outside the neurons of the hippocampus and other regions of the brain.

3. Aggregations of fibrils (Neurofibrillary tangles, NFT) accumulate within cell bodies and dendritic processes of the neurons of the hippocampus, neurocortex, entorhinal cortex, and other brain parts.

Pictures of Brain Degradation

Degradation cont’d

Senile Plaques

• Densely packed fibrous structures called amyloid bodies.

• Consists of mainly protein, 4-kDa peptide.

• Many isoforms make up the amyloid proteins.

• Amyloid precursor protein another source of which can lead to AD. Functional role unknown.

Neurofibrillary Tangles

• Consist of helical filaments called PHF.– Intertwined protein strands made of tau protein

molecules.

• Formation of NFT’s not unique to AD.– Found in many other neurodegenerative disorders

with dementias, affecting the brain.

• Scientists believe that the amyloid proteins lead to the formation of the neurofibrillary tangles, and both can lead to AD symptoms.

Diagnosis

• Only definitive way is to use brain scans (CT) to see plaques or tangles in brain tissue.

• Tests used to exclude other diseases.

Treatments

• No treatment can prevent Alzheimer’s

• Drugs for early stages– Cognax, Aricept, Exelon, or Razadyne

• Severe stages– Memantine (Namenda)

• Medicines used to control symptoms, allow caregivers to provide easier care.

Research

• Neuroimaging– Finding damaged parts of the brain

• Alzheimer’s Genetics• Anti-oxidants• Ginkgo biloba

– Using to stimulate memory

• Estrogen – Tested for levels found in AD patients, which

are women

References

• Pasternak, J. Jack. Introduction to Molecular Genetics. 2nd edition.2005. pg. 403-408.

• www.bic.ucs.edu/images/alz3d.jpg• www.ahaf.org• www.nia.nih.gov/Alzheimers/Publications