This document discusses Alzheimer's disease including its causes, symptoms, diagnosis and treatment. It is a neurodegenerative disease that causes memory loss and cognitive decline. The main pathologies involved are beta-amyloid plaques and neurofibrillary tangles composed of tau proteins. Diagnosis involves assessing cognitive impairment and ruling out other conditions, while treatments can help symptoms but currently there is no cure as brain cells continue to be lost.

2.  What is Alzheimer’s disease
 Incidence & Prevalence
 Signs & Symptoms
 Causes
 Mechanisms
 Diagnosis
 Treatment & Management

3.  Neurodegenerative dementia causing memory loss &
cognitive decline.
 Cause shrinkage of the brain.
 Discovered by German psychiatrist &
neuro-pathologist Alois Alzheimer in 1906.
 Most common cause of dementia in adults.

4.  Mostly diagnosed in people over 65 years of age (Late-
onset Alzheimer’s disease).
 Early-onset AD may occur within 30-60 years.
 In 2006, throughout the world 26.6 million people were
affected.
 Within 2050, among 85 people, 1 will be affected
globally.

5.  Memory loss.
 Difficulty performing familiar tasks.
 Problems with language.
 Disorientation to time & space.
 Poor/decreased judgment.
 Problems with abstract thinking.
 Misplacing things.
 Changes in mood & behavior.
 Changes in personality.
 Loss of initiative.

6. 1. Genetic cause
2. Cholinergic hypothesis
3. Amyloid hypothesis
4. Tau hypothesis
5. Others

7. Genetic Cause:
 Involvement of Amyloid precursor protein(APP),
Presenilin 1 & Presenilin 2.
 Carrying APOEε4 causes 40-80% of Late-onset AD.
 Other genes responsible for causing AD are-
CLU, PICALM, CR1, BIN1, MS4A, ABCA7, EPHA1, CD33,
CD2AP, ATP5H, EXOC4, CTNA3, RNF219, TREM2 etc.

8. Cholinergic Hypothesis:
Reduced synthesis of neurotransmitter , acetylcholin.
Large scale aggregation of amyloids.
Results in neuroinflammation & degeneration of
neurons.

9. Amyloid Hypothesis:
 Deposition of β-Amyloid proteins.
 APP present on chromosome 21 together with Down
syndrome causes 90% of Early-onset AD.
 N-APP triggers self destruct pathway by binding to a
neuronal receptor, Death Receptor 6 (DR6).

10. Tau Hypothesis:
 Degeneration of tau proteins.
 Formation of neurofibrillary tangles.
 Initiation of AD.

11. Others:
 Involvement of Herpes simplex virus carrying
susceptible version of apoE gene.
 Oxidative stress in brain.
 Dys-hemostasis of bio metal metabolism.

12. Formation of β-Amyloid plaques:
 Normally, α-secretase produces APP & γ-secretase
creates another shorter version of APP which is then
degraded.
 In case of AD, β-secretase together with γ-secretase
produces longer, sticky form of β-amyloid proteins (Aβ).
 Accumulation of Aβ proteins produce senile plaques.

13. Enzymes act on the APP (amyloid precursor protein) and cut
it into fragments. The beta-amyloid fragment is crucial in
the formation of senile plaques in AD.

14. Formation of Neurofibrillary Tangles:
 In neurons, signal transduction occurs through microtubules
which are stabilized by tau proteins.
 In AD, tau proteins are degenerated.
& causes microtubules to disintegrate.
 Leads to formation of neurofibrillary
tangles of tau proteins.
 Causes neuron degeneration.

16.  Based on patient’s history, relatives’ history &
observation of his behavior.
 Assessment of intellectual functioning by memory
tests.
 Exclusion of other cerebral pathology of dementia
using-
Computed tomography (CT)
Magnetic resonance imaging (MRI)
Single photon emission computed tomography
(SPECT)
Positron emission tomography (PET)

17. .

18.  No known treatment found yet as, death of brain cells can’t
be halted or reversed.
 Some therapeutic drugs are available that can help a
patient to live ably. Those includes-
• Donepezil
• Alantamine
• Rivastigmine
• Tacrine
• Menantine etc.

19.  Some potential treatment may involve-
Application of chaperone molecules.
Gene therapy in reversing memory loss.
Application of Dab2 protein, which exhibits
neuroprotective effects.
Regulation of TGF- β1/SMAD signaling.
 Most important thing an AD patient needs is
proper nursing & care.