Alzheimer Disease: Clinical Update

ALZHEIMER DISEASE
STUDENT ID

ALZHEIMER DISEASE: CLINICAL UPDATE 1
Contents
INTRODUCTION.....................................................................................................................................2
RISK FACTORS........................................................................................................................................3
CLINICAL MANIFESTATION....................................................................................................................4
DIAGNOSTIC PROCEDURES....................................................................................................................5
TREATMENT OPTIONS...........................................................................................................................7
CONCLUSION.........................................................................................................................................9
REFERENCES........................................................................................................................................10

ALZHEIMER DISEASE: CLINICAL UPDATE 2
INTRODUCTION
Alzheimer’s disease is known to be an irreversible and progressive neurological disorder that
primarily impacts the functionality of the brain in particularly aged persons. The main
symptom of the disease is memory loss which is followed by inability to think and carrying
out regular tasks along with the progression of the disease (Alzheimer Association, 2015).
This disease is considered as a type of Dementia. It is estimated that 60-70% Dementia cases
are Alzheimer’s disease. The Australian Institute of Health and Welfare claims that Dementia
is second leading cause of death in Australia. Per year there are 11,000 deaths due to
Dementia. In 2016, it was found that 354,000 people in Australia had Dementia. In the same
year, it was estimated that 1 in 10 Australians aged 65 years or above had Dementia (Ashby-
Mitchell, Burns, R., Shaw, & Anstey, 2017). The statistics from World Health Organization
states that in entire world there are about 50 million people who have Dementia with
Dementia being the 7th leading cause of death (Mental health). About 5%-8% people aged
above 65, 15%- 20% people aged above 75, and 25%-50% people aged above 85 are affected
with this Alzheimer’s disease (Livingston et al., 2017).
The neurons in the hippocampus region of brain responsible for memory and learning gets
injured and starts dying which initiates the pathophysiology of Alzheimer’s disease (AD).
Simultaneously this spreads to the entire brain making the disease more intense (Kumar &
Singh, 2015). The most common neuro-pathological characteristic of AD is presence of
extracellular amyloid plaques and the intracellular neurofibrillary tangles (NFTs). Amyloid
beta (Aβ) mostly involved in development of neurons aggregation that result into formation
of amyloid fibrils. These amyloid fibrils deposit outside neurons called as plaques (Attems,
McAleese & Walker, 2018). A protein associated with microtubule, expressed by the neurons
called tau protein aggregates inside nerve cells are known as intracellular neurofibrillary

ALZHEIMER DISEASE: CLINICAL UPDATE 3
tangles (NFTs) (Singh, Srivastav, Yadav, Srikrishna & Perry, 2016). This hinders the
communication among neurons. The other basic characteristics of Alzheimer’s disease are
synaptic dysfunction, mitochondrial impairment, blood-brain barrier disruption, oxidative
stress and neuro-inflammation. The most common risk factor for AD is ageing. Above 65
years of age there is increased risk of developing this diseases and it has been observed this
risk rate doubles in every five years. The other causing factors include genetics followed by
health, environmental and lifestyle factors (Weinstein, 2018)
RISK FACTORS
Age
Depending on the age of the patient at which the disease starts, Alzheimer’s disease is
divided into two types. The first type is the early onset of the disease (EIOD) and second is
the late onset the disease (LOAD). EIOD occurs in age group of 30 to mid-60 years whereas
LOAD constitutes the age group of mid-60s or above. There is a 50% chance of getting AD
after an age of 85 years (Desikan et al., 2017).
Genetics
The early onset of the disease (EIOD) sometimes is a result of change in of the three genes
results into a condition called Early-onset familial Alzheimer's disease (FAD) or autosomal
dominant Alzheimer disease (ADAD). The single gene mutation on chromosomes 21, 14, and
1 are known to cause ADAD. Mutation in chromosome 1 cause formation of abnormal
presenilin 2, mutation in chromosome 14 leads to abnormal presenilin 2 and mutation in
chromosome 21 leads to the abnormal formation of abnormal amyloid precursor protein
(APP). Abnormal APP is known to cause harmful amyloid plaques. Late onset Alzheimer’s
disease (LOAD) is the most common form of AD. Though there is no specific cause behind