Early, accurate diagnosis and treatment of Alzheimer’s disease is beneficial for several reasons. They keep improved the quality of life of the patient for a longer period of time. This is because most medicines currently available work more efectively for people in the early or middle stages of the disease.
The clinical diagnosis of Alzheimer’s disease (AD) consists of
- Identifying signs and symptoms that identify with AD,
- Conducting lab tests on blood and cerebrospinal fluid (CSF) for diagnosis and to rule out other conditions that can cause dementia
- Imaging studies include Ct scan, MRI and PET scan
The neurologist begins with a physical and neurological examination, which involves evaluating the mental status and neuropsychological testing
The clinical diagnosis of Alzheimer’s disease is usually made during the mild stage of the disease, by examining the signs and symptoms of the patient.
This is done by asking the patient to explain the symptoms as well as taking the point of view of a close family member or friend about the impact on daily life. Additionally, the doctor does some tests to assess the patient’s memory, thinking skills, nd mental functions.
Your doctor will perform a physical exam to evaluate the general neurological health by testing the following:
- Muscle tone and strength
- Sense of sight and hearing
- Coordination and balance
Subsequent follow-up visits will help to track the progression of symptoms.
There are no blood tests that will specifically diagnose AD but they will help your doctor rule out other potential causes of dementia such as a thyroid disorder or vitamin deficiencies.
A lumber tap is performed to obtain the sample of the cerebrospinal fluid (CSF). The sample is tested in the lab for levels of tau and phosphorylated tau, which are often elevated in AD whereas amyloid levels are usually low. Presently, routinely measuring tau and amyloid in CSF is not recommended.
Brain imaging studies for AD
Imaging studies are most important in the diagnosis of AD and help to rule out other potential causes of cognitive decline, such as chronic subdural hematoma or normal-pressure hydrocephalus, which can be successfully treated.
These studies help clinicians to diagnose Alzheimer’s disease with more certainty and rule out other causes of cognitive change such as strokes, trauma, or tumors.
New imaging methods may enable doctors to detect specific brain changes caused by Alzheimer’s.
- Magnetic resonance imaging (MRI). MRI uses radio waves and a strong magnetic field and produces detailed images of the brain. Doctors usually prefer it to a CT scan for the assessment of dementia. MRI may show shrinkage of brain areas associated with Alzheimer’s disease. It also helps to rule out other conditions that can cause dementia.
- Computerized tomography (CT scan). A CT scan produces cross-sectional images (slices) of your brain. It helps to rule out head injuries, strokes, and tumors.
- Positron emission tomography (PET). Imaging of the brain can also be performed with positron emission tomography (PET). It is done by injecting a low-level radioactive tracer to look for a particular aspect of the brain. PET imaging may include the following:
- Fluorodeoxyglucose (FDG) PET scans show areas of degeneration that can help differentiate between Alzheimer’s disease and other types of dementia.
- Amyloid PET imaging can identify amyloid deposits in the brain. This imaging is primarily used in research.
Drugs approved by the US Food and Drug Administration (FDA) for treating AD are symptomatic treatments that regulate the neurotransmitters, acetylcholine or glutamate.
Two types of drugs are currently used to treat cognitive symptoms. The standard drugs used include cholinesterase inhibitors (ChEIs) and a partial N-methyl-D-aspartate (NMDA) antagonist. They only slow down the progress of memory symptoms and other cognitive changes. They do not treat the underlying cause of AD nor halt the rate of decline.
- Cholinesterase inhibitors boost the levels of neurotransmission by preserving acetylcholine, a chemical neurotransmitter that is depleted in the brain by Alzheimer’s disease. This drug brings about modest improvements in neuropsychiatric symptoms, such as agitation or depression. Commonly used cholinesterase inhibitors include donepezil (Aricept), galantamine (Razadyne ER), and rivastigmine (Exelon). The common side effects include diarrhea, nausea, loss of appetite, and sleep disturbances. Cardiac arrhythmia may occur in people with certain heart conditions.
- Memantine (Namenda) works on another neurotransmission network and slows down the progression of symptoms in patients with moderate to severe Alzheimer’s disease. It is sometimes used in combination with a cholinesterase inhibitor. Side effects are rare and include dizziness and confusion.
- Aducanumab (Aduhelm). In June 2021, the FDA approved aducanumab (Aduhelm) for the treatment of some cases of Alzheimer’s disease. This is the first drug that treats the underlying cause of Alzheimer’s by removing the amyloid plaques in the brain. However, further studies are still being conducted to identify which patients may benefit from the drug.
Other psychotropic medications are sometimes used to manage secondary symptoms that may be present such as agitation, aggression, depression, delusions, seizures, and sleep disorders : They include:
- Antiparkinsonian agents
- Antiepileptic drugs
- Amyloid-directed antibody
As the disease progresses, patients start to require assistance with daily routine activities such as dressing, bathing, and toilet use.
Ultimately, they experience difficulties with walking and swallowing. Feeding may become necessary only by gastrointestinal tube because of difficulty in swallowing, which may lead to aspiration pneumonia.
Death is inevitable and can come anytime between 3 years to 10 or more years after diagnosis.
Patients who develop AD early in life tend to experience a more aggressive and rapid course than those with late-onset AD. The primary cause of death is a secondary illness, such as aspiration pneumonia.
Healthy lifestyles can reduce the risk of developing the disease. Following certain lifestyle activities can help:
- Regular physical activity
- Regular aerobic exercises for cardiorespiratory fitness
- Diet: Although no specific dietary recommendations have been made for AD, the Mediterranean diet provides nutritional benefits that could help in AD prevention.