Diagnosis-Alzheimer's disease

It is most important that a doctor should diagnose Alzheimer’s disease, as many other treatable conditions (such as hypothyroidism, vitamin deficiency, hypoglycaemia, anaemia and depression) have symptoms similar to Alzheimer's disease. Other causes of Alzheimer's disease-like symptoms include an adverse reaction to prescribed medicine or a harmful combination of medicines.

To check whether a person has Alzheimer’s disease, the doctor will first do a memory test and then a physical examination in order to eliminate other possible causes of the patient’s mental impairment. Therefore the clinical diagnosis of Alzheimer's disease is a diagnosis by exclusion. Verbal tests, as well as interviews with family members may be the next step, although these methods will not yield definitive results.

Other tests to diagnose possible Alzheimer's disease should include:

Blood tests
Brain scan
Electrocardiogram (ECG, a recording of the electric activity of the heart)
Electroencephalogram (EEG, a recording of the electric activity of the brain)

Brain scans can provide valuable information about the brain. These include:

Computerised axial tomography (CAT) – to exclude disorders with similar symptoms to Alzheimer's disease. CAT scans may reveal changes that are characteristic of the disease.
Magnetic resonance imaging (MRI) – this type of scan provides information about physical structure and chemicals, distinguishes between moving blood and static brain tissue and may add diagnostic information.
Positron emission tomography (PET) – a new instrument that researchers can use to learn more about the brain. It can provide information about blood flow in the brain, metabolic activity and the way that specific receptors are distributed in the brain.
Single photon emission computerised tomography (SPECT) – another instrument available to researchers to help them look for the abnormalities typical of Alzheimer’s disease.