There isn’t one particular test that can be used to determine if you have dementia. Your doctor will diagnose your particular type of dementia after taking a careful medical history, conducting a thorough physical examination, and performing laboratory tests to observe your thinking process, day-to-day functions and behaviour. Doctors can determine if you have dementia but it's harder to determine the exact type of dementia because the symptoms often overlap. In some cases, a doctor may diagnose "dementia" and not specify a type at all.
Following types of tests are generally conducted to diagnose dementia:
Cognitive and neuropsychological tests: These will be used to evaluate your cognitive (thinking) abilities such as memory, orientation, reasoning, language and attention.
Neurological evaluation: These types of tests will be used to evaluate your movement, balance and reflexes.
Brain scans: Brain imaging tests such as a computerized tomography (CT) scan or magnetic resonance imaging (MRI) can be used to check for evidence of stroke and rule out the possibility of a tumour.
Laboratory tests: Causes of reversible dementia such as vitamin B-12 deficiency or underactive thyroid gland can be determined with simple blood tests. One test is a lumbar puncture, which a painful procedure of collecting fluid sample from your spine. A needle will be inserted into your spine to extract fluid. The fluid sample thus collected is an important part of diagnosing DRD. This procedure is done in the neurophysiology lab. The cerebrospinal test will support the diagnosis of normal pressure hydrocephalus
Psychiatric evaluation: A mental health specialist such as psychologist or psychiatrist may evaluate whether depression or another psychological condition may be causing your symptoms, which appear to be the same as dementia symptoms at times.