Early diagnosis offers the best hope to treat and manage the symptoms of the disease. An early and accurate diagnosis also helps families plan for the course of treatments and social supports with input from the patient. The most accurate diagnostic tool is a brain biopsy, but this drastic test is rarely performed and is unnecessary to make a diagnosis. Doctors can clinically diagnose Alzheimer’s disease correctly up to 90 percent of the time using non-invasive means. Before conducting tests, a physician will usually determine that a patient has cognitive impairment in multiple areas that impact daily living, and that the identified deficiencies are chronic and progressive.
- Questions about the patient’s general health, past medical problems, and ability to carry out daily activities
- Tests of cognition, such as memory, problem solving, attention, and language
- Medical tests such as blood, urine, spinal fluid (rare), and brain scans
Once a doctor determines that a patient’s memory loss or confusion indicate a change in mental function enough to diagnose dementia, he will look for a cause. Alzheimer’s disease is the leading cause of dementia - identified in about 65% of the cases.
Other common causes include vascular disease of the brain (i.e., multiple strokes leading to vascular dementia), Parkinson’s disease, Lewy Body disease, and other potentially reversible causes such as depression, polypharmacy, vitamin B12 deficiency, thyroid disease, a tumor, or hydrocephalus.