Alzheimer's disease is an illness that is difficult to diagnose. An extensive battery of medical tests has been developed in order to verify dementia, but the diagnosis of Alzheimer's as the cause of dementia in patients is often only 90 percent accurate. The basic elements of an Alzheimer's test are mental and physical assessments and a family medical history. Ultimately, the only method of obtaining a definitive diagnosis is an autopsy, during which medical professionals can document shrinkage of the brain and damage to brain cells, which are hallmarks of this disease.
Diagnosing Alzheimer's disease is so difficult that an Alzheimer's test is more about ruling out other illnesses than it is about pinpointing the disease itself. Thus, testing will start with questions concerning medications and other factors that could be causing abnormal symptoms. A healthcare provider will inquire about medications, supplements, diet and alcohol consumption, recent injuries and other diagnoses. A head injury, alcohol use or side effects from medication, for example, could explain slurred speech and problems with balance. Mental health issues such as depression can result in impaired social skills, confusion and memory loss, which are some symptoms of Alzheimer's.
Family medical history is a key issue in determining the likelihood of Alzheimer's disease. If a patient's relatives have suffered from dementia or a related illness, this will be taken into consideration during the Alzheimer's test. Paired with test results that indicate cognitive impairment, related family history can point strongly toward a positive diagnosis. If a patient is not able to answer questions about medical history and current medical issues himself or herself, a caregiver or family member can provide the information that is required.
Mental status assessment is the next step in the Alzheimer's test. The purpose of this test is twofold. It allows the doctor to determine how much information the patient knows about himself or herself and his or her surroundings, as well as whether he or she is aware of any mental impairment. A mini-exam of the patient's mental state is the most common text for assessing a patient's mental capacity. The doctor will ask questions concerning the date, time, location, objects in the room and names of people.
The patient might also be asked to remember words or phrases and repeat them or to follow a set of simple instructions. Results of the exam typically are scored out of a possible 30 points. A score of 24 to 20 indicates mild dementia, a score between 13 and 20 indicates moderate dementia and a score of less than 13 indicates severe dementia.
A comprehensive physical examination is the last element of an Alzheimer's test. Hearing and vision tests could rule out an Alzheimer's diagnosis, because problems seeing and hearing can cause the confusion, communication issues and dizziness often associate with the disease. Blood pressure, thyroid and liver function, lung function and temperature also will be measured. These are important considerations in ruling out additional conditions that have Alzheimer's-like symptoms.
The neurological portion of the physical entails assessment of walking, reflexes, coordination, muscle tone, speech and eye movement. Detecting any damage to the nervous system or identifying neurological disorders in the patient could rule out Alzheimer's disease as a possibility. Dizziness, mobility issues and impaired speech are common signs of neurological issues unrelated to dementia.
Lab tests are not always performed as part of an Alzheimer's test, but blood and urine testing can play a role in eliminating other health issues. A blood test, for example, could identify anemia and vitamin B12 deficiency as the cause of hallucinations, which often are symptoms of dementia. Folate, blood glucose and electrolyte tests also might be administered, because abnormal levels of these substances can cause a gradual mental decline. Additionally, a computed tomography (CT) scan, positron emission tomography (PET) scan or magnetic resonance imaging (MRI) exam might be used to check for blood clots, tumors and evidence of stroke.
Medical professionals have worked to increase the potential of MRIs in Alzheimer's testing. It has been determined that the brain of an Alzheimer's patient shrinks with the progression of the disease, and this could be identified via an MRI. Further use of PET scans also might be utilized in the future to recognize reduced brain cell activity in certain areas of the brain. A definite link between this activity and a definite Alzheimer's diagnosis has not been found, but advances in the diagnosis of the disease likely will lead to increasingly accurate methods of Alzheimer's testing.