Dementia Medical Tests & Diagnosis Methods & Tools

Conditions & Diseases: Brain & Nervous System

Dementia

Medical Tests & Diagnosis Methods/Tools

It is important for a doctor to distinguish treatable conditions like depression, normal pressure hydrocephalus and vitamin B12 deficiency from that of dementia since the former exhibits similar symptoms. Early diagnosis can help the families of the patients take remedial steps from a deteriorating condition by usage of certain drugs. A number of steps have been identified to diagnose dementia with reasonable accuracy, they include:

Medical History:
The doctors enquire about the individual’s general health and past medical history to know and understand if the individual is facing any difficulty in performing his/her routine activities. In the process the doctor may discuss with his/her family, friends and colleagues to collect more information. Family members may deny the symptoms of dementia to avoid detection thus the doctor may have to adopt some additional steps/techniques to confirm or rule out dementia (4).

Basic Medical Tests:
Routine basic diagnostic tests such as blood tests, thyroid and liver function tests, glucose tests etc., indicating illnesses are conducted to rule out other diseases. Depression screening may also be conducted and at times - spinal fluid collected is for testing (10).

In addition, the doctor will also enquire about diet, nutrition and consumption of alcohol. The doctor also reviews all the medications including over-the-counter drugs and supplements. The doctor will try to identify other disorders that can cause loss of memory, confusion, attention deficit or symptoms similar to dementia that include:

Anemia, malnutrition or vitamin deficiencies
Excess consumption of alcohol
Side effects of medication
Diabetes
Kidney or liver disease
Thyroid abnormalities
Problems with the heart, lung or blood vessels (11)

Neurological Exam:
This is an important test to assess the proper functioning of nervous system as a whole and brain in particular to identify the disorders. The physician may test for reflexes, coordination and balance, muscle tone and strength, eye movement, speech and sensation (11).

Mini-Mental State Exam (MMSE):
This is one of the most common tests used to “assess mental function” of the patient. It involves various questions typically framed to examine the mental skills required to perform day-to-day routine activities. The questions may be as follows:

To remember and recall the names of three common objects such as lock, pen and penny after a few minutes.
To state the current date, day of the week, year and season.
Count backwards from 100 by 7s or spell a word backwards.
Name a couple of familiar objects that the doctor points out.
Tell a common proverb or saying.

Various other such questions are posed and the results evaluated. A maximum score of 30 MMSE points are taken for consideration. A score of 20-24 suggest mild dementia, 13-20 suggest moderate dementia and below 12 indicates severe dementia. On an average, the score declines by 2-4 points every year for a person suffering from AD (11) & (4).

Brain Imaging:
Doctors may use various “…scans to identify strokes, tumors or other problems that may cause dementia” (4). Brain scans identify changes in brain structure and functions (4).

Structural Imaging: This technique furnishes the information such as shape, position or volume of brain tissue. These techniques include magnetic resonance imaging (MRI) and computed tomography (CT).

Functional Imaging: This technique reveals the working of cells in various regions of brain by “showing how actively the cells use sugar or oxygen” (11). The techniques include positron emission tomography (PET) and functional MRI (fMRI) (11).

Electroencephalograms (EEGs): In this technique, electrodes are placed at various places over the scalp to detect and record electrical activities and abnormalities. EEGs can help diagnose Alzheimer’s disease and CJD.

Single Photon-Emission Computed Tomography (SPECT) is used detect the distribution of blood in brain and Magneto Encephalography (MEG) is used to “…show the electromagnetic fields produced by the brain's neuronal activity” (4).

Psychiatric evaluation:
Psychiatric evaluation is done to determine the nature of disorder such as depression or any other psychiatric disorder (4).

Article by Kona Vishnu, MS
Medical Writer,
OmniMedicalSearch.com