Thursday, November 10, 2011

Why Neuropsychological Testing Is Helpful in Dementia Evaluations

If you or a loved one is concerned that dementia may be present, a neuropsychological evaluation can be critical to confirming this, specifying the exact type, and guiding treatment. Dementia is a general term referring to a significant loss of intellectual and cognitive (thinking) abilities without impairment of perception or consciousness. There are many different types of dementia, with Alzheimer’s disease being the most common. Most forms of dementia are progressive and irreversible (such as Alzheimer’s disease and fronto-temporal dementia) although some forms are non-progressive (static) and reversible. An example of a static form of dementia is dementia due to severe traumatic brain injury. An example of reversible dementia is dementia due to unrecognized thyroid disease or vitamin deficiency.

Most forms of dementia begin with memory loss but other cognitive difficulties (naming problems, getting lost) can also serve as the initial symptoms. Sometimes, behavioral symptoms are the initial prominent symptom such as the decline in personal and social conduct that is typical of fronto-temporal dementia. Usually, a person with these symptoms will initially be evaluated by a primary care physician. This typically results in sending the patient for blood tests and a brain MRI (magnetic resonance imaging) to search for reversible causes of dementia and determine if there are any visible abnormalities in the brain. The MRI may show tissue loss (atrophy), abnormal areas of tissue (known as lesions), a mass such as a brain tumor, or other types of abnormalities.

The person may also be sent to a neurologist, which is a type of physician specializing in the neurological system. The neurological exam will typically consist of a brief interview and a physical exam focusing on the cranial nerves, reflex testing, and sensory-motor functioning. There will usually be some brief testing of thinking skills. This could merely involve asking the date and/or memory for a few words but can involve the use of a brief formal screening test of thinking such as the Mini-Mental State Examination. These screening measures are broad tests of thinking skills that are designed to pick up on red flags that may prompt a referral for more detailed cognitive testing. While screening measures may detect some difficulties that support a diagnosis of dementia, these tests are fairly easy, are not meant to replace a comprehensive neuropsychological evaluation, and are not good at differentiating between types of dementia.

There are several advantages to a neuropsychological evaluation. First, a neuropsychologist specializes in understanding the relationship between brain functioning, thinking, emotions, and behaviors. This is important because there are psychological conditions that are common in the elderly (e.g., major depressive disorder) that can mimic a neurologically progressive dementia (e.g., Alzheimer’s disease). Thus, an expert in how psychological and neurological conditions present is very important and neuropsychology offers that level of expertise.

Second, neuropsychologists spend hours upon hours with their patients to understand the history, obtain and thoroughly review relevant medical records, perform a detailed clinical interview (with the patient and a close informant[if possible]) and detailed testing. This degree of detail cannot be obtained in a physician’s office due to significant time constraints.

Third, neuropsychologists apply specialized procedures to formally estimate the estimated intellectual status before a suspected dementing condition began. Additional specialized tests include measures of memory, learning new information, attention/concentration, expressive and receptive language (e.g., naming, vocabulary, command following), IQ, visual-spatial and visual constructional skills, motor and sensory functioning, information processing speed, and executive functioning. Executive functioning refers to higher-level thinking skills such as abstract thinking, multi-tasking, planning, judgment, problem-solving, and organizational skills. Test performance is compared to groups of people who are in the same age group as the patient with have no history of brain damage. Some tests are also compared to groups of normal controls with the same/similar educational backgrounds and also for gender. Some tests of personality and emotional functioning can also be administered.

Neuropsychologists review the objective information from the testing and look for areas of impairment, the degree (level) of impairment, and patterns of performance. Specific thinking and sensori-motor skills are controlled by  different areas of the brain. The neuropsychologist then integrates this information with the information obtained from the clinical interview, medical records review, behavioral observations, and knowledge of how various neurological and psychological conditions present. These results can help determine the specific diagnosis, which leads to specific treatment recommendations as not all dementias are treated identically. These recommendations not only may include medication suggestions but also include practical suggestions to improve daily functioning. Treatment is drastically different if dementia is due to Alzheimer’s disease, a reversible thyroid condition, malnutrition, or a severe psychological disorder.

It is also worth noting that neuropsychological testing may not reveal dementia but instead show Mild Cognitive Impairment, which is stage between normal aging and dementia. This is important to know as it also effects treatment and not all of these cases convert to dementia.

One needs to be careful in selecting a neuropsychologist and some guidance on how to do so is offered here.

No comments:

Post a Comment

Your comments are welcome.