Tag Archives: memory

Alzheimer’s Diagnosis: How do you know for sure?

Alzheimer’s Diagnosis Overview:

Currently there are no definitive tests to determine an Alzheimer’s diagnosis, except for an autopsy which may be performed after death. Instead, the current approach for establishing an Alzheimer’s diagnosis basically involves a process of elimination, ruling out other conditions which may mimic or exacerbate memory conditions such as depression, Huntington’s disease, or hypothyroidism. An Alzheimer’s diagnosis is essentially made based upon data from the patient’s history, mental status exams and interviews with the patient, family members and friends over a period of time. Studies have indicated that a diagnosis of Alzheimer’s disease based upon such clinical features are accurate in about 90% of the cases.

According to the Diagnostic and Statistical Manual of Mental Disorders (DSM- IV), among other things, a combination of memory impairment and other cognitive deficits, such as difficulty communicating which is severe enough to affect social and job functioning must be found as well as a memory decline which is determined to be gradual in onset.

Although slightly less important than clinical features in making an Alzheimer’s diagnosis, laboratory imaging studies are also useful in providing additional information. Laboratory tests look for certain proteins or genes associated with Alzheimer’s disease while imaging techniques examine the brain for shrinkage. There is no foolproof test currently available including having a genetic predisposition to Alzheimer’s disease. Genetic predisposition does not mean that a specific individual will develop the disease and coincidentally many normal brains exhibit shrinkage.

Laboratory tests for an Alzheimer’s disease diagnosis:

Recently, two new tests have been developed called the ADmark Assays. One of these assays measures beta-amyloid and tau protein in the spinal fluid (requiring a spinal tap). The other assay considers the probability that an individual’s dementia is due to Alzheimer’s disease based upon whether the specific form of the gene that makes APOE (designated as e4) is present in the individual’s system. This test is usually discouraged in asymptomatic individuals, however. According to a panel of experts assembled by the National Institutes of Health, testing for this APO e4 gene should not be performed currently because there is presently no cure for Alzheimer’s disease as well as no treatment that has been recommended to lower the risk of developing it. It is believed that knowledge of the gene’s presence could produce unnecessary anxiety in an individual and can lead to discrimination by employers or health insurance companies.

Alzheimer’s diagnosis and imaging studies:

Imaging studies may eventually aid in the Alzheimer’s disease diagnosis before the onset of symptoms. Positron emission tomography (PET), single photon emission computer tomography (SPECT) and magnetic resonance imaging (MRI) scans are all currently used to examine brain structure or function in Alzheimer’s disease patients. Currently however, the scans are not routinely used in Alzheimer’s diagnosis, although they can rule out other possible causes of dementia.

Some information from The Johns Hopkins Medical Guide to Health After 50

By Paul Susic Ph.D. Licensed Psychologist

Memory Loss and the Dementia Diagnosis Page #2

Memory loss and recent memory:

Memory loss related to recent memory (secondary memory) is frequently referred to as short-term memory loss. The anatomic site of dysfunction for immediate memory is believed to be the limbic system. Individuals with a lesion in this area may have little difficulty repeating digits immediately, but experience memory loss related to a rapid decay of these memories. Sometimes, within minutes, an individual with a lesion in the limbic system may be totally unable to recall the digits or even that the test has even been administered. Thus, immediate memory involves memory loss or inability to recall information that was previously registered by the primary memory. Clinically, to test recent memory, an individual may be asked to remember three objects by an examiner. They will then be distracted for three to five minutes and will then be asked to recall the previously registered three objects. Sometimes, the examiner may give a demented individual a clue (such as “one of the objects you missed was a color”) and the individual will then correctly identify the object. If this occurs, memory testing should be scored as “three out of three with a clue” which is considered to be a slight impairment. Giving clues to an individual with memory loss associated with their immediate recall is pointless, because the information has not been registered in the first place. Wernicke-Kosakoff syndrome is an example of a condition in which immediate recall may be intact, while recent memory has been impaired.

Memory loss related to remote (tertiary) memory:

Memory loss associated with long-term memory or what may be referred to as remote memory, is usually associated with memories from the past. Remote or long-term memory capacity is believed to be relatively unlimited, with such memories believed to be permanently retained. Accessed tertiary memories are slow and the anatomical dysfunction and long-term memory dysfunction is to believed to be in the association cortex. In the early stages of dementia, long-term memories or remote memories usually remain intact. This type of memory loss is usually tested by instructing the individual to remember personal information or material from the past. An important factor that may influence an individual’s ability to remember may be whether the memory had some personal significance. An example may be that a woman who worked as a seamstress may remember many details related to her occupation, but not recall the names of the past three presidents, or some of the major cities in the United States. Thus, an individual’s memory loss of significant past information is an ominous finding. Collateral data from informants such as family members is essential in the proper assessment of memory functioning. In summary, problems with immediate and short-term memories are frequently impaired in individuals with dementia, while long-term or remote memories are often spared until much later in the course of the disease.

Some information from DSM-IV-TR Mental Disorders: Diagnosis, Etiology & Treatment by Michael B. First and Allan Tasman

Additional information and webpage By Paul Susic Ph.D. Licensed Psychologist

Dementia: What are the different diagnoses?

Dementia overview:

Dementia disorders are characterized by the development of multiple cognitive deficits (including memory loss) but are differentiated on the basis of the etiology (i.e. Dementia of the Alzheimer’s type, Dementia due to Pick’s Disease, Dementia due to Parkinson’s Disease, Dementia due to Huntington’s Disease, Vascular Dementia, Dementia due to HIV disease, Dementia due to Head Trauma, dementia due to other general medical conditions, substance-induced persisting dementia, and dementia due to multiple etiologies). The first information presented in this section will be related to general dementia information.

Dementia diagnosis:

Dementia as it is defined in the DSM-IV-TR is a series of disorders which are characterized by the development of multiple cognitive deficits (including memory loss) that are due to the direct effects of a general medical condition, the continuing effects of a substance, or multiple etiologies. Dementias share some common features but are basically classified according to their believed etiology. The cognitive deficits must be to the degree that they interfere significantly with an individual’s occupational or social functioning. Also, the deficits must show a progressive decline from the individual’s previous higher-level of cognitive functioning and must not be the result of delirium. However, delirium may be superimposed on a dementia and both may be diagnosed if the dementia diagnosis is evident previous to the development of the delirium. Dementia is a chronic disease that typically occurs even though an individual has clear sensory abilities such as hearing and vision. If it is believed that an individual’s consciousness is somewhat clouded, they will usually receive a diagnosis of delirium. Another factor essential to the diagnosis of dementia, is the presence of cognitive deficits that include memory impairment in a least one of the following cognitive abnormalities: aphasia, agnosia, apraxia, or a disturbance of executive functioning.

Memory functioning in the dementia diagnosis:

A dementia diagnosis will require testing of memory abilities. The memory function is usually divided into three different departments that can be easily evaluated during a mental status examination. These three departments of memory functioning include immediate recall (primary memory), recent memory (secondary) and remote memory (tertiary).

Immediate recall is characterized by a limited capacity to remember things that one has been exposed to recently. It is believed that the anatomic site of destruction of immediate memory is the reticular activating system resulting in an inability to register new information. Immediate or primary memory can be tested in several ways including asking an individual to remember three words in a row and asking the individual to repeat them in the same order. This inability to immediately register new information accounts in part for an individual’s confusion and the frustration an individual may feel when confronted with unexpected changes in their daily routine.

Some information from DSM-IV-TR Mental Disorders: Diagnosis, Etiology & Treatment by Michael B. First and Allan Tasman

Additional information and webpage By Paul Susic Ph.D. Licensed Psychologist