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

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