Dementia Essays - Cognitive Disorders, Psychiatric Diagnosis

Dementia Essays - Cognitive Disorders, Psychiatric Diagnosis Dementia What is Dementia ? Dementia is an organic brain syndrome which results in global cognitive impairment. Dementia can occur as a result of a variety of neurological diseases. Some of the more well known dementing diseases include Alzheimers disease (AD), multi-infarct dementia (MID), and Huntingtons disease (HD). Throughout this essay the emphasis will be placed on AD (also known as dementia of the Alzheimers type, and primary degenerative dementia), because statistically it is the most significant dementing disease occurring in over 50% of all demented patients (see epidemiology). The clinical picture in dementia is very similar to delirium, except for the course. Delirium is an acute transitory disorder. By contrast Dementia is a long term progressive disorder (with the exception of the reversible dementias). The course of AD can range anywhere from 1.5 to 15 years with an average of about years (Katzman, Lasker AD is usually divided into three stages mild, moderate, and severe. Throughout these stages a specific sequence of cognitive deterioration is observed (Lezak, 1995). The mild stage begins with memory, attention, speed dependent activities, and abstract reasoning dysfunction. Mild language impairments also begin to surface at this period. In the moderate stage, language deficits such as aphasia and apraxia become prominent. Dysfluency, paraphasias, and bizarre word combinations are common midstage speech defects. In the severe stage the patient is gradually reduced to a vegetative state. Speech becomes non-fluent, repetitive, and largely non-communicative. In addition, Auditory comprehension becomes exceedingly limited, with many patients displaying partial or complete mutism. Late in the course of the disease many neuropsychological functions can no longer be measured. Furthermore, primitive reflexes such as grasp and suck emerge as well. Death usually results from a disease such as pneumonia which overwhelms the limited vegetative functions of the patient. Dementia is commonly differentiated along two dimensions age and cortical level. The first dimension, age, serves to distinguish between senile and presenile dementia. Senile dementia is used to describe patients who become demented after the age of 65, whereas presenile dementia applies to patients who become demented prior to that age. Late onset AD (LOAD) also known as senile dementia of the Alzheimers type (SDAT) is the predominant cause of senile dementia. Early onset AD (EOAD) is the most frequent cause of presenile dementia, but HD, Picks disease, and Creutzfeldt-Jakob disease though not as frequent are also important causes in presenile dementia. The second dimension, cortical level, differentiates between cortical and subcortical dementia. Cortical dementia is used to describe dementia which results from brain lesions at the cortical level, whereas sub- cortical dementia applies to dementia which results from subcortical brain lesions. AD and Picks disease are amongst the best known examples of cortical dementia; whereas HD, Parkinsons disease (PD), and progressive supranuclear palsy (PSP) are good examples of subcortical dementia (Derix, 1994). When dementia with both cortical and subcortical features occurs, the term mixed dementia is used. MID is a common example of mixed dementia. Historical Developments in Dementia Pre-Modern Developments The use of the term dementia dates back to Roman times. The Latin word demens did not originally have the specific connotation that it does today. It meant being out of ones mind and as such was a general term for insanity (URen, 1987). It was the encylopedist Celsus who first used the word dementia in his De re medicina, published around AD 30. A century later the Cappadocian physician Aretaeus first described senile dementia with the word dotage: The dotage which is the calamity of old agedotage commencing with old age never intermits, but accompanies the patient until death (URen, 1987, P. 1). Curiously, dementia was mentioned in most systems of psychiatric classification throughout pre-modern times, though the precise meaning of the word is often unclear (URen, 1987). Nineteenth Century It can be argued that the origins of the scientific study of dementia date back to the early nineteenth century. The initial steps were undertaken by the great French psychiatrist Pinel at the beginning of that century. Pinels observations led him to conclude that dementia is caused by idiotism. He used the term dementia in relation to the progressive mental changes seen in some idiots (URen, 1987,3). Furthermore, Pinel thought that dementia was a distinct abnormal entity,