Psychological Disorders: Alzheimer American
Description 1. Memory impairment (impaired ability to learn new information or to recall previously learned information) 2.
One (or more) of the following cognitive disturbances:
1. Other central nervous system conditions that cause progressive deficits in memory and cognition (e.g., cerebrovascular disease, Parkinson's disease, Huntington's disease, subdural hematoma, normal-pressure hydrocephalus, brain tumor) 2. Systemic conditions that are known to cause dementia (e.g., hypothyroidism, vitamin B12 or folic acid deficiency, niacin deficiency, hypercalcemia, neurosyphilis, HIV infection) 3. Substance-induced conditions
Problem
Areas (When Initially Diagnosed) Onset
and Course Usually
the onset is insidious, with early deficits in recent memory followed
by the development of aphasia, apraxia, and agnosia after several
years. European
Description There are characteristic changes in the brain: a marked reduction in the population of neurons, particularly in the hippocampus, substantia innominata, locus ceruleus, and temporoparietal and frontal cortex; appearance of neurofibrillary tangles made of paired helical filaments; neuritic (argentophil) plaques, which consist largely of amyloid and show a definite progression in their development (although plaques without amyloid are also known to exist); and granulovacuolar bodies. Neurochemical changes have also been found, including a marked reduction in the enzyme choline acetyltransferase, in acetylcholine itself, and in other neurotransmitters and neuromodulators. As originally described, the clinical features are accompanied by the above brain changes. However, it now appears that the two do not always progress in parallel: one may be indisputably present with only minimal evidence of the other. Nevertheless, the clinical features of Alzheimer's disease are such that it is often possible to make a presumptive diagnosis on clinical grounds alone. Dementia in Alzheimer's disease is at present irreversible. Diagnostic
Guidelines (a) Presence of a dementia as described above. (b) Insidious onset with slow deterioration. While the onset usually seems difficult to pinpoint in time, realization by others that the defects exist may come suddenly. An apparent plateau may occur in the progression. (c) Absence of clinical evidence, or findings from special investigations, to suggest that the mental state may be due to other systemic or brain disease which can induce a dementia (e.g. hypothyroidism, hypercalcaemia, vitamin B12 deficiency, niacin deficiency, neurosyphilis, normal pressure hydrocephalus, or subdural haematoma). (d) Absence of a sudden, apoplectic onset, or of neurological signs of focal damage such as hemiparesis, sensory loss, visual field defects, and incoordination occurring early in the illness (although these phenomena may be superimposed later). In a certain proportion of cases, the features of Alzheimer's disease and vascular dementia may both be present. In such cases, double diagnosis (and coding) should be made. When the vascular dementia precedes the Alzheimer's disease, it may be impossible to diagnose the latter on clinical grounds. Includes:
Differential
Diagnosis Dementia in Alzheimer's disease may coexist with vascular dementia (to be coded F00.2), as when cerebrovascular episodes (multi-infarct phenomena) are superimposed on a clinical picture and history suggesting Alzheimer's disease. Such episodes may result in sudden exacerbations of the manifestations of dementia. According to postmortem findings, both types may coexist in as many as 10-15% of all dementia cases. |