Diagnostic decision tree in dementia

Diagnostic decision tree in dementia Diagnostic criteria for dementia include memory impairment plus impairment in at least one other cog-nitive function, including aphasia, apraxia, agnosia, or disturbance in executive functioning. 4 These deficits must represent a decline from a previous level of functioning and be sufficiently severe to cause significant impairment in social or occupational performance. The diagnosis of dementia begins with a patient presenting with memory difficulties or other complaints. These can include apathy or lack of initiative, disorientation, judgment. The patient may be self-referred or brought to the clinician's attention by concerned family members , friends, neighbors, or health care professionals. While several decision trees for dementia exist, 5,6 the process of differential diagnosis can be summarized in three questions (Table I): • Does the patient have dementia? • Does the patient have dementia alone or dementia comorbid with some other condition(s)? • What is the etiology of the patient's dementia? A comprehensive work-up for dementia includes a thorough history, with reports from informants as well as the patient, a mental status evaluation, and physical, neuro-logical, and neuropsychological examinations. 7 Neuro-imaging and specific laboratory tests are recommended, depending upon findings from the history and physical examination. The first question requires the diagnostician to distinguish dementia from depression, delirium, intoxication, and other conditions such as mental retardation, schizo-phrenia, bipolar disorder, and malingering. Important issues for the clinician to consider at this stage include whether objective findings of impairment support a diagnosis of dementia, because memory complaints unaccompanied by objective impairment may indicate depression. 8 Additionally, a cognitive profile suggestive of depression may include decreased working memory, psychomotor slowing, and responses that suggest lack of motivation or effort, as well as prominent mood symptoms or somatic complaints. 9 Clear consciousness and a stable course would tend to rule out delirium, a potentially fatal condition that is often reversible when the cause (eg, medication or substance, nutritional deficiency , infection) is remedied. Substance use history, including use of alcohol and prescription medications, could suggest intoxication. An impairment of recent origin with a history of good premorbid functioning would likely rule out mental retardation and serious psy-chopathology, although new onset of psychotic disorders in middle to late life is more common than previously thought. 10 Finally, the presence of secondary gain and inconsistent performance on neuropsychological testing (eg, poorer performance on easier items than on more difficult items) might suggest malingering. Approximately …