Dementia is a clinical syndrome involving a sustained loss of intellectual functions and memory of sufficient severity to cause dysfunction in daily living. Its key features include: Progressive decline of intellectual (usually over months to years) Loss of short-term memory and at least one other cognitive deficit No disturbance of consciousness Deficit severe enough to cause impairment of function Not delirious
Dementia in the geriatric population can be grouped into two broad categories: Reversible or partially reversible dementias Nonreversible dementias
Dementia is an acquired persistent and progressive impairment in intellectual function, with compromise of memory and at least one other cognitive domain, most commonly: language impairment apraxia (inability to perform motor tasks, such as cutting a loaf of bread, despite intact motor function) agnosia (inability to recognize objects) impaired executive function (poor abstraction, mental flexibility, planning, and judgment). The diagnosis of dementia requires a significant decline in function that is severe enough to interfere with work or social life.
Depression and delirium are also common in elders, may coexist with dementia, and may also present with cognitive impairment. Depression is a common concomitant of early dementia. A patient with depression and cognitive impairment whose intellectual function improves with treatment of the mood disorder has an almost fivefold greater risk of suffering irreversible dementia later in life. Delirium, characterized by acute confusion, occurs much more commonly in patients with underlying dementia.
Cognitive Impairment Although there is no consensus at present on whether older patients should be screened for dementia, the benefits of early detection include identification of potentially reversible causes, planning for the future (including discussing values and completing advance care directives), and providing support and counseling for the caregiver.
The combination of a clock drawing task with a three- item word recall (also known as the "mini-cog") is a simple screening test that is fairly quick to administer. Although a number of different methods for administering and scoring the clock draw test have been described, pre-drawing a four inch circle on a sheet of paper and instructing the patient to "draw a clock" with the time set at 10 minutes after 11. Scores are classified as normal, almost normal, or abnormal. When a patient is able to draw a clock normally and can remember all 3 objects, dementia is unlikely. When a patient fails this simple screen, further cognitive evaluation with the Folstein Mini Mental State Exam (MMSE) or other instruments is warranted.
It is common for a cognitively impaired elder to face a serious medical decision and for the clinicians involved in his care to ascertain whether the capacity exists to make the choice. There are five components of a thorough assessment: (1) ability to express a choice (2) understanding relevant information about the risks and benefits of planned therapy and the alternatives, in the context of ones values, including no treatment (3) comprehension of the problem and its consequences (4) ability to reason (5) consistency A patients choice should follow rationally from an understanding of the consequences.
Cultural sensitivity must be used in applying these five components to people of various cultural backgrounds. Decision-making capacity varies over time: A delirious patient may regain his capacity after an infection is treated, and so reassessments are often appropriate. The capacity to make a decision is a function of the decision in question. A woman with mild dementia may lack the capacity to consent to coronary artery bypass grafting yet retain the capacity to designate a
Signs and Symptoms The clinician can gather important information about the type of dementia that may be present by asking about: (1) the rate of progression of the deficits as well as their nature (including any personality or behavioral change) (2) the presence of other neurologic symptoms, particularly motor problems (3) risk factors for HIV (4) family history of dementia (5) medications, with particular attention to recent changes. Work-up is directed at identifying any potentially reversible causes of dementia. However, such cases are indeed rare.
AD typically presents with early problems in memory and visuospatial abilities (eg, becoming lost in familiar surroundings, inability to copy a geometric design on paper), yet social graces may be retained despite advanced cognitive decline. Personality changes and behavioral difficulties (wandering, inappropriate sexual behavior, agitation) may develop as the disease progresses. Hallucinations may occur in moderate to severe dementia. End-stage disease is characterized by near-mutism; inability to sit up, hold up the head, or track objects with the eyes; difficulty with eating and swallowing; weight loss; bowel or bladder incontinence; and recurrent respiratory or urinary infections.
"Subcortical" dementias (eg, the dementia of Parkinson disease, and some cases of vascular dementia) are characterized by psychomotor slowing, reduced attention, early loss of executive function, and personality changes.
Dementia with Lewy bodies may be confused with delirium, as fluctuating cognitive impairment is frequently observed. Rigidity and bradykinesia are the primary signs, and tremor is rare. Response to dopaminergic agonist therapy is poor. Complex visual hallucinations—typically of people or animals—may be an early feature that can help distinguish dementia with Lewy bodies from AD. These patients demonstrate a hypersensitivity to neuroleptic therapy, and attempts to treat the hallucinations may lead to marked worsening of extrapyramidal symptoms.
Frontotemporal dementias are a group of diseases that include Pick disease, dementia associated with amyotrophic lateral sclerosis, and others. Patients manifest personality change (euphoria, disinhibition, apathy) and compulsive behaviors (often peculiar eating habits or hyperorality). In contrast to AD, visuospatial function is relatively preserved. Dementia in association with motor findings, such as extrapyramidal features or ataxia, may represent a less common disorder (eg, progressive supranuclear palsy, corticobasal ganglionic degeneration, olivopontocerebellar atrophy).
Physical Examination The neurologic examination emphasizes assessment of mental status but should also include evaluation for sensory deficits, possible previous strokes, parkinsonism, or peripheral neuropathy. The remainder of the physical examination should focus on identifying comorbid conditions that may aggravate the individuals disability.
Laboratory Findings Laboratory studies should include a complete blood count, electrolytes, calcium, creatinine, glucose, t hyroid-stimulating hormone (TSH), and vitamin B12 levels. HIV testing, RPR (rapid plasma reagin) test, heavy metal screen, and liver biochemical tests may be informative in selected patients but should not be considered part of routine testing.
Imaging Most patients should receive neuroimaging as part of the diagnostic work-up to rule out subdural hematoma, tumor, previous stroke, and hydrocephalus (usually normal pressure). Those who are younger and those who have focal neurologic symptoms or signs, seizures, gait abnormalities, and an acute or subacute onset are most likely to yield positive findings and most likely to benefit from MRI scanning. In older patients with a more classic picture of AD in whom neuroimaging is desired, a noncontrast CT scan is sufficient.
Treatment Soon after diagnosis, patients and families should be made aware of the Alzheimers Association (http://www.alz.org) as well as the wealth of helpful community and online resources and publications available. Caregiver support, education, and counseling can prevent or delay nursing home placement. Education should include the manifestations and natural history of dementia as well as the availability of local support services such as respite care. Collaborative care models and disease management programs appear to improve the quality of care for patients with dementia.
Cognitive Impairment Demented patients have greatly diminished cognitive reserve, they are at high risk for experiencing acute cognitive or functional decline in the setting of new medical illness. Consequently, fragile cognitive status may be best maintained by ensuring that comorbid diseases such as congestive heart failure and infections are detected and treated.
Acetylcholinesterase inhibitors: The majority of experts recommend considering a trial of acetylcholinesterase inhibitors (eg, donepezil, galantamine, rivastigmine) in most patients with mild to moderate AD. Memantine In clinical trials, patients with more advanced disease have been shown to have statistical benefit from the use of memantine, an N- methyl- D-aspartate (NMDA) antagonist, with or without concomitant use of an acetylcholinesterase inhibitor.
Behavioral Problems:Nonpharmacologic approaches Behavioral problems in demented patients are often best managed with a nonpharmacologic approach. Initially, it should be established that the problem is not unrecognized delirium, pain, urinary obstruction, or fecal impaction. Caregivers are taught to use simple language when communicating with the patient, to break down activities into simple component tasks, and to use a "distract, not confront" approach when the patient seems disturbed by a troublesome issue. Additional steps to address behavioral problems include the discontinuation of all medications except those considered absolutely necessary and correction, if possible, of sensory deficits.
Behavioral Problems: Pharmacologicapproaches Patients with depressive symptoms may show improvement with antidepressant therapy. Patients with dementia with Lewy bodies have shown clinically significant improvement in behavioral symptoms when treated with rivastigmine (3–6 mg orally twice daily). For those with AD and agitation, no agents, including acetylcholinesterase inhibitors and antipsychotics, have demonstrated consistent efficacy. Despite the lack of strong evidence, antipsychotic medications have remained a mainstay for the treatment of behavioral disturbances, largely because of the lack of alternative agents. The newer atypical antipsychotic agents (risperidone, olanzapine, quetiapine, aripiprazole, clozapin e, ziprasidone) are reported to be better tolerated than older agents but should be avoided in patients with vascular risk factors due to an increased risk of stroke and
Prognosis Life expectancy after a diagnosis of AD is typically 3–15 years. Other neurodegenerative dementias, such as dementia with Lewy bodies, show more rapid decline. Hospice is often appropriate for patients with end- stage dementia.
When to Refer Referral for neuropsychological testing may be helpful in the following circumstances: to distinguish dementia from depression, to diagnose dementia in persons of very poor education or very high premorbid intellect, and to aid diagnosis when impairment is mild.
Question 1 ___________ is an acquired persistent and progressive impairment in intellectual function, with compromise of memory and at least one other cognitive domain. A. Depression B. Dementia C. Delirium D. Immobility
Question 2 The clinician can gather important information about the type of dementia that may be present by asking about which of the following, except: A. the rate of progression of the deficits as well as their nature (including any personality or behavioral change) B. the presence of other neurologic symptoms, particularly motor problems C. risk factors for Syphilis D. family history of dementia E. all of the above