Peter V. Rabins
Although overall rates of mental disorders are similar across the adult age span, the elderly are the least likely to seek help for mental illness. Those who do are most likely to receive treatment from a primary care provider during a routine medical visit.
General Principles
Importance of Diagnosis
Making the correct diagnosis is a crucial first step in determining proper treatment. The most common mistakes made in assessing psychiatric symptoms in older patients are ascribing them to normal aging, confusing symptoms with syndromes, and not appreciating the frequent interaction between physical and psychiatric disorders. Asking the appropriate questions and attempting to elicit the classic signs and symptoms should lead to the correct diagnosis even when the presentation is unusual.
Relationship between Physical and Mental States
Physical and psychiatric illnesses commonly coexist in the elderly. A prudent strategy when facing a patient with both physical and psychiatric complaints is to establish a differential diagnosis for each symptom before assuming that either the physical or the psychiatric disorder is primary. The two types of symptoms may be related in a number of ways.
Importance of Psychosocial Factors
Psychosocial factors are important to consider in patients of all ages. They become particularly important in the elderly because widowhood, reduced physical mobility, isolation from family and friends, and financial limitations are more common and can directly interfere with the treatment of medical and psychiatric disorders. For elderly patients with mental illness, referring the patient to a social service agency or enlisting the help of the patient's family
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may be especially important in ensuring successful treatment and follow-through. Even when dementia is present, psychosocial interventions provide an important avenue for relieving morbidity.
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TABLE 26.1 Components of a Mental Status Examination |
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Importance of Cognitive Assessment
Because dementia and delirium are common disorders of the elderly, it is important to be familiar with the assessment of cognitive function and to perform a cognitive mental status examination on all patients in whom a psychiatric symptom is present. Table 26.1 displays the mental status examination, which allows the clinician to identify the types of cognitive deficits the patient is experiencing and to provide a comparison for future examinations. The Mini-Mental Status Examination is a reliable, brief, widely used screening tool (1) that permits standardized scoring and facilitates following patients over time. However, it may be normal in patients with mild dementia. Formal neuropsychometric testing and/or reevaluation of patients at a later time may be useful in such situations.
Specific Psychogeriatric Disorders
Psychiatric disorders in older patients may present with the classic symptoms described in other chapters of this book. The following pages focus on several syndromes that are particularly important in the elderly.
Depression
Depressive Symptoms
Symptoms of depression and sadness become more common in late life even though the syndrome of major depression is less common in the elderly. This dissociation may be caused by both the criteria used to make diagnoses and intrinsic differences between the young and old. The Diagnostic and Statistical Manual of Mental Disorders, 4th Edition (DSM-IV), divides mood disorder into several categories (seeChapter 24). The differences among them depend on both symptom clustering and course. The presentation of these disorders in older patients may differ from the presentation in younger patients in several ways.
An adjustment disorder with depressed mood is characterized by sad or low mood that follows, within 3 months, a clearly identifiable stressor or precipitant. In elderly patients, stressors such as illness, decreases in functional status, isolation, and financial limitations (seeImportance of Psychosocial Factors, above) are particularly common. The approaches to office psychotherapy described in Chapter 20 are fully applicable to elderly patients with adjustment disorders.
A dysthymic disorder, conversely, is characterized by the presence of depressive symptoms for more than 2 years. Mood often fluctuates widely but in no discernible pattern. The patient may experience hours, days, or weeks of improved mood, mixed with prolonged periods of unhappiness. In the elderly, a dysthymic disorder should be considered when the patient reports chronic depressive symptoms throughout his or her life and denies the cyclicity and periods of normal mood found in recurrent depressive or bipolar disorder (see Chapter 24). It may require specialty referral because of its chronicity.
Major Depression
The diagnostic criteria of the major affective disorders and their treatment, as described in Chapter 24, are generally applicable to the elderly. Hypochondriacal features, agitation, and suspiciousness or frank paranoia often accompany depression in the elderly and are common sources of diagnostic confusion. A study demonstrated that the elderly with major depressive disorder are less likely to report being sad than the young (2). Therefore, denial of sadness does not rule out the diagnosis of major depression.
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Elderly patients with a hypochondriacal focus usually deny that their mood is sad but focus on physical symptoms for which there is minimal or no evidence of abnormality on physical examination or laboratory assessment. Depressed hypochondriacal patients often have changes in their vital sense (“something is wrong with me”) and a negative self-attitude (“I’ve done something to deserve this or cause this”). Therefore, the patient should be asked specifically about these cardinal features of major depression when hypochondriasis is present.
Because suspiciousness and paranoia are common in depressed elderly patients, other evidence for a major depression should be sought when these symptoms are present. When paranoia and depression coexist, depression is most commonly the primary disorder.
As in younger patients, major depression in the elderly often requires pharmacotherapy or electroconvulsive therapy. Chapter 24 gives practical details about these modes of treatment. Selective serotonin reuptake inhibitor (SSRI) antidepressants are the treatment of choice for the initiation of antidepressant pharmacotherapy. Sertraline (Zoloft) should be started at a dosage of 25 to 50 mg in the morning; 200 mg is the maximum dosage. Paroxetine (Paxil) should be started at a dosage of 10 mg in the morning; 30 mg is the maximum dosage. Citalopram (Celexa) should be started at a dosage of 15 mg in the morning. The maximum dose is 45 mg. The long half-life of fluoxetine (Prozac) suggests that it should be used in lower dosages in the elderly than in young patients, starting at a dosage of 10 mg in the morning. The maximum dosage is 40 to 60 mg. Tricyclic antidepressants with the most pronounced anticholinergic properties (e.g., amitriptyline and doxepin) should be avoided. The tricyclics with the highest likelihood of causing orthostatic hypotension (e.g., amitriptyline and imipramine) should also be avoided or closely monitored because elderly patients are at higher risk of falls and are more likely to be receiving antihypertensive drugs or other compounds that also can cause orthostasis. Nortriptyline and desipramine are the tricyclic agents that are least likely to cause these side effects. A usual starting dosage in the otherwise healthy elderly person is 10 to 25 mg at bedtime; however, a dosage of 10 mg should be prescribed in the frail elderly or in patients with the potential for medical complications from the drugs.
Electroconvulsive therapy is sometimes safer than pharmacotherapy for older patients with cardiac disease. It is equally effective in all age groups (see details regarding electroconvulsive therapy, Chapter 24). Low-dose antipsychotic drugs (see Table 25.3) are indicated whendelusions complicate depression, especially when the suspiciousness is significantly interfering with the patient's function, is life threatening (e.g., the patient will not eat because he or she believes that the food is poisoned), or causes distress for the patient or those close to him or her.
Depression-Induced Cognitive Impairment
Patients with the onset of depression in late life can present with the belief that they are becoming demented. Some depressed patients perform poorly on routine tests of cognitive function. Previously this condition was called pseudodementia, but this term has fallen into disfavor because patients with this syndrome perform in the demented range on standardized tests of cognitive function and because up to 50% of these patients eventually develop a progressive dementing illness (3). Nonetheless, recognition of the syndrome is important because both the mood disorder and cognitive function can improve with antidepressant treatment. Depression-induced cognitive impairment should be considered when the onset of cognitive impairment has been subacute (less than 6 months and particularly less than 3 months), when the history of an episode of depression earlier in life is elicited, when a dementia is complicated by hypochondriacal or bizarre delusions (4), when the patient constantly emphasizes his or her cognitive disability (a behavior that is uncommon in Alzheimer disease), or when a cognitively impaired patient reports early morning awakening, lack of energy, self-blame, or guilt. At times it is difficult to determine whether the patient has a primary dementing illness with secondary depression or primary depression with reversible dementia. In such cases a therapeutic trial of an antidepressant (e.g., at least 4 weeks at a therapeutic dosage, as described in Chapter 24) may be the best way to determine which disorder is primary.
Depression Coexisting with Brain Disease
Major depression may complicate organic disorders of the central nervous system. Stroke, Parkinson disease, and AD are three common late-life disorders in which major depressive symptoms occur in 20% to 50% of patients. The importance of recognizing these as coexisting disorders is that the physical disorder and the psychiatric disorder may both need to be treated if either problem is to improve. For example, depression has been shown to interfere directly with rehabilitation from stroke. Thus, the treatment of depression after stroke improves the degree of recovery from the stroke; at the same time, gains from rehabilitation improve the patient's morale and mood (see details inChapter 91). In Parkinson disease, depressive symptoms and parkinsonian symptoms (e.g., psychomotor retardation) often overlap, and it can be difficult to determine which disorder is causing specific symptoms. In planning treatment, it is best to focus on the depressive or parkinsonian symptoms separately and to treat first the disorder that is causing the worst impairment in function. Chapter 90 describes the treatment of Parkinson disease. The treatment of depression in patients with Alzheimer disease or multi-infarct dementia can improve behavior, and mood, although cognitive impairment will persist (5).
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Paranoia and Suspiciousness
Suspiciousness is more common among the elderly than in younger people. This becomes clinically relevant when the suspiciousness interferes with the patient's life. Several types of disorders can present with suspiciousness.
Suspiciousness as an Isolated Symptom
Some elderly people become more suspicious as they age but have no accompanying signs or symptoms of other mental illness. It is important to determine whether there is a basis for the patient's suspiciousness because financial abuse of the elderly is not uncommon and concerns about the environment being unsafe can be appropriate. An understandable reaction to difficult circumstances should not be assumed, however, and a review of symptoms that explores other psychiatric conditions is necessary.
Suspiciousness Complicating Depression
As noted above, suspiciousness occurs in some elderly patients with major depression. Depression should be considered primary if the person feels deserving of persecution or punishment or has changes in vital sense and other manifestations of depression (see Chapter 24).
Late-Life Schizophrenia or Paraphrenia
Older patients occasionally develop a syndrome similar to schizophrenia in young people (see Chapter 25). Such patients have delusions(fixed, false, idiosyncratic ideas) and auditory or visual hallucinations and lack symptoms of depression or cognitive impairment.
The treatment of late-life schizophrenia and paranoia is similar to that for younger patients (see Chapter 25) except that significantly lower dosages of antipsychotic drugs are effective. Although no single antipsychotic drug is more efficacious than another, those likely to induce orthostatic hypotension, such as chlorpromazine (Thorazine), should be avoided, if possible. A starting dosage of 0.25 mg of risperidone (Risperdal) two to three times daily, olanzapine (Zyprexa) 2.5 mg at bedtime, quetiapine 12.5 to 25 mg at bedtime or perphenazine 1 mg at bedtime (may be increased to 2 mg twice daily) is recommended. Perphenazine and haloperidol are less expensive than quetiapine, risperidone or olanzapine. So-called second-generation drugs (olanzapine, risperidone and quetiapine) were thought to produce less tardive dyskinesia than first-generation drugs such as haloperidol, but this has been called into question (6). Of note, all antipsychotic drugs, with the possible exception of clozapine, are associated with increased mortality in patients with dementia (7,8). Chapter 25 describes the use of antipsychotic drugs in detail.
Paranoia and Persecutory Delusions as Symptoms of an Organic Disease
Paranoia can be symptomatic of a focal brain disease (e.g., tumor or stroke), a diffuse brain disease such as AD, a systemic condition such as a metabolic disorder (e.g., hyperthyroidism or hypoparathyroidism), or psychoactive substance abuse. Any patient with a persistent suspicious belief should have a clinical assessment for evidence that supports the presence of one of these causes.
Mild Cognitive Impairment
Some older patients complain of memory loss or slower rate of processing information, or members of their families notice these phenomena, but a history from both the patient and family reveals no social or occupational dysfunction and screening cognitive tests reveal minimal impairment in memory. Recent research suggests that 6% to 12% of these individuals develop dementia each year over the next 5 years (9). Those unlikely to have a dementia complain of such things as misplacing keys or having more difficulty remembering names or words than they once did; on questioning they acknowledge that names and words often come to them minutes later and that they have not forgotten important engagements or events. Patients who are especially concerned about memory difficulties and report a decline in function in social, personal, or occupational realms should be referred to a neuropsychologist for formal neuropsychologic evaluation to better formulate the problem. Impairments in memory and executive function are the best predictors of subsequent decline (10). Careful attention should be given to the medical status of such patients because they could have a subclinical delirium (see Delerium). When no dysfunction is identified and objective testing makes a progressive dementia unlikely, reassurance and an agreement to reassess the patient in 6 months may help relieve the anxiety associated with this condition.
Dementia
Definition and Epidemiology
Dementia is characterized by a decline in cognitive abilities from a previous level, multiple impairments in cognitive function such as memory (amnesia) or language (aphasia), and the presence of clear consciousness. Dementia can have many etiologies, but fewer than 2% of affected patients have dementia caused by a reversible etiology (10). Moderate to severe dementia affects approximately 8% of people older than 65 years. However, most dementia occurs among the very old; prevalence is 20% to 25% in people 80 years of age and older and approximately 30% to 40% in people older than 90 years. Prevalence rates are similar in European, North American, and
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Asian prevalence studies. A study from Africa suggests lower rates in Nigeria (11).
Etiologic Evaluation
The assessment of a person with complaints of cognitive decline has three purposes. The first purpose is to identify the probable cause of the dementia, including the identification of treatable disorders. The three most common causes of treatable dementia in elderly patients are medication toxicity, depression, and thyroid disease. Commonly used medications that have been associated with global cognitive impairment are the benzodiazepines (most common), H2 blockers, and anticholinergic drugs. The second purpose of assessment is to identify treatable symptoms and comorbidity. Because few patients have a truly reversible dementia, the treatment of medical and behavioral comorbidity is the main focus of both the assessment and the treatment of almost all patients in the ambulatory setting. The third purpose is to identify issues in the caregiver and environment that are amenable to intervention.
Clinical Characteristics
In considering possible etiologies, it is useful to determine whether the dementia has the clinical characteristics of a subcortical or cortical dementia (12). Most treatable dementias present as subcortical dementias. Subcortical dementias are characterized by memory loss, apathy, slowness, and movement disorder with intact language (i.e., the patient is able to name objects, repeat a phrase, and follow a command) and normal visuospatial function (i.e., the patient is able to copy a diagram) (Table 26.1). Causes of subcortical dementia include hypothyroidism, Parkinson disease, multiple sclerosis, normal pressure hydrocephalus, the dementia syndrome of depression, and most instances of vascular dementia. The cortical dementias are characterized by memory loss plus multiple defects in higher cortical functions:aphasic language (making paraphasic errors such as substituting a letter, as in “tee” instead of “tie,” or saying an incorrect word, such as “paper” instead of “pencil”), apraxia (inability to perform skilled movements such as showing how to drink with a cup on command), andagnosia (inability to recognize common objects or sensory stimuli). Alzheimer disease is the most common cortical dementia, but frontal dementias, Lewy body dementia (LBD), and rare dementias such as Creutzfeldt-Jakob disease are included in this category.
Screening Tests
The Agency for Health Care Policy and Research (AHCPR) 1996 Consensus Statement (13) on the differential diagnosis of dementia suggests the following inexpensive screening tests, each targeted at potentially treatable causes, for all patients: complete blood count (CBC), serum electrolyte levels, creatinine clearance (CrCl), liver function tests, calcium and phosphate concentrations, thyroid-stimulating hormone (TSH), vitamin B12 level, and serologic tests for syphilis. The more recent clinical practice guidelines published by the American Academy of Neurology recommends screening for depression, B12 deficiency, and hypothyroidism but, because of its rarity in the United States, recommends against routinely screening for syphilis, except in high prevalence regions or high-risk patients (13). Imaging of the brain is listed as optional by the AHCPR and as appropriate by the American Academy of Neurology. It is reasonable to obtain a noncontrast computed tomography (CT) study on all patients with symptoms of less than 2 years’ duration, onset before age 70, or focal findings on neurologic examination. CT or magnetic resonance imaging (MRI) can identify focal lesions such as a tumor, subdural hematoma, or abscess; demonstrate findings compatible with hydrocephalus; or provide confirmatory evidence for vascular etiology of the dementia. However, it is impossible to diagnose AD solely by any imaging study. Overreliance on CT or MRI reports of “white matter hyperintensities” has led to an overdiagnosis of vascular dementia.
Alzheimer disease is diagnosed by inclusion and exclusion criteria. The diagnosis should be made when other specific causes of dementia, including vascular disease, have been excluded, when the condition has been slowly progressive, and when the cognitive disorder includes language impairment, apraxia, or agnosia in addition to memory impairment.
Vascular dementia should be diagnosed when the history suggests distinct episodes of worsening (a stair-step course); when evidence of vascular disease and hypertension are present on examination; when the neurologic examination reveals asymmetries in reflexes, strength, or sensation; and when a lesion on CT or MRI correlates with the abnormalities or neurologic examination. Evidence of prior stroke on neurologic examination or imaging study is necessary because a history of stroke without confirming evidence is an unreliable indicator of vascular dementia.
The frontotemporal dementias (FTDs) are a group of slowly progressive diseases that present with pronounced changes in behavior, personality and language early in the disease. They are neuropathologically heterogeneous. On CT or MRI they show disproportionate frontal atrophy. The only Medicare-supported indication for brain PET scan is to distinguish between AD and FTD.
Lewy body dementia presents in a fashion similar to AD but also has extrapyramidal symptoms (rigidity and parkinsonian tremor), hallucinations, delusions, frequent falls, and episodes of worsening early in the course. Antipsychotic medications should be avoided, if possible, because they can cause marked worsening of the parkinsonian symptoms.
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Management
The management of irreversible dementia can be divided into six aspects:
The evaluation process should elicit specific problems in behavior caused by the dementia (Table 26.2). Difficulty in speaking, dressing, and performing potentially dangerous activities as driving, smoking, and cooking should be inquired about. When present, these problems should be explained as the result of the illness. The family or other caregivers should then try to adapt the environment to the disordered behaviors and should take steps to eliminate dangerous behaviors. Helping caregivers to specifically identify each problem can enable them to institute common-sense solutions they have not otherwise tried. In regard to the patient who continues to drive, the practitioner should instruct the patient to stop driving rather than asking a family member to do so. Most states require periodic relicensure for older people, and some even require health care practitioners to report all patients with dementia. Because these regulations can be helpful, it is important to be aware of them in one's state.
Families needing legal and financial advice should be advised to seek this out early and not wait for a crisis. Chapter 19 describes guidelines for assessing competence or for obtaining legal guardianship.
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TABLE 26.2 Behavior Problems of Patients and Problematic Activities of Daily Living Cited by Families of Demented Patientsa |
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and avoiding situations that frustrate the patient. Reminiscence therapy can improve the morale of patients with dementia (15). It is prudent to have the demented patient wear a medical alert bracelet that describes his or her condition.
Antipsychotic medications should be used only when other approaches have failed and a specific target symptom (hallucinations, delusions, aggression) is present that presents a danger to the patient or others or is very distressing to the patient (16). Importantly, these drugs are not indicated for controlling wandering or swearing. The usual dosages for these drugs are listed above (see Late-Life Schizophrenia or Paraphrenia). After target symptoms have been controlled for several months, the dosage can often be lowered, and drugs can be discontinued in about one-fourth of patients. Patients taking these drugs must be monitored for two common side effects, orthostatic hypotension and extrapyramidal symptoms (see details in Chapter 25). If only insomnia is a problem, trazodone, 50 to 100 mg at bedtime, causes the least paradoxical agitation and the least daytime drowsiness.
Aggressive behavior may be treated with antipsychotic drugs or divalproex sodium (Depakote). The starting dosage of the latter is 125 mg daily, in a pill or sprinkles. The dosage can be increased cautiously to 250 mg twice daily. Dosage should be adjusted based on clinical response and blood levels. Ataxia/delirium or gastrointestinal distress can occur. Antipsychotic drugs are associated with increased mortality at 12 weeks in patients with dementia and agitation and psychosis.
Depression is present in at least 20% of patients with dementia (17, 18). When it has the characteristics of an adjustment disorder or demoralized state (see above), it is best managed with supportive therapy (see Chapter 20). However, major depressions with symptoms of early morning awakening, anorexia, self-blame, worthlessness, nihilistic attitudes, or morbid hypochondriasis also occur and should be treated with antidepressants. Their treatment is discussed under major depression, above.
In a catastrophic reaction, an overwhelming sense of frustration, fear, anger, or anxiety occurs when the patients are brought into a situation in which they are forced to confront their failing aptitudes. These poorly controlled emotions further impair the patient's already limited functional ability, leading to total decompensation of a previously coping patient.
These catastrophic reactions can have an adverse impact on both the patient and the patient's family. The explanation of their cause and their prevention through avoidance of provoking circumstances can forestall the need for institutionalization. The use of small dosages of an antipsychotic drug (see Late-Life Schizophrenia or Paraphrenia, above) may be beneficial in patients in whom episodes like this recur despite the caregiver's best efforts.
The Alzheimer Disease Association can provide information about nearby resources and has a toll-free telephone number (1-800-272-3900 and website (http://www.alz.org/). It is also helpful to recommend a book, such as The 36-Hour Day (seehttp://www.hopkinsbayview.org/PAMreferences), which explains dementia and offers practical advice for dealing with the vexing problems created by a demented family member.
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listening approach helps family members to feel supported.
Case Study
A 72-year-old woman with a history of several small strokes experienced moderate forgetfulness and confusion but was generally calm and pleasant. Keeping track of the date with a calendar and making copious notes to herself, she managed to maintain an independent existence at home. At the supermarket checkout counter she could not find her wallet but insisted she had money to pay for her food. The clerk grew impatient, and the patient became increasingly agitated, tearful, and accusatory. When the store manager was called, she picked up grocery items and began throwing them.
Drugs for Dementia
Three cholinesterase inhibitors have been approved for the treatment of cognitive impairment in patients with AD. Their effectiveness is quite modest (about 6 months improvement in some measures of cognitive function on average). All cause GI side effects (nausea, vomiting, and diarrhea), anorexia, and gait disorder. The starting dosage of donepezil (Aricept) is 5 mg at bedtime. If no side effects develop it should be increased to 10 mg at bedtime in 4 to 6 weeks. Rivastigmine (Exelon) is started at 15 mg twice daily and increased monthly to 6 mg twice a day. Galantamine (Razadyne) is started at 4 mg twice a day and increased monthly to a total of 16 or 24 mg daily. Memantine (Namenda) has been approved for the treatment of moderate-severe AD. It is started at 5 mg daily and increased weekly in 5 mg intervals to 10 mg twice daily if tolerated.
Ginkgo biloba, an herbal alternative, has been shown to improve cognitive and social functioning modestly in one study, but this has not been replicated (21,22). Side effects, most commonly gastrointestinal complaints or headaches, are rare (see Chapter 5).
Delirium
Definition and Diagnosis
The essential features of delirium are cognitive impairment, clouding of consciousness, and difficulty sustaining and shifting attention. Delirium usually has rapid onset, brief duration, and marked fluctuation throughout the day. Delirious patients may appear drowsy or hyperalert (hypervigilant), trail off in the middle of sentences, fail to answer questions or ask that questions be repeated, or appear perplexed. Perceptual disturbances such as illusions (misinterpretations of real external stimuli) or hallucinations are common. Delirium is especially common in patients with dementia. Although patients with either dementia or delirium may experience memory impairment, disorientation, hallucinations, delusions, and disturbed thinking, the patient with dementia is alert, whereas the delirious patient is drowsy and fluctuates in alertness over minutes or hours. The abrupt onset of delirium (within hours or days) differs from dementia, which develops over months or years in most instances.
The presence of cognitive impairment and rapid fluctuation distinguishes delirium from schizophrenia and other psychotic disorders. The hallucinations and delusions associated with delirium are often fleeting and poorly systematized in comparison with those of other psychotic disorders, in which they are sustained and well organized. The electroencephalogram (EEG) in the delirious patient often reveals a generalized slowing of background activity, whereas the EEG is generally normal in schizophrenic and depressed patients.
In some patients, the manifestations of delirium may be so subtle that they are not recognized by an examiner who is unfamiliar with the patient's baseline status. At other times the symptoms suggest depression, dementia, or schizophrenia. Older age is a strong risk factor for developing delirium but underlying dementia is the single
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strongest risk factor. Delirium can be precipitated by many drugs and acute medical illnesses, drug toxicity, and dehydration.
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TABLE 26.3 Etiologic Classification of Delirium |
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The key to accurate diagnosis of delirium is a high index of suspicion in any elderly patient with a history of recent or sudden change in mental status and behavior (23). The EEG shows diffuse slowing in both delirium and dementia. In delirium, the EEG slowing is often marked, even when the cognitive and behavioral impairment is minor; conversely, severe cognitive impairment and a mildly abnormal EEG are most common in dementia.
Etiologic Evaluation
Delirium can result from a wide range of organic causes that adversely affect brain metabolism (Table 26.3). Special attention should be given to medications in the elderly because they may produce a delirium at therapeutic dosages. β-Blockers, H2 blockers, benzodiazepines, and the many compounds with anticholinergic activity are common causes of delirium. Although electrolyte disturbances are the most common metabolic cause of delirium, any disorder of metabolic homeostasis can cause delirium. Withdrawal from alcohol or sedatives is often overlooked in the elderly as a possible cause of delirium. Multiple causes are suspected, and no one specific cause is identified in 30% to 50% of cases. When there is no obvious cause for a patient's apparent delirium, an EEG may be helpful in confirming that delirium is present.
The key to treatment is the identification of the underlying causes when they can be identified. The physical, neurologic, and laboratory examination should focus on causes that are likely in a particular patient. Attention to nutrition, fluid intake, and electrolyte balance is crucial (23).
The treatment of the behavioral and emotional complications of delirium can become as urgent as the identification of the underlying cause. Frequent reorientation and reassurance, a well-lighted environment, and avoidance of overstimulation are important aspects of treatment. If the agitation, hallucinations, or delusions do not respond to environmental intervention and are overwhelming to the patient or adversely affecting the patient's safety, then a low dosage antipsychotic drug given by mouth or intramuscularly (e.g., haloperidol, 0.5 to 1.0 mg every 4 hours) can be ordered.
Specific References*
For annotated General References and resources related to this chapter, visit http://www.hopkinsbayview.org/PAMreferences.