Confused Elderly Patient              09/29/2000 Nakahara

Initial Approach
Yet not all cognitive problems in the elderly are due to dementia.
Only after delirium and psychiatric disorders have been ruled out can dementia be diagnosed in an elderly patient with cognitive impairment. Because delirium is associated with an increased risk in mortality, it should always be considered first when a physician confronts a patient with cognitive impairment.
DDD(Delirium, Depression, Dementia)を鑑別する。


チューブや点滴を取ろうとするなどのagitationや、活動減少 型(日中うとうと)がある。短期記憶や見当識も傷害される。環境変化(入院当日や術後)、ストレスなどがリスクになる!
  Common Causes of Delirium
    Metabolic disorders
    Electrolyte abnormalities
    Acid-base disturbances
    Hypoglycemia or hyperglycemia
    Decreased cardiac output
    Acute blood loss
    Acute myocardial infarction
    Congestive heart failure
    Stroke (small cortical)
    Intoxication (alcohol and/or other substances)
    Hypothermia or hyperthermia
    Acute psychoses
    Transfer to unfamiliar surroundings
    Fecal impaction
    Urinary retention
Risk R/O Electrolyte, Dehydration, Infection
      Urinary retention.
      Hearing or Visual disorder

Delirium and dementia may coexist. Dementia is a known risk factor for delirium. As many as 22 percent of community-dwelling elderly persons with dementia have coexisting delirium. At any one time, 15 percent of hospitalized patients over the age of 70 years are delirious. In this situation, treatment of the delirium often improves the patient's cognitive and/or functional abilities


   Check DSM-Ⅳ Criteria
   2wk depressed mood+5/8 “SIGECAPS”


     Memory impairment and at least one of the following:
     Impaired executive functioning (e.g., planning, organizing, abstracting)
     Significant impairment in social functioning.(これも必須項目)
     Significant decline from previous level of functioning
     Deficits that do not occur exclusively during the course of delirium

 ・Memory impairment
     Have any difficulties with finding the right word to say?
     Substitute an incorrect word, such as "chair" for "table"?
     Break off in midsentence or lose his or her train of thought?
     Stutter or repeat words over and over?
     Dressing or bathing alone?
     Using a brush or comb?
     Feeding himself or herself?
     If the answer to any of the above is yes, follow up with: Do you think it's a physical
      problem, or is it because he or she is having trouble figuring out how to do it?
     Familiar people or places?
     Familiar objects or personal items?

Mental Status Examination

The Mini-Mental State Examination (MMSE) is the most widely used method for grading cognitive status. A score of less than 24 is considered abnormal, but this score should be adjusted to account for the educational bias associated with the instrument. An abnormal score on the MMSE is not diagnostic of dementia or delirium, but it does reflect the severity of cognitive impairment.

Medication Review

Polypharmacy and adverse drug reactions are major causes of confusion in the elderly. Since many commonly used drugs can cause delirium.

Medications Associated with Confusion in the Elderly
    (narcotic and nonnarcotic)
  Antiparkinsonian drugs
  Cardiovascular drugs
  Psychotropic drugs
   Cimetidine (Tagamet)



Physical Examination

the physician should focus the physical examination on the cardiovascular, neurologic and psychiatric systems. Note that the physical examination is frequently normal in patients with early DAT.
The physical evaluation should include an assessment of the patient's level of arousal and orientation. Patients who lack alertness or have a clouded consciousness are more likely to have delirium than dementia. Focal neurologic changes are signs of an underlying neurologic disorder. Unfortunately, focal changes are not associated exclusively with delirium or dementia.

Treatable Dementia

Dementia can be classified as reversible or irreversible. Potentially reversible causes include thyroid dysfunction, deficiencies of vitamins such as B12 and folate, infections such as neurosyphilis, metabolic abnormalities such as uremia, and normal-pressure hydrocephalus.

Laboratory Tests

   Test         Possible underlying causes that can be detected

     Urinalysis      Urinary tract infection, diabetes
     Electrolytes      Electrolyte imbalance
     Serum, calcium    Hypercalcemia, hypocalcemia
     BUN, creatinine    Uremia
     Liver enzymes    Hepatic dysfunction, encephalopathy
     Thyroid hormones  Hyperthyroidism, hypothyroidism
     Serum B12      VB12 deficiency
     VDRL        Neurosyphilis

CBC, Chemi, Renal/Liver, TSH, B12(Folate), VDRL

Electroencephalograms (EEGs)

can be used to detect patterns characteristic of delirium, especially when a previous EEG is available for comparison. Electroencephalograms (EEGs) in patients with Alzheimer's disease may be normal or show diffuse slowing and are not obtained in the routine evaluation of dementia. However, an EEG may be helpful when seizure or Creutzfeldt-Jakob disease is suspected (in the latter, an EEG shows both diffuse slowing and periodic complexes).

Lumbar puncture

is not needed in the evaluation of most patients with dementia. However, spinal fluid examination may be indicated in those with specific clinical and laboratory findings
Acute or subacute onset (<8 wk)
Evidence of immunosuppression
Fever or presence of meningeal signs
Atypical presentation of dementia (eg, severe headaches, seizures, cranial neuropathies)
Clinical findings suggestive of normal-pressure hydrocephalus
Positive serum fluorescent treponemal antibody absorption test
Abnormalities on computed tomographic or magnetic resonance imaging brain scan (eg, meningeal enhancement)

Diagnostic imaging

Computed tomography (CT) or magnetic resonance imaging (MRI) of the brain has become a routine part of the workup of suspected dementia. Yet the value of these expensive tests in the evaluation of dementia continues to be questioned. In actual practice, both families and physicians often are not satisfied that a "thorough" workup has been done unless an imaging test has been performed. However, CT or MRI should not be considered a substitute for thorough history taking and physical examination.

As a general rule, imaging should be performed in most patients with dementia. However, it may not be warranted in patients in whom the medical history reveals no significant findings, the results of physical and neurologic examination are normal, and the onset and progression of cognitive decline are consistent with Alzheimer's disease. Imaging may be helpful in diagnosis of atypical dementias, meningitis, hydrocephalus, tumor, stroke, focal lesions or atrophy, and hematomas. CT or MRI is particularly recommended in patients with an atypical presentation, rapid deterioration, incontinence, focal neurologic signs, past history of head injury, or systemic diseases that prominently affect the brain (eg, HIV infection, systemic lupus erythematosus).

Apolipoprotein E

the recommendation is that apo E genotyping should be limited to use in patients with cognitive deficits who are members of autosomal-dominant families with a history of early-onset DAT

Diagnostic Approach to the Confused Elderly Patient - March 15, 1998 - American Academy of Family Physicians
Initial evaluation of suspected dementia: asking the right questions. Postgrad Med 1999:106(5):72-83