Diagnostic Tests for Alzheimer's Disease

Alzheimer's Disease: Diagnostic Tests

The list of diagnostic tests mentioned in various sources as used in the diagnosis of Alzheimer's Disease includes:

• Urine tests
• Blood tests
• Neuropsychological tests
• Memory tests
• Cognitive tests
• Brain scans
  • Brain CT scan
  • Brain MRI scan
  • Brain PET scan

Home Diagnostic Testing

These home medical tests may be relevant to Alzheimer's Disease:

• Home Andropause Tests
• Prostate Health: Home Testing:
  • Home Prostate Tests
  • Home PSA Antigen Tests
  • Home Testosterone Tests
• Brain & Neurological Disorders: Related Home Testing:
  • ADHD -- Home Tests
  • Drug Screening Kits

Tests and diagnosis discussion for Alzheimer's Disease:

Alzheimer's Disease: NWHIC (Excerpt)

Doctors at specialized centers can diagnose probable AD correctly 80-90 percent of the time. They can find out whether there are plaques and tangles in the brain only by looking at a piece of brain tissue under a microscope. It can be painful and risky to remove brain tissue while a person is alive. Doctors cannot look at the tissue until they do an autopsy, which is an examination of the body done after a person dies.

Doctors may say that a person has "probable" AD. They will make this diagnosis by finding out more about the person's symptoms. The following is some information the doctor may need to make a diagnosis:

• A complete medical history: The doctor may ask about the person’s general health and past medical problems. He or she will want to know about any problems the person has carrying out daily activities. The doctor may want to speak with the person’s family and friends to get more information.

• Basic medical tests: Tests of blood and urine may be done to help the doctor eliminate other possible diseases. In some cases, testing a small amount of spinal fluid also may help. In addition, scientists are busy trying to develop a test to diagnose AD that will be easy and accurate.

• Neuropsychological tests: These are tests of memory, problem solving, attention, counting, and language. They will help the doctor pinpoint specific problems the person has.

• Brain scans: The doctor may want to do a special test, called a brain scan, to take a picture of the brain. There are several types of brain scans including a computerized tomography (CT) scan, a magnetic resonance imaging (MRI) scan, or a positron emission tomography (PET) scan. By looking at a picture of the brain, the doctor will be able to tell if anything does not look normal. Information from the medical history and any test results help the doctor rule out other possible causes of the person’s symptoms. For example, thyroid problems, drug reactions, depression, brain tumors, and blood vessel disease in the brain can cause AD-like symptoms. Some of these other conditions can be treated.

NIA's Progress Report on Alzheimer's Disease, 1998: NIA (Excerpt)

Through the work of many researchers, the diagnosis of AD in living people has become more and more accurate. In specialized research facilities, clinicians now can diagnose AD with up to 90 percent accuracy, as confirmed later at autopsy. The diagnosis includes taking a personal history from patients and their families, doing a physical exam and tests, and administering memory and psychological tests to patients. A team of NIA-funded researchers based at the Harvard University ADC (Solomon et al., 1998) proposed a preliminary 7-minute screening test that might be used to distinguish between people who might have AD and those experiencing normal memory loss. The utility of this screening test has yet to be thoroughly evaluated. (Source: excerpt from NIA's Progress Report on Alzheimer's Disease, 1998: NIA)

Diagnosis of Alzheimer's Disease: medical news summaries:

The following medical news items are relevant to diagnosis of Alzheimer's Disease:

• Alert caregiving for Alzheimer's patients
• Alzheimer's disease epidemic
• Blood pressure and cholesterol drugs may greatly benefit some dementia sufferers
• Dementia differences
• Dementia link to cranial blood flow
• Dementia more prevalent in black Americans
• Early Alzheimer's test being developed
• Normal pressure hydrocephalus frequently misdiagnosed in the elderly
• PET scans have a 91 percent accuracy for Alzheimer's diagnosis
• More news »

Diagnostic Tests for Alzheimer's Disease: Online Medical Books

16 MEDICAL BOOKS ONLINE! Review excerpts from medical books online, free, without registration, for more information about the diagnostic tests for Alzheimer's Disease.

AMNESIA: DIAGNOSTIC WORKUP
(Algorithmic Diagnosis of Symptoms and Signs)

All patients with a history of amnesia deserve a CT scan or magnetic resonance imaging (MRI). The CT scan would be more cost-effective and would be the diagnostic test of choice because it also helps detect acute brain hemorrhages. Patients with fever should have a spinal tap as well as CBC, urinalysis, and chemistry panel. These patients also probably should have a blood culture. An electroencephalogram (EEG) should be ordered to rule out epilepsy and toxic metabolic inflammatory diseases of the brain.

If all these studies are negative and an organic cause is still considered, then referral to a neurosurgeon or neurologist is in order. If these studies are negative and a psychiatric disorder is suspected, a psychiatrist should be consulted.

» READ BOOK EXCERPT ONLINE »

Source: Algorithmic Diagnosis of Symptoms and Signs, 2003

DELIRIUM: DIAGNOSTIC WORKUP
(Algorithmic Diagnosis of Symptoms and Signs)

Routine laboratory tests include a CBC, sedimentation rate, ANA, chemistry panel including electrolytes and BUN and VDRL tests, a blood alcohol level, urinalysis, and urine drug screen. A CT scan of the brain and EEG is usually indicated also. Acute delirium may be an indication to administer intravenous glucose and thiamine. If there is fever, blood cultures and a spinal tap for analysis and culture need to be done. Arterial blood gases and carboxyhemoglobin should be determined. Generally, a neurologist or neurosurgeon should be consulted early.

» READ BOOK EXCERPT ONLINE »

Source: Algorithmic Diagnosis of Symptoms and Signs, 2003

DEMENTIA: DIAGNOSTIC WORKUP
(Algorithmic Diagnosis of Symptoms and Signs)

Routine laboratory tests include a CBC, sedimentation rate, chemistry panel, VDRL test, HIV antibody titer, ANA, blood alcohol level, urine drug screens, thyroid profile, serum B ₁₂ , and folic acid. A CT scan should probably be done in all cases. An EEG may be helpful in demonstrating drug intoxication. A spinal tap may need to be done to diagnose central nervous system lues. The best test for that is the fluorescent treponema antibody absorption test (FTA-ABS). MRI may be useful in distinguishing Alzheimer's disease from cerebral arteriosclerosis, as in cerebral arteriosclerosis small infarcts may be demonstrated. A radioiodinated serum albumin (RISA) cisternography study is useful to diagnose normal pressure hydrocephalus. Arterial blood gases should be drawn. Psychiatric testing will help differentiate organic brain syndrome from other psychiatric disorders and malingering. A neurologist or psychiatrist should be consulted before ordering expensive diagnostic tests.

» READ BOOK EXCERPT ONLINE »

Source: Algorithmic Diagnosis of Symptoms and Signs, 2003

APHASIA, APRAXIA, AND AGNOSIA: DIAGNOSTIC WORKUP
(Algorithmic Diagnosis of Symptoms and Signs)

All patients should have a CBC, sedimentation rate, chemistry panel, a VDRL test, and a CT scan of the brain. The CT scan may demonstrate an infarct, a space-occupying lesion, a degenerative disease, or multiple sclerosis. If this is negative, a neurologist should be consulted before ordering MRI or a spinal tap.

If the patient presents with intermittent aphasia, apraxia, or agnosia, an EEG should be done to rule out epilepsy, and a carotid scan should be done to rule out carotid stenosis or carotid plaques with ulceration. Four-vessel angiography may need to be considered, but a neurologist should be consulted before this is done.

» READ BOOK EXCERPT ONLINE »

Source: Algorithmic Diagnosis of Symptoms and Signs, 2003

Amnesia: History and physical examination
(Handbook of Signs & Symptoms (Third Edition))

Because the patient typically isn’t aware of his amnesia, you’ll usually need help in gathering information from his family or friends. Throughout your assessment, notice the patient’s general appearance, behavior, mood, and train of thought. Ask when the amnesia first appeared and what types of things the patient is unable to remember. Can he learn new information? How long does he remember it? Does the amnesia encompass a recent or remote period?

Test the patient’s recent memory by asking him to identify and repeat three items. Retest after 3 minutes. Test his intermediate memory by asking, “Who was the president before this one?” and “What was the last type of car you bought?” Test remote memory with such questions as “How old are you?” and “Where were you born?”

Take the patient’s vital signs and assess his level of consciousness (LOC). Check his pupils: They should be equal in size and should constrict quickly when exposed to direct light. Also, assess his extraocular movements. Test motor function by having the patient move his arms and legs through their range of motion. Evaluate sensory function with pinpricks on the patient’s skin. (See Amnesia: Common causes and associated findings.)

» READ BOOK EXCERPT ONLINE »

Source: Handbook of Signs & Symptoms (Third Edition), 2006

Confusion: History and physical examination
(Handbook of Signs & Symptoms (Third Edition))

When you take his history, ask the patient to describe what's bothering him. He may not report confusion as his chief complaint, but may suffer from memory loss, persistent apprehension, or the inability to concentrate. He may be unable to respond logically to direct questions. Check with a family member or friend about its onset and frequency. Find out, too, if the patient has a history of head trauma or a cardiopulmonary, metabolic, cerebrovascular, or neurologic disorder. Which medications is he taking, if any? Ask about any changes in eating or sleeping habits and in drug or alcohol use.

Perform an assessment to determine the presence of systemic disorders. Check the patient's vital signs, and assess him for changes in blood pressure, temperature, and pulse.

Next, perform a neurologic assessment to establish the patient's level of consciousness.

» READ BOOK EXCERPT ONLINE »

Source: Handbook of Signs & Symptoms (Third Edition), 2006

Amnesia: History and physical examination
(Professional Guide to Signs & Symptoms (Fifth Edition))

Because the patient often isn’t aware of his amnesia, you’ll usually need help in gathering information from his family or friends. Throughout your assessment, notice the patient’s general appearance, behavior, mood, and train of thought. Ask when the amnesia first appeared and what types of things the patient is unable to remember. Can he learn new information? How long does he remember it? Does the amnesia encompass a recent or a remote period?

Test the patient’s recent memory by asking him to identify and repeat three items. Retest him after 3 minutes. Test his intermediate memory by asking, “Who was the president before this one?” and “What was the last type of car you bought?” Test remote memory with such questions as “How old are you?” and “Where were you born?”

Take the patient’s vital signs and assess his level of consciousness (LOC). Check his pupils: They should be equal in size and should constrict quickly when exposed to direct light. Also, assess his extraocular movements. Test motor function by having the patient move his arms and legs through their range of motion. Evaluate sensory function with pinpricks on the patient’s skin. (See Amnesia: Causes and associated findings.)

» READ BOOK EXCERPT ONLINE »

Source: Professional Guide to Signs & Symptoms (Fifth Edition), 2006

Apraxia: History and physical examination
(Professional Guide to Signs & Symptoms (Fifth Edition))

If you detect apraxia, ask about previous neurologic disease. If the patient fails to report such disease, begin a neurologic assessment. First, take the patient’s vital signs and assess his level of consciousness. Be alert for any evidence of aphasia or dysarthria. Ask the patient if he has recently experienced headaches or dizziness. Then test the patient’s motor function, observing for weakness and tremors. Next, use a small pin or another pointed object to test sensory function. Check deep tendon reflexes for quality and symmetry. Finally, test the patient for visual field deficits.

Be alert for signs and symptoms of increased intracranial pressure (ICP), such as headache and vomiting. If you detect these, elevate the head of the bed 30 degrees and monitor the patient closely for altered pupil size and reactivity, bradycardia, widened pulse pressure, and irregular respirations. Have emergency resuscitation equipment nearby, and be prepared to give mannitol I.V. to decrease cerebral edema.

If the patient is experiencing seizures, stay with him and have another nurse notify the physician immediately. Avoid restraining the patient. Help him to a supine position, loosen tight clothing, and place a pillow or other soft object beneath his head. If the patient’s teeth are clenched, don’t force anything into his mouth. If his mouth is open, protect the tongue by placing a soft object, such as a washcloth, between his teeth. Turn the patient’s head to provide an open airway.

After completing the examination and ensuring the patient’s safety, take a history. Ask about previous cerebrovascular disease, atherosclerosis, neoplastic disease, infection, or hepatic disease. Then assess the apraxia further to help determine its type. (See Apraxia: Causes and associated findings, page 72.)

» READ BOOK EXCERPT ONLINE »

Source: Professional Guide to Signs & Symptoms (Fifth Edition), 2006

Confusion: History and physical examination
(Professional Guide to Signs & Symptoms (Fifth Edition))

When you take his history, ask the patient to describe what’s bothering him. He may not report confusion as his chief complaint but may complain of memory loss, persistent apprehension, or the inability to concentrate. He may be unable to respond logically to direct questions. Check with a family member or friend about the onset and frequency of the patient’s confusion. Find out, too, if the patient has a history of head trauma or a cardiopulmonary, metabolic, cerebrovascular, or neurologic disorder. Which medications is he taking, if any? Ask about any changes in eating or sleeping habits and in drug or alcohol use.

Perform an assessment to determine the presence of systemic disorders. Check vital signs, and assess the patient for changes in blood pressure, temperature, and pulse.

Next, perform a neurologic assessment to establish the patient’s level of consciousness.

» READ BOOK EXCERPT ONLINE »

Source: Professional Guide to Signs & Symptoms (Fifth Edition), 2006

Confusion: Physical examination
(The 10-Minute Diagnosis Manual: Symptoms and Signs in the Time-Limited Encounter)

 A. Focused physical examination. This should include vital signs, psychomotor characteristics, assessment of skin, hair, and nail beds; and
a funduscopic examination. A screening neurologic examination should include a check for nuchal rigidity, and an assessment of Kernig’s and Brudzinski’s signs. Positive findings warrant further testing. The Folstein Mini-Mental State examination (2) can help assess cognitive functioning (Chapter 4.5). The Confusion Assessment Method may be used to help detect delirium (3).

Testing

 A. Clinical laboratory tests. These should include a complete blood count with differential, urinalysis, toxicology screen, serum chemistry panel, and appropriate medication levels. Vitamin B₁₂ and folate levels, serologic test for syphilis, and thyroid function studies can be drawn. As clinically indicated, blood gases can also be checked. Based on history and examination, additional studies may include cerebrospinal fluid examination, heavy metals screen, and erythrocyte sedimentation rate (and others, as needed for vasculitis). An electroencephalogram (EEG) can be particularly useful in distinguishing delirium from psychiatric presentations—in delirium, the EEG will show diffuse slowing, except in cases of sedative drugs and withdrawal when low amplitude fast activity is seen; the EEG is normal in psychiatric syndromes.

 B. Diagnostic imaging. Magnetic resonance imaging is indicated for first psychotic breaks, new onset of confusion after age 50 years, and in the presence of focal neurologic findings.

Diagnostic assessment

. Assume organic causes until proved otherwise. Delirium is more likely in those populations noted above, and is typically characterized by disorientation, a fluctuating symptom course, and alterations in the sleep–wake cycle. Paranoia may be seen. Be alert to the presence of visual hallucinations, which can suggest the possibility of delirium. A dementia history is typically one of long intellectual decline with usual levels of alertness and attention. Orientation is often impaired, as are recent and remote memory. Perceptual disturbances are often absent, unlike delirium (4). Acute psychoses caused by schizophrenia are often characterized by hallucinations, delusions, and formal thought disorder and do not typically include disorientation or altered levels of consciousness. Symptoms tend not to fluctuate and memory is intact. Psychoses that develop as part of major depression or mania follow the onset of affective symptoms. Conversion disorders can involve hallucinations in the absence of other psychotic symptoms. La belle indifference may be present, but no symptom fluctuation or sleep–wake alteration is seen. Dissociative states can include loss of memory, including personal data, and perhaps disorientation, but these are not embedded in other changes. Episodes are usually short and perceptual disturbances are rare. Anxiety-like symptoms may precede dissociation. Acute and posttraumatic symptoms follow traumatic events. Acute stress disorder, by definition, remits within 4 weeks, but has symptoms similar to posttraumatic stress disorder. Orientation is intact, concentration can be impaired, and increased vigilance may be present. Patients may seem detached or in a daze. Nightmares and flashbacks often occur but no perceptual disturbances or thought disorganization is seen. Memory is intact, except perhaps for the traumatic event. Signs of autonomic arousal may be seen, especially with recall of the event. EEG changes are absent in psychiatric disorders.

References

1. American Psychiatric Association. Diagnostic and statistical manual of mental disorders, 4th ed. Washington, DC: American Psychiatric Association, 1994.

2. Folstein MF, Folstein SE, McHugh PR. The Folstein Mini-Mental State Examination: a practical method for grading the cognitive state of patients for the clinician. J Psychiatric Res 1975;12:189–198.

3. Inouye SK, vanDyck CH. Clarifying confusion: the confusion assessment method. Ann Intern Med 1990;113:941–946.

4. Lipowski ZJ. Delirium (acute confusional states). JAMA 1987;258:1789–1792.

» READ BOOK EXCERPT ONLINE »

Source: The 10-Minute Diagnosis Manual: Symptoms and Signs in the Time-Limited Encounter, 2000

Delirium: Physical examination.
(The 10-Minute Diagnosis Manual: Symptoms and Signs in the Time-Limited Encounter)

Because of the fluctuating nature of delirium, serial examinations are valuable.

 A. Mental status. Observe the patient and take note of changes of level of consciousness, orientation, agitation, combativeness, hallucinations, or inability to concentrate. Evaluate the mental status by using the Mini Mental Status Examination (4) or a similar tool to standardize the findings (Chapter 4.5).

 B. Physical status. Obtain vital signs and evaluate for clinical signs of dehydration, malnutrition, urinary retention, or fecal impaction. The physical examination should be guided by the history, keeping in mind the multifactorial nature of delirium. Evaluate for signs of infection, look for cardiopulmonary decompensation, and complete a thorough neurologic examination with special attention to identifying any focal neurologic deficit.

Testing

 A. Laboratory. All patients should have a complete blood count, serum chemistries including electrolytes, hepatic and renal function, albumin and calcium, and a urinalysis. Additional studies will be directed by clinical suspicions based on the history and the physical examination. These may include thyroid studies, serum medication levels, serum and urine drug screens, lumbar puncture with spinal fluid studies, HIV status, syphilis test, vitamin B₁₂ and folate levels, or serum markers of cardiac damage such as creatine kinase-MB or troponin.

 B. Additional studies. All patients should have an electrocardiogram and a chest roentgenogram as well as arterial blood gases or oxygen saturation level tests. With no history of trauma or focal neurologic deficit, a computed tomography scan is of limited value. An electroencephalogram is also of limited value unless the diagnosis of seizure is being considered.

Diagnostic assessment.

 Delirium can be a medical emergency, and a high index of suspicion must be maintained to accurately diagnose and treat the condition. Diagnosis is complicated by the similarity of presentation of depression, dementia and delirium, and by overlapping signs and symptoms. It is essential to rule out an underlying dementia or depression before the diagnosis of delirium can be made. This has particular impact on the treatment and prognosis of the illness.

 A. Dementia is characterized by a gradual onset of decreased functioning in the areas of memory, execution of the activities of daily living, and social functioning. It is less likely for delirium to cause changes in sensorium, cognition, attention; it is also less likely for delirium to fluctuate from hour to hour. Delirium can coexist with an underlying dementia and should always be considered when a previously diagnosed dementia patient exhibits an acute change in mental status.

B. Depression is characterized by a depressed mood with psychomotor retardation or agitation. Look for a gradual onset of anhedonia, sleep disturbances, fatigue, feelings of guilt or worthlessness, or a previous history of depression (Chapter 3.3).

 C. Other diagnoses. Consider in the differential diagnosis functional psychosis and bipolar disease, especially the manic phase. Both can produce hallucinations, although those of delirium tend to be visual or tactile, whereas those of psychosis tend to be auditory in nature. Epilepsy, especially temporal lobe seizures, can mimic delirium. Multi-infarct dementia, with its characteristic labile emotional state, must be considered. Remember that delirium is a complex, multifactorial condition and can present superimposed on a variety of other medical psychiatric conditions. A careful history and physical examination will help clarify the diagnosis and guide the physician and patient toward the correct treatments.

References

1. American Psychiatric Association. Diagnostic and statistical manual of mental disorders, 4th ed. Washington, DC: American Psychiatric Association, 1994:129–133.

2. Johnson JC. Delirium in the elderly. Emerg Med Clin North Am 1990;8:255–265.

3. American Psychiatric Association Practice Guidelines. Am J Psychiatry 1999;
156:S1–S20.

4. Folstein MF, Folstein SE, McHugh PR. Mini-mental status examination: a practical method for grading the cognitive state of patients for the clinician. J Psychiatr Res 1975;12:189–198.

» READ BOOK EXCERPT ONLINE »

Source: The 10-Minute Diagnosis Manual: Symptoms and Signs in the Time-Limited Encounter, 2000

Dementia: Physical examination.
(The 10-Minute Diagnosis Manual: Symptoms and Signs in the Time-Limited Encounter)

The patient should undergo a thorough general and neurologic examination and Mini-Mental Status Examination (MMSE). Look for focal neurologic deficits and assess cognitive function (memory, language, perception, praxis, attention, judgment, calculation and visuospatial function). Other neuropsychiatric testing is available.

Testing

 A. Clinical laboratory tests. The major value in laboratory tests is to look for potentially treatable causes of dementia. Basic tests should include complete blood count, electrolytes, basic chemistry (glucose, calcium, lipid panel), liver and thyroid function tests, vitamin B₁₂, folate, urinalysis, erythrocyte sedimentation rate, and serologic test for syphilis. In addition, if the history indicates, consider human immunodeficieny virus (HIV) testing as well as heavy metals and toxic screens.

 B. Diagnostic imaging. Computerized tomography is usually sufficient to rule out surgical (subdural hematoma, normal pressure hydrocephalus, tumor) and most cerebrovascular causes of dementia. Although more expensive, magnetic resonance imaging is superior to visualize small lacunae and temporal lobe atrophy (2). Positive emission tomography scanning is very expensive and seems to have greater resolution and sensitivity, but for now seems to be more of a research tool.

C. Other testing. Electroencephalography generally shows nonspecific changes except in cases of seizures, CJD, and hepatic encephalopathy. The MMSE, which is a widely used, simple tool that requires less than 10 minutes to perform, enables assessment of cognitive function (Chapter 4.5). Expected results somewhat depend on the patient’s educational level.

Diagnostic assessment.

The differential diagnosis in dementia most commonly includes age-associated memory impairment (AAMI), delirium, depression, schizophrenia, chronic alcoholism, and mental retardation. AAMI is a normal aging process with gradual memory loss in absence of dementia or medical conditions. Delirium has a subacute onset with hallucinations, delusions, and psychomotor agitation (Chapter 4.3). Common causes include infection (urinary tract infection, pneumonia), electrolyte imbalance, hypoglycemia, hepatic or renal dysfunction, endocrine abnormalities (thyroid), and medications or toxins (anticholinergics, benzodiazepines, narcotics).

References

1. Richards SS, Hendrie HC. Diagnosis, management, and treatment of Alzheimer dementia. Arch Intern Med 1999;159:789–798.

2. Crevel HV, van Gool WA, Walstra GJM. Early diagnosis of dementia: which tests are indicated? What are their costs? J Neurol 1999;246:73–78.

3. Weiner MF, ed. The dementias, diagnosis, management and research, 2nd ed. Washington, DC: American Psychiatric Press, Inc., 1996.

4. Kaye JA. Diagnostic challenges in dementia. Neurology 1998;51(Suppl):S45–S52.

» READ BOOK EXCERPT ONLINE »

Source: The 10-Minute Diagnosis Manual: Symptoms and Signs in the Time-Limited Encounter, 2000

Amnesia: Diagnostic Approach
(Field Guide to Bedside Diagnosis)

Amnesia is characterized by an inability to recall prior events and to learn new information, despite a normal level of consciousness. There must be injury to both temporal lobes in order for amnesia to occur.

» READ BOOK EXCERPT ONLINE »

Source: Field Guide to Bedside Diagnosis, 2007

Dementia: Diagnostic Approach
(Field Guide to Bedside Diagnosis)

Many patients are concerned about age-related forgetting of details, a normal phenomenon. This usually results from decreased attention. The fact that they recognize and worry about this distinguishes them from patients with early dementia. Normal forgetting preserves vocabulary and spelling and improves with cues. For example, patients with Alzheimer disease cannot recall a list of related words any better than random words. Patients with dementia on the other hand have difficulty with one or more of the following: learning and retaining new information (e.g., remembering events); handling complex tasks (e.g., balancing a checkbook); reasoning (e.g., inability to cope with unexpected events); spatial orientation (e.g., getting lost in familiar places); language (e.g., word finding); and/or behavior.

Subtle impairments in memory, attention, and concentration are often easily compensated for and therefore hard to pinpoint. Impaired judgment and abstraction on increasingly simple matters and personality changes (notably irritability) are usually noted first. The time course of onset is helpful in distinguishing dementia from delirium, but acute exacerbations of an underlying dementia that mimic delirium are common with drugs and acute physical illness.

The Mini Mental State Exam (MMSE) measures across domains of cognitive function: memory, executive function, attention, language, praxis, and visuospatial ability. A total score of less than 24/30 suggests dementia or delirium. Scores of 20 to 24 suggest mild impairment; 16 to 19, moderate; and 15 or below, severe. It also provides a quantitative assessment useful in following the course of the disease or response to therapy.

Mini-Cog Repeat three objects, Clock Drawing Test (hands at 8:20), then recall three objects. Suggestive of dementia when either 0/3 objects are recalled or when 1 to 2 are missed and CDT is abnormal.

» READ BOOK EXCERPT ONLINE »

Source: Field Guide to Bedside Diagnosis, 2007

Delirium/Hallucinations: Diagnostic Approach
(Field Guide to Bedside Diagnosis)

Delirium is characterized by gross disorientation in the presence of alertness and vigilance, disorders of perception with vivid illusions, and psychomotor and autonomic hyperactivity. It usually develops over a short time and is associated
with fluctuating mental status, decreased attention, disorganized thinking as indicated by rambling, irrelevant, or incoherent speech, and a decreased level of consciousness. The most sensitive findings are variability in level of arousal, impaired short-term memory (e.g., digit span), and disorientation to time. Relatives or friends are helpful sources of information about the tempo and degree of impairment.

Fever, tachycardia, or hypertension should prompt a careful evaluation for a medical cause. Infection is a common cause in the elderly, especially pneumonia or urinary tract infection. Visual hallucinations are organic in origin, due to factors such as drugs, rather than due to schizophrenia.

Confusion Assessment1) Change in mental state (from baseline) that is acute and fluctuates. 2) Difficulty focusing attention or trouble keeping track of what is said. 3) Disorganized thinking (rambling or irrelevant conversation, unpredictable switching between subjects, illogical flow of ideas). 4) Altered level of consciousness (lethargy, stupor, or hyperalert). A positive test requires 1 and 2 positive, and either 3 or 4.

» READ BOOK EXCERPT ONLINE »

Source: Field Guide to Bedside Diagnosis, 2007

Apraxia: Physical assessment
(Signs & Symptoms: A 2-in-1 Reference for Nurses)

Perform a neurologic assessment. First, take the patient’s vital signs and assess his level of consciousness. Be alert for any evidence of aphasia or dysarthria. Then test the patient’s motor function, observing for weakness and tremors. Next, use a small pin or other pointed object to test sensory function. Check deep tendon reflexes for quality and symmetry. Finally, test the patient for visual field deficits.

» READ BOOK EXCERPT ONLINE »

Source: Signs & Symptoms: A 2-in-1 Reference for Nurses, 2007

Confusion: Physical assessment
(Signs & Symptoms: A 2-in-1 Reference for Nurses)

Perform an assessment to determine the presence of systemic disorders. Check vital signs, and assess the patient for changes in blood pressure, temperature, and pulse. Next, perform a neurologic assessment to establish the patient’s level of consciousness.

» READ BOOK EXCERPT ONLINE »

Source: Signs & Symptoms: A 2-in-1 Reference for Nurses, 2007

Amnesia: History and physical examination
(Nursing: Interpreting Signs and Symptoms)

Because the patient typically isn't aware of his amnesia, you'll usually need help in gathering information from his family and friends. Throughout your assessment, notice the patient's general appearance, behavior, mood, and train of thought. Ask when the amnesia first appeared and what the patient is unable to remember. Can he learn new information? How long does he remember it? Does the amnesia encompass a recent or remote period?

Test the patient's recent memory by asking him to identify and repeat three items. Retest after 3 minutes. Test his intermediate memory by asking, “Who was the president before this one?” and “What was the last type of car you bought?” Test remote memory with such questions as “How old are you?” and “Where were you born?”

Take the patient's vital signs and assess his level of consciousness (LOC). Check his pupils: They should be equal in size and should constrict quickly when exposed to direct light. Assess his extraocular movements. Test motor function by having the patient move his arms and legs through their range of motion. Evaluate sensory function with pinpricks on the patient's skin.

» READ BOOK EXCERPT ONLINE »

Source: Nursing: Interpreting Signs and Symptoms, 2007

Confusion: History and physical examination
(Nursing: Interpreting Signs and Symptoms)

When you take his history, ask the patient to describe what's bothering him. He may not report confusion as his chief complaint, but may suffer from memory loss, persistent apprehension, or the inability to concentrate. He may be unable to respond logically to direct questions. Check with a family member or friend about its onset and frequency. Find out, too, if the patient has a history of head trauma or a cardiopulmonary, metabolic, cerebrovascular, or neurologic disorder. Which medications is he taking, if any? Ask about any changes in eating or sleeping habits and in drug or alcohol use.

Perform an assessment to determine the presence of systemic disorders. Check the patient's vital signs, and assess him for changes in blood pressure, temperature, and pulse.

Next, perform a neurologic assessment to establish the patient's level of consciousness.

» READ BOOK EXCERPT ONLINE »

Source: Nursing: Interpreting Signs and Symptoms, 2007