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Evaluation of Dementia

David Lu , MDWashington VAMC


Dementia

• a growing medical and social problem• occurring at all ages but most frequent in the

population over age 75

• an estimated 600,000 cases of advanced dementia in the United States, and milder degrees of altered mental status are very common

• long-term care cost estimated at $40 billion a year for people age 65 and older


National Institute of Aging Consensus

• Issues addressed– definition– diagnosis– reversible dementing diseases– initial evaluation

– indicated diagnostic tests– priorities of future research


Definition

• a syndrome characterized by progressive decline of intellectual ability from a previously attained level

• the decline in mental inability usually involves variable deterioration in

• speech • memory• judgment • mood

without alteration of consciousness


Clinical Presentation

• onset of dementia it is usually insidious• dementia is often progressive (degenerative disease) but

may be static (post-traumatic brain injury)• initial presentation may include slight forgetfulness, attention

and concentration deficits, and increasing repetitiousness or inconsistencies in usual behavior

• later presentation may display impaired judgment, inability to abstract or generalized, and personality change with rigidity, perseveration, irritability, and confusion; affective disturbances may be prominent with loss of personality and self-care


Neurologic Diseases Associated with Intellectual Dysfunction

DISEASE PHYSICAL SIGNS CLINICAL FEATURES

Alzheimer's disease Frontal lobe release signs; Enlarged ventricles and cortical atrophy extrapyramidal signs by CT or MRI

Normal pressure Gait disorder , incontinence Enlarged ventricles with little or no cortical atrophy hydrocephalus

Multi-infarct dementia Focal deficits Stepwise course; multiple areas of infarction, often subcortical by CT or MRI

Parkinson's disease Extrapyramidal signs Usual present only after disease evident for several years

Intracranial tumor Focal signs, papilledema Often subacute evolution, seizures possible

Neurosyphilis Frontal lobe signs, optic atrophy, Positive serology serum and CSF Argyll-Robertson pupils

HIV infection Variable systemic involvement Positive HIV, cortical atrophy; dementia may bepresenting symptom


Neurologic Diseases Associated with Intellectual Dysfunction

DISEASE PHYSICAL SIGNS CLINICAL FEATURES

Creutzfeldt-Jakob Myoclonus , cerebellar signs, Subacute course; EEG has specific abnormalities,

eye movement abnormalities brain biopsy diagnostic

Huntington's disease Choreiform movements, Often positive family history; caudate atrophy corticospinal signs by CT or MRI

Multiple sclerosis Brainstem signs, optic atrophy, Usually long-standing disease; episodic illness corticospinal signs with remissions; often extensive white matter

abnormalities by MRI

Wilson's disease Extrapyramidal signs , hepatic Onset in adolescence or young adult life, dysfunction, Kayser-Fleischer psychiatric disordersrings

Progressive Failure of vertical downgaze, Eye movement abnormalities; differentiate fromsupranuclear extrapyramidal signs Parkinson's disease; unresponsive or onlypalsy transiently responsive to levodopa

* = invariably present; all other physical signs are neither invariably present nor pathognomonic.


Alzheimer’s Disease

• one of the leading cause of dementia with unknown etiology• >4% of people over 65 exhibit moderate to severe dementia

and about 2/3 of these fall into the category of idiopathic senile dementia or Alzheimer’s disease

• most cases are sporadic, although there is a familial autosomal dominant form

• no specific physical signs - frontal lobe release signs and extrapyramidal features may be present


Alzheimer’s Disease

• brain atrophy with ventricular enlargement• absent or minimal vascular disease• neuropathologic studies

– neuronal loss– neurofibrillary tangles– senile plaquesin– accumulation of beta-amyloid


Vascular Dementia

• Multi-infarct dementia - multiple strokes can leave the patient with impaired cognition and produced a true dementia– small lacunar strokes may present subclinically– large strokes with clear-cut neurologic injury

• in the very elderly (>85), vascular dementia rivals Alzheimer’s disease as the leading etiology

• groups at high risk include– African-Americans, Japanese– elderly patients with hypertension, diabetes, smoking, atrial

fibrillation, or known carotid disease


Normal-Pressure Hydrocephalus

• refers to slow ventricular enlargement without cortical atrophy due to poor cerebrospinal fluid (CSF) absorption

• blockage of CSF absorption due to– remote meningeal inflammation– subarachnoid hemorrhage

• classic triad (wacky, wobbly, and wet)– dementia, gait disturbance, urinary and fecal incontinence

• ventriculoperitoneal shunt may lead to dramatic clinical improvement -response to serial lumbar punctures may predict those who will respond


Space Occupying Lesions

• development of progressive unilateral headache, new neurologic deficit, or changing personality may provide a clue to the presence of a mass lesion– chronic subdural hematoma– slow-growing tumors

• on the orbital surface of the frontal lobe• on the medial surface of the temporal lobe

may present primarily with cognitive defects unassociated with other focal signs


Other Neurologic Conditions

• Depression• Parkinson’s disease• Wilson’s disease• severe multiple sclerosis• Jacob’s disease

• neurosyphilis• Huntington’s disease


Systemic Conditions Associated with Intellectual Impairment

• InfectiousSyphilis with CNS involvementHIV infection with CNS involvementCryptococcal infection of the CNS

• EndocrineHypothyroidism and hyperthyroidismPanhypopituitarismHigh-dose glucocorticosteroid therapy

• MetabolicVitamin B12 deficiency (Pernicious anemia)Thiamine deficiency (Korsakoff’s)Niacin deficiency (pellagra)

• Chemical PoisonsAlcoholMetals (lead, mercury)Aniline dyes

• Drug IntoxicationsBarbituratesOpiatesAnticholinergicsLithiumBromidesHaloperidolAntihypertensives


Differential Diagnosis

• Alzheimer's disease 70%• Multi-infarct dementia 10% - 20%• brain tumors 5%

• unknown causes 10-15%

• Among the very old (over age 85), vascular dementia and Alzheimer's disease account for the vast majority


Workup

• History

• Physical Examination• Laboratory studies


History - etiology

• the most important component of the initial evaluation• adequate history with help of a family member is critical

– description of• cognitive, memory, and behavior problems

• effect on daily life - difficulty with driving, work, or family relationships

– details on temporal course of illness• chronic• progressive (Alzheimer or other neurodegenerative disease)• stepwise (multi-infarct)• static (traumatic injury, episode of severe hypotension)


History - treatable causes

• Vascular dementia - presence of cardiovascular risk factors (smoking, HTN, chol, diabetes)

• Normal pressures hydrocephalus - triad of dementia, gait, incontinence with a prior history of meningitis or subarachnoid hemorrhage

• Mass lesion - history of head trauma, unexplained focal neurologic deficit, unilateral headache worsening over time

• Parkinson’s disease - resting tremor and rigidity• Wilson’s disease - hepatocellular disease and dementia• HIV and neurosyphilis - high-risk sexual behavior• hereditary - family history dementia, Down’s syndrome, psychiatric

disorders


History - treatable causes

• B12 deficiency - previous gastric surgery

• B12, thiamin, niacin deficiency - inadequate nutrition, alcohol abuse

• medications - opiates, sedative-hypnotics, analgesics, anticholinergics, anticonvulsants, corticosteroids, centrally acting anti-hypertensives, psychotropics

• symptoms of hypothyroidism, pituitary insufficiency• occupational history - exposure to toxic substances (aniline dyes, heavy

metals)


Mental Status Examination

• Examination should be geared to both the detection of focal lesions and to signs of general brain dysfunction– immediate memory testing (three object recall, recite digits forward

and backward, recall a short story)– remote memory testing (recall of historical events, family milestones,

or recent local or international news)– reproducible drawings– discern similarities among objects– decision-requiring tasks (finding a stamped letter or seeing a fire in a

theater)


Mini-Mental Status Tests

Score Orientation:

5 What is the (year) (season) (month) (date) (day)?

5 Whare are we (state) (county) (town) (hospital) (floor)?

Registration:

3 Name 3 objects: 1 second to say each. Then ask the patient all 3 after you have said them. Give 1 point for each correctanswer. Then repeat them until he learns all 3. Count trialsand record.

Attention and Calculation:

5 Serial 7's. 1 point for each correct. Stop after 5 answers. Alternatively spell "world" backwards.


Mini-Mental Status Tests

Score

Recall:

3 Ask for 3 objects repeated above. Give one point for each. Language:

2 Name a pencil and watch (2 points).

1 Repeat the following: "No ifs ands or buts."

3 Follow a 3-stage command: "Take a paper in your right hand: fold it in half, and put it on the floor." (3 points).

1 Read and obey the following: "Close your eyes."

1 Write a sentence.

1 Copy design.

Total Score: [ ] Maximum Score: 30


Physical and Neurologic Examinations

• Check for focal evidence of neovascular risk factors - carotid bruits, signs of alcoholism, hepatocellular injury, renal insufficiency, other systemic illnesses

• specific neurologic abnormalities– frontal lobe release signs (grasp, suck, snout, root)

– visual field cut and extraocular movement limitations

– abnormal pupillary reactions

– extrapyramidal features (carditis dyskinesis, tumors, asterixis, Korea, monoclonal disc, it)

– sensory deficit and gait disorder


Screening Laboratory Studies

1. Complete blood count and sedimentation rate

2. Chemistry panel (electrolytes, calcium, albumin, BUN, creatinine, transaminase)

3. Thyroid-stimulating hormone (TSH)

4. VDRL test for syphilis

5. Urinalysis

6. Serum B12 and folate levels

7. Chest x-ray

8. Electrocardiogram

9. Head computed tomography (CT)


Neuroimaging

• Head CT or MRI is appropriate in the presence of1) history suggestive of a mass lesion

2) focal neurologic signs or symptoms

3) dementia of abrupt onset

4) history of seizures

5) history of stroke

• MRI with gadolinium contrast enhancement is superior to CT for the diagnosis of multi-infarct dementia and problems referrable to the posterior fossa


Other Ancillary Studies

• Lumbar puncture – routine LP for initial evaluation of dementia is not justified– may be indicated when other clinical findings suggest an

active infection or vasculitis and as part of the evaluation of normal pressure hydrocephalus

– sugar, protein, cell count, cultures, gamma globulins, the serology for stiffness should be obtained



• Electroencephalogram (EEG)– usually normal or with nonspecific rhythm slowing– indicated in patients with episodic altered consciousness

and in whom seizures may be suspected– may occasionally raise suspicion of a particular etiology:

• focal, delta slowing is seen with tumor

• unilateral attenuation of voltage may suggest an extracranial mass such as subdural hematoma

• excessive beta activity may be consistent with drug ingestion

• Creutzfeldt-Jakob disease has a highly specific EEG pattern



• Formal neuropsychologic evaluation – appropriate for more specific information when the diagnosis is in

doubt – also helpful in providing additional information about the nature of

impairment following focal brain injury

• Speech analysis – may improve patient and family communication with therapy

• Formal psychiatric assessment – may be desirable if depression in addition to dementia is suspected


Studies of Limited or Uncertain Utility

• Cerebral blood flow and metabolism measurements– PET and SPECT scans have no routine use at present

• Brain biopsy– rarely justified for non-neoplastic or noninfectious diseases

– Progressive multifocal leukoencephalopathy or Creutzfeldt-Jakob disease is diagnosed by biopsy

• Noninvasive neurovascular studies (carotid ultrasound, Doppler flow studies)– if MRI or CT demonstrates infarction, or– clinical course or physical examinations is suggestive of

cerebralvascular disease


Symptomatic Management and Counseling

• Improving mental functioning

• Management of confusion and agitation

• Maintaining the patient at home

• Risk factor reduction and attention to underlying etiologies


Improving Mental Functioning

• no established treatment for Alzheimer’s disease or for patients with multi-infarct dementia

• findings of degeneration of cholinergic neurons and depletion of choline-acetyl transferase in Alzheimer's disease have led to attempts at improving cholinergic transmission

– lecithin supplements (dietary choline repletion)

– tacrine (a centrally active, reversible cholinesterase inhibitor)

• There is no evidence to support the use of: restorative therapy with nerve growth factor, protective therapy with antioxidants, preventive therapy with drugs that inhibit beta amyloid formation, and “cerebral vasodilators” (papaverine, dihydroergotoxine) to improve memory


Management of Confusion and Agitation

• The chronic use of sedatives and psychoactive agents in the confused patient should be avoided unless persistent extreme agitation hampers care

• The lowest possible doses should be used and for the shortest time possible– thioridazine (10 to 25 mg qhs)– haloperidol (0.5 to 1 mg bid or tid )

often a first choice in the setting of delusions and hallucinations; must be careful to avoid long-term use because of the risk of inducing tardive dyskinesia


Management of Confusion and Agitation

• Avoid regular use of sedative/hypnotic agents for sleep • Beta-blocking agents and anticholinergics may exacerbate

confusion• Patients with depression may improve with a tricyclic

compound with low anticholinergic side effects• desipramine (25 to 50 mg qhs)

• A recent study of nursing home patients demonstrated substantial improvement in many patients when chronically prescribed psychotropic drugs were discontinued or reduced in dose


Maintaining the Patient at Home

• An important task is helping the family maintain and care for the patient at home

• The goal is to sustain the highest level of function possible:– facilitate and promote an orderly home situation– regular routine use of calendars, television, newspapers, and other

means of orientation– limit the use of potentially dangerous appliances– provide convenient toilet facilities – advice against driving when early impairment of judgment and spatial

concepts is present


Maintaining the Patient at Home

• Families can often find help in local support groups, day care and group therapy services, and social service agencies

• When care at home begins to exhaust and strain the family, sensitive counseling can do much to help a family cope with the difficult decision regarding institutionalization

• some dementing diseases are infectious (eg, HIV infection) and that the bodily fluids and tissues of such patients require special handling to avoid transmission. It is particularly important to emphasize when home care is rendered by lay persons


Risk factor reduction and attention to underlying etiologies

Central to an effective outcome :

• control of cerebrovascular risk factors as hypertension, diabetes mellitus, smoking , hyperlipidemia , and coronary artery disease

• endarterectory deserves consideration when a vascular etiology is strongly suspected and a significant stenosis is found

• Avoidance of toxins, correction of vitamin deficiencies, discontinuation of causative drugs, initiation of hormonal replacement therapy in cases of deficiency, and treatment of underlying infectious etiologies


References

• Avorn J, Soumerai SB, Everitt DE, et al. A randomized trial of a program to reduce the use of psychoactive drugs in nursing homes. N Engl J Med 1992;327:168.

• Clarifield AM. The reversible dementias: Do they reverse? Ann Intern Med 1988;109:476. • Consensus Conference. Differential diagnosis of dementing diseases. JAMA

1987;258:3411. • Growdon JH. Treatment for Alzheimer's disease. N Engl J Med 1992;327:1306. ( Excellent

summary of current approaches to therapy.) • Jenkyn LR. Examining the aging nervous system. Semin Neurol 1989;9:82. ( Good

overview of signs associated with normal aging.)• Larson EB, Reiffler BV, Sumi SM, et al. Diagnostic tests in the evaluation of dementia. Arch

Intern Med 1986;146:1917. • Lindenbaum J, Healton EB, Savage DG, et al. Neuropsychiatric disorders caused by

cobalamin deficiency in the absence of anemia or macrocytosis. N Engl J Med 1988;318:1720.


References

• Mace NL. The 36 hour day: A timely guide to caring for persons with Alzheimer's disease. Baltimore, Johns Hopkins Press, 1981. Petersen RC. Memory function in normal aging. Neurology 1992;42:396.

• Price RW, Brew BJ. The AIDS dementia complex. J Infect Dis 1988;158:1079• Siu AL. Screening for dementia and investigating its causes. Ann Intern Med 1991;115:122. • Skoog I, Nilsson L, Palmertz B, et al. A population-based study of dementia in 85-year-

olds. N Engl J Med 1993;328:153.

Entomology

Health & Medicine

cerebellar signs

cortical atrophy dementia

optic atrophy

insidious dementia

specific abnormalities

mental inability

neurologic diseasesassociated

subacute course eeg