Evaluation of Dementia

1
Evaluation of Dementia

• David Lu , MDWashington VAMC

2
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

3
National Institute of Aging Consensus

• Issues addressed
• definition
• diagnosis
• reversible dementing diseases
• initial evaluation
• indicated diagnostic tests
• priorities of future research

4
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

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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

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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 be presenting symptom

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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
  disorders rings
• 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.

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Alzheimers Disease

• one of the leading cause of dementia with unknown
  etiology
• gt4 of people over 65 exhibit moderate to severe
  dementia and about 2/3 of these fall into the
  category of idiopathic senile dementia or
  Alzheimers 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

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Alzheimers Disease

• brain atrophy with ventricular enlargement
• absent or minimal vascular disease
• neuropathologic studies
• neuronal loss
• neurofibrillary tangles
• senile plaquesin
• accumulation of beta-amyloid

10
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 (gt85), vascular dementia
  rivals Alzheimers 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

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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

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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

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Other Neurologic Conditions

• Depression
• Parkinsons disease
• Wilsons disease
• severe multiple sclerosis
• Jacobs disease
• neurosyphilis
• Huntingtons disease

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Systemic Conditions Associated with Intellectual
Impairment

• InfectiousSyphilis with CNS involvementHIV
  infection with CNS involvementCryptococcal
  infection of the CNS
• EndocrineHypothyroidism and hyperthyroidismPanhy
  popituitarismHigh-dose glucocorticosteroid
  therapy
• MetabolicVitamin B12 deficiency (Pernicious
  anemia)Thiamine deficiency (Korsakoffs)Niacin
  deficiency (pellagra)

• Chemical PoisonsAlcoholMetals (lead,
  mercury)Aniline dyes
• Drug IntoxicationsBarbituratesOpiatesAnticholin
  ergicsLithiumBromidesHaloperidolAntihypertensi
  ves

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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

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Workup

• History
• Physical Examination
• Laboratory studies

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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)

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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
• Parkinsons disease - resting tremor and rigidity
• Wilsons disease - hepatocellular disease and
  dementia
• HIV and neurosyphilis - high-risk sexual behavior
• hereditary - family history dementia, Downs
  syndrome, psychiatric disorders

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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)

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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)

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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 correct answer.
  Then repeat them until he learns all 3. Count
  trials and record.
• Attention and Calculation
• 5 Serial 7's. 1 point for each correct. Stop
  after 5 answers. Alternatively spell "world"
  backwards.

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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

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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

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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)

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Neuroimaging

• Head CT or MRI is appropriate in the presence of
• 1) 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

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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

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Other Ancillary Studies

• 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

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Other Ancillary Studies

• 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

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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

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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

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Improving Mental Functioning

• no established treatment for Alzheimers 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

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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

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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

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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

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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

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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

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References

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