Dementia: A brief overview
Author: Renee Flores, MD & Naysia Ahmed, MD
Dementia describes a syndrome caused by chronic and/or progressive brain disease affecting higher cortical function.
It is estimated that the prevalence of Alzheimer 's disease will triple by 2050.
Mild cognitive impairment (MCI) may be described as a transition phase between cognitive changes from normal aging and dementia.
Dementia is an umbrella term that includes:
- Alzheimer's Disease
- Damage to the brain includes development of plaque, neurofibrillary tangles, synaptic loss, neuronal atrophy
- Clinical manifestations may include impairment of memory, functional impairment, apraxia, aphasia, agnosia, executive function dysfunction
- Insidious progression
- Vascular Dementia
- Accounts for 33% of dementias
- History or presence of cerebrovascular accident with positive radiologic infarct finding
- Progression may be both rapid and related to stroke-like event or stepwise delayed recall
- Concomitant depression is common
- Frontotemporal Dementia
- Pathology of frontal and anterior temporal areas; frontotemporal lobar degeneration
- Early age of onset
- Early behavioral changes are a red flag: disinhibition, apathy, hyperorality, inappropriate social interaction
- Poor execute and language function and relatively spared memory
- Parkinson Disease Dementia
- Typical subcortical pattern: impairments in attention, executive function and visuospatial function
- Insidious onset
- Variable rates of progression
- Depression is very prevalent (some estimates up to 50%)
- Dementia with Lewy Bodies
- Triad of symptoms – fluctuating cognition, Parkinson-like symptoms and visual hallucination
- Other symptoms may include REM sleep disorders and frequent falls
Risk factors include:
- Advancing age
- Family history and genetics
- History of psychiatric disorders
- History of head trauma
- Cardiovascular disease and related risk factors
- Alcohol misuse, drug misuse, and toxins
- Endocrine disorders
Assess for delirium before dementia. The CAM is a recommended screening tool:
Some comparative facts include
|Comparing Dementia and Delirium
||Insidious, with an uncertain starting point
||Rapid, usually with a certain starting point
||Loss of memory, particularly for a recent event(s)
||May be related to an underlying brain disorder, such as Alzheimer disease, vascular dementia, or Lewy body dementia
||Nearly always related to underlying acute change, such as dehydration, infection, or starting or stopping medications
|Level of consciousness
||May be normal until advanced stages
||Fluctuates from being lethargic to hyperalert
||May be problematic with word choices
||Slowed or rapid speech, frequently with incoherent and/or inappropriate language
||Slowly progresses, gradually but eventually greatly impairing all mental functions
||Causes variations in mental function- people are alert one moment and sluggish and drowsy the next
||Fluctuates; days to weeks to months
||Needed but less urgently; slows progression but does not cure
||Immediate; usually reversible
Once delirium is ruled out, the next steps are:
- The evaluation of a patient with suspected dementia should focus upon the history.
- Family members or other informants who know the patient well are invaluable resources for providing an adequate history of cognitive and behavioral changes.
- Adequate time should be arranged for a full assessment of cognitive function, followed by a complete physical examination, including neurologic examination.
- Ask simple yes or no questions
- Diagnostics include:
- Neuropsychological testing
- Cognitive screening tests- St. Louis University Mental Status (SLUMS) or the Mini-Cog
- Depression screening tests – Geriatric Depression Scale (GDS) or Hamilton Depression Rating Scale (HDRS)
- Functional Level of Independence – Katz Index of Activities of Daily Living (ADL) or Lawton Instrumental Activities of Daily Living Scale (IADL)
- Laboratory evaluation – Complete blood count, complete metabolic panel, thyroid screen, Vitamin B12 and folate, C reactive protein, RPR, Lipid panel, HIV screen, sedimentation rate and other test as indicated by the history and physical
- Neuroimaging, MRI (preferred) or CT to rule out potentially treatable intracerebral lesions (Normal Pressure Hydrocephalus, subdural hematoma) and to rule out cortical and subcortical infarcts, white matter changes, localized atrophy.
- Other investigations – CSF fluid evaluation, genetic testing, and EEG
- Dependent on stage and type of dementia
- Goals include:
- Stabilize cognitive ability
- Improve mood
- Promote autonomy
- Effective future planning
- Interprofessional team interventions include both non-pharmacologic and pharmacologic strategies.
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