Dementia is progressive deterioration in intellectual function and other cognitive skills, leading to a decline in the ability to perform activities of daily living.
Diagnosis is by history and physical examination.

Facts to remember:

• Mild slowing of cognitive processes is normal with aging and, it does not suggest dementia.
• Dementia is typically preceded by a state of mild cognitive impairment, which may last for several years.
• In every patient, evaluation for dementia requires a thorough review of drugs, including OTC drugs.
• Being in a familiar, supportive environment and remaining active helps mild and moderate cases decline slowly in function.
• Currently used drugs may modestly improve cognitive performance or temporarily delay cognitive and functional decline due to dementia.
• Treating depression, which is common among patients with dementia, may improve function and quality of life.
• Providing a source for ongoing education and support is main activity.
• As early in the disorder as possible, decisions about a surrogate to handle finances and a health care proxy should be made.

Prevalence

The prevalence of dementia doubles every 5 yr after age 60 until about age 90. Dementia affects only 1% of people aged 60 to 64 but 30 to 50% of those > 85

Cause
Causes are difficult to differentiate because definitions and clinical criteria for diagnosis of many causes are not exact.
Alzheimer's disease is the most common type in 2/3 of cases of established dementia. Vascular dementia is probably the next most common type, and dementia with Lewy bodies may account for many cases.

The following are some of the symptoms of Dementia:

The history varies depending on the cause of dementia.
• However, typically, intellectual and other cognitive functions decline over 2 to 10 yr.
• Symptoms can be divided into mild (early), moderate and severe (late).
• Personality and behavior changes may develop during any stage.
• Depression affects up to 40% of patients with dementia, usually when dementia is mild or moderate, and may cause vegetative symptoms (eg, withdrawal, anorexia, weight loss, insomnia).
• Depression can aggravate disability in dementia; distinguishing between cause and effect is often difficult.
• Many people who develop dementia lose weight before other symptoms appear.
• The incidence of seizures increases throughout the course of dementia.
• Psychosis (hallucinations, delusions, or paranoia) occurs in about 25% of patients with dementia.

Mild dementia: Followings functions can be affected.

• Short-term memory is impaired
• Language functions, especially word finding.
• Aphasia (impaired ability to comprehend or use language)
• Agnosia (impaired ability to identify objects despite intact sensory function)
• Apraxia (impaired ability to perform previously learned motor activities despite intact motor function) can develop
• Executive function (eg, ability to plan, organize, and sequence) is impaired.
• Apathy is common.
• Progressive difficulty with formerly mastered complex activities (eg, driving) and moderately complex daily activities (instrumental activities of daily living; eg, handling finances, preparing meals, housekeeping).
• Less likely to take the initiative.
• Difficulty following directions.
• Emotional fluctuation is common. Patients may be irritable, hostile, and agitated.
• Although mild dementia may not compromise sociability, family members may report that patients are not doing uncharacteristic things (eg, a miserly widower gives thousands of dollars to a questionable charity). Poor judgment is common.

Moderate dementia:

• The ability to perform simple daily activities (basic activities of daily living; eg, bathing, dressing, toileting) becomes impaired.
• Patients cannot learn new information.
• Normal environmental and social cues for time and place do not register,
• Increasing disorientation.
• Patients remain ambulatory but are at increased risk of falls and accidents due to confusion and poor judgment.
• Personality changes may progress. Patients may become irritable, anxious, self-centered, inflexible, or angry more easily, or they may become more passive, with a flat affect, depression, indecisiveness
• Lack of spontaneity, or general withdrawal from social situations.
• Psychotic symptoms may occur. Significant paranoia (eg, specific, often persecutory delusions; generalized suspicion) occurs in about 25% of patients.
• The most common delusions are of stealing and that a spouse is unfaithful.
• Loss of self-recognition in mirrors; some patients with this delusion worry that strangers have entered the home, but others enjoy the "visitor's" company. • Patients often misidentify other people at this point (eg, thinking their husband is their father or their daughter is their wife).
• Wandering can be a significant problem, returning to familiar surroundings is very difficult.
• Patients may become physically aggressive or agitated or act in sexually inappropriate ways.
• Sleep patterns are often disorganized.

Severe:

• Patients cannot perform the most basic activities (eg, eating, walking) and become totally dependent on other people.
• Memory for recent and remote events is completely lost.
• Patients may be unable to recognize even close family members.
• The ability to walk is variably affected in different dementias but is usually lost in the late stages; patients may become unable to move even while in bed.
• Reflex motor function (eg, ability to swallow) is lost, putting patients at risk of dehydration, undernutrition, and aspiration (which increases risk of pneumonia).
• The combination of immobility and undernutrition increases risk of pressure ulcers. Eventually, patients become mute.
• Total functional dependence usually requires that patients be placed in a nursing home or that similar support be implemented in the home.
• End-stage dementia results in coma and death, usually due to infection originating in the respiratory tract, skin, or urinary tract.

Diagnosis

For all elderly patients, mental status should be evaluated at each regular checkup and whenever a change in mental status is suspected.
The Folstein Mini-Mental State Examination is most commonly used.
The patient's appearance should be observed because it may provide clues (eg, poor hygiene) that confirm poor judgment or difficulty with some daily activities.
If dementia is diagnosed, the cause of the dementia is identified, and potentially reversible contributing factors are sought.
Diagnosis can be done by Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition Text Revision (DSM-IV-TR)

Other testing:As per the underlying cause.

Thyroid functions and vitamin B12
Routine use of CBC
Renal function tests
Liver function tests
Electrolyte and albumin measurement
Cerebrospinal fluid (CSF) - for evidence of infection.
Non contrast CT or MRI
Positive emission tomography (PET)
Single-photon emission CT (SPECT)

• Physician should usually disclose the diagnosis to the patient.
• If the patient has difficulty understanding, the physician may talk with family members first
• Correction of contributing factors: Treatment or elimination of all potentially reversible contributing factors may substantially improve daily functioning and quality of life and may delay severe disability and institutionalization. The drug of choice is usually an SSRI
• Environmental measures: The next step is to create an appropriate, safe, and supportive environment in which patients can function optimally.
• Nursing-home care: Nursing homes should be designed to reinforce orientation and to be cheerful; they should provide regular low-stress activities and minimal new stimulation
• Drugs: Eliminating or limiting drugs with CNS activity often improves function. Sedating and anticholinergic drugs, which tend to worsen dementia, should be avoided.
• Caregiver support is important factor.