Alternative names
Chronic brain syndrome


Dementia refers to a group of symptoms involving progressive impairment of brain function.

Causes, incidence, and risk factors

Disorders that cause dementia include conditions that impair the vascular (blood vessels) or neurologic (nerve) structures of the brain. Some causes of dementia are treatable. These include normal pressure hydrocephalus, brain tumors, and dementia due to metabolic causes and infections. Unfortunately, most disorders associated with dementia are progressive, irreversible, and degenerative.

The two major degenerative causes of dementia are Alzheimer’s disease and vascular dementia (loss of brain function due to a series of small strokes). The two conditions often occur together, and vascular dementia may speed the progression of Alzheimer’s disease. Neither condition can be diagnosed definitively until autopsy.

Dementia may be diagnosed when two or more brain functions are impaired. These functions include language, memory, visual-spatial perception, emotional behavior or personality, and cognitive skills (such as calculation, abstract thinking, or judgment). Dementia usually appears first as forgetfulness. Other symptoms may be apparent only with neurologic examination or cognitive testing.

Dementia progresses slowly from decreased problem solving and language skills to difficulty with ordinary daily activities to severe memory loss and complete disorientation with withdrawal from social interaction.


  • Progressive memory loss  
  • Inability to concentrate  
  • Decrease in problem-solving skills and judgment capability  
  • Confusion, severe  
  • Hallucinations and delusions  
  • Altered sensation or perception  
  • Impaired recognition (agnosia)       o Impaired recognition of familiar objects or persons       o Impaired recognition through the senses  
  • Altered sleep patterns       o Insomnia       o Need for increased sleep       o Disturbance or change in sleep-wake cycle  
  • Motor system impairment       o Impaired skilled motor function (apraxia)           + Inability to reproduce geometric figures           + Inability to mimic hand positions           + Inability to dress self       o Gait changes       o Inappropriate movements       o Other motor system impairment  
  • Disorientation       o Person, place, time disorientation       o Visual-spatial disorientation       o Inability to interpret environmental cues  
  • Specific disorders of problem-solving or learning       o Inability to generalize       o Loss of abstract thinking       o Impaired calculating ability       o Inability to learn  
  • Memory deficit       o Short-term memory problems (can’t remember new things)       o Long-term memory problems (can’t remember past)  
  • Absent or impaired language ability (aphasia)       o Inability to comprehend speech       o Inability to read       o Inability to write       o Inability to speak, without muscle paralysis       o Inability to form words       o Inability to name objects       o Poor enunciation       o Inappropriate speech; use of jargon or wrong words       o Inability to repeat a phrase       o Persistent repetition of phrases       o Other language impairment  
  • Personality changes       o Irritability       o Poor temper control       o Anxiety       o Depression       o Indecisiveness       o Self-centeredness       o Inflexibility       o No observable mood (flat affect)       o Inappropriate mood or behavior       o Withdrawal from social interaction       o Inability to function or interact in social or personal situations       o Inability to maintain employment       o Decreased ability to care for oneself       o Decreased interest in daily living activities  
  • Lack of spontaneity

Additional symptoms that may be associated with this disease are as follows:

  • Swallowing problems  
  • Incontinence

Signs and tests

A neurologic examination may reveal abnormalities. Early signs of dementia include mild problems with memory or attention. Over time, the following cognitive difficulties may appear:

  • Language problems  
  • Disorientation  
  • Personality changes  
  • Visual or spatial problems  
  • Slow thinking  
  • Impaired skilled motor function (apraxia)  
  • Impaired recognition (agnosia)  
  • Difficulty with planning and organizing  
  • Weakness  
  • Incontinence  
  • Falling

The extent of damage and cause of dementia may be indicated by tests and procedures that include, but are not limited to, the following:

  • Serum electrolytes  
  • Blood chemistry (chem-20)  
  • Serum calcium  
  • Glucose test  
  • Thyroid stimulating hormone level  
  • Thyroid function tests  
  • Liver function tests  
  • Blood ammonia levels  
  • B-12 level  
  • Drug or alcohol levels (toxicology screen)  
  • Urinalysis  
  • Blood gas analysis  
  • EEG (electroencephalograph)  
  • Head CT  
  • MRI of head  
  • CSF (cerebrospinal fluid) analysis

The goal of treatment is to control the symptoms of dementia. Treatment varies with the specific disorder. Hospitalization may be needed for a short time. The underlying causes should be identified and treated, this includes treating reversible organic lesions such as tumors.

Stopping or changing medications that worsen confusion or that are not essential to the care of the person may improve cognitive function. Medications that contribute to confusion include anticholinergics, analgesics, cimetidine, central nervous system depressants, lidocaine, and others.

Disorders that contribute to confusion should also be treated. These include heart failure, decreased oxygen (hypoxia), thyroid disorders, anemia, nutritional disorders, infections, and psychiatric conditions such as depression. Correction of co-existing medical and psychiatric disorders often greatly improves mental functioning.

Medications may be needed to control aggressive or agitated behaviors that are dangerous to the person with dementia or to others. These are usually given in very low doses and adjusted as necessary.

Possible medications for this use include the following:

  • Anti-psychotics, given at night  
  • Serotonin-affecting drugs (trazodone, buspirone)  
  • Dopamine blockers (haloperidol, Risperidal, olanzapine, clozapine)  
  • Cholinesterase inhibitors [donepezil (aricept), rivastigmine (exelon), or the newly approved galantamine (reminyl) for Alzheimer’s-type dementia]  
  • Fluoxetine, imipramine, or Celexa to help stabilize mood  
  • Stimulant drugs (such as methylphenidate) to increase activity and spontaneity  
  • Vitamin E

Sensory function should be evaluated regularly and hearing aids, glasses, or cataract surgery should be provided as needed.

Formal psychiatric treatment such as psychotherapy or group therapy is seldom helpful because it may overload the limited cognitive resources in the person with dementia.


Providing a safe environment, controlling aggressive or agitated behavior, and meeting the physiologic needs of a person with dementia may require monitoring and assistance in the home or in an institutionalized setting. Possible options include in-home care, boarding homes, adult day care, and convalescent homes.

Visiting nurses or aides, volunteer services, homemakers, adult protective services, and other community resources may help in caring for the person with dementia. In some communities, support groups may be available (see elder care - support group), and family counseling can help family members cope with home care.

In any care setting, there should be familiar objects and people. Lights can be left on at night to reduce disorientation. The activity schedule should be simple. Behavior modification may help some people to control unacceptable or dangerous behavior. This consists of rewarding appropriate behaviors and ignoring inappropriate ones (within the bounds of safety). Reality orientation, with repeated reinforcement of environmental and other cues, may also help reduce disorientation.

Legal advice may be appropriate early in the course of the disorder, before the person with dementia becomes too incapacitated to make decisions. Advance directives, power of attorney, and other legal actions may make it easier to decide about the care of the person with dementia.

Expectations (prognosis)
The outcome varies. Acute disorders that cause delirium may coexist with chronic disorders causing dementia. Chronic brain syndromes are often progressive and usually result in decreased quality of life and decreased life span.

Complications depend on the cause of the dementia, but they may include the following:

  • Loss of ability to function or care for self  
  • Loss of ability to interact  
  • Increased infections anywhere in the body  
  • Reduced life span  
  • Abuse by an overstressed caregiver  
  • Side effects of medications used to treat the disorder

Calling your health care provider

  • Call your health care provider if dementia develops or a sudden change in mental status occurs.  
  • Call your health care provider if the condition of a person with dementia deteriorates and you are unable to cope with caring for that person in the home.

Most causes of dementia are not preventable. The risk of vascular dementia, which is caused by a series of small strokes, can be reduced by quitting smoking and controlling high blood pressure and diabetes. Eating a low-fat diet and exercising regularly may also reduce the risk of vascular dementia. Vascular dementia may also play a role in the progression of Alzheimer’s disease.

Johns Hopkins patient information

Last revised: December 6, 2012
by Simon D. Mitin, M.D.

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