Dementia is a gradual worsening loss of memory and related cognitive functioningDelirium is a confused state that develops over a short period of time. Amnestic disorders are memory impairments that are more limited than those seen in dementia or delirium. Dementia and amnestic disorders are often associated with specific identifiable changes in the brain tissue. Dementia, delirium, and amnestic disorders are listed as Cognitive Disorders in DSM-IV-TR.

Cognitive processes include perception, attention, memory, reasoning and decision-making. Neurologists are the doctors who diagnose and treat patients with cognitive disorders. Neuropsychologists are psychologists who assess individuals for cognitive impairments.

Delirium

The primary symptom of delirium is a clouding of consciousness in association with a reduced ability to maintain and shift attention. The onset of symptoms is very rapid – from a few hours to several days. The symptoms are usually worse at night and often disturbs the sleep/wake cycle. Comas may occur if symptoms are allowed to progress.

Dementia

The earliest signs of dementia are often vague. One sign of dementia is difficulty remembering names of people and familiar objects. Over time however, intellectual and motor functions may disappear almost completely. Memory loss is the diagnostic hallmark. Retrograde amnesia is the loss of memories from the past. Anterograde amnesia is the inability to learn or remember new information. An individual with dementia may experience problems with verbal communication. For example, aphasia is a loss or impairment in language. Apraxia is difficulty performing purposeful movements in response to verbal commands. Dementia may affect an individual’s ability to attach meaning to perception. This perceiving without attaching meaning is called agnosia. It can be associated with visual, auditory, or tactile sensation and can be specific or more generalized. An individual with dementia might have problems interpretting words with multiple meanings. They also are more likely to interpret things very literally.  Obviously all these issues cause disruptions in an individual’s ability to make decisions. Impulsive and careless behaviors are often the product of the demented person’s poor judgment. Activities such as shopping, driving, and using tools can create serious problems.

Individuals with dementia often show changes in personality and emotion. Hallucinations and delusions are seen in at least 20% of dementia cases. They are more common during the later stages of the disorder. Emotional consequences are varied. Individuals with dementia may become apathetic or emotionally flat. Their emotions may be exaggerated and unpredictable.

Physically, their movements may become agitated, pacing restlessly or wandering away from familiar places.

Amnestic Disorder

The person exhibits a severe impairment of memory while other higher level cognitive abilities are unaffected. Korsafoff’s syndrome is an alcohol-induced persisting amnestic disorder. Alcohol can cause brain damage regardless of the person’s nutritional habits.

Mini mental state exam

  1. What is the (year, season, date, day, month)?
  2. Where are we (state, city, hospital)?
  3. Name three objects (pen, sky, dog), then ask patient to repeat them.
  4. Spell “world” backwards.
  5. Ask for names of three objects given in question 3.
  6. Point to a pencil and a watch. Ask the patient to name each as you point.
  7. Ask the patient to repeat, “No ifs, ands, or buts.”
  8. Three-stage command:“Take this paper in your right hand. Fold the paper in half. Put the paper on the floor.”
  9. Ask the patient to read and obey the following (write on card in large letters): “CLOSE YOUR EYES.”
  10. Have the patient write a sentence of his or her choice.
  11. Have the patient copy two intersecting pentagons.

Assessment of Cognitive Impairment

Neuropsychological assessment is the process that involves administration of psychological tests to indicate whether a person has a brain disorder. It can be used to infer about the location of a brain lesion. One test is the Halstead-Reitan Neurological Test Battery.

Diagnosis

Alois Alzheimer (1864- 1915) conducted a microscopic examination of deceased patient’s brain and found neurofibrillary tangles and amyloid plaques.

Diagram of the brain of a person with Alzheime...

Image via Wikipedia

Many specific disorders are associated with dementia. They are distinguished primarily on the basis of known neuropathology—specific brain lesions that have been discovered throughout the twentieth century.

Dementia of the Alzheimer’s Type

The speed of onset serves as the main feature to distinguish Alzheimer’s disease from the other types of dementia listed in DSM-IV-TR. However, a definite diagnosis can only be determined by autopsy. Cognitive impairments appear gradually.

Frontotemporal Dementia (Pick’s Disease)

Picks’s Disease is a rare form of dementia associated with circumscribed atrophy of the frontal and temporal lobes. It is very similar to Alzheimer’s disease in terms of both behavioral symptoms and cognitive impairment. Such individuals show problems in memory and language.

Huntington’s disease

Unusual involuntary muscle movements known as chorea is symptomatic of Huntington’s disease. These movements are relatively subtle at first. There is an autosomal dominant pattern of transmission.

Parkinson’s Disease

A stroke is a severe  interruption of blood flow to the brain. Small strokes that occur over time, scattered in different sites, may cause cognitive impairment as well. Strokes often are the cause of Parkinson’s Disease.

Vascular Dimentia

Rounded deposits found in nerve cells.

Often found in the brain-stem nuclei of Parkinson’s disease.

Frequency

Detailed evidence regarding the prevalence of delirium is not available. It seems to be one of the most frequent symptoms of disease among elderly people. At least 15% of elderly hospitalized medical patients exhibit symptoms of delirium. Although it can appear in people as young as 40 to 45, the average age of onset is much later. By the year 2030, more than 9 million people in the US will be affected by Alzheimer’s disease.

Prevalence of Dementia

Samples in North America and Europe:

The prevalence of dementia in people between the ages of 65 and 69 is approximately 1%.

Between the ages of 75 and 79, the prevalence rate is approximately 6%.

Increases dramatically in older age groups.

Almost 40% of people over 90 years of age exhibit symptoms of moderate or severe dementia.

Causes

Genetic Factors

Until recently, no twin studies have been used extensively to study the influence of genetics.

Swedish study: concordance rate in monozygotic twins was over 50%, more than double the dizygotic rate.

Medication

Delirium can be caused by many different kinds of medication, including the following:

• Psychiatric drugs: (antidepressants,  antipsychotics, and benzodiazepines)

• Drugs used to treat heart conditions

• Painkillers

• Stimulants (including caffeine)

Neurotransmitters

The specific mechanisms that are involved have not been identified.

Parkinson’s disease seems to be related to a degeneration of the dopamine pathway.

Huntington’s disease appears to be related to deficiencies in the GABA.

Viral infections

Some forms of primary dementia are known to be the products of “slow” viruses—infections that develop over a much more extended period of time than do most viral infections. Creutzfeldt-Jakob disease is one example.

Immune system dysfunction

The presence of beta-amyloid at the core of amyloid plaques is one important clue to the possible involvement of immune system dysfunction.

Environmental Factors

Some types of dementia, especially Alzheimer’s disease, may be related to environmental factors. One example is head injury, which can cause a sudden increase of amyloid plaque.

Treatment

Accurate diagnosis is paramount with regard to treatment of cognitive disorders. The distinction between delirium and dementia is important because many conditions that cause delirium can be treated.

When the person clearly suffers from a primary type of dementia, such as dementia of the Alzheimer’s type, a return to previous levels of functioning is extremely unlikely.

Medication

Acetylcholine (ACh) is a neurotransmitter that is involved in memory and whose level is reduced in patients with

Stalevo for treatment of Parkinson's disease

Image via Wikipedia

Alzheimer’s disease.

Donepezil (Aricept) usually works for only six to nine months and is not able to reverse the relentless progression of the disease.

Environmental and Behavioral Management

Patients with dementia experience fewer emotional problems and are less likely to become agitated if they follow a structured and predictable daily schedule.

It is useful to help the person remain active and interested in everyday events.

Preserve familiar routines and surroundings.