Cognitive Disorders



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Chapter 2 : Cognitive Disorders



Cognitive Disorders arrow_upward


  • Cognitive function: the general ability to organize, process, and recall information
  • Cognitive skills: mental capabilities or underlying skills needed to process and learn information, to think, remember, read, understand and solve problems
  • Cognitive disorders: disorders in which the central feature is the impairment of memory, attention, perception, and thinking
  • Mental conditions that cause people to have difficulty thinking clearly and precisely
  • Patients experience a confused mental state and changes in behavior.
  • Disturbances of cognitive function may occur in a variety of disorders.
  • Major cognitive disorders are:
    • Delirium
    • Dementia
    • Amnesia

    Delirium arrow_upward


  • Clinical state characterized by an acute change in a person’s mental status
  • A global, potentially reversible change in cognition and consciousness that is relatively acute in onset
  • A syndrome of many different causes characterized by confusion and loss of short-term memory
  • Also called “acute confused state,” represents a serious and often unrecognized neuropsychiatric disturbance of cognition and attention, common in the elderly and chronically ill patients
  • The hallmark of delirium is confusion, or, as it also has been called, “clouding of the sensorium.”
    • Patients may appear somewhat dazed and unclear about their surroundings

    Major features of delirium

    • A fluctuating level of consciousness
    • Alterations in cognition
    • Development over a period of hours to days
    • Presence of medical or substance-related precipitants
    • Disturbance in sleep-wake cycle
    • Hallucinations (seeing, hearing, or feeling things that are not there)
    • The patient’s speech may be circumstantial, tangential, or incoherent
    • Limited or absent memory formation

    Etiology (the study of origination) of delirium

  • Delirium stems from a global disturbance in cerebral functioning.
  • The syndrome of delirium reflects brain dysfunction due to identifiable systemic or cerebral disease.
  • Delirium is multi-factorial: produced by a combination of minor illnesses and minor metabolic derangements (mild anemia, mild hypoxia).
  • Occurs because of:
    • Damage of enzyme systems, blood brain barrier, or cell membranes
    • Reduced brain metabolism

    Dementia arrow_upward


  • A loss of cognitive and emotional functions
  • A progressive deterioration of brain functions, marked by impairment of memory, confusion and inability to concentrate
  • In addition to memory loss, a person with dementia may have trouble carrying out everyday tasks.
  • Caused by a disease that damages tissues in the brain, causing disturbed brain functioning

  • Symptoms of dementia

  • Decline in short term memory
  • Impaired comprehension
  • Personality changes
  • Lives in the past
  • Decline in problem solving abilities
  • Mood changes
  • The hallucinations may be either visual or, less commonly, auditory

  • Causes of dementia

  • The most common causes of dementia are:
    • Alzheimer’s disease
    • Vascular dementia
    • Dementia with Lewy bodies
    • Parkinson’s disease
  • There are many other rarer diseases that may lead to dementia including HIV, head trauma.

  • Alzheimer’s disease

  • The most common cause of dementia, for approximately 50% of all dementia types
  • A progressive, degenerative disease of the brain, which results in impaired memory, thinking and behavior
  • Causes the gradual death of brain tissue due to biochemical problems inside individual brain cells

  • Vascular dementia

  • Caused by changes in the brain’s blood vessels
  • Develops when impaired blood flow to parts of the brain deprives cells of food and oxygen

  • Dementia with Lewy bodies

  • A common cause of dementia, accounting for 15-20% of total cases
  • A neuropsychiatric disorder causing dementia
  • Lewy bodies are abnormal clumps of the proteins found in nerve cells throughout the outer layer of the brain and deep inside the midbrain or brainstem.

  • Parkinson’s disease

  • A progressive disorder of central nervous system, caused by deterioration of brain cells
  • Caused by the loss of nerve cells in the area of brain that produce dopamine, an important neurotransmitter that helps nerve cells to communicate

  • Amnesia arrow_upward


  • Defined as the total or partial loss of memory
  • A significant loss of the memory, despite no loss of other cognitive functions
  • Characterized by memory impairment as manifested by impairment in the ability to learn new information or the inability to recall previously learned information
  • The basic feature of amnestic disorder is a disordered mental status.

  • Etiology of amnesia

  • Often associated with bilateral dysfunctions in the medial temporal and diencephalic regions of the brain
  • Amnestic disorder may be caused due to a general medical condition or substance related.
  • May develop as a result of alcohol dependence, associated with dietary and vitamin deficiency

  • Treatment of Cognitive Disorders arrow_upward


  • Surgical treatment involves removal of tumors; relieve pressure caused by tumors, restore ruptured blood vessels.
  • Psychotherapy helps patient deal with emotional aspects of the disorders.
  • Medication should be given to prevent, control, and reduce symptoms; also control accompanying emotional problems.
  • Psychosocial treatment of delirium involves reassuring the person to help him/her deal with the agitation, anxiety & hallucinations.
  • Psychosocial treatment of dementia involves:
    • Focus on enhancing the lives of people with dementia & their families
    • Teach them skills to compensate for their lost abilities
    • Provide clues to help people safely navigate around their home
    • Provide supportive counseling to caregivers


    Thank You from Kimavi arrow_upward


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