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Cognitive Impairment

What is Cognitive Impairment?

The term “cognitive impairment” – which we are using in relation to survivors of critical illness - refers to persistent deficits in the brain’s ability to function effectively. People with cognitive impairment often have problems in the following areas.

  • Memory
  • Attention
  • Processing speed
  • Executive functioning, which involves organizing, planning, and problem solving

Depending on the severity of the cognitive impairment, long-lasting consequences can negatively impact an individual’s functioning in areas including work and school, social functioning, driving and the management of money and medication. In severe cases, it can limit independence and result in people being significantly more reliant on family, friends, and institutional support of various kinds in order to function.


How often does Cognitive Impairment occur?

  • Between one third and two thirds of survivors of critical illness develop some form of cognitive impairment.
  • Cognitive impairment after critical illness may improve over time—some people improve completely while others slightly improve but never return to baseline. In certain instances, individuals continue a pattern of decline that is suggestive of dementia.

Causes of Cognitive Impairment

Relatively little research has been done on the causes of cognitive impairment after critical illness, but experts think the following factors, either by themselves, or in combination, may play a role:

  • Inadequate brain oxygenation – common in mechanically ventilated patients
  • Delirium
  • Infections, which lead to inflammatory responses
  • Glucose dysregulation
  • Certain medical illnesses, which may themselves have direct effects on the brain
  • Medications

People most likely to get Cognitive Impairment

Some individuals are likely more susceptible than others to developing cognitive impairment after critical illness. Individuals at greatest risk may include those who:

  • Have pre-existing cognitive problems that make them especially vulnerable
  • Are advanced in age
  • Have delirium for long duration
  • Require mechanical ventilation
  • Have a diagnosis of sepsis or ARDS
  • Have lengthy and complex hospital and ICU stays

Signs of Cognitive Impairment

Depending on how severe symptoms are, signs of cognitive impairment are sometimes obvious and sometimes very subtle. In general, survivors of critical illness with cognitive impairment may:

  • Display problems with memory including difficulties such as remembering names, finding words, and remembering items from a shopping list.
  • Forget events such as doctor’s appointments or social engagements
  • Ramble and lose focus in conversations
  • Use poor judgment
  • Feel easily overwhelmed by tasks or responsibilities that used to be easy to manage
  • Have problems managing money or medications and make careless errors
  • Act impulsively

Can anything be done for Cognitive Impairment?

Cognitive impairment can reflect a wide range of potential problems and is sometimes reversible but in typical cases is not. Nevertheless, there may be ways to either (A) improve cognitive impairment or (B) reduce its’ impact. These include:

  • Vigorous exercise (consult your doctor) which have been found in some studies to significantly improve thinking abilities
  • “Brain Exercise” which could take the form of crossword puzzles, Sudoku games, and other mental challenges.
  • The use of adaptive devices and adaptive strategies that can help leverage strengths and limit the impact of cognitive deficits
  • Accessing available social support
  • Addressing issues like anxiety and depression – these conditions can worsen cognitive problems and in some cases, if they improve, cognitive abilities can improve
  • Bring glasses, hearing aids.
  • Formal cognitive rehabiliation with a psychological professional
  • A medical evaluation to identify and rule out any medical causes

Medical professionals of various kinds specialize in the diagnosis and management of cognitive impairment including neurologists (MD) or neuropsychologists (PhD or PsyD). If you or a family member has questions or concerns about your cognitive functioning, addressing them with one of these professionals is very appropriate and may be critically important.