Signs and symptoms

The term MCI describes a set of symptoms, rather than a specific disease.

A person with MCI has mild problems with one or more of the following:

• memory - for example, forgetting recent events or repeating the same question

  • Working memory - Holding and manipulating information in the mind, as when reorganizing a short list of words into alphabetical order (Luo L, 2008)

  • verbal and visuospatial working speed, memory, and learning, with visuospatial cognition more affected by aging than verbal cognition (Jenkins L, 2000)

  • Episodic memory – Personal events and experiences (Luo L, 2008)

  • Processing speed (Head D, 2008)

  • Prospective memory – The ability to remember to perform an action in the future (eg, remembering to fulfill an appointment or take a medication (Luo L, 2008)

  • Ability to remember new text information, to make inferences about new text information, to access prior knowledge in long-term memory, and to integrate prior knowledge with new text information (Hannon B, 2009)

  • Recollection (Parks CM, 2010)

• reasoning, planning or problem-solving - for example, struggling with thinking things through

• attention - for example, being very easily distracted

• language - for example, taking much longer than usual to find the right word for something

• visual depth perception - for example, struggling to interpret an object in three dimensions, judge distances or navigate stairs.

 

A person with MCI may also experience:

• Depression

• Irritability and aggression

• Anxiety

• Apathy

 

Epidemiology

The prevalence of mild cognitive impairment increases with age.

The prevalence is 10% in those aged 70-79 years and 25% in those aged 80-89 years (Roberts RO, 2008)

Many studies indicate that the risk of Alzheimer disease (AD) is significantly higher in women than in men.

 

Diagnosis

Although no single feature of the general physical examination characterizes MCI, the following should be included in the overall assessment of the patient:

• Evaluation of mental status

• Examination for the presence of potential causative comorbid conditions

• Examination for the presence of sensory and/or motor deficits as potential causes or exacerbating factors

 

No specific diagnostic studies exist for mild cognitive impairment.

However, most clinicians perform a basic workup at minimum to exclude potential treatable causes (eg, thyroid disease, cobalamin deficiency).

 

Research is ongoing in the search for biologic markers that may help differentiate between the large number of conditions that may progress from MCI to full dementia.

Brain imaging with magnetic resonance imaging (MRI) or computed tomography (CT) is often performed in patients with MCI. In general, MRI is preferred, as whole brain and hippocampal volume on MRI can predict progression from MCI to Alzheimer disease (AD) (Risacher SL, 2009).