Mild Cognitive Impairment (MCI)

Background

• Mild cognitive impairment (MCI) is a heterogeneous syndrome in which cognitive impairment leads to no or minimal impairment of activities of daily living and does not meet criteria for dementia.
• MCI can be subclassified into amnestic MCI (memory impairments dominate) vs. nonamnestic MCI, and single-domain (impairment mostly isolated to 1 cognitive domain) vs. multiple-domain MCI.
• Prevalence increases with age from 6.7% in patients aged 60-64 years to 37.6% in patients ≥ 85 years old.
• Risk factors include apolipoprotein E gene (APOE) e4 allele, hormone replacement therapy, lower educational level, male sex, older age, prior critical illness, sleep-disordered breathing, vascular risk factors (such as diabetes and hypertension), and vitamin D deficiency.
• Dementia within 2 years reported in 14.9% of patients with MCI > 65 years old, with a greater risk for patients with amnestic MCI, APOE e4 allele(s), diabetes, less education, and stroke.

Evaluation

• Suspect cognitive impairment in patients with concerns over changes in cognition as reported by patient, clinician, or other informant (Strong recommendation).
• Take careful history from patient and knowledgeable informants and perform physical to help with further assessments.
• Conduct routine blood work and structural brain imaging to assess for potential causes of symptoms.
• Perform cognitive assessment using a validated tool.
• If cognitive assessment suggests cognitive impairment, perform in-depth clinical assessment.
  • Assess for functional impairment to differentiate between MCI (in which function is mostly preserved) and dementia (in which function is impaired) (Strong recommendation).
  • If an impairment in activities of daily function is suspected, consider dementia as a diagnosis (see Dementia Evaluation for details).
  • Otherwise, use established diagnostic criteria to determine diagnosis of MCI.
• Also attempt to determine etiology and assess for potentially modifiable causes of symptoms and risk factors.

Management

• Discuss diagnosis and uncertainties regarding prognosis, including advising patients and family members to discuss long-term planning topics (Strong recommendation).
• Wean patients from medications that can contribute to cognitive impairment (if possible) and address potentially modifiable risk factors (Strong recommendation).
• Advise general lifestyle strategies associated with reduced risk of poor health.
• Assess for behavioral and neuropsychiatric symptoms and manage accordingly (Strong recommendation).
• Advise regular exercise as part of an overall management strategy (Strong recommendation).
• Consider cognitive interventions (Weak recommendation).
• Advise patients and families that there are currently no medications or dietary agents shown to have symptomatic cognitive benefits in patients with MCI and that there are no FDA-approved medications for MCI (Strong recommendation).
  • Consider not offering cholinesterase inhibitors (Weak recommendation).
  • If offering a cholinesterase inhibitor, first discuss with the patient that there is no empirical evidence for benefit and that cholinesterase inhibitors are not indicated for MCI (Strong recommendation).
• Perform serial assessments over time to monitor for changes in cognitive impairment (Strong recommendation).