Mild Cognitive Impairment

The prevalence of MCI increases with age. A systematic review found the one-year risk of developing MCI to be ^[4]:

• 2.2% in the 75-79-year age group
• 4.1% in the 80–84-year age group
• 6% in the over 85-year age group. 

There are no significant sex differences in the prevalence of MCI ^[5].

MCI is a considered a high-risk state for dementia, however not all patients with MCI will go on to develop dementia. Meta-analyses have found that 14-40% of individuals with MCI progress to a dementia diagnosis [2].

Given the variable clinical course of MCI, there is an opportunity for doctors to address factors contributing to cognitive impairment and to educate patients on lifestyle changes that can optimise cognition.

Diagnosing MCI necessitates a comprehensive approach integrating history-taking, cognitive assessments, and basic investigations.

• Patient history: Complemented by collateral information from family members or caregivers, patient history offers valuable insights into the nature, progression, and functional impact of cognitive concerns [1]. (go to 'GP Assessment and Management > Consultation 2 - baseline information collection' in pathway)
   
• Cognitive assessments: Tools such as the Montreal Cognitive Assessment (MOCA), or Mini-Mental State Examination (MMSE) with the clock drawing test, provide objective evaluation [1]. Consideration of factors such as pre-morbid baseline, education level, and cultural/language context can enhance diagnostic accuracy [1]. (go to 'GP assessment and management' in pathway)
   
• Specialist services: In complex cases, neuropsychological assessments or referral to a Cognitive, Dementia and Memory Service (CDAMS) may be warranted to elucidate differential diagnoses, or to guide cognitive rehabilitation [1]. (go to 'Cognitive Dementia and Memory Service (CDAMS)' in pathway)
   
• Investigation of underlying or contributing causes: Basic investigations, including full blood count, metabolic panel, liver function tests, thyroid function tests, vitamin B12, folate levels, and neuroimaging (CT or MRI of the brain), may help identify potential underlying or contributing causes [1]. (go to 'Investigation of suspected dementia' in pathway)
   

Upon MCI diagnosis, transparent communication with the patient and their family (with consent), is crucial. Providing written information can assist understanding of the condition and available interventions [1]. Emphasizing the distinction between MCI and dementia, alongside the variability in disease progression, may encourage patient engagement with interventions that may improve their overall health and cognitive function [1].

Management of MCI involves identifying and addressing modifiable risk factors.

• Medical risk factors: These may include polypharmacy, sleep disorders, hearing and visual impairment, as well as a strong association between MCI and cardiovascular disease. These should be optimised where feasible. Medication review is essential, with a focus on deprescribing medications associated with cognitive impairment, such as those with cholinergic action [1].
   
• Lifestyle modifications:
   
  • Physical activity: regular exercise adhering to national guidelines has demonstrated benefits in preserving cognitive function [2]. See: https://www.health.gov.au/topics/physical-activity-and-exercise/physical-activity-and-exercise-guidelines-for-all-australians/for-older-australians-65-years-and-over. Referral to an exercise physiologist or physiotherapist may be beneficial in cases where comorbidities or fall risks are a concern.
     
  • Diet: Adherence to recommended diets such as the MIND or Mediterranean-DASH diet may benefit cognitive health [1]. See: https://alzheimersresearch.org.au/eating-for-good-brain-health/
     
  • Smoking cessation and alcohol moderation: advised for maintaining overall health [1].
     
• Nutritional supplements: Compounds like Fortasyn Connect, as found in Souvenaid, may have some effect in slowing cognitive decline in early Alzheimer’s disease and MCI due to Alzheimer’s disease ^[6][7] Patients should be informed of its availability.
   
• Cognitive stimulation: Mentally engaging activities and memory training are key components of MCI management. Cognitive rehabilitation programs tailored to individual needs may enhance cognitive functioning and quality of life [1].

Currently, no pharmacological treatment is recommended for MCI [2]^[8]. Acetylcholinesterase inhibitors, commonly used in mild to moderate Alzheimer’s disease, have not been shown to have efficacy in treatment of MCI and may have adverse effects [8]. The emerging availability of monoclonal antibodies that remove cerebral amyloid will increase the urgency to identify biomarkers indicating MCI related to amyloid accumulation. 

Monitoring cognitive function and functional impairment is essential due to the variable clinical course of MCI. A repeat evaluation should be conducted 6-12 months after the initial cognitive assessment and at least every 12 months thereafter. Early reviews may be warranted if concerns about changes in status are raised by the patient or family, if there is recent deterioration in health or hospitalisation, or if new neurological, mood, or behavioural symptoms emerge [1].

Follow-up assessments should include re-administration of a validated cognitive assessment, along with structured reports comparing current functional status and carer burden to previous assessments. It's important to note that currently, there are no validated biomarkers for predicting the progression of MCI [1].

Long-term planning should aim to engage both the patient and their family. A multidisciplinary team approach is essential. GP Management Plans and annual health checks may be useful for facilitating holistic, multidisciplinary team management [1].

Patients and families should be encouraged to consider future wishes and values in respect to Advanced Care Planning and appointment of an EPOA. Discussion of how potential disease progression may affect a patient’s work and driving should be considered. Driving may not necessarily need to be reviewed unless specific concerns are raised [1]. (go to 'Medicolegal issues' in pathway)

• MCI is the presence of subtle cognitive deficits without significant functional impairment.
   
• Roughly 1/4 to 1/3 of individuals with MCI proceed to develop dementia.
   
• Diagnosis necessitates a comprehensive approach, including thorough history-taking, validated cognitive assessment, neuroimaging, and screening for potential contributing factors.
   
• Monitoring for progression over time is essential.
   
• Management strategies involve medical optimisation, lifestyle strategies and cognitive stimulation.
   
• As MCI may progress, it is important to consider the long-term implications and discuss these with the patient and their family at a time when all parties are able to participate.