Mild cognitive impairment

Disease Description (Causes and Symptoms)

• Definition: Mild cognitive impairment (MCI) is a condition in which some cognitive functions, such as memory, attention, language, visuospatial ability, and judgment, are reduced compared with others of the same age, while independence in daily life is maintained. It is classified as an intermediate stage between normal aging and dementia (particularly Alzheimer’s disease).
• Causes/Pathophysiology: The most common cause is age-related degenerative change, and it may progress to the prodromal stage of Alzheimer’s disease. Reversible causes, such as vascular changes, metabolic diseases (e.g., hepatic encephalopathy), depression, and medication effects, also need to be differentiated.
• Main symptoms: Recent memory decline (repeating the same questions, missing appointments or failing to relay phone messages), visuospatial impairment (difficulty finding one’s way), language impairment (being unable to recall the names of objects), reduced attention and concentration, and sometimes impaired judgment and emotional changes (depression, apathy). Daily activities can generally still be performed independently.

Treatment Methods

• Goals: Identify the cause and correct reversible causes, monitor the progression of cognitive decline, and use lifestyle interventions to reduce the risk of progression.
• Medication treatment: At present, there is insufficient evidence that medications can reliably prevent progression to dementia at the MCI stage. Routine use of Alzheimer’s disease treatments (such as cholinesterase inhibitors) is not standard practice, but may be considered in individual situations at the discretion of a neurologist.
• Non-medication treatment (recommended):
  • Regular aerobic and strength exercise (3–5 times per week)
  • Quit smoking and actively manage vascular risk factors such as blood pressure, diabetes, and lipids
  • Ongoing social activities and mental activities (reading, learning, puzzles, playing a musical instrument, etc.)
  • Sufficient sleep and treatment of depression and anxiety (mental health evaluation if needed)
  • A balanced diet (fruit and vegetable intake is recommended) and avoidance of excessive alcohol consumption (moderation is recommended)
  • Correction of sensory impairments, such as hearing support (treatment of hearing loss)
• Follow-up and monitoring:
  • Regular cognitive function testing (e.g., at least once a year) and neurocognitive assessment
  • If necessary, evaluation of the cause using brain imaging (MRI) and functional testing (PET)
• Precautions (for self-management):
  • Observation by a caregiver is important because people may tend to underestimate their condition or conceal their symptoms
  • Even if independence can be maintained, safety-related functions such as driving and financial management need to be checked periodically
• Risk of complications:
  • Risk of progression to dementia, such as Alzheimer’s disease (an annual progression rate of approximately 10–15%, higher than the 1–2% rate in people without MCI)
  • Risk of accidents due to functional decline (e.g., falls), social isolation, and worsening depression

Outpatient Visit Checkpoints (Including Suggested Preparations and Questions)

• Items to prepare (recommended to bring)
  • A list of currently used medications and health supplements (including doses and administration times)
  • Recent test results (blood tests, MRI, etc.) or records of test dates
  • The onset and pattern of symptom changes (e.g., when they began, gradual/acute onset, aggravating factors)
  • Observations from a caregiver or family member (specific examples of changes in the ability to perform daily activities)
  • Lifestyle information (sleep, alcohol consumption, smoking, exercise, and social activities)
• Information that is useful to tell the doctor during the visit
  • Specific recent examples of forgetfulness (e.g., missing a dose of medication, forgetting an appointment)
  • Difficulties with daily activities (cooking, financial management, driving, etc.)
  • Changes in mood (depression or anxiety) or sleep problems
• Possible tests during the visit
  • Neurocognitive testing, brief screening tests (MMSE, MoCA, etc.), blood tests for reversible causes (anemia, thyroid disease, vitamin B12 deficiency, etc.), brain MRI, etc.

Examples of General Questions to Ask the Doctor

• "Has my (or the patient’s) current condition been diagnosed as MCI? What are the other possible causes?"
• "How high is the risk of progressing to dementia? What tests should be performed regularly?"
• "What lifestyle changes are recommended, and are there any specific behaviors that should be avoided?"
• "Could any of the medications I am currently taking affect my memory?"
• "How do depression or sleep problems affect cognition, and how are they treated?"

Examples of Condition-Specific Questions

• "Could you explain which areas showed the most noticeable decline on the cognitive function testing? (e.g., memory versus executive function)"
• "If there are no significant findings on the MRI or PET scan, what follow-up interval and types of tests are recommended going forward?"