What is the most appropriate next step for a 72-year-old patient with a history of Hypertension (HTN) and hypothyroidism on levothyroxine, presenting with worsening forgetfulness over the last 3 months and impaired cognitive function, as evidenced by inability to recall three common words during examination?

Cognitive Assessment for Elderly Patient with Memory Concerns

The most appropriate next step for this 72-year-old patient with worsening forgetfulness is to perform a comprehensive cognitive assessment using a validated tool such as the Montreal Cognitive Assessment (MoCA), along with basic laboratory tests including thyroid function, vitamin B12, complete blood count, and comprehensive metabolic panel. 1, 2

Initial Assessment Strategy

Cognitive Screening

• Use the Montreal Cognitive Assessment (MoCA) as the primary screening tool due to:
  • High sensitivity (90%) for detecting mild cognitive impairment 1
  • Superior assessment of executive function compared to other tools
  • Ability to evaluate multiple cognitive domains including memory, attention, language, and visuospatial abilities

Basic Laboratory Evaluation

• Order the following tests to rule out reversible causes of cognitive impairment:
  • Thyroid function tests (TSH, free T4) - especially important given patient's history of hypothyroidism 2, 3
  • Complete blood count
  • Comprehensive metabolic panel (including electrolytes, glucose, calcium)
  • Vitamin B12 and folate levels
  • Homocysteine level

Rationale for This Approach

1. Patient Risk Factors:

   • Advanced age (72 years)
   • History of hypertension (vascular risk factor)
   • Hypothyroidism (can affect cognition)
   • Word recall deficit on examination (objective evidence of cognitive impairment)

2. Guidelines Support:

   • The Journal of Internal Medicine recommends MoCA for patients without an available informant 2
   • Basic laboratory tests are recommended to identify potentially reversible causes of cognitive impairment 2, 3
   • The Canadian Stroke Best Practice Recommendations emphasize the importance of evaluating vascular risk factors in cognitive assessment 2

3. Clinical Significance:

   • The inability to recall three common words during examination suggests memory impairment that warrants formal assessment
   • The 3-month duration of symptoms is significant but not so prolonged that intervention would be futile

Next Steps After Initial Assessment

Based on the results of cognitive testing and laboratory evaluation:

1. If MoCA confirms cognitive impairment and labs are normal:

   • Obtain structural brain imaging (MRI preferred, CT if MRI contraindicated) 2
   • Consider referral for comprehensive neuropsychological testing 2

2. If thyroid function is abnormal:

   • Optimize levothyroxine dosage before reassessing cognition
   • Untreated or suboptimally treated hypothyroidism can contribute to cognitive symptoms 4, 5

3. If other laboratory abnormalities are found:

   • Address specific deficiencies (e.g., vitamin B12 supplementation)
   • Reassess cognitive function after correction

Important Clinical Considerations

• Involve an informant: The son's observations are valuable; consider using informant-based tools like the AD8 or Alzheimer's Questionnaire if available 2, 1

• Medication review: Assess if the patient is taking any anticholinergics or sedatives that could affect cognition 2

• Hypertension management: Ensure blood pressure is well-controlled, as hypertension is a significant risk factor for vascular cognitive impairment 2

• Sleep assessment: Although the patient reports adequate sleep (7-8 hours), evaluate sleep quality for conditions like sleep apnea that could impact cognition 2

• Avoid premature diagnosis: Do not assume Alzheimer's disease without proper evaluation, as many conditions can cause cognitive impairment in older adults 2

By following this approach, you will be able to identify potentially reversible causes of cognitive impairment and establish an appropriate baseline for monitoring the patient's cognitive function over time.