A 72-year-old man with a history of type 2 diabetes mellitus, hypertension, and hyperlipidemia presents to his primary care provider for concerns about his cognitive decline. His wife has noticed that he has a worsening ability to organize, plan, and exhibit impulse control over the last month. The patient states that he is able to complete his activities of daily living without assistance, but has some weakness of his left upper and lower extremities that began 3 months prior. He needs reminders from his wife about daily tasks to complete. He enjoys spending time with his spouse, playing cards with his friends, and taking daily walks around his neighborhood. His temperature is 98.2°F (36.8°C), blood pressure is 149/87 mmHg, pulse is 87/min, and respirations are 12/min. Physical exam reveals an elderly man who is oriented to person, place, and time. He has 4/5 left-sided weakness of the upper and lower extremities and associated pronator drift of the left upper extremity. A mini-mental status exam reveals he is able to remember 2 out of 3 words after 4 minutes. He is able to appropriately draw a clock. A magnetic resonance imaging study of the brain is shown in Figure A. Which of the following is the most likely diagnosis?
Normal aging
Vascular dementia
Pseudodementia
Mild cognitive impairment
Vascular dementia
This patient with cardiovascular risk factors (hypertension, type 2 diabetes mellitus, hyperlipidemia) who presents with sudden cognitive decline of executive function and neurologic symptoms consistent with vasculopathy and possible prior stroke given his neurologic exam likely has vascular dementia, which can be corroborated with magnetic resonance imaging revealing white matter focal involvement consistent with vascular infarcts.

Vascular dementia is a form of dementia that results from compromise of blood supply to the brain, such as minor strokes or microinfarcts to the white matter. These insults lead to worsening cognitive abilities and presents classically as a stepwise decline (sudden/sharp declines in cognitive function that occur at distinct periods of time, not gradually) in cognitive function (thinking, planning, self-control, flexibility in thought). This is often associated with neurologic deficits as byproducts of these strokes. Unlike other forms of dementia, this presentation is step-wise. Treatment involves optimizing medical management to treat underlying medical comorbidities (managing cardiovascular risk factors such as hypertension, type 2 diabetes mellitus, hyperlipidemia), physical therapy/rehab for stroke symptoms, and caregiver support at home. Magnetic resonance imaging reveals focal white matter changes consistent with small vascular infarcts.

Khan et al. review the diagnosis and management of vascular dementia while including commentary on recent updates in the literature. They found that risk factors for vascular diseases such as stroke, high blood pressure, high cholesterol, and smoking also raise the risk of vascular dementia. They thus recommend medical management of underlying medical comorbidities such as hypertension, diabetes mellitus, or hyperlipidemia as treatments for vascular dementia.

Figure/Illustration A shows magnetic resonance imaging with white matter small vessel ischemic changes (red arrows) characteristic of vascular dementia within a background of diffuse generalized atrophy.

Incorrect Answers:
Answer A: Alzheimer disease is a form of dementia that presents with progressive forgetfulness as the first and most jarring clinical symptom, followed by worsening visual/spatial recognition, and then worsening behavioral function. It is most common in patients over the age of 75. It is not associated with focal deficits or weakness on neurological exam.

Answer B: Mild cognitive impairment is a stage between the expected cognitive decline of normal aging and forms of dementia. Patients and family members may notice problems with memory, thinking, or judgment, but they are not significant enough to cause interference with activities of daily living.

Answer C: Normal aging does not involve a noticeable decline in cognition and does not involve neurologic deficits. Declines are present, but are infrequent and do not impede activities of daily living.

Answer D: Pseudodementia is the result of untreated depression, which can present as forgetfulness in the elderly. This etiology can be distinguished by screening for signs or symptoms of depression, which might include sleep disturbance, anhedonia, lack of energy, increased or decreased appetite, fatigue, and/or loss of concentration. These symptoms are absent in this case.

Bullet Summary:
Vascular dementia presents with a step-wise decline in executive cognitive function and neurologic deficits in a patient with cardiovascular risk factors and is associate with MRI findings including white matter changes consistent with vascular infarcts.