What is the likely cause of a patient's memory loss, and would a carotid ultrasound (U/S) and computed tomography (CT) scan of the head be appropriate to evaluate vascular and structural causes?

From the Guidelines

The patient should undergo a CT head without IV contrast as the initial imaging to evaluate structural causes of memory loss, and an MRI head without IV contrast or CT head without IV contrast is usually appropriate to assess vascular causes, as they are equivalent alternatives 1. The patient was referred to neurologist Dr. Sobonia but likely missed a phone call about this appointment. Education was provided explaining that a carotid ultrasound would assess potential vascular causes of memory loss, while a CT scan of the head would evaluate structural causes. The patient agreed to have these imaging tests reordered today. Several spelling corrections are needed: "most likely" instead of "most liekly," "carotid" instead of "coartiod," "assess" instead of "access," "structural" instead of "structrual," and "imaging" instead of "imagining." Key points to consider in the evaluation of this patient include:

• The importance of identifying vascular causes of memory loss, such as carotid atherosclerotic disease, to guide treatment decisions and long-term management 1
• The use of imaging modalities, such as CT or MRI, to evaluate the mechanism of stroke and assess risk of future stroke 1
• The need to prioritize the patient's safety and well-being, and to ensure that any imaging tests ordered are necessary and appropriate for their care. Given the patient's presentation and the need to evaluate both structural and vascular causes of memory loss, a CT head without IV contrast is the most appropriate initial imaging test, as it is a widely available and effective modality for evaluating structural causes of memory loss 1.

From the Research

Diagnostic Approach for Memory Loss

The patient's report of memory loss and the decision to undergo a carotid ultrasound and CT of the head are crucial steps in diagnosing the underlying cause of memory loss.

• A carotid ultrasound can help identify vascular causes of memory loss, such as carotid artery stenosis or atherosclerosis 2, 3.
• A CT of the head can evaluate structural causes of memory loss, such as brain atrophy or infarcts 4, 5.

Association between Carotid Artery Disease and Cognitive Impairment

Studies have shown that carotid artery disease is associated with cognitive impairment and an increased risk of stroke 2, 3, 5.

• Carotid atherosclerosis has been linked to poorer cognitive performance in older adults, particularly in verbal memory and executive function 2.
• Internal carotid artery intima-media thickness has been associated with a higher prevalence of silent cerebral infarcts, large white matter hyperintensity, and lower total brain volume 2.
• Low-grade carotid artery stenosis has been linked to progression of brain atrophy and cognitive decline, including declines in executive functioning and memory 5.

Imaging Biomarkers for Carotid Artery Disease

Brain imaging biomarkers, such as white matter hyperintensities, silent or covert brain infarctions, cerebral microbleeds, and regional and generalized cerebral volume loss, can be used to identify downstream effects of carotid artery disease 3.

• These biomarkers can be detected using various imaging modalities, including CT, MR, and advanced imaging techniques 3.
• Multiparametric MRI, including structural MRI, functional MRI, diffusion tensor imaging, and magnetic resonance spectroscopy, can provide information on anatomical and functional changes in the brain and aid in the diagnosis of Alzheimer's disease and mild cognitive impairment 4.