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Published on: August 14, 2019
Delirium due to brain microembolism: diagnostic value of diffusion-weighted MRI
Pablo Irimia1, Eduardo Martinez-Vila, Antonio Martinez-Cuesta
1Department of Neurology, Clinica Universitaria de Navarra, University of Navarra, Pio XII 36, 31008-Pamplona, Spain. pirimia@unav.es
Abstract:
Delirum is a common complication in hospitalized patients and it is characterized by acute disturbances of consciousness, attention, cognition, and perception. Despite the frequency with which it is observed, ischemic stroke is generally considered as an unusual cause of delirium. A subtype of brain embolism is characterized by multiple small emboli in different vascular territories, a condition known as "brain microembolism." Given the high contrast of acute ischemic lesions in diffusion weighted imaging (DWI) this technique is particularly helpful to detect these small infarctions. We present here a patient with pulmonary metastases who was treated with bronchial artery embolization and who subsequently developed delirium due to brain microembolism. The embolic material crossed through pulmonary arteriovenous fistulas, producing multiple areas of cerebral ischemia. The ischemic lesions could be visualized only on DWI, and they affected the periventricular region, caudate nucleus, thalamus, and cerebellum.
Insights
Delirium in hospitalized patients can stem from unusual causes like brain microembolism. This case highlights how pulmonary arteriovenous fistulas can facilitate embolic material, leading to cerebral ischemia and delirium.
Area of Science:
- Neurology
- Radiology
- Oncology
Background:
- Delirium is a frequent complication in hospitalized individuals, marked by acute changes in consciousness and cognition.
- Ischemic stroke is an uncommon cause of delirium, but brain microembolism presents a specific subtype.
- Pulmonary arteriovenous fistulas can allow embolic material to bypass pulmonary circulation.
Observation:
- A patient with pulmonary metastases underwent bronchial artery embolization.
- The patient subsequently developed delirium attributed to brain microembolism.
Findings:
- Embolic material traversed pulmonary arteriovenous fistulas, leading to widespread cerebral ischemia.
- Diffusion-weighted imaging (DWI) was crucial for visualizing small, acute ischemic lesions in the periventricular region, caudate nucleus, thalamus, and cerebellum.
Implications:
- This case highlights brain microembolism as a potential, albeit unusual, cause of delirium in specific clinical scenarios.
- DWI is essential for diagnosing subtle cerebral microinfarctions that may otherwise be missed.
- Understanding paradoxical embolism through pulmonary arteriovenous fistulas is critical for managing patients undergoing embolization procedures.
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