Case Report
Acute Amnesia due to Isolated Mammillary Body Infarct

Presented as Electronic Excerpta at 2014 American Society of Neuroradiology (ASNR) 52nd Annual Meeting and Symposium, May 2014, Montreal, Canada.
https://doi.org/10.1016/j.jstrokecerebrovasdis.2015.06.038Get rights and content

Background

There are limited reports describing acute amnesia after mammillothalamic tract infarction. Furthermore, acute infarction isolated to the mammillary body has never been reported. We present the first case of anterograde amnesia after isolated acute infarction of the mammillary body in a patient without concurrent or prior thalamic or mammillothalamic tract injury.

Methods

A retrospective review of the patient's electronic medical record including inpatient notes and all radiological examinations was performed.

Results

A 50-year-old woman presented with acute onset of confusion and constant repetition of the same questions. Magnetic resonance (MR) imaging of the brain showed isolated acute infarct of the left mammillary body without concurrent abnormality of the thalamus or mammillothalamic tract. MR angiography showed severe stenosis of the proximal posterior cerebral artery at the origin of the perforating mammillary artery.

Conclusions

Isolated injury to the mammillary body is rare. In addition to recognized memory-related structures such as the thalamus and mammillothalamic tract, mammillary body injury may also play a role in memory dysfunction. Knowledge of the vascular supply of memory-related structures is important in diagnosing and understanding memory dysfunction.

Section snippets

Case Report

A 50-year-old woman with hypertension, diabetes, and previously normal behavior was brought to the emergency room by her daughter with acute onset of confusion. She was constantly repeating the same questions and had difficulty forming new memories. She could recall that a plumber came to her house the morning of admission but she did not recall him leaving.

On arrival, her temperature was 37°, blood pressure was 142/82 mm Hg, and her heart rate was 77 and regular. On mental status testing, she

Discussion

The mammillary bodies lie at the posterior margin of the hypothalamus and are a part of the circuit of Papez, which also includes the hippocampal formation, anterior thalamus, cingulate gyrus, and their interconnections. Although Papez originally suggested that this pathway was the basis for emotion, current understanding suggests that it has a unique role in memory and cognition.1

Within this network of structures involved in memory, the anterior thalamic nuclei and the direct

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The work was performed at the Department of Neuroradiology, Columbia University Medical Center, 622 West 168th Street, PB 1-301, New York, NY 10032.

The authors declare that they did not receive any grant support, have nothing to disclose, have no author contributions, and have no conflict of interest.

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