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Updated: Jul 5, 2026
08:25
Circumscribed Capsular Infarct Modeling Using a Photothrombotic Technique
Published on: June 2, 2016
[Pure amnesia due to the right capsular genu infarction]
Yuji Kato1, Yoshikazu Mizoi, Toshimasa Yamamoto
1Department of Neurology, Saitama Medical University.
Nihon Ronen Igakkai Zasshi. Japanese Journal of Geriatrics
|April 29, 2008
Summary
A lacunar infarction in the right internal capsule’s genu caused severe amnesia. This brain lesion disrupted thalamo-cortical pathways, leading to significant memory impairments.
Area of Science:
- Neurology
- Neuroimaging
- Neuropsychology
Background:
- Memory disturbance is a common neurological complaint.
- Lacunar infarcts are small ischemic strokes often affecting deep brain structures.
- The internal capsule is a critical white matter tract connecting the thalamus and cerebral cortex.
Observation:
- A 77-year-old woman presented with severe verbal and visual memory deficits.
- Brain MRI revealed a lacunar infarction in the genu of the right internal capsule.
- Technetium-99m ethyl cysteinate dimer single-photon emission computed tomography (99mTc-ECD SPECT) showed reduced perfusion in the right thalamus and frontal lobe.
Findings:
- The infarction in the genu of the internal capsule likely damaged fibers from the anterior and inferior thalamic peduncles.
- This resulted in the disconnection of the thalamo-cortical tract.
- The observed memory impairments were directly attributed to this specific lacunar infarction.
Implications:
- Lacunar infarcts in the genu of the internal capsule can cause profound and persistent amnesia.
- This case highlights the importance of precise lesion localization in understanding cognitive deficits.
- Neuroimaging and neuropsychological assessments are crucial for diagnosing and explaining memory disturbances after stroke.
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