Related Experiment Video
Updated: Jun 26, 2026

Brain Infarct Segmentation and Registration on MRI or CT for Lesion-symptom Mapping
Published on: September 25, 2019
Skew deviation as the initial manifestation of left paramedian thalamic infarction
Edward Margolin1, Dana Hanifan, Mary K Berger
1Department of Ophthalmology, University of Michigan Health System, Ann Arbor, Michigan, USA.
Abstract:
We describe a 73-year-old man who developed diplopia as the initial manifestation of a left thalamic infarction. By the time he reached the emergency department, clouded consciousness precluded localization of the lesion. Results of brain MRI were initially interpreted as negative. Ophthalmologic examination several hours later disclosed a small vertical ocular misalignment attributed to skew deviation. This finding led to careful scrutiny of the upper brainstem on MRI. Comparison of the diffusion, apparent diffusion coefficient, and exponential apparent diffusion coefficient MRI studies allowed a diagnosis of subtle left thalamic infarction. The recognition of skew deviation in this setting is important because it may be the most specific indicator of a brainstem lesion.
Related Concept Videos
Ischemic Stroke ll: Pathophysiology
Ischemic Stroke l: Introduction
Hemorrhagic Stroke ll: Pathophysiology
Types of Skewness
For instance, in the middle of a pandemic, the geographical distribution of vaccine coverage may be positively skewed towards populations in the global north countries. However,...
Transient Ischemic Attack l: Introduction
Visual Agnosia

