Horizontal gaze deviation on computed tomography: the visual criterion and lesion characteristics in ischemic stroke

Area of Science:

• Neurology
• Radiology
• Medical Imaging

Background:

• Horizontal gaze deviation (HGD) on computed tomography (CT) is a recognized sign for identifying ischemic stroke.
• Standardizing the visual determination of HGD and understanding its association with lesion characteristics can improve its clinical utility.

Purpose of the Study:

• To establish a reliable criterion for visually determining HGD on CT scans.
• To investigate the frequency and characteristics of HGD in relation to stroke subtypes and lesion locations.

Main Methods:

• Reviewed CT scans and clinical records of 327 ischemic stroke patients and 193 controls.
• Determined HGD criterion using control data (cutoff of 14°).
• Analyzed HGD frequency in stroke subgroups using Fisher's exact test and logistic regression for middle cerebral artery (MCA) stroke.

Main Results:

• A cutoff of 14° for unidirectional eye deviation identified pathological HGD in 4.9% of controls.
• HGD was significantly more frequent in most stroke subgroups, notably MCA cardioaortic embolism and posterior inferior cerebellar artery (PICA) strokes.
• In MCA strokes, HGD probability decreased over time and was associated with cardioaortic embolism and lenticular nucleus lesions.

Conclusions:

• A criterion of ≥14° unidirectional HGD on CT is proposed for pathological HGD.
• HGD is prevalent in specific stroke types like MCA cardioaortic embolism and PICA stroke but may not pinpoint exact lesions.
• HGD in MCA stroke is influenced by time, stroke subtype, and lesion location, suggesting its potential as a valuable diagnostic aid.