Video head impulse testing in patients with isolated (hemi)nodular infarction

Area of Science:

• Neurology
• Neuroscience
• Ophthalmology

Background:

• Isolated (hemi)nodular strokes are rare causes of acute dizziness, with knowledge gaps in their clinical presentation.
• Lesions in the nodulus can cause various vestibulo-ocular deficits, but bedside assessments of the angular vestibulo-ocular reflex (aVOR) are limited.

Purpose of the Study:

• To characterize the clinical presentation spectrum of isolated (hemi)nodular strokes.
• To hypothesize that the aVOR is within normal limits in these specific stroke cases.

Main Methods:

• Retrospective analysis of patients with isolated (hemi)nodular stroke from a prospective stroke registry.
• Standardized neuro-otological assessment and quantitative video-based head-impulse testing (vHIT) of all six semicircular canals were performed.

Main Results:

• Six patients with isolated nodular or heminodular ischemic stroke were included between 2015-2021.
• Most patients presented with acute or episodic vestibular syndrome, exhibiting ocular motor abnormalities and ataxia.
• All patients demonstrated normal bedside head-impulse tests and normal angular vestibulo-ocular reflex (aVOR) gains via vHIT.

Conclusions:

• Quantitative vHIT confirmed preserved aVOR integrity in isolated (hemi)nodular strokes.
• Widespread deficits in ocular stability, postural control, and volitional eye movements were observed, consistent with prior research.