Transient Vestibulopathy in Wallenberg's Syndrome: Pathologic Analysis.

Area of Science:

• Neuroscience
• Neurology
• Pathology

Background:

• Lateral medullary stroke (LMS) can present with acute vestibular syndrome (AVS).
• The horizontal vestibulo-ocular reflex (h-VOR) is typically normal in LMS, unlike peripheral vestibulopathies.
• Transient vestibular symptoms mimicking peripheral lesions are unusual in LMS.

Observation:

• A 61-year-old man presented with AVS and left LMS, showing transient horizontal nystagmus and decreased h-VOR gain.
• MRI suggested medial vestibular nucleus (MVN) involvement, but rapid symptom resolution suggested transient ischemia.
• Postmortem neuropathological examination confirmed LMS near the MVN, with spared MVN neurons and glia.

Findings:

• The neuropathology correlated with imaging findings of LMS affecting the lateral medulla and pontomedullary junction.
• Spared MVN neurons explained the rapid normalization of ocular motor signs and h-VOR gain.
• Truncal lateropulsion was attributed to infarction in the lateral vestibulospinal tract and lateral reticular nucleus.

Implications:

• LMS can rarely present as or mimic peripheral vestibulopathy, challenging clinical diagnosis.
• This case provides the first neuropathological evidence of LMS with transient vestibular findings.
• Understanding these rare presentations is crucial for accurate diagnosis and management of vestibular disorders.