Lateral Medullary Syndrome (Wallenberg syndrome)

61-year-old woman presented with unsteady gait and decreased pain/temperature sensation over the right side of trunk.

In this case, DWI shows increased signal intensity with low apparent diffusion coefficient (ADC) at the lateral medulla, consistent with acute infarction. The neurological deficits caused by Wallenberg syndrome can be due to involvement of vestibular nuclei, restiform body, trigeminal tracts and nuclei, and spinothalamic tract at the medulla (hatch-marked area in the sketch diagram). The most common pattern of sensory abnormality with lateral medullary infarcts is loss of pain and temperature sensation in the ipsilateral face (trigeminal tracts and nuclei) and the contralateral trunk and limbs (spinothalamic tracts).