Presentation
Sudden onset dysphonia with right facial droop and dysphasia. Bilateral nystagmus worse with upwards gaze. External CT shows right V4 dissection but no perfusion defect.
Patient Data
The DWI sequence demonstrates an acute lateral medullary infarct posteriorly on the right. No other acute changes. The time-of-flight MRA reconstructions show a patent right V4, however there is reduced flow signal and two focal apparent areas of flow loss/filling defect which could represent dissection or recanalized occlusion. No evidence of dissecting aneurysm. Reduced flow signal in the patent proximal right PICA.
Impression
Acute lateral medullary infarct which is presumably from perforators from the proximal right PICA secondary to localized (recanalized) focal dissection or embolus.
Case Discussion
Case example of the arterial territory of the posterior circulation.