2026 American Academy of Neurology Abstract Website

Objective:

To present a rare case of dominant PICA territory acute infarction

Background:

The posterior inferior cerebellar artery (PICA) classically arises from the V4 segment of the vertebral artery, with infarctions resulting in lateral medullary and inferior cerebellar involvement. Numerous PICA variants have been described in the literature. However, dominant PICA territory infarction involving both ipsilateral and contralateral medial inferior cerebellar hemispheres, ipsilateral anterior inferior cerebellar artery (AICA) and superior cerebellar artery (SCA) territories, has not been described.

Design/Methods:

N/A

Results:

A 56-year-old male with hypertension presented with sudden-onset dizziness. Initial CT head revealed bilateral cerebellar infarction and CTA head and neck revealed a focal area of critical stenosis with sub-occlusive thrombus in the left (L) V4 area. He was emergently transferred to our comprehensive stroke center, where he was found to have an NIHSS of 33. Repeat imaging showed worsening mass effect, herniation and obstructive hydrocephalus requiring emergent intubation, suboccipital hemicraniectomy, and EVD placement.

MRI brain revealed a large confluent area of infarction involving the L inferior cerebellum, cerebellar vermis, L lateral medulla and L inferior cerebellar peduncle (L PICA territory), L superior cerebellum (L SCA), L middle cerebellar peduncle and inferolateral pons (L AICA) and medial R cerebellum (contralateral PICA). Despite his deficits on arrival, he was extubated successfully with subsequent uneventful EVD wean and remarkable preservation of neurologic exam. Further workup was significant for multifocal pulmonary emboli, deep vein thrombosis, and a large patent foramen ovale (PFO) with interatrial septal aneurysm.

Conclusions:

Herein, we present a rare case of a patient with multiple territories of infarction in the posterior circulation initially raising suspicion for multi-arterial involvement. However, the infarcts were confluent without sparing of interceding areas. Subsequent review of CTA revealed a single dominant L PICA artery occlusion, most likely caused by paradoxical embolization through PFO.