partial anterior circulation infarct partial anterior circulation infarct partial anterior circulation infarct (paci) is a type of cerebral infarction affecting part of the anterior circulation supplying one side of the brain. partial anterior circulation infarctdiagram of the arterial circulation at the base of the brain (inferior view). anterior circulation represented by top half of diagram (with circle of willis).specialtyneurology partial anterior circulation stroke syndrome (pacs) refers to the symptoms of a patient who clinically appears to have had a partial anterior circulation infarct, but who has not yet had any diagnostic imaging (e.g. ct scan) to confirm the diagnosis. it is diagnosed by any one of the following 2 out of 3 features of higher dysfunction dysphasia visuospatial disturbances homonymous hemianopia motor and sensory defects (>2/3 of face, arm, leg) higher dysfunction alone partial motor or sensory defect if all of the above symptoms are present, a total anterior circulation infarct is more likely. for more information, see stroke.