Lesion Location-Based Prediction of Visual Field Improvement after Cerebral Infarction.

BACKGROUND: Although the prognosis of ischemic stroke is highly dependent on the lesion location, it has rarely been quantitatively utilized. We investigated the usefulness of regional extent of ischemic lesion (rEIL) predicting the improvement of visual field defect (VFD) in patients with posterior cerebral artery infarction. METHODS: The rEILs were measured in each individual cortex after transforming the lesions to a standard atlas. Significant improvement of VFD was tentatively defined as 20% improvement at 3 months after stroke. The performances of clinical and imaging variables predicting significant improvement were measured by support vector machine. The maximum performance of variables predicting the significant improvement was compared between subgroups of variables (clinical, baseline severity and lesion volume) and the effect of adding rEIL to those subgroups of variables was evaluated. RESULTS: A total of 35 patients were enrolled in this study. Left PCA infarct, MR-time from onset, rEILs in the lingual, calcarine, and cuneus cortices were good prognostic indicators of hemi-VFD (performance for predicting the significant improvement: 72.8±11.8%, 66.1±11.2%, respectively). A combination of the rEILs of each cortical subregions demonstrated a better predictive performance for hemi-VFD (83.8±9.5%) compared to a combination of clinical variables (72.8±11.8; p<0.001), baseline severity (63.0±11.9%; p<0.001), or lesion volume (62.6±12.7%; p<0.001). Adding a rEIL to other variables improved the prognostic prediction for hemi-VFD (74.4±11.6% to 91.3±7.7%; p<0.001). CONCLUSIONS: An estimation of rEIL provides useful information regarding the ischemic lesion location. rEIL accurately predicts the significant improvement of VFD and enhances the prediction power when combined with other variables.

Beyond textbook neuroanatomy: The syndrome of malignant PCA infarction.

Given its limited vascular territory, occlusion of the posterior cerebral artery (PCA) usually does not result in malignant infarction. Challenging this concept, we present 3 cases of unilateral PCA infarction with secondary malignant progression, resulting from extension into what would classically be considered the posterior middle cerebral artery (MCA) territory. Interestingly, these were true PCA infarctions, not "MCA plus" strokes, since the underlying occlusive lesion was in the PCA. We hypothesize that congenital and/or acquired variability in the distribution and extent of territory supplied by the PCA may underlie this rare clinical entity. Patients with a PCA infarction should thus be followed closely and offered early surgical decompression in the event of malignant progression.

Clinical characteristics and rehabilitation outcomes of patients with posterior cerebral artery stroke.

OBJECTIVES: To describe the demographics, clinical profile, and functional outcomes in posterior cerebral artery (PCA) stroke and to identify factors associated with functional change during rehabilitation and discharge disposition. DESIGN: Retrospective study of patients with PCA stroke admitted to a rehabilitation hospital over an 8-year period. SETTING: Free-standing urban rehabilitation hospital in the United States. PARTICIPANTS: Eighty-nine consecutive patients with PCA stroke (48 men, 41 women; mean age, 71.5y) met inclusion criteria. INTERVENTION: Inpatient multidisciplinary comprehensive rehabilitation program. MAIN OUTCOME MEASURES: Demographic, clinical, and discharge disposition information were collected. Functional status was measured using the FIM instrument, recorded at admission and discharge. The main outcome measures were the discharge total FIM score, the change in total FIM score (DeltaFIM), and the discharge disposition. Multiple and logistic regression analyses were performed to identify factors associated with the main outcome measures. RESULTS: The most common impairments were motor paresis (65%), followed by visual field defects (54%) and confusion or agitation (43%). The mean discharge total FIM score +/- standard deviation was 88.3+/-28.2. The mean DeltaFIM was 23.3+/-16.4. Fifty-five (62%) patients were discharged home. On multiple regression analysis, higher admission total FIM score, longer length of stay (LOS), and a rehabilitation stay free of interruptions were associated with higher discharge total FIM score and greater DeltaFIM. Absence of diabetes mellitus and younger age were also associated with higher discharge total FIM scores, and male sex had greater DeltaFIM. On logistic regression analysis, younger patients, higher discharge FIM scores, presence of a caregiver, and the nonnecessity for 24-hour support were associated with a discharge to home. CONCLUSIONS: Motor, visual, and cognitive impairments are common in PCA stroke, and good functional gains are achievable after comprehensive rehabilitation. Higher admission FIM scores, longer LOS, and younger and male patients were associated with better functional outcomes. Most patients were discharged home, particularly those with caregivers and those for whom 24-hour support was not required. Further research should aim at the development of functional outcome measures of greater breadth and sensitivity to visual and cognitive deficits and should compare PCA stroke outcomes with outcomes of strokes in other vascular territories.