Acute bilateral PCA territory infarction with a large olfactory groove meningioma
Presentation
A known hypertensive presented with a sudden loss of consciousness, GCS 3/15.
Patient Data
There are areas of T1 hypointensities, T2/FLAIR hyperintensities in the cortical and subcortical regions of the occipital lobes, posteromedial temporal lobes, thalami, and the midbrain (bilateral PCA territory). It shows restricted diffusion on DWI and corresponding ADC. There is no appreciable enhancement post gadolinium administration. This appearance is consistent with acute infarction.
MRA shows stenosis/ occlusion of the PI segments of PCA worse on the left with non-visualization of bilateral PCOM arteries.
There is a well-defined extra-axial mass (measuring 71x68x49 mm in its widest dimensions) with lobulated margins arising from the olfactory groove and floor of the anterior cranial fossa, extending to the suprasellar region. It appears heterogeneous but predominantly isointense on T1 and T2 sequences and shows heterogeneous avid enhancement post gadolinium administration. It also demonstrates the characteristic spoke wheel appearance on T2 and T2* sequences. It shows patchy areas of diffusion restriction on DWI and corresponding ADC. There is extensive vasogenic edema in the frontal lobes extending into the parietal lobes. The mass shows the white mater buckling sign and CSF cleft sign confirming its extra-axial location. It exerts a positive mass effect on the frontal lobes, midbrain and effaces the lateral and third ventricles.
Case Discussion
This case illustrates acute bilateral PCA infarction in a known hypertensive patient who presented with a sudden loss of consciousness. MRI also shows an incidental finding of a large olfactory groove meningioma. Prior to the presentation, the patient had no symptoms of an intracranial space-occupying lesion. Meningiomas may be found incidentally and entirely asymptomatic 1.Though larger tumors present with symptoms of SOL such as headache, paresis, or change in mental status.
Mass effect from the large meningioma may be the possible cause of the bilateral PCA territory infarction in this patient. The PCAs arise below the tent and have to get above it to get to the occipital lobes, so they get pinched against it and get occluded.