Here we present a case of cerebral foreign body reaction (CFBR) with resultant punctate strokes in a middle‐aged man caused by a flow diverting stent (FDS). The patient initially presented due to spontaneous SAH with extensive intraventricular involvement and severe hydrocephalus Hunt Hess 5, modified Fisher 2. An FDS was placed after an incidental carotid cave aneurysm was identified on further workup of the SAH. Following placement of the FDS, the patient experienced disorientation, confusion, and aphasia. Subsequent MRI demonstrated multifocal restricted diffusion bilaterally and punctate foci of enhancement on T1 sequences in the bilateral cerebral hemispheres. Infectious, metabolic and malignancy workups were unremarkable. CSF was significant for only a mild elevation of nucleated cells (7) with lymphocytic predominance, normal protein and glucose. A diagnosis of CFBR was made and the patient was given a trial of IV methylprednisone for 3 days with monitoring of clinical response and, after demonstration of clinical improvement, continued on an oral prednisone taper over 2 months. At his follow up visit, repeat MRI demonstrated resolution of previously identified punctate infarcts and regions of enhancement and his clinical exam demonstrated full return to cognitive baseline. Although rare, perivascular inflammation in the setting of a recently placed stent with hydrophilic polymer coatings should raise suspicion for foreign body reaction. Early recognition of this syndrome is important for stroke and endovascular specialists as it will avoid unnecessary further workup and initiation of appropriate treatment. In this case, clinical improvement was observed following a course of steroids.
Miller et al. (Sat,) studied this question.