Abnormal white matter changes after cerebral aneurysm treatment with polyglycolic-polylactic acid coils

Background: Polyglycolic-polylactic acid (PGLA) coils induce inflammation within a cerebral aneurysm, which in turn is hypothesized to decrease aneurysm recurrence. We present 2 patients, who after aneurysm coiling with PGLA coils, developed mild symptoms and extensive magnetic resonance imaging (MRI) white matter changes. Methods The first patient was a 46-year-old woman who underwent coiling of a 6.8 × 6.8 × 7.0-mm incidentally discovered basilar apex aneurysm. Approximately 1 month after her aneurysm coiling, she developed scintillating scotoma, and an MRI of her brain revealed bilateral white matter changes with punctate enhancement. The second patient, a 56-year-old woman, developed paresthesias and gait instability 1 month after retreatment of a ruptured 12 × 8-mm basilar tip aneurysm with stent assisted coiling. MRI of the brain also revealed bilateral white matter changes with punctate enhancement as well as an area of restricted diffusion in her pons. Results Both patients underwent aneurysm coiling with PGLA coils. An extensive clinical evaluation revealed no specific etiology. The patients' symptoms and MRI abnormalities improved spontaneously over a period of weeks. Conclusions Conclusions: After extensive evaluation for alternate causes of disease, we hypothesize that the patients' symptoms and MRI findings, which were not all within the territory supplied by the coiled vessel, were due to an overexuberant inflammatory response related to the PGLA coils. These cases highlight the importance of heightened clinical suspicion of neurologic complaints in the subacute period after aneurysm coiling. We recommend a low threshold for neuroimaging of these patients.