A patient develops transient unique cerebral and cerebellar lesions after unruptured aneurysm coiling

Abstract

Background: We describe a case of a very unusual complication following a coiling procedure in which the patient developed transient unique cerebral and cerebellar lesions. Lesions were examined not only by magnetic resonance imaging (MRI) but also by positron emission tomography-computed tomography (PET-CT) and proton magnetic resonance spectroscopy ((1)H-MRS).

Case presentation: A 33-year-old woman presented an incidental 3.7 × 3.3-mm unruptured cerebral aneurysm (CAn) in her basilar artery, which was successfully coiled with balloon assistance. A follow-up brain MRI at 1 and 2 months showed a gradual increase in several white matter hyperintense lesions in the left cerebellar, bilateral occipitotemporal and left parietoccipital lobe during fluid-attenuated inversion recovery (FLAIR). These were the only lesions associated with perfused CAn. However, the patient did not show any additional symptoms such as visual disturbance throughout the entire course. (11)C-methionine-PET (MET-PET) showed an obvious increase in methionine uptake in the lesion corresponding to enhanced areas with gadolinium-enhanced MRI. MRS showed a decrease in the N-acetylaspartate/creatine (NAA/cr) ratio and a slight elevation of the choline/creatine (cho/cr) ratio and a lactate peak in the lesion. A follow-up MRI at 6 and 12 months showed a gradual decrease in the initial hyperintense lesions in FLAIR without any treatment.

Conclusion: We present a case of an unusual complication after a coiling procedure. Although it is difficult to identify this etiology without a pathological examination, it is importance to increase awareness of such a potential complication arising from coiling procedures, because interventional procedures have become the first choice of treatment for cerebrovascular diseases in many countries.

Figure 1

Findings of brain and spinal MRI, and angiography after the first admission for aneurysm coiling and after aneurysm coiling. No lesions were observed with axial slices of a fluid-attenuated inversion recovery (FLAIR) image (A-D). Brain MRA showed a 4 × 4 mm unruptured cerebral aneurysm (CAn) in the basilar artery located at the origin of the right superior cerebellar artery (E, arrowhead). Precoiling posterior angiography showed an unruptured CAn (F) and postcoiling angiography showed the occlusion of CAn and the patency of all vessels (G). After aneurysm coiling, left cerebellar, bilateral occipitotemporal, and left parietoccipital lobe lesions were observed with the axial slices of the FLAIR image (L-O, arrowheads) without a positive signal of the diffusion-weighted image (H-K, arrowheads) at 1 month after coiling, which expanded markedly in size at 2 months after coiling (P-S, arrowheads).

Figure 2

Brain MRI, PET-CT, and MRS findings at 4 months after coiling. 2-deoxy-2-[F-18]fluoro-D-glucose (FDG) and ¹¹C-methionine (MET) PET studies showed that glucose uptake in the lesion with hyperintense areas by FLAIR image (A-D, arrowheads) and enhanced areas by gadolinium-enhanced MRI (E-H, arrowheads) increased slightly or remained at the baseline level (I-L, arrowheads), whereas methionine uptake increased (M-P, arrowheads). ¹H-MRS showed a slight increase of the choline (cho) peak and a marked decrease of the N-acetylaspartate (NAA) peak with an elevated lactate peak in the lesion (Q-S).

Figure 3

Chronological changes of the brain MRI after the second admission. All lesions observed at 4 months after coiling (A-D, arrowheads) diminished gradually in size at 6 months (E-H, arrowheads) and at 12 months (I-L, arrowheads) after coiling.