Subdural Effusion Evolves into Chronic Subdural Hematoma after Deep Brain Stimulation Surgery: Case Report and Review of the Literature

Abstract

Background: Although chronic subdural hematoma (CSDH) has been known for over several hundred years, the etiology and pathogenesis of it are still not completely understood. Neurosurgical procedures resulting in CSDH are a rare clinical complication, and there was no report about how subdural effusion (SDE) evolves into CSDH after deep brain stimulation (DBS) surgery. The formation mechanism of CSDH after surgery, especially in DBS surgery, and the effect of recovery, need to be explored.

Methods: We present two cases, complicated with SDE after DBS surgery, serious dysfunction complications such as hemiplegia and aphasia occurred on the postoperative day 36 and 49 individually, and images showed CSDH. Fusion image showed the bilateral electrodes were significantly shifted. Then, they were performed to drill craniotomy with a closed system drainage.

Result: The symptoms of hemiplegia and aphasia caused by CSDH were completely recovered, and the follow-up images showed CSDH was disappeared. However, DBS stimulation is poorly effective, it cannot reach the preoperative level, especially in the ipsilateral side of CSDH.

Conclusions: The iatrogenic SDE that evolved into CSDH in the present two cases shows that SDE is one of the causes of CSDH. Patients develop SDE after DBS, which increases the risk of developing CSDH. CSDH after DBS can be successfully treated. however, the postoperative efficacy of DBS will decline.

Keywords: chronic subdural hematoma (CSDH); deep brain stimulation (DBS); subdural effusion (SDE).

Figure 1

The change in MRI and CT images of the patient 1. (a) Conventional brain MRI, T2 image showed mild atrophy and dilation of the ventricles; (b) The image of the intraoperative 3 dimensional T1-weighted sequence showed no subdural effusion in bilateral frontal areas; (c) At 5 day after DBS surgery, CT shows a small amount of subdural effusion and pneumocephalus in the right frontal lobe; (d,e) At 36 days after DBS surgery, CT and T1 MRI images of the brain shows right chronic subdural hematoma, with the midline obviously shifted to the left, and a marked shift in electrode positioning; (f) At 2 days after drainage, CT shows that most of the hematomas were drained out and the electrode shift has been corrected.

Figure 2

The change in CSDH volume in pre- and post-operative evacuation in case 1. At 5 day after DBS surgery, CT shows the volume of subdural effusion (SDE) in the right frontal lobe was 6 ml; at 36 days after DBS surgery, the volume of right chronic subdural hematoma is 75 mL; at 2 days after drainage, residual hematomas volume was 15 mL; until day 60, the hematoma was completely absorbed.

Figure 3

MRI images in patient 2 before the formation of chronic subdural hematoma. (a,b) Preoperative MRI shows cerebral atrophy, and that the left subarachnoid space is wider than the right; (c–f) Five days postoperatively, MRI (3DT1 and T2 image)shows bilateral subdural effusion that is more obvious on the left side. The lateral ventricle is slightly reduced, and the fornix-hypothalamus electrode passes through the bilateral lateral ventricles.

Figure 4

The change in CT images in patient 2. (a) On the first day after deep brain stimulation (DBS), CT shows bilateral subdural effusion and pneumocephalus, more obvious on the left side; (b) At 49 days after DBS, CT shows a CSDH on the left side, and a slight contralateral shift of the midline; (c,d) Fused with the early CT, the bilateral electrodes are substantially shifted; (e) At 3 days after drainage, CT fusion shows that the electrode shift is corrected; (f) At 77 days after drainage, CT shows complete hematoma absorption.

Figure 5

The change in CSDH volume in pre- and post-operative evacuation in case 2. At 1 day after DBS surgery, CT shows the volume of subdural effusion (SDE) in the left frontal lobe was 13 mL; at 49 days after DBS surgery, the volume of right chronic subdural hematoma is 51 mL; at 3 days after drainage, residual hematomas volume was 18 mL; until day77, the hematoma was completely absorbed.

Figure 6

PRISM flowchart of the selection of the studies for this review.