Adverse events related to extraoperative invasive EEG monitoring with subdural grid electrodes: A systematic review and meta‐analysis

Abstract

Summary Purpose Implantation of subdural grids and invasive electroencephalography (EEG) monitoring is important to define the ictal‐onset zone and eloquent cortex in selected patients with medically refractory epilepsy. The objective of this systematic review is to summarize data about adverse events related to this procedure. Methods English‐language studies published up to July 2012, reporting such adverse events were reviewed. Outcome measures included demographic variables; surgical protocol including number of subdural electrodes implanted per patient, duration of monitoring, antibiotic, and steroid prophylaxis; and adverse events. Key Findings Twenty‐one studies were identified including a total of 2,542 patients. The reported mean number of electrodes per patient and duration of monitoring varied from 52 to 95 and 5 to 17 days, respectively. There is a trend toward more uniform use of antibiotics and steroids in the perioperative period. Neurologic infections (pooled prevalence 2.3%, 95% confidence interval 1.5–3.1), superficial infections (3.0%, 1.9–4.1), intracranial hemorrhage (4.0%, 3.2–4.8), and elevated intracranial pressure (2.4%, 1.5–3.3) were found to be the most common adverse events. Up to 3.5% of patients required additional surgical procedure(s) for management of these adverse events. Increased number of electrodes (≥67) was found to be independently associated with increased incidence of adverse events. Significance Although providing critical information for patients with medically refractory epilepsy, subdural grids implantation and invasive EEG monitoring entails risks of infection, hemorrhage, and elevated intracranial pressure. The prevalence estimates, likely to be conservative due to selective reporting, are expected to be helpful in counseling patients.

A Retrospective Analysis of Stereoelectroencephalography and Subdural Electroencephalography for Preoperative Evaluation of Intractable Epilepsy

“…Subdural EEG and SEEG are different approaches to iEEG. Both methods have advantages and disadvantages, and the choice between them is the subject of controversy [5,7,8,9]. Subdural electrodes are widely used given their extensive and intensive electrode points [2,10], whereas deep electrodes are useful due to their 3D characteristics and ability to record from deep structures [11,12,13].…”

Long-term outcomes of resective epilepsy surgery after invasive presurgical evaluation in children with tuberous sclerosis complex and bilateral multiple lesions

“…Recently, we have shown prolonged invasive monitoring to be associated with increased incidence of adverse events by 4% per day after 8 days of monitoring. 2 Hence, prolonged invasive monitoring on a raw surgical bed may be a factor that has limited wider adaptation of prolonged monitoring with subdural electrodes. 14 We expect that increasing experience in different institutions with diverse approaches will result in accumulation of outcome and safety data and probably lead to convergence of different surgical approaches to define the optimal strategy.…”

A meta‐analysis of complications of subdural electrode placement

“…We recently read with great interest an article by Arya et al 1 In this study, the authors conducted a PubMed search to identify studies that reported adverse events related to subdural electrode (SDE) implantation and invasive electroencephalography (EEG) monitoring. A total of 21 studies with 2,542 patients met the authors search criteria and were included in the systematic review and metaanalysis.…”

“…As mentioned in our Methods section, only those studies were excluded which reported patients with only depth electrodes. 1 We included the studies that provided data about both subdural and depth electrodes. The study by Tanriverdi et al 2 reports data from a total of 6,415 electrodes including 2,943 depth electrodes (45.9%) and 2,490 cortical electrodes (38.8%).…”