Abstracts

Rationale: The factors associated with the incidence of SEEG associated complications among pediatric populations has not been clearly established. We investigate whether decreased skull thicknesses among pediatric patients should limit traditional bolt-based anchoring of SEEG electrodes. Specifically, we describe the (1) safety profile, (2) complications, and (3) technical adaptations of placing SEEG electrodes in pediatric patients at our single-center experience.

Methods: We retrospectively reviewed all patients aged 12 or younger at time of SEEG implantation at our institution. Post-implantation computed tomography scans were used to measure skull thickness at the entry point of each SEEG lead.

Results: Patient demographics and skull thickness: A total of 53 patients under the age of 12 were reviewed. Patients’ ages ranged from 2 to 12 years old, and mean age was 8.8 ± 2.6 years old (IQR, 6.2-11.4 years). The average length of evaluation was 8 ± 4 days. An average of 13.0 electrodes were used for each patient, with 6.96 ± 4 electrodes located on the left side of the skull and 6.13 ± 5 electrodes on the right. The median skull thickness engaged by these electrodes was 4.1 mm (IQR, 3.15-5.2 mm). The thinnest skull thickness measured at electrode entry was 1 mm and the thickest was 24.4 mm. _x000D_
Complications: There were 5 complications in total. These patients had an average skull thicknesses within the IQR reported. One patient had a retained bolt fragment requiring surgical removal. This patient was 8 years old and had a skull thickness of 4.6 mm at the site of complication. A second patient had a small, asymptomatic, right temporal intracranial hemorrhage (ICH) after SEEG explantation and removal of bolts. This patient was 9 years old and had an average skull thickness at electrode implantation sites of 3.4 mm. Three patients had a thin, asymptomatic SDH. These patients had an average skull thickness of 4.3 mm at the electrode implantation sites. Two occurred after SEEG placement, and one SDH occurred after removal of the electrodes and bolts. One patient did have a 10-mm SDH but remained asymptomatic. During hospital stay, the patient progressively improved toward baseline, moving all extremities symmetrically in full strength, and didn’t require further treatment for the SDH. Patients with complications had 3.5 electrodes placed into thin skull (< 3 mm) on average, and those without complications had 2.9 electrodes placed into thin skull on average. This difference was not significantly different (p = .58).
_x000D_ Technical adaptations: One 2 year-old patient, with an average skull thickness of  3.8 mm (range, 2.0-4.9) at the point of entry, had all 8 SEEG electrodes anchored by suturing rather than bolt placement. _x000D_
Conclusions: Based on our experiences, we conclude that skull thickness need not be a roadblock for SEEG use among pediatric patients. In selected patients where skull bolt placement may be of concern, suturing electrodes to the scalp may be a suitable alternative. Further studies of factors influencing the safety of SEEG in the pediatric population should be performed.

Funding: Not applicable