Placement of leads for stereotactic electroencephalography without the use of anchor bolts: technical note

Abstract

OBJECTIVEStereotactic electroencephalography (SEEG) is an increasingly common technique that neurosurgeons use to help identify the epileptogenic zone. The anchor bolt, which typically secures the electrode to the skull, can be problematic in very thin bone or in electrodes placed in the occiput.METHODSA technique is described to place electrodes without the use of an anchor bolt. Accuracy data for entry point, target point, and depth were collected and compared between electrodes placed with and those placed without an anchor bolt.RESULTSA total of 58 patients underwent placement of 793 electrodes, of which 25 were boltless. The mean entry and depth errors at target were equivalent, although there was a trend toward greater depth error with boltless electrodes (3.4 mm vs 2.01 mm and 2.59 mm in the bolted groups, respectively). The mean lateral target error was slightly but significantly smaller for boltless electrodes. The majority (60%) of boltless leads were placed into thin temporal squamous bone. The average skull thickness at the entry point for all boltless leads was 1.85 mm.CONCLUSIONSBoltless SEEG electrodes can be placed through thin bone, adjacent to a cranial defect, or in the occiput with equivalent accuracy to electrodes placed with anchor bolts.

Stereoelectroencephalography in the very young: Case report

“…SEEG has generally been avoided in the very young. Among series of SEEG involving pediatric patients, the overall reported age range has been 20 months to 69 years [1] , [4] , [5] , [6] , [7] , [8] , [10] , [11] , [12] , [13] , [14] , [15] , [16] , [18] , [19] , [20] , [21] . Five groups have included patients under three years old, and four groups under two years old, with the youngest patient reported being 20 months old, three months older than our patient [8] , [11] , [18] , [19] .…”

“…Concern has also been raised regarding the security of the electrode bolts in thin skull post-operatively. Pediatric epilepsy neurosurgeons have reported a variety of techniques to avoid use of bolt fixation [17] , [21] .…”

Surgical evaluation in children <3 years of age with drug‐resistant epilepsy: Patient characteristics, diagnostic utilization, and potential for treatment delays

“…Additionally, many centers have started to safely and successfully perform stereo-EEG for seizure localization in very young children with modified surgical techniques to address concerns regarding skull thickness. [23][24][25][26][27] With knowledge of some of the logistic barriers or inherent limitations to testing in this age group, careful selection of ancillary testing tailored to the patient may help identify appropriate surgical candidates and reduce lag time between the development of drug resistance and eventual surgery.…”

“…This is the population that might best benefit from a more comprehensive evaluation, which may include ancillary testing that has been less utilized in this age group. Additionally, many centers have started to safely and successfully perform stereo‐EEG for seizure localization in very young children with modified surgical techniques to address concerns regarding skull thickness 23–27 …”

Letter to the Editor. Boltless stereoelectroencephalography: a necessity in very young children

“…TO THE EDITOR: We read with interest the article by Karsonovich et al 1 (Karsonovich T, Alexander A, Graber S, O'Neill BR. Placement of leads for stereotactic electroencephalography without the use of anchor bolts: technical note.…”