Article Figures & Data
Figures
- Figure 1.
Diagram of the video EEG digital radiotelemetry monitoring unit. The transceivers receive EEG data from the implanted transmitters via Bluetooth, which is connected via cables (not shown in diagram) to the communication link controller, which then communicates via cable to the computer that stores the data outside of the telemetry room. With three cameras, up to six pigs could be recorded with video at the same time with large pigs taking two pens in a total of eight pens. Pigs were separated for their weekly night of video EEG recording.
- Figure 2.
EEG implant and montage. A, The 59 × 38 × 15 mm EEG transmitter with electrodes exiting the top of the implant, the antennae projecting off the right of the implant, and tabs on the sides and bottom that are used to suture the implant in place. B, Pigs received bilateral cortical impact through the burr holes. The electrode array before the application of dental cement. C, A schematic of the three-channel bipolar montage with electrode sites (teal circles) centered around the sites of cortical impact (large blue circles). Black lines represent the sagittal and coronal sutures.
- Figure 3.
Interictal spikes and electrographic seizure on our three-channel array (channel 1, top trace; channel 2, middle trace; channel 3, bottom trace; Fig. 2C, montage). A, A simple spike. B, Complex spikes. C, A train of complex spikes. D, Clusters of waves with spikes. E, An electrographic seizure accompanied by tonic-clonic convulsions.
- Figure 4.
Artifact on our three-channel array (channel 1, top trace; channel 2, middle trace; channel 3, bottom trace; Fig. 2C, montage). A, High-amplitude artifact was observed while the animal was playing with a toy or during a vigorous head shake (not shown). B, High-amplitude artifact in response to anticipation of feeding (including jumping up on side of pen) followed by low-amplitude muscle artifact of eating.
- Figure 5.
Still images of behavior recorded on video. A–C, This subject displayed an array of stereotypical automatisms including yawning (A, B) the tongue out before tonic-clonic convulsions (C). C, One round of a tonic-clonic convulsion with legs extended (left) and then legs relaxed with the head back (right) with the animal laying on its side.
- Figure 6.
The evolution of screw location. A, B, Because of the significant accretion of skull over time with the development of the nuchal ridge, screws initially placed to just contact the dura eventually were completely embedded within the skull (A; arrow), exposed to air in the sinuses, or embedded within the brain (B; arrow; ruler units = centimeters). Screw indentations were observed in both swine that did and did not develop PTE and did not appear to be a cause of PTE.
Tables
Event Age (months) Weight (kg) Time after cortical
impact (months)Number Cortical impact or
sham surgery4.92 ± 0.37 (3.1–5.5) 21.5 ± 2.8 (16–25) N/A N = 13: 10 injured, 3 shams
(8 implanted at the time
of cortical impact)Implantation of EEG for those
not implanted at the time of
cortical impact10.45 ± 1.2 (8.4–11.6) 43.2 ± 2.6 (36–47.5) 6.43 ± 0.64 (4–6) N = 5 Killing after development of
PTE was detected13.1 ± 4.1 (7–16) 68.0 ± 12.7 (53– 84) 9.2 ± 2.5 (5.6–11.4) N = 4 Scheduled killing: did not or
did not develop PTE17.6 ± 0.7 (16.3–18.5) 82.3 ± 9.4 (62– 92) 12.4 ± 1.0 (11.5–14.2) N = 9 Values are average ± SD (range), unless otherwise indicated.
- Table 2
Procedures and medications initiated to prevent infection above and beyond standard large-animal survival surgery standards
Measures Description Preoperative measures All surfaces of the operating room including the walls and ceiling were sanitized with Quatricide PV-15 (Pharmacal) prior to each surgery Swine received a Hibiclens (chlorhexidine gluconate) bath over the entire body the day before and the day of surgery All hair clipping was performed before entering the OR Feet were wrapped with Vetrap before entering the OR Xeroform Petrolatum gauze inserted in the ears Head, ears, and neck were washed with 2% chlorhexidine wipes before entering the operating room Staff replaced all personal protective equipment before entering OR Additional scrub and drape measures Ears were wrapped with sterile Vetrap Tegaderm was placed over the top of the snout, over the eyes, and around the ears creating a perimeter around the surgical site on the head A dedicated scrub pack was used separate from the instrument pack with the surgeon rescrubbing/regowning after scrub Three-step scrub instead of two-step scrub: incision sites prepped with 70% ethanol then with betadine using gauze held with a dedicated scrub hemostat, then with a ChloraPrep wand Three layers of drapes instead of two: sterile Steri-Drapes were placed around the incision sites then site was covered by Ioban then with a large split-sheet sterile drape placed over the entire surgical area Prophylactic antibiotics Vancomycin (10–20 mg/kg, i.v.) infused over 30 min prior to the first incision Cephalexin (10–20 mg/kg, orally) three times/d for 7 d Other Using dedicated instruments for the neck site (not used at the head site) and a new pair of surgical gloves to handle the EEG transmitter All instruments were heat/pressure sterilized as possible. Chemical sterilization with ethylene oxide was not used The EEG transmitter was prevented from touching the skin of the pig by adding new drapes and packing sterile gauze around the incision site Surgical sites were heavily irrigated with sterile saline prior to closing Postsurgically, the skin of the pig was oiled regularly to prevent irritation and scratching Placards placed on the swine pen indicated areas approved for scratching by caretakers avoiding incision sites OR, Operating room.
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