Elizabeth A. Eldredge

The effect of propofol on intraoperative electrocorticography and cortical stimulation during awake craniotomies in children

Propofol has been proposed as a sedative agent during awake craniotomies. However, there are reports of propofol suppressing spontaneous epileptiform electrocorticography (ECoG) activity during seizure surgery, while others describe propofol‐induced epileptiform activity. The purpose of this study was to determine if propofol interferes with ECoG and direct cortical stimulation during awake craniotomies in children. Children scheduled for awake craniotomies for resection of epileptic foci or tumours were studied. An intravenous bolus of 1–2 mg·kg−1 followed by infusion of 100–200 μg·kg−1·min−1 of propofol was administered to induce unconsciousness. Fentanyl (0.5 μg·kg−1) was administered incrementally to provide analgesia. After the cortex was exposed, the propofol infusion was stopped and the patient permitted to awaken. Cortical electrodes were applied. ECoG was recorded continuously on a Grass polygraph. Motor, sensory, language, and memory testing were done throughout the procedure. The cortex was stimulated with a hand‐held electrode using sequential increases in voltage to map the relevant speech and motor areas. We studied 12 children (aged 11–15 years) with intractable seizures. The raw ECoG did not reveal any prolonged β‐waves associated with propofol effect. Electroencephalogram spikes due to spontaneous activity or cortical stimulation were easily detected. Cognitive, memory and speech testing was also successful. We conclude that propofol did not interfere with intraoperative ECoG during awake craniotomies. Using this technique, we were able to fully assess motor, sensory, cognitive, speech and memory function and simultaneously avoid routine airway manipulation.

Stereotactic craniotomy: methods and results using the Brown-Roberts-Wells stereotactic frame.

Combining the power of stereotactic precision with open craniotomy in a stereotactic craniotomy technique decreases surgical time, morbidity, and postoperative hospitalization. Indications for its use are deep intrinsic masses 3.5 cm or less in diameter; small, superficial lesions otherwise difficult to localize; and lesions associated with motor, visual, or speech areas. Using the standard Brown-Roberts-Wells system allows a) precisely planned cortical entries, b) gross total lesion excisions under direct vision, c) use of probe-guided resection margins, d) small craniotomies through linear incisions, and e) use of local anesthetic alone for resections. The method and results of this universally available and relatively inexpensive technique are discussed in reference to 20 patients.

Neurologic complications of cerebral angiography in childhood moyamoya syndrome.

Purpose. To determine the incidence of neurologic complications of cerebral angiography in children with moyamoya syndrome (MMS) as compared to children without MMS. Materials and methods. One-hundred-ninety consecutive cerebral angiograms obtained in 152 children were evaluated. Sixty of these angiograms were obtained in 40 children with MMS. Patients underwent neurologic evaluation prior to and after the procedure. For this study, a neurologic complication was defined as any new focal neurologic deficit or alteration in mental status occurring during the procedure or within the ensuing 24 hours. Results. There were 2 neurologic complications within 24 hours of angiography, one in the MMS group and one in the non-MMS group. One patient with MMS became mute following angiography. The symptom resolved within 12 hours. One patient without MMS being examined postoperatively for residual arteriovenous malformation developed intracranial hemorrhage requiring reexploration 12 hours after the angiogram. Using a two-tail Fishers exact test, there was no significant statistical difference in the ischemic (P = 0.3) or hemorrhagic (P = 1.0) complication rates between the group of patients with MMS and the non-MMS groups. Conclusion. The risk of a neurologic complication from cerebral angiography in children with MMS is low and not statistically different from the risk in children with other cerebrovascular disorders.

Anaesthetic management of children with tuberous sclerosis

Summary Background: Tuberous sclerosis (TS) is a hamartomatous disease that usually presents with cutaneous and intracranial lesions, but can also affect other organ systems.

Perioperative considerations in a hypothyroid infant with hepatic haemangioma

Hepatic haemangiomas in infants are rare. An infant with both a hepatic haemangioma and a severe hypothyroid condition, unresponsive to conventional thyroxine therapy, will be described. This case presented here is the perioperative management of a critically ill infant who had myocardial depression secondary to hypothyroidism and a hepatic haemangioma that required embolization. To our knowledge, this is the first published report describing intravenous triiodothyronine as a therapeutic modality to stabilize a hypothyroid infant prior to undergoing a general anaesthetic.