Angelman syndrome (AS) is characterized by a partial deficit of paired autosomal chromosome 15, which contains a subunit of the GABA receptor¹. Important considerations include the unpredictable effects of drugs that act on the central nerve system, epilepsy, the dominance of the vagal tone with potential refractory bradyarrytmia and airway difficulties. There were no incidents during surgery in our patient but the characteristics of the procedure can lead to intraoperative difficulties that the anesthesiologist should not underestimate. Our main objective is to transmit the basic knowledge through this case.
 We describe the general anesthesia of a 14 year-old patient with AS who underwent surgery for vagus nerve stimulation (VNS) due to unresponse to antiepileptic drug (AED) treatment. He had developmental delay, speech disorder, ataxia, microcephaly and myoclonus epilepsy. He was premedicated with midazolam, fentanyl and atropine and general anesthesia was induced with propofol and rocuronium and maintained with propofol and remifentanil. We could extubate the patient without reversal agents.
VNS with surgical placement is a treatment modality for medically refractory epilepsy². Stimulation at high intensities has a chronotropic effect on the heart. Bradycardia, complete atrio-ventricular block and ventricular asystole after initial left vagus nerve intraoperative stimulation have been reported in literature. Postoperative complications include seizures, peritracheal hematoma, vocal cord paralysis, hoarseness and dyspnea. Seizures should be considered in patients with delayed awakening.
There are few studies with AS patients and they show different results and recommendations³. Discrepancies involve hypersensitivity versus insensitivity to the hypnotics (both volatile and endovenous), benzodiazepines and neuromuscular blockers. AEDs must be maintained perioperatively, which can alter the metabolism of drugs related with cytochrome p450 enzyme. Medicines have different effects on seizure threshold and it should be avoided those who predispose patients to seizures, as ketamine² and enfluorane.
We must be cautious when we deal with an AS patient who has been programmed for a VNS implant. Pathology and surgery have different, but at the same time summative, mechanisms that can trigger the complications of this pathology more often than usual.

05 / Vagus nerve stimulator in a patient with Angelman Syndrome. A challenge for the anesthesiologist. A case report.