Anaesthesia for Angelman syndrome

Vagal nerve stimulation for medically refractory epilepsy in Angelman syndrome: a series of three cases

BACKGROUND

We describe three children with Angelman syndrome and medically refractory epilepsy.

METHODS

Case series of three pediatric patients with Angelman syndrome and medically refractory epilepsy. All three patients failed medical treatment and were recommended for vagal nerve stimulator (VNS) implantation.

RESULTS

Following VNS implantation, all three patients experienced reduction in seizure frequency greater than that afforded by medication alone.

CONCLUSION

We present vagal nerve stimulator implantation as a viable treatment option for medically refractory epilepsy associated with Angelman syndrome.

Anesthetic Considerations for Angelman Syndrome: Case Series and Review of the Literature

Background

Angelman syndrome is a rare neurodevelopmental disorder characterized by intellectual disability, severe speech impairment, ataxia, seizures, happy demeanor, distinctive craniofacial features, high vagal tone, and gamma-amino butyric acid receptor abnormalities. The aim of this report is to review our experience of patients with Angelman syndrome undergoing anesthetic management.

Methods

We retrospectively reviewed perioperative course of patients with Angelman syndrome who underwent procedures under anesthesia from 2000 to 2016.

Results

Six patients with Angelman syndrome underwent 18 procedures; 14 performed under general anesthesia, and 4 with monitored anesthetic care, many for minor procedures (e.g., dental and diagnostic). Five patients had profound developmental delay and were nonverbal and 4 of them had epilepsy. The perioperative courses were uncomplicated except a 2 year-old girl having an intraoperative bronchospasm, a 16 year-old girl requiring flumazenil administration, and 28 year-old man who was electively intubated with a videolaryngoscope because of airway management concerns. No patients were documented as having postoperative pain.

Conclusions

Angelman syndrome patients often require anesthesia for relatively innocuous procedures, and their speech impairment and happy demeanor can confound postoperative pain assessment. Patients can have atypical responses to benzodiazepines. Craniofacial abnormalities can complicate airway management. Although not encountered in this series, anesthesiologists need to be aware that Angelman syndrome patients have developed malignant bradydysrhythmias while anesthetized.

Sedation with dexmedetomidine for conducting electroencephalogram in a patient with Angelman syndrome: a case report

INTRODUCTION

Angelman syndrome is characterized by severe mental retardation and speech and seizure disorders. This rare genetic condition is associated with changes in GABAA receptor. Patients with Angelman syndrome need to be sedated during an electroencephalogram ordered for diagnostic purposes or evolutionary control. Dexmedetomidine, whose action is independent of GABA receptor, promotes a sleep similar to physiological sleep and can facilitate the performing of this examination in patients with Angelman syndrome.

CASE REPORT

Female patient, 14 years old, with Angelman syndrome; electroencephalogram done under sedation with dexmedetomidine. The procedure was uneventful and bradycardia or respiratory depression was not recorded. The examination was successfully interpreted and epileptiform activity was not observed.

CONCLUSION

Dexmedetomidine promoted satisfactory sedation, was well tolerated and enabled the interpretation of the electroencephalogram in a patient with Angelman syndrome and seizure disorder.

Perioperative considerations in the patient with Angelman syndrome

Angelman syndrome arises by one of 4 genetic mechanisms. Patients often have craniofacial abnormalities, vagal hypertonia, skeletal muscle atrophy or underdevelopment, a history of seizure disorders, and pharmacodynamic unpredictability. Its pathogenesis, clinical manifestations, diagnosis and treatment options, and perioperative anesthetic considerations are presented.

Are children with Angelman syndrome at high risk for anesthetic complications?

OBJECTIVES/AIMS

To review seven children with Angelman syndrome (AS) undergoing 16 general anesthetics for both invasive and noninvasive procedures to determine if these children are at greater risk for anesthetic-related complications than the general population.

BACKGROUND

Children with AS may exhibit unpredictable responses to GABA agonists because of abnormal GABA receptors. These abnormal receptors may affect AS patients' responses to sedation and general anesthesia.

METHODS

The study design was a retrospective chart review of seven patients with AS who underwent a total of 16 general anesthetics for a variety of invasive and noninvasive procedures between the years 4/25/2005 and 12/31/2010. We reviewed the preoperative orders, anesthesia record and PACU records for preoperative medication orders and intraoperative and PACU adverse events.

RESULTS

We could not find documentation of complications attributed to the delivery of general anesthesia regardless of chromosomal defect, the use of GABA activating drugs, or a history of seizures. Six patients received a propofol-based anesthetic while 10 patients received potent inhalation agent for anesthetic maintenance. There were no statistical differences between the PACU lengths of stay (LOS) for AS patients as compared to the average PACU LOS for the 60 969 postprocedure patients cared for between 1/1/06 through 12/31/10.

CONCLUSIONS

We found no data to suggest that these patients demonstrate exaggerated responses to GABA stimulating drugs. In fact, it appears that regardless of the anesthetic agent, the perioperative course was unremarkable.

[Anesthesia and Angelman syndrome]

Angelman syndrome (AS) is a rare neurodevelopmental disorder with an incidence of 1:10,000-1:40,000 caused by deficient genetic imprinting in the chromosomal segment 15q11-q13. Experimental data suggest that the gamma-aminobutyric acid A (GABA(A)) receptor as well as the N-methyl-D-aspartate (NMDA) or α-amino-3-hydroxy-5-methyl-4-isoxazole proprionic acid (AMPA) receptors may be affected by this condition. The first description of the syndrome goes back to 1965 when the British pediatrician Harry Angelman (1915-1996) recognized similar clinical features in three children. Angelman's description of puppet children was changed to happy puppet syndrome 2 years later before this euphemistic denotation was replaced by the concept Angelman syndrome over the years. Angelman syndrome is characterized by ataxia, jerky movements especially hand flapping, a seizure disorder with a characteristic electroencephalogram (EEG), severe learning difficulties, a happy disposition, lack of verbal communication and dysmorphic facial features. Most hospitalizations are caused by epilepsy and the most common indications for surgical procedures are in dental medicine. The first anesthesiology case report to be published dates back to 2001. A total of 13 cases have now been published and in 11 cases the age was registered (mean age 11.6 years, standard deviation 11.7 and 2 outliers aged 27 and 40 years). In this paper, the published case reports are contrasted with 15 cases of anesthesia in 6 patients with AS who underwent surgery during 14 years of routine operations at a Berlin anesthesiology clinic (mean age 15.9 years, standard deviation 4.2 with no outliers). Besides neurosurgical and orthopedic operations most were dental interventions. Summarized, these cases of anesthesia and the results of the published case reports allow the formulation of guidelines for administration of anesthesia in AS cases but do not permit conclusions on which method of anesthesia is the safest for AS patients. For the preoperative consultation and anesthetization, communication with the patients requires the aid of parents or other relatives. Water and reflecting surfaces may be used to gain contact with AS patients. Patients with AS feel pain like any other person although they are frequently smiling and laughing and this has to be considered especially in major surgery (e.g. scoliosis surgery). The most important life-threatening complication is bradycardia due to vagal hypertonia which can lead to asystole with delayed response to atropine. None of the Berlin patients had severe bradycardia but the complication has to be taken into consideration. The use of drugs to ensure complete reversal of neuromuscular relaxation should be avoided because anticholinergic agents could cause bradycardia. The use of sugammadex in cases of AS has not been tested. To avoid elevation of the vagal tone, the indications for laparascopy have to be considered very carefully. There is no evidence that any drug or hypnotic may be more appropriate or advantageous. Balanced anesthesia and total intravenous anesthesia are possible but the duration of drug effect has to be taken into account. If ketamine is used the side-effects of the drug (psychomimetic reactions, muscular rigidity) should be prevented by the consistent administration of propofol, midazolam or thiopental. Usually AS patients are agitated so that regional anesthesia techniques are difficult to administer. If regional anesthesia does have considerable advantages over general anesthesia in a particular case, peripheral regional anesthesia should be preferred, especially because scoliosis is often present. There is no evidence that AS patients cause more intubation problems but because of facial dysmorphia accurate evaluation is needed in advance. This is even more important for older AS patients because the dysmorphia tends to accelerate during the course of life. Although epilepsy is the primary feature of AS, not every EEG alteration indicates the presence of epilepsy. The advantage in using neuromonitoring for measuring the depth of anesthesia is limited. Administration of anticonvulsants must be continued if they were used preoperatively.