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.