Central hypoventilation in a paediatric patient with angelman syndrome

Abstract

Introduction: Sleep problems are recognised to be a feature of Angelman syndrome (AS) but minimal is reported regarding sleep related breathing disorders in this population. We present an unusual case of a paediatric patient with AS presenting with altered consciousness and central hypoventilation Case Report: A 9-year-old female with AS presented with 1-week history of increasing sleepiness and lethargy. On initial assessment the patient was drowsy (GCS 10) with SpO2 desaturations to 84% and a compensated respiratory acidosis (PCO2 63mmHg, HCO3 33mmol/L). Relevant history was of tonic-clonic seizures treated with clobazam and sodium valproate. The patient was ventilated due to deteriorating conscious level (GCS 6) and underwent an urgent MRI brain, which showed no acute changes. Acute EEG showed changes consistent with AS but no evidence of non-convulsive status. Metabolic and infection screens were unremarkable but IV antibiotics were given as a precaution. A decision was also made to withhold clobazam. No obvious cause for the acute presentation was determined but the patient improved over a few days and was extubated to air. Persistent desaturations to low 80s and a noted respiratory rate of 8/min with episodes of apnoea led to a formal polysomnography (PSG). PSG diagnosed severe central hypoventilation with prolonged episodes of periodic breathing and a central apnoea index of 50.6/hr. Moderate obstructive disease was also noted (OAHI 5.5/hr). Adenotonsillectomy was undertaken and patient was commenced on non-invasive bilevel support with good effect in the sleep lab. Despite significant attempts by parents, treatment could not however be sustained at home due to behavioural challenges. Adjustments to anticonvulsants were also made during this time, changing from clobazam to levetiracetam and parents reported significant improvement in sleep and overnight respiratory pattern. Repeat PSG is planned to re-assess further following this change in medication. Discussion: In children with AS the focus is often on difficulties with sleep routines and circadian abnormalities. This case highlights the potential for significant sleep disordered breathing in AS. The possible contributing effect of anticonvulsant medications such as benzodiazepines also needs to be considered in children with AS with sleep disturbance.L6246118542018-11-01 <br />