Abstracts

Rationale: Paroxysmal Autonomic Instability with Dystonia (PAID) is a syndrome of intermittent agitation, diaphoresis, hyperthermia, hypertension, tachycardia and tachypnoea previously described in patients with traumatic brain injury. It is also known as 'autonomic storming'. We describe two females with Rett Syndrome (RS) and a male with Trisomy 21 (T21) with autonomic paroxysms. Although autonomic dysfunction in RS is well known, effective treatments are not well described. We believe these to be the first cases of successfully treated PAID described in patients with neurodisabling conditions. Methods: This is a case series of three patients with neurodevelopmental disorders who presented to Southampton University Hospital, UK for evaluation of worsening seizures. Results: Case 1 A 15 year old girl with classical RS was referred with increasingly resistant seizures over the preceding six years. Multiple anti-epileptic drugs (AEDs) were tried but prolonged episodes of tachypnoea, dystonia, pallor, tachycardia and sweating continued. 24 hour EEG showed no EEG changes during the episodes. Autonomic paroxysms were suspected and a trial of propranolol was commenced, wich lead to resolution of her symptoms. Case 2 A 12 year old girl with classical RS had a two year history of episodes of agitation, often with screaming. These episodes persisted despite dental extraction, multiple AEDs and optimal treatment of gastro-oesophageal reflux and constipation. A directly observed episode in paediatric outpatients consisted of pallor, sweating, tachycardia, agitation with an expression of fear and greatly increased hand-wringing. This led to a clinical diagnosis of autonomic storms and successful treatment with labetalol. Case 3 A three year old boy with Trisomy 21 was referred to our Paediatric Neurology ward with a reported increase in seizure activity. He initially presented aged sixteen months with epileptic spasms associated with hypsarrythmic EEG and normal MRI Brain. He was diagnosed with infantile spasms and treated with prednisolone, which rendered him seizure free for twelve months. On this admission, he had a two-week history of prolonged episodes of stiffening, arching and laboured breathing. Observation of the episodes showed dystonic posturing, tachypnoea, stertor, increased work of breathing and sweating. EEG during the episodes showed no epileptiform activity. PAID was suspected and propranolol and clonazepam were commenced with significant reduction in episode frequency. Two months later clonidine was added for breakthrough episodes, with a good therapeutic response. Conclusions: Paroxysmal episodes in patients with neurodisabling conditions are common. These can be due to a variety of causes and are frequently assumed to be epileptic in nature. In the presence of the clinical features described above and the absence of correlating activity on an EEG during the episodes, PAID should be considered as a likely cause. Carefully monitored treatment with beta-blockers or clonidine and/or clonazepam can provide significant improvement in this distressing condition.