Prolonged Sinus Pauses Revealing A Paroxysmal Extreme Pain Disorder: Is It A Frequent Situation? A Case Report

Title : Paroxysmal extreme pain disorder (PEPD) is an autosomal dominant painful neuropathy with many,but not all, cases linked to gain-of-function mutations in  SCN9A which encodes voltage-gated sodium channel Na.1.7. It is a very rare condition featured by flushing of the lower half of the body and excruciating burning pain caused by any stimulus below the waist or in the perianal region. PEPD may be associated with cardiovascular instability, especially prolonged sinus pauses, and thus has anesthetic implications. Pacemaker implantation is the alternative therapeutic option, but its indications have not been clarified yet. Background: This condition is well described in neurological literature, but to our knowledge, this is the first case report of a patient with paroxysmal extreme pain disorder with prolonged sinus pauses requiring anesthesia for an epicardial pacemaker even with the peri-operative risk of the pathology.This clinical observation can help for a better management and understanding of the cardiac risk complications of PEPD especially for an infant whose diagnostic is frequently made at the stage of complication This clinical observation can put the item on the necessity of establishing recommendations for management of cardiac complications during PEPD. Case report : We extensively searched the literature on cardiac pacing in patients with PEPD and we described a new case of a 9 month old infant who was admitted in the emergency department for an episode of malaise apnea and hemifacial cyanosis relevant to PEPD. The neurologic exploration was normal. The diagnostic was confirmed by genetic study. The 24 hours recording demonstrated long pauses of 15 seconds during the crisis justifying the implantation of epicardial pacemaker without peri-operatory complications due to the high anesthetic risk of this pathology. Conclusion : Paroxysmal extreme pain disorder is a highly distinctive sodium channelopathy with incompletely carbamazepine-sensitive bouts of pain and sympathetic nervous system dysfunction. It is most likely to be misdiagnosed as epilepsy and, particularly in infancy, as hyperekplexia and reflex anoxic seizures. Clinicians must evocate this diagnostic even any clinical suspicion given the severity of  cardiac complications.