Hereditary neuropathy with liability to pressure palsies in childhood: case series and update from the literature

Introduction: HNPP presentation in childhood is rare and diverse and most of the published literature is based on case reports. Materials and Methods: we analyzed the data of 11 children with deletion in PMP22 gene, reviewed the published reports of HNPP in children and compared our data with the reports from the literature review. Results: Peroneal palsy was the most common presentation (50%) followed by the brachial plexus palsy in 30% of cases. The trigger of the demyelinating event was identified only in 27%. 72% of our cohort developed only one acute episode of nerve palsy. Nerve conduction studies were always suggestive of the diagnosis demonstrating 60% of cases a polyneuropathy, 50% of cases conduction block but 100% of bilateral or unilateral electrophysiologic entrapment of the median nerve at the carpal tunnel. Conclusion: The clinical presentation of HNPP in childhood is heterogeneous and EMG findings are abnormal. Any unexplained mononeuropathy or multifocal neuropathy should lead to PMP22 gene testing to look for the deletion. Early diagnosis is important for the genetic counselling but also for the appropriate care of these patients.