Facial Paresthesia, a Rare Manifestation of Hereditary Neuropathy With Liability to Pressure Palsies: A Case Report

Trigeminal sensory neuropathy can be caused by a variety of conditions, including local, traumatic, iatrogenic, or systemic causes. Diagnosis and management remain a challenge for maxillofacial surgeons and neurologists. Therefore, a good clinical examination and objective tests and imaging are needed when diagnosing patients who present with facial numbness. We present a case with spontaneous episodes of facial paresthesia. He was diagnosed with hereditary neuropathy with liability to pressure palsies (HNPP), a rare condition that affects the peripheral nerves. Only a few case reports that describe involvement of the cranial nerves in patients with HNPP were found in the literature, and facial paresthesia has not been previously reported.

Hereditary neuropathy with liability to pressure palsies: a case report

Hereditary neuropathy with liability to pressure palsies (HNPP) is a rare hereditary disorder characterized by recurrent episodes of nerve compression. The first attack usually occurs in the second or third decade of life. In the majority of cases, HNPP is associated with a mutation at chromosome 17 p11.2-12 comprising the gene encoding peripheral myelin protein 22 (PMP22). Here we present a case report of a 43-year-old male with HNPP confirmed by DNA testing. The patient complained of recurrent episodes of bilateral foot extensor muscles weakness and/or hyperesthesia on the outer surface of the hands and forearms, which started after a prolonged posture maintaining and without evident precipitating factors. We also describe typical clinical, electrophysiological, and nerve ultrasound characteristics of the disease.

A New Point Mutation in the PMP22 Gene in a Family Suffering From Atypical HNPP

Hereditary neuropathy with liability to pressure palsies (HNPP) is an autosomal dominant inherited disorder commonly presenting with acute-onset, non-painful focal sensory and motor mono neuropathy. In 80% of cases, the genetic defect is a 1.5 Mb deletion on chromosome 17p11.2, including PMP22. Only few cases of partial deletion and point mutations in PMP22 are involved in HNPP. We investigated a 62-years-old man with lower limb plexopathy first considered as Garland’s syndrome. A month later, his 29 years old son also consulted for paresthesia on the peroneal nerve. Targeted sequencing of the PMP22 gene identified a c.370delT (p.Trp124Glyfs*31) in both affected patients. We report a new PMP22 point mutation associated with an atypical clinical phenotype of HNPP, a painful plexopathy of the lower limb worsenen by diabetes and a mere paresthesia, but a typical ENMG. This study illustrates the large spectrum of the disease, and emphasizes the importance of a complete ENMG and family history.