When CIDP Isn’t Typical: Unraveling Polyneuropathy in Pediatric Patient with HERC1 Mutation

Case Diagnosis: Pediatric CIDP in patient with a genetic mutation

Case Description or Program Description: A pre-teen patient with a history of seizure disorder presented with persistent gait ataxia and predominantly distal weakness. History remarkable for Guillain-Barré syndrome diagnosed 2 years ago, based on clinical, radiological and serological evidence of AIDP. Patient made near full recovery with IVIG, corticosteroid and courses of physical therapy. Patient then developed a respiratory infection with significant functional decline requiring admission to PICU. Extensive diagnostic work up led to conclusion of chronic inflammatory demyelinating polyneuropathy.

Setting: Outpatient Pediatric Rehabilitation Clinic

Assessment/Results: Upon discharge, patient continued to exhibit diffuse weakness in lower extremities, absent deep tendon reflexes and poor balance. Patient required assisted device for ambulation and minimal to moderate assist for transfers. Weekly IVIG treatment had been initiated in conjunction with intensive physical therapy. Initial courses had led to improvement in clinical functional ability. However patient recovery was impeded by another respiratory infection with presence of predominantly distal weakness. Initial genetic study revealed HERC-1 mutation.

Discussion (relevance): CIDP is a rare pathology in children. Treatment guidelines are not well defined. There has not been a reported case of genetic neuropathy as a HERC-1 mutation phenotype. The presence of HERC-1 mutation may potentially affect myelination in the peripheral nervous system, raising possibilities as a complicating factor in this case. This presents a challenge in diagnosis and treatment in this patient who developed AIDP followed by CIDP with prolonged functional recovery.

Conclusions: Distinguishing the difference between pediatric CIDP from genetic neuropathy is crucial for guiding treatment. Unlike adult patients, there are no standardized guidelines for diagnosing pediatric CIDP. Physiatry holds an important role in intervention by preserving level of function through structured rehabilitation, adaptive strategies, and use of assistive devices, while ensuring continuous monitoring of progress to optimize long-term outcomes.