To report cases of CIDP-like neuropathy that were caused by inflammatory ischemic nerve injury

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is a treatable inflammatory neuropathy with well-defined diagnostic criteria but has no biomarker. A routine sensory nerve biopsy is generally not considered as part of diagnostic workup of CIDP unless the clinical presentation is atypical.  Microvasculitis and ischemic nerve injury was shown to be causative pathogenesis for lumbosacral radiculoplexus neuropathy (LRPN). The clinical, electrodiagnostic and laboratory abnormalities in LRPN differ from CIDP. However, in some cases of LRPN, a clinical picture of subacute, progressive symmetrical weakness in the lower extremities predominate similar to CIDP. Here we report two cases of CIDP-like neuropathy that had nerve biopsy showing perivascular inflammation and ischemic nerve injury.     

Case 1: a 62-year-old female had progressive painless weakness and numbness in both legs for 4 months.  Neurological examination showed severe leg weakness and sensory loss. Electrophysiologic studies revealed active axonal sensorimotor neuropathy. CSF protein was elevated on 2 occasions. She was diagnosed with CIDP and received IVIg for 7 months with only minimal response. Case 2: a 69-year-old female had neuropathic pain in both feet for one year and progressive distal leg weakness for 5 months.  Neurological examination showed bilateral foot drop and sensory loss. Electrophysiologic studies showed severe subacute sensorimotor neuropathy. CSF protein was elevated. She was diagnosed with CIDP and received IVMP weekly without benefits. Both cases had sural nerve biopsies showing similar findings of perivascular inflammatory infiltrates with multifocal fiber loss, perineurial thickening, neovascularization and injury neuroma suggesting microvasculitis and ischemic nerve injury.

Inflammatory ischemic nerve injury can be underlying pathogenesis in CIDP-like neuropathy. Lack of demyelination and unresponsiveness to a conventional immunotherapy may require a nerve biopsy to look further into an alternative cause.