Acute-onset chronic inflammatory demyelinating polyneuropathy with anti-neurofascin-155 antibodies and bilateral facial nerve enhancement.

A 26-year-old female presented with acute onset distal paraparesis, upper limb tremor and bilateral facial palsy. Neurophysiology revealed a sensorimotor demyelinating polyneuropathy and lumbar puncture revealed an albuminocytologic dissociation. Neuroaxis MRI revealed bilateral facial nerve and cauda equina enhancement. Initially diagnosed as Guillain-Barré Syndrome, poor response to intravenous immunoglobulin, persistent deterioration, anti-neurofascin-155 antibodies and clinical response to steroid therapy led to diagnosis of acute-onset chronic inflammatory demyelinating polyneuropathy (CIDP). CIDP patients with anti-neurofascin-155 antibodies are younger, with distal predominant weakness, tremor, and poor response to intravenous immunoglobulin. Up to 16% can present acutely, however bilateral facial weakness is rare.