Sarcoid Polyneuropathy Masquerading as Chronic Inflammatory Demyelinating Polyneuropathy

Introduction: Sarcoid polyneuropathy is a rare and clinically heterogeneous disorder that may be the initial presentation of sarcoidosis. Methods: We report the clinical, electrophysiological, and pathological findings of a patient who carried a diagnosis of sensory-predominant chronic inflammatory demyelinating polyneuropathy (CIDP) for over a decade but was ultimately found to have sarcoid polyneuropathy. Results: A 36-year-old man presented with a several-week history of gait difficulty and muscle cramps. He had a diagnosis of CIDP but had not received lasting benefit from steroid-sparing immunosuppressive drugs. Electrodiagnostic studies were consistent with a chronic demyelinating polyradiculoneuropathy with conduction blocks. After he developed systemic symptoms, tissue biopsies revealed granulomatous disease. Symptoms improved with steroid therapy. Conclusions: Sarcoid polyneuropathy presents a diagnostic challenge, but, in patients with atypical neuropathy, characteristic systemic symptoms, or a poor response to standard treatment, nerve and muscle biopsies can help diagnose this treatable disorder. Muscle Nerve 52: 664–668, 2015 Sarcoidosis is a rare multisystem granulomatous disorder that typically affects lungs, lymph nodes, skin, and eyes. It affects women more commonly than men, with a prevalence of approximately 10 in 100,000 in Caucasian populations and approximately 35 in 100,000 in African Americans. Clinical involvement of the central or peripheral nervous system occurs in 5%–15% of cases, although there is likely a significant proportion of subclinical neurosarcoidosis cases. Isolated neurosarcoidosis without systemic signs may occur in 20% of patients with neurological involvement. The most common neurological manifestations of sarcoidosis include optic neuritis, cranial neuropathies, and myelopathies. Peripheral polyneuropathy is rare, although there have been reports of acute Guillain–Barr e syndrome (GBS)-like presentations, focal or multifocal axonal polyneuropathies, and demyelinating polyneuropathies. Peripheral nervous system involvement is usually accompanied by systemic signs of sarcoidosis, but sometimes it is the presenting symptom. We report the clinical course and histological findings of a patient with sarcoid polyneuropathy masquerading as chronic inflammatory demyelinating polyneuropathy (CIDP).