An Unusual Case of Peripheral Nerve Vasculitis

Area of Science:

• Neurology
• Immunology
• Vascular Medicine

Background:

• Peripheral neuropathy is a known complication of systemic vasculitis.
• Systemic vasculitic neuropathy (SVN) typically involves medium and small vessels, presenting as multifocal, distal symmetric, or overlapping neuropathy.
• Distal symmetric polyneuropathy, or stocking-glove pattern, is a common presentation of SVN.

Observation:

• A 73-year-old woman presented with acute-on-chronic, bilateral upper and lower extremity weakness, sensory changes, and pain.
• Clinical findings included elevated ESR, CRP, c-ANCA, PR3, and creatine kinase (CK), along with purpuric lesions and distal gangrene.
• Electromyography (EMG) revealed severe, distal symmetric axonal polyneuropathy with acute denervation, which is unusual for ANCA-associated vasculitis.

Findings:

• The patient's presentation of widespread symmetric polyneuropathy was atypical for ANCA-associated systemic vasculitis.
• The rapid progression and severity of neuropathy on EMG were unexpected.
• Muscle biopsy showed neurogenic atrophy without myositis.

Implications:

• This case underscores the importance of considering atypical presentations of SVN, even when symptoms deviate from classic patterns.
• Early recognition and appropriate treatment, including steroids and rituximab, are crucial for managing severe vasculitic neuropathy.
• Further research may be needed to understand the mechanisms behind rapidly progressive and severe neuropathies in ANCA-associated vasculitis.