What is the appropriate workup and treatment for a patient suspected of having Chronic Inflammatory Demyelinating Polyneuropathy (CIPD)?

Workup for Chronic Inflammatory Demyelinating Polyneuropathy (CIDP)

Begin with electrodiagnostic studies (nerve conduction studies and EMG) as these are mandatory for diagnosis, showing characteristic demyelination patterns including reduced conduction velocities, temporal dispersion, and conduction blocks. 1

Clinical Presentation to Confirm

• Progressive weakness and sensory loss evolving over at least 8 weeks (this timeline distinguishes CIDP from Guillain-Barré syndrome) 1
• Large-fiber abnormalities predominate: weakness affecting both distal and proximal muscles, ataxia, and reduced/absent deep tendon reflexes 2
• Symmetric motor-predominant pattern is most common (72% of cases), though asymmetric multifocal presentations occur in 28% 3
• Small-fiber symptoms (pain, autonomic dysfunction) are less common but can occur 2

Essential Diagnostic Testing

Electrodiagnostic Studies (First Priority)

• Nerve conduction studies and EMG are mandatory and show slowed conduction velocities, temporal dispersion, and conduction blocks characteristic of demyelination 1, 2
• These studies differentiate CIDP from axonal neuropathies and other mimickers 1

Cerebrospinal Fluid Analysis

• Perform lumbar puncture looking for albuminocytologic dissociation: elevated protein (typically >45 mg/dL) with normal or mildly elevated white blood cell count 1
• Marked pleocytosis suggests alternative diagnoses 4

MRI Imaging

• Obtain MRI of entire spine with and without contrast to rule out compressive lesions and evaluate for nerve root enhancement/thickening 1
• This is critical because 47% of motor CIDP patients have associated inflammatory, infectious, or neoplastic conditions 1
• Consider MRI brain if cranial nerve involvement is present 4

Comprehensive Serum Testing

• Screen for CIDP mimickers and reversible causes: 1, 4
  • HbA1c (diabetes screening)
  • Vitamin B12 and folate levels
  • TSH (thyroid function)
  • HIV testing
  • Serum protein electrophoresis with immunofixation (to detect monoclonal gammopathies) 1
• Additional testing based on clinical suspicion: 4
  • ANA, ESR, CRP, ANCA for vasculitic screening
  • Anti-ganglioside antibodies if acute-onset presentation
  • Paraneoplastic antibody panel (anti-Hu/ANNA-1)

Important Diagnostic Considerations

Timing and Pattern Recognition

• Symptoms must evolve over at least 8 weeks to meet CIDP criteria (versus acute inflammatory demyelinating polyneuropathy/Guillain-Barré syndrome which evolves over days to 4 weeks) 1
• Treatment-related fluctuations and relapses support CIDP diagnosis 1

When to Obtain Neurology Consultation

• Consult neurology early, particularly for grade 2 or higher symptoms, to guide electrodiagnostic interpretation and differentiate CIDP from mimickers like amyloidosis, vasculitic neuropathy, or paraneoplastic syndromes 1

Nerve Biopsy (Rarely Needed)

• Can confirm demyelination with onion bulb formation and inflammatory infiltrates, but not routinely required if clinical, electrodiagnostic, and CSF findings are consistent 1

Common Pitfalls to Avoid

• Do not rely on CSF protein alone - while typically elevated, this finding is not specific for CIDP 2
• Do not miss monoclonal gammopathies - always perform serum protein electrophoresis with immunofixation as these can cause CIDP-like presentations requiring different management 1, 2
• Do not overlook compressive lesions - MRI spine is essential as structural lesions can mimic CIDP 1
• Do not diagnose CIDP if symptoms evolved in less than 8 weeks - this suggests Guillain-Barré syndrome instead, which has different treatment implications 1