CIDP Variants Affecting Nerve Roots

Diagnostic Considerations

MRI of the brachial or lumbosacral plexus can help identify focal or diffuse peripheral nerve abnormalities in CIDP variants 1
Nerve biopsy may be particularly useful in evaluating atypical forms of CIDP, as these variants may have distinctive pathological features 1
Electrophysiological studies can distinguish between CIDP and other conditions like Guillain-Barré syndrome (GBS), which also affects nerve roots but has an acute onset 3
Cerebrospinal fluid analysis typically shows cytoalbuminologic dissociation (elevated protein with normal cell count) in both CIDP and GBS 3, 4

Unlike Guillain-Barré syndrome, which is acute and monophasic with progression over days to weeks, CIDP progresses over more than 2 months 3
CIDP must be distinguished from other causes of polyradiculoneuropathy such as diabetic polyradiculoneuropathy 4
CIDP must also be distinguished from leptomeningeal metastases 4
Infectious causes (HIV, cytomegalovirus, Lyme disease) and systemic inflammatory disorders like lupus should also be considered in the differential diagnosis 4, 5

Multifocal Acquired Demyelinating Sensory and Motor Neuropathy (MADSAM or Lewis-Sumner Syndrome) is characterized by asymmetric involvement with preserved reflexes in areas not affected by weakness 1, 2