European Federation of Neurological Societies and the Peripheral Nerve Society reported criteria for the diagnosis of Chronic Inflammatory Demyelinating Polyradiculoneuropathy (CIDP). One element involves supportive features.
Supportive findings:
(1) elevated CSF protein AND CSF WBC count < 10 per microliter
(2) MRI findings: gadolinium enhancement and/or hypertrophy of one or more of:
(2a) the cause equina, lumbosacral or cervical nerve roots
(2b) brachial plexus
(2c) lumbosacral plexus
(3) abnormal sensory electrophysiology in >= 1 nerve
(3a) normal sural AND (abnormal median or radial sensory nerve action potentials SNAPS at the wrist) with exclusion of carpal tunnel syndrome
(3b) conduction velocity < 80% of lower limit of normal
(3c) conduction velocity < 70% if SNAP amplitude is < 80% of lower limit of normal
(3d) delayed somatosensory evoked potentials without CNS disease
(4) objective clinical improvement after immunomodulatory therapy
(5) nerve biopsy shows definite demyelination and/or remyelination on EM or on teased fiber analysis
