Diagnostic Value of MRI in CIDP (P07.055)

OBJECTIVE: Demonstrate extensive nerve root involvement in CIDP, and the importance of MRI in aiding the diagnosis of CIDP. BACKGROUND: CIDP is a treatable, relapsing, immune mediated disorder, which can be challenging to diagnose. Traditionally, clinical presentation, CSF analysis, and electro-diagnostic studies are sufficient to evaluate patients with peripheral sensorimotor deficits. Recently, imaging has gained importance in providing supplemental information to identify CIDP. Hypertrophy and gadolinium enhancement have been noted in multiple nerve roots, with variable clinical correlation. We present a patient with undiagnosed CIDP and massive hypertrophy of multiple nerve roots. DESIGN/METHODS: A 62 y/o male presented with progressive weakness in all four extremities, and bilateral foot drop over an 8 year period. On exam, he had normal cranial nerve function, significant atrophy, paresis in all extremities (distal > proximal, legs > arms), symmetrically decreased ankle jerks, no ataxia, and no plantar responses with stimulation. Clinical evaluation was consistent with a severe length dependent sensorimotor peripheral neuropathy. RESULTS: Labs for etiologies of neuropathy were all within normal limits. Initial EMG/NCS was limited due to severe distal nerve damage. MRIs showed thickened and enhancing CN V1-V3 segments, mastoid segments of CN VII, the jugular nerve complex, the entire brachial plexus, as well as the intradural, foraminal, and extraforaminal segments of cervical and lumbar nerve roots. His extensive lumbar root hypertrophy prevented a successful lumbar puncture for CSF protein analysis. Two rounds of 2 grams/kg of IVIG were administered with minimal improvement. Repeat EMG/NCS 6 months later, with dedicated testing of the cranial nerves, confirmed the diagnosis of CIDP with predominantly demyelinating sensorimotor polyneuropathy. CONCLUSIONS: CIDP can be challenging to diagnose, making MRIs necessary for appropriate diagnosis, especially if classic diagnostic tools (CSF and EMG/NCS) are initially unyielding. The identification of multiple hypertrophied nerve roots may also be indicative of refractoriness to immunotherapies. Supported by: 1) Clinical and imaging findings in three patients with advanced inflammatory demyelinating polyradiculoneuropathy associated with nerve root hypertrophy. Beydoun SR, Muir J, Apelian RG, Go JL, Lin FP. J Clin Neuromuscul Dis. 2012 Mar;13(3):105-12. 2) Cranial nerve, spinal root and plexus hypertrophy in chronic inflammatory demyelinating polyneuropathy. Shah S, Chandrashekar H, Manji H, Davagnanam I. Pract Neurol. 2012 Feb;12(1):68-9. 3) Cranial nerve hypertrophy in pediatric chronic inflammatory demyelinating polyradiculoneuropathy. McMillan HJ, Miller E. Pediatr Radiol. 2010 Dec;40 Suppl 1:S176. Epub 2010 Oct 13. 4) MRI shows increased sciatic nerve cross sectional area in inherited and inflammatory neuropathies. Sinclair CD, Miranda MA, Cowley P, Morrow JM, Davagnanam I, Mehta H, Hanna MG, Koltzenburg M, Reilly MM, Yousry TA, Thornton JS. J Neurol Neurosurg Psychiatry. 2011 Nov;82(11):1283-6. Epub 2010 Oct 22. Disclosure: Dr. Ghavami has nothing to disclose. Dr. O9Dwyer has nothing to disclose. Dr. Balish has nothing to disclose. Dr. Zhai has nothing to disclose.