Presence of deep tendon reflexes may not exclude a diagnosis of Chronic Inflammatory Demyelinating Polyradiculoneuropathy (CIDP) (P11-8.015)

Abstract

<h3>Objective:</h3> To identify if there are chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) patients who do not meet clinical criteria but satisfy electrodiagnostic criteria. Our hypothesis is that these patients do not differ from patients who meet criteria for CIDP and possible CIDP. <h3>Background:</h3> The diagnosis of CIDP remains challenging due to lack of a biomarker or a single diagnostic test. The European Academy of Neurology/Peripheral Nerve Society (EAN/PNS) 2021 revision of the diagnostic criteria for CIDP advocate a stepwise approach to the diagnosis of CIDP which requires clinical criteria including absent or reduced deep tendon reflexes before the application of electrodiagnostic criteria. <h3>Design/Methods:</h3> We applied the 2021 EAN/PNS criteria to our cohort of 39 patients receiving intravenous immunoglobulin (IVIG) for CIDP. We compared clinical and electrodiagnostic criteria between those who fulfilled electrodiagnostic criteria but not clinical criteria and patients with CIDP or possible CIDP <h3>Results:</h3> Of our cohort 39-patients, 21 (53.8%) were classified as CIDP, 6 (15.3%) as possible CIDP and 12 patients didn’t meet criteria. Of the 10 patients who didn’t meet clinical criteria, 6/10 (60%) met electrodiagnostic criteria. These patients did not qualify as CIDP or Possible CIDP due to the presence of reflexes. There were no significant differences in the clinical phenotypes and demographics between these patients and CIDP or possible CIDP patients in our cohort. There was also no significant difference in the electrodiagnostic parameters between these patients and those with CIDP or possible CIDP. However, the patients with preserved reflexes tended to have more frequent conduction velocity slowing (p = 0.08) than patients with CIDP or possible CIDP. <h3>Conclusions:</h3> The presence of reflexes should not exclude the diagnosis of CIDP if the patient meets electrodiagnostic criteria. This could be indicative of a subset of patients with CIDP who have more involvement of the intermediate segments of nerve rather than proximal segments. <b>Disclosure:</b> Dr. Strathdee has nothing to disclose. The institution of Dr. Rodrigues has received research support from Australian Brain Foundation. The institution of Dr. Kapoor has received research support from Bethlehem Griffiths Research Foundation . Dr. Zhang has nothing to disclose. Dr. Faragher has stock in Argo P/L. Dr. Faragher has stock in Australian Foundation P/L. Dr. Faragher has stock in Argo Infrastructure P/L. Bruce Day has nothing to disclose. The institution of Dr. Hutton has received research support from Lundbeck. The institution of Dr. Hutton has received research support from Daewoong Pharmaceuticals . The institution of Dr. Hutton has received research support from Xalud. The institution of Dr. Hutton has received research support from Ipsen. The institution of Dr. Hutton has received research support from Abbvie. The institution of Dr. Hutton has received research support from Cerecin. Dr. Hutton has a non-compensated relationship as a Board Member with Brain Foundation (Vic) that is relevant to AAN interests or activities. Dr. Hutton has a non-compensated relationship as a President-elect with Australian and New Zealand Headache Society that is relevant to AAN interests or activities. Dr. Stark has received personal compensation in the range of $5,000-$9,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Lundbeck. Dr. Stark has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Abbvie. Dr. Stark has received personal compensation in the range of $5,000-$9,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Teva. Dr. Stark has received personal compensation in the range of $5,000-$9,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Eli Lilly. Dr. Stark has stock in CSL. Dr. Stark has stock in Multiple ASX listed (non-medical) companies. Dr. Stark has received personal compensation in the range of $10,000-$49,999 for serving as a TCMC Committee chair with AMA Victoria.