Presence of deep tendon reflexes may not exclude a diagnosis of Chronic Inflammatory Demyelinating Polyradiculoneuropathy (CIDP)
James Strathdee1, Edrich Rodrigues1, Mahima Kapoor1, Wenwen Zhang1, Mark Faragher2, Bruce Day1, Elspeth Hutton1, Richard Stark1
1The Alfred Hospital, Melbourne, 2Cabrini Hospital
Objective:
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.
Background:
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.
Design/Methods:
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
Results:
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.
Conclusions:
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.