P53-T Evaluation of atypical chronic autoimmune inflammatory polyneuropathies - clinical and neurophysiological comparison

Abstract

Background Chronic autoimmune inflammatory polyneuropathies (CAIP) is a group of rare and potentially treatable conditions that are often underdiagnosed due to non-compatibility with recognized diagnostic criteria that might be partially related to incomplete neurophysiological investigation or lack of follow-up. Methods Case series study of 4 CAIP patients with atypical clinical and/or neurophysiological features. Results Case 1. 10 year history of distal weakness in upper extremities (UE), NCS – diffuse conduction slowing with conduction block (CB) and marked sensory involvement. Improvement with IVIG. Case 2. Slow progression of asymmetrical weakness in distal UE and right lower extremity (LE), NCS – axonal loss with CB in all extremities. No response to glucocorticoids, improvement on IVIG. Case 3. Progressive weakness in distal UE with marked sensory involvement and diffuse severe fasciculations, 1st ENMG – no CB, slight axonal loss with demyelination not below 75% of lower normal, slight sensory impairment, with diffuse fasciculations. Follow up ENMG – 1 definitive CB, 2 probable CB (1 in Erb point), with significant demyelination and sensory impairment in UE. Slight improvement with glucocorticoids. Case 4. Progressive asymmetrical tetraparesis LE > UE, with sensory signs proximally in LE and distally in UE and LE. NCS – axonal loss with conduction slowing not below 75% normal range, no CB, no increase in distal latencies, significant sensory nerve involvement. No improvement on IVIG, marked response to glucocorticoids. Conclusions NCS should be comprehensive, including proximal stimulations. Follow-up ENMG studies and immunomodulatory treatment should be considered in all patients with suspected CAIP.