CISP-Plus: Expanding the Spectrum of Chronic Immune Sensory Polyradiculopathy (CISP)

Objectives:Sensory loss with normal nerve conduction studies (NCS) from focal sensory root inflammatory demyelination is characteristic of chronic immune sensory polyradiculopathy (CISP). However, non-pure cases involving motor and distal sensory nerves exist (CISP-plus). We hypothesize that CISP-plus and CISP are fundamentally part of the same syndrome through comparison of clinical, neurophysiological and pathological features.Methods:CISP-plus (primary dorsal root with lesser motor and sensory nerve involvement) and CISP cases were retrospectively analyzed (1986-2019).Results:We identified 44 CISP-plus and 28 CISP cases (n=72) with 86% (38/44) of CISP-plus and 79% (22/28) of CISP patients experiencing imbalance. On examination, large fiber sensory loss was present in 98% (43/44) of CISP-plus and 96% (27/28) of CISP. Gait ataxia was evident in 93% (41/44) of CISP-plus and 79% (22/28) of CISP. Mild distal weakness was common in CISP-plus (75%, 33/44). NCS showed mild abnormalities in all CISP-plus and were normal (by definition) in all CISP. Elevated cerebral spinal fluid (CSF) protein, slowing of somatosensory evoked potentials and MRI root enhancement occurred in most CISP-plus and CISP cases. Eleven CISP-plus nerve biopsies showed loss of large myelinated fibers and onion-bulb formation most prominent in rootlet biopsies. Immunotherapy resulted in marked improvement of gait ataxia in 84% (27/32) of CISP-plus and 93% (14/15) of CISP cases with return to normal neurological examination in half (25/46).Conclusion:The recognition of CISP-plus expands the spectrum of CIDP by combining CISP-plus (predominant sensory polyradiculopathy with mild motor and sensory nerve involvement) with pure-CISP (focal sensory polyradiculopathy) together as proximal sensory CIDP.

Carpal tunnel decompression in patients with normal nerve conduction studies

Some patients present with typical clinical features of carpal tunnel syndrome despite normal nerve conduction studies. This study compared the preoperative and 1-year postoperative QuickDASH scores in patients with normal and abnormal nerve conduction studies, who underwent carpal tunnel decompression. Of the 637 patients included in the study, 19 had clinical features of carpal tunnel syndrome but normal nerve conduction studies, and underwent decompression after failure of conservative management. Preoperative QuickDASH scores were comparable in both groups (58 vs 54.8). However, there were significant differences between the normal and abnormal nerve conduction study groups in the QuickDASH at 1 year (34.9 vs 21.5) and change in QuickDASH postoperatively (23.1 vs 33.4). Patients with normal nerve conduction studies had comparable preoperative disability scores compared with those with abnormal studies. Although they had a significant improvement in QuickDASH at 1 year, this was significantly less than those with abnormal nerve conduction studies. Level of evidence: III