Preliminary Studies Of Clinical, Electrophysiological And Skin Biopsy Of Chemotherapy-Induced Peripheral Neuropathy

ObjectivePart 1:To identify the sensitive scale and the change of nerve conduction properties for chronic oxaliplatin-induced peripheral neuropathy (OXLIPN). If acute OXLIPN was correlated with chronic OXLIPN.Part 2:To identify whether intraepidermal nerve fibre density (IENFD) was lower in chemotherapy-induced peripheral neuropathy (CIPN) patients. Whether skin biopsy could be an auxillary examination for CIPN.MethodsPart 1:Between December 2014 and August 2015, from department of Oncology, Chinese PLA General Hospital,16 colorectal cancer patients confirmed by pathology, scheduled to receive XELOX, completed the acute neurotoxic symptoms questionnaire at the end of 1 cycle, completed Clinical version of the Total Neuropathy Score (TNSc)?National Cancer Institute-Common Toxicity Criteria (NCI-CTC) at the baseline and the end of 4 cycles. Nerve conduction studies were performed in 11 patients at the baseline and the end of 4 cycles.Part 2:Between June 2014 and October 2015, from department of Neurology, Chinese PLA General Hospital,7 patients after chemotherapy, complain of sensory disturbance in the distal limbs, like numbness, pain and so on. Completed TNSc, skin biopsy (10cm above the left lateral malleolus), electrophysiological examination and nerve conduction studies.ResultsPart 1:After 4 cycles of chemotherapy, TNSc increased 1-9 points for all patients, while NCI-CTC increased 1 point for only 9 patients, the remaining 7 patients had same NCI-CTC score before and after chemotherapy, where TNSc increased 1-6 points. Left sural nerve amplitude of sensory nerve action potential (a-SNAP) was 15.3±5.8?V before chemotherapy and 12.3±5?V after chemotherapy. Right sural nerve a-SNAP was 17.4±8.6?V before chemotherapy and 13.3±6.7?V after chemotherapy. After 4 cycles of chemotherapy, these datum were significantly reduced for bilateral sural nerve a-SNAP, left sural nerve sensory conduction velocity (SCV) and left peroneal nerve distal and proximal amplitude of compound muscle action potential (a-CMAP) (P<0.05). After 4 cycles of chemotherapy, TNSc was correlated significantly with the acute neurotoxic symptoms questionnaire (spearman r=0.698 P=0.003).Part 2:The median of TNSc was 8 (5,12) points for 7 patients, mainly included sensory symptoms 3 (2,4) points, pin sensibility 2 (1,3) points and deep tendon reflexes 2 (2,4) points. Needle electromyography was normal. Left peroneal nerve MCV was a bit slower for 2 patients,40m/s,42.5m/s. Left peroneal nerve distal and proximal a-CMAP were a little lower for 1 patients,2mV. Left median nerve MCV was a bit slower for 1 patients,46.8m/s. Left ulnar nerve MCV was a bit slower for 1 patients,43.3m/s. Sensory nerve conduction was almost abnormal. Four sensory nerves SNAP were absent for 2 patients. Sensory nerve conduction was nomal for only one patient. IENFD was lower than 5th percentile for 2 patients. IENFD was lower than median for 7 patients.ConclusionPart 1:TNSc was more sensitive than NCI-CTC to the severity and changes in chronic OXLIPN. Sural nerve a-SNAP had a higher sensitivity for the changes of nerve conduction studies in chronic OXLIPN. Patients who had a more symptoms of acute neurotoxicity were those who eventully developed more severe chronic OXLIPN.Part 2:Intraepidermal nerve fibre density (IENFD) was lower in some chemoztherapy-induced peripheral neuropathy (CIPN) patients. Skin biopsy could be an auxillary examination for CIPN.