Assessment of chemotherapy‐induced peripheral neuropathy using the LDI_FLARE technique: a novel technique to detect neural small fiber dysfunction

Abstract

IntroductionThe diagnosis and quantification of chemotherapy-induced peripheral neuropathy (CIPN) remains a challenge. Conventional methods including quantitative sensory testing (QST), nerve conduction tests, and biopsy are unable to detect subclinical changes, and do not consistently correlate with severity of patients' symptoms and functional impairment. This study aims to determine the utility of the LDI (laser Doppler imager) FLARE technique in the diagnosis of CIPN and whether it correlates with symptom severity.Materials and MethodsWe assessed 24 patients with established CIPN [12 due to platinum analogs (PA) and 12 to Taxanes (TX)] and 24 matched healthy controls (HC). All underwent neurophysiological examination including vibration perception threshold (VPT), sural nerve amplitude (SNAP) and conduction velocity (SNCV), LDIFLARE, and fasting biochemistry. The QLQ-CIPN20 questionnaire was used to assess symptom severity.ResultsHC, combined chemotherapy (CG), PA, and TX groups were matched for age, sex, BMI, and blood pressure. The LDIFLARE was significantly reduced in CG compared to HC (P =< 0.0001), whereas SNAP (P = 0.058) and SNCV (P = 0.054) were not. The LDIFLARE correlated with the QLQ-CIPN20 symptom scores in all three categories namely, CG (P =< 0.0001), PA (P = 0.001) and TX (P = 0.027) whilst, VPT, SNAP, and SNCV did not.ConclusionOur findings suggest that the LDIFLARE technique is more helpful in confirming the diagnosis of CIPN in patients with distal sensory symptoms than current commonly used methods. Moreover, this novel test fulfils the unmet need for a diagnostic test that relates to the severity of symptoms. This may be useful in quantifying early changes in small fibre function indicating early CIPN.

A device to measure secretion of individual sweat glands for diagnosis of peripheral neuropathy

“…In several conditions – diabetes (Sumner et al, ; Said, ) , chemotherapy‐induced neuropathy (Sharma et al, ) , Sjögren's syndrome (Chai et al, ) , amyloidosis (Marian et al, ) and alcohol‐related neuropathy (Zambelis et al, ) – evidence suggests that small nerve fibers are among the earliest to be involved in peripheral neuropathy. Neuropathy is expected to affect the sudomotor C fibers, which innervate SGs, in parallel with other nerve fiber types, especially small unmyelinated fibers.…”

Quantitative assessment of chemotherapy‐induced peripheral neurotoxicity using a point‐of‐care nerve conduction device

“…A previous study failed to establish the utility of this POCD in a similar patient group: neither SNAP nor SNCV differed significantly between 24 patients with CIPN and 24 age‐matched healthy volunteers . Moreover, SNAP and SNCV did not correlate with the severity of CIPN.…”

Electronic von Frey as an objective assessment tool for oxaliplatin‐induced peripheral neuropathy: A prospective longitudinal study

“…Laser Doppler Imager Flare technique correlated well with EORTC QLQ-CIPN20 scores (Sharma et al, 2015) and Vibratron II correlated well with the cumulative chemotherapy dose (Chaudhry et al, 1994).…”

“…PainVision measures were associated with the onset of neuropathic symptoms (Sato et al., 2017) and correlated significantly with NCI‐CTCAE grades in patients receiving paclitaxel (Tanabe et al., 2013); however, it showed no significant correlation with visual analogue scale scores when used for assessment of OXLIPN (Yoshida et al., 2015). In patients on platinum‐ or taxane‐based regimens, Laser Doppler Imager Flare technique correlated well with EORTC QLQ‐CIPN20 scores (Sharma et al., 2015) and Vibratron II correlated well with the cumulative chemotherapy dose (Chaudhry et al., 1994). Another study suggested that Sudoscan, a device that measures electrochemical skin conductance, could be used to screen and follow CIPN (Saad et al., 2016).…”