Quantitative Sensory Testing Is Highly Sensitive in Detecting Chemotherapy-Induced Peripheral Neuropathy

Background: We tested for chemotherapy induced peripheral neuropathy (CIPN) in pediatric survivors of acute lymphoblastic leukemia using quantitative sensory testing (QST).

Methods: In a cross-sectional, bicentric study, we assessed 46 pediatric ALL-survivors (age: 5.7 ± 3.5 years, 4.2 ± 2.5 years after diagnosis; males: 28). Inclusion criteria: ≥6 years of age and ≥3 months after last therapy following standard ALL protocols (cumulative dose of vincristine: 12 mg/m²). We used a clinical reduced Pediatric-modified Total Neuropathy Score (rPed-mTNS), sensory nerve conduction studies of the median and sural nerve, and QST according to the standardized protocol of the German Research Network on Neuropathic Pain.

Results: The clinical rPed-mTNS detected abnormal findings in 32.6% of patients, that is, a score of 4 or higher. Sensory nerve conduction velocity (sNCV) was reduced in 15.2% of patients. With QST more than half of patients showed pallhypesthesia (71.7%) and tactile hypoesthesia (63%). Also hyperalgesia to blunt pressure (41.3%), dynamic mechanical allodynia (35%), and increased mechanical pain sensitivity (26%) were unveiled with QST. Of seven patients with reduced sNCV, six (86%) revealed pallhypesthesia or tactile hypoesthesia with QST.

Conclusion: QST proved signs of large fiber neuropathy in more than half and signs of small fiber neuropathy in one third of long-term ALL survivors. QST and rPed-mTNS are valuable tools besides standard nerve conduction studies for the assessment of CIPN indicating different subgroups of CIPN patients.

Keywords: acute lymphoblastic leukemia, chemotherapy-induced peripheral neuropathy, vincristine, pediatric-modified total neuropathy score, quantitative sensory testing