Chemotherapy - Induced Peripheral Neuropathy (CIPN). Could There be a Role for Physical Therapy Treatment?

A common side effect is chemotherapy induced peripheral neuropathy (CIPN). CIPN is a small fibre sensory neuropathy that develops in the hands/feet and worsens with increasing dose and duration of treatment. It impacts the Aβ, Aδ, and C-Fiber function involved in light touch and vibration sense, thermal detection and thermal pain. This results in a variety of positive and/or negative sensory symptoms including hypoesthesia, dysesthesias, hyperalgesia, allodynia and neuropathic pain. Quantitative sensory testing (QST) are a variety of non-invasive tests aimed at quantifying sensory perceptions used in research to clinically assess neuropathy. It is used for sensory detection and pain thresholds for both mechanical and thermal stimuli. QST provides information on large myelinated (Aβ), small thinly myelinated (Aδ) and unmyelinated (C-fiber) function or dysfunction. Deep pressure threshold measured by a pressure algometry stimulates intramuscular afferents, and can be used as a measure of central sensitization when used at a distant site from the site of pain. Aδ fibres transmit cool detection threshold, while warm detection threshold is transmitted by C-fibers. Both noxious heat and noxious cold transmit via C-fiber and Aδ fibers. An increased sensitivity to thermal pain thresholds, results in thermal hyperalgesia.

Physical therapy treatment for nerve disorders is well established in orthopedics and plastic surgery for entrapment neuropathies, neuropathic pain, post-operative nerve repair and regeneration. Nerve gliding exercises are frequently used exercises in physical therapy to improve neural excursion across joints, improve pain and decrease inflammation. Patient reported symptoms (patient questionnaires NPRS, S-LANSS and DASH) and quantitative sensory testing (QST) specifically pain pressure thresholds and vibration were used for the primary purpose in evaluating the role for an upper extremity nerve mobilization physical therapy home program during chemotherapy for the prevention and management of CIPN.

Primary Outcome Measures was the NPRS and reported as those having no vs no pain. Grip strength, Vibration, DASH and S-LANSS were identified outcome measures prior to the trial that would best describe sensory impairment and function for the physical therapy question

Additional QST measures collected included warm/cool, Hot/Cold Pain thresholds that were used with the vibration data to compare quantitative data on the right and left side to evaluate possible a possible dual nerve disorder when combined with surgery as well as identifying different sensory profiles of QST data between those reporting neuropathic pain and non-neuropathic pain using the S-LANSS

A sub analysis of data was completed dividing participants that remained active throughout compared to less active participants to evaluate the effect of exercise on sensory preservation. This was not an intended analysis at the beginning of the trial and these participants were not randomized.