Comparison of High Tone Therapy and TENS Therapy in Chemotherapy-induced Polyneuropathy

One of the most common adverse side effects of chemotherapeutic agents especially in taxanes, platins or vinca alkaloids is chemotherapy-induced peripheral neuropathy (CIPN). Prevalence of CIPN was reported in 30% to 40% of patients treated with neurotoxic chemotherapy and may be transient or permanent. It appears predominantly as sensory neuropathy and affects the peripheral parts of the extremities in a "stocking and glove"-distribution. CIPN often presents with symptoms like paresthesia, pain, numbness or tingling, but motor symptoms can occur as well. Symptoms of CIPN may lead to dose reduction or even early cessation of chemotherapy and therefore may affect overall survival in cancer patients. Currently, no evidence-based treatment (drug or non-drug therapy) is available for CIPN. Several approaches to manage peripheral neuropathy have been proposed, but evidence showing a benefit of these procedures regarding clinically relevant endpoints is scarce. One promising approach to ease CIPN symptoms is the application of electrotherapy. Different types of electrical sensory interventions have been explored in the literature e.g. transcutaneous electrical nerve stimulation (TENS) and high-tone external muscle stimulation (HTEMS).TENS is used in medical settings and in self-administration of patients at home. In TENS only the frequency is modulated. The device sends electrical impulses through conductive rubber electrodes to the skin of the impaired region. The applied frequencies range from 2 to 120 Hertz. The pain region must be in the middle of the two electrodes, which have a maximum distance of 20cm. In contrast to the TENS therapy, the HTEMS operates in-depth directly on the muscle and produces pleasant, but intense and thus effective contractions. Additionally in HTEMS, the amplitude and the frequency are modulated simultaneously. The applied frequencies range continuously from 4096 to 32768 Hertz. Different frequencies activate structures of different size. For this reason, it is important to offer a broad spectrum of frequencies. The electrical stimulation is applied by using conductive rubber electrodes. On the upper limbs as well as on the lower limbs the electrodes are positioned as far as possible proximal and distal. During the treatment the muscle is stimulated to contraction through intervals. One interval consists of three seconds ramp-up time (intensity rises), three seconds holding time (intensity maintains on maximum) and three seconds pause (no stimulation).

The application of HTEMS has been shown to be more effective than TENS in the therapy of diabetic peripheral neuropathy. Furthermore, HTEMS demonstrated improvement in pain, discomfort, sleep disturbance and quality of life in patients with end-stage renal disease due to uremic peripheral neuropathy. So far, little research on HTEMS or TENS in CIPN has been carried out, even if this approach is used in clinical practice. The aim of this study is to evaluate the effect and feasibility of home-based HTEMS in patients with chemotherapy-induced peripheral neuropathy.

This pilot study will be based on a single blinded randomised controlled trial study design with an observation time of eight weeks. Patients with cancer receiving a taxan-or platin-based chemotherapy and symptoms of CIPN will be included. Subjects will be stratified by treatment delivery, taxan and platin. The therapy will start after completed adjuvant chemotherapy after a time period of 4 weeks minimum to exclude patients with spontaneous remission of CIPN and in order to reduce the effect of any known or unknown biases related to the treatment regime. Potential study participants will receive information about the study as soon as symptoms occurred to plan inclusion, randomisation and allocation of appointments. Patients will receive a TENS or HTEMS device after randomisation. Participants who are allocated to the control intervention group will receive TENS therapy. The participant is educated for home-based therapy and the treatment should be used daily for 30 minutes for 8 weeks. Additionally, participants' compliance will be checked by reading out the tool box. Participants are asked to fill out the EORTC CIPN 20 (chemotherapy-induced) and EORTC QLQ-C30 (quality of life) questionnaire at baseline and after 8 weeks. Clinical examination encompassing vibration sensibility, tendon reflexes, temperature sensibility perception of touch and muscel strength will be conducted at the same time points.

The investigators would prefer not to constrain patients to specific daily time points and disturb their individual rhythm. Therefore, the investigators recommend performing the intervention at a regular daily time point adapted to the individual daily routine. The primary endpoint is a change in the EORTC-QLQ-CIPN20 score during the eight weeks of intervention. For our primary endpoint the investigators will use an intention-to-treat analysis according to the CONSORT statement. Furthermore, the investigators will analyse the intensity of intervention (compliance) and the effect on the primary endpoint (for example comparison of infrequently and frequently use of device). A minimum use on 5 of 7days per week is required.