TENS

TENS means transcutaneous electrical nerve stimulation.

TENS was developed as a result of the gate theory of pain (stimulating skin mechano-receptors produces presynaptic spinal inhibition of pain transmission). High frequency TENS (80Hz to 200Hz) is thought to work this way, but conventional low frequency TENS (2Hz to 6Hz) is thought to release endogenous opioids in the spinal cord and midbrain (like acupuncture).

There has been little research into the use of TENS in cancer pain, but individual reports suggest it can be helpful. In one descriptive study 34 out of 49 cancer patients had improved pain control, and some were able to reduce pain medication.

It is reasonable to try TENS on any patient who is open to the idea. Many cancer patients have musculo-skeletal pains (cervical spondylosis, for example, is a common condition) for which TENS can be helpful.

TENS is rarely helpful in nerve pain and tends to exacerbate it.

Summary of optimum conditions for TENS:

• Compliant patient

• Competent patient or carer

• Self-adhering 2.5mm electrodes

• Use of good contact medium

• Frequency of 4Hz

• Intensity set to cause distinct pulsation (not pain)

• Electrodes applied to acupuncture points

• 15 to 20 minute treatment (usually daily)

The TENS machine should be small, portable, and have a frequency range of 0Hz to 200Hz, and a minimum of two channels. The patient should rent the machine for a trial, before considering purchase. 

Electrode location needs to be precise, and is most effective when anatomical acupuncture points are used. Small electrodes are more effective.

Duration of treatment – Low frequency TENS should be used for only 15 to 20 minutes to prevent habituation (the nervous system tunes out a repetitive signal). The effect can last for hours or days. If low frequency TENS is ineffective, a trial of high frequency TENS is worthwhile, but the effect is usually short-lived (from a few minutes to 2 hours). A newer TENS device stimulates multiple points in random fashion (to avoid habituation) and may prove more effective.

Contraindications:

• Cardiac pacemaker

• Inflamed or infected skin

The author and publisher have taken precautions to ensure that the information in this book is error-free. However, readers must be guided by their own personal and professional standards of good practice in evaluating and applying recommendations made herein. The contents of this book represent the views and experience of the author, and not necessarily those of the publisher.