Scrambler therapy
Scrambler therapy involves the use of electronic stimulation on the skin with the goal of overwhelming pain information with non-pain information. In a therapy session, "electrocardiographic-like pads are placed around the area of pain".
Limited research has been done on the effectiveness of scrambler theory. There is no strong evidence that it is effective in treating neuropathic pain, although there is tentative evidence that it may be effective for chemotherapy-induced peripheral neuropathy. There is preliminary evidence that is effective for chronic pain.
Medical Uses
Scrambler therapy has been used in several types of chronic pain, including neuropathic pain, cancer pain and opioid-refractory pain. Scrambler therapy involves 16 types of waveforms, each varying slightly in their morphology. The waveforms are combined to create a variety of sequences of electrical stimulation, with the pattern of sequences being varied during the treatment session based on an algorithm in the scrambler machine. The electrical stimulation is applied to the skin via pairs of electrodes, which are applied in the painful dermatomes proximally and distally to the painful area. The intensity of signal is increased in five to ten minute intervals until the patient feels a relief of pain or until the scrambler signal intensity begins to cause pain. This intensity of electrical stimulation is then continued. Each treatment session lasts for about 30-40 minutes, and may be repeated on other days during the treatment cycle.The electrical signals in scrambler therapy are thought to stimulate C-fibers of the affected dermatomes. These nerve fibers then transmit the electrical signal to the brain and lead to changes in pain perception in the central nervous system. These changes include decreased central nervous system hyper-responsiveness to the pain signal and a decrease in continuous pain signal input. The decrease in continuous pain input is thought to be due to the pain signal travelling from the affected area being "scrambled" or diluted by many other scrambler signals also travelling to the brain from the affected area. Scrambler therapy has also been shown to decrease certain pro-inflammatory, pro-nociceptive peptides such as nerve growth factor, and this effect is thought to lead to a sustained analgesic effect after the treatment session.
Unlike transcutaneous electrical nerve stimulation, another form of transcutaneous electrical stimulation for pain relief, in which the analgesic benefit has only been seen during and sometimes in the immediate hours after treatment, treatment with scrambler therapy has been shown to produce long lasting pain relief. Pain relief with scrambler therapy is often sustained for weeks, months or even years after the treatment sessions are completed.