What are the phisiological bases of Transcuteaneous electrical nerve stimulation? 

Transcutaneous electrical nerve stimulation (TENS) is the noninvasive, trasncutaneous use of electrical stimulation to produce analgesia. It is base on activation of inhibitory interneurons in the substantia gelationosa in the dorsal horn of the spinal cord by stimulation of large diameter fibres which inhibit the transmission of nociceptive signals from small diameter fibres (A-delta an C). Another postulated mechanismof pain relief is the promotion of endorphin release, leading to a vasodilatation in injured tissue. 

What can we treat with? 

One of the most important utilities of it is Chronic neck pain. It is a highly prevalent condition that can limit the daily activities leading to work absenteeism and economic implications. Nowadays, the ageing of population increses chronic conditions like neck pain, so, is an important topic to treat 

The objetive of this paper is to evaluate the efectiveness of TENS compared with sham or other clinical intervetions for the treatment of chronic neck pain. The TENS should be applied to the cervical región and not be used together with acupuncture needles. 

They analise pain, disability, use of medication for pain, range of motion, work disability and quality of life as goals of treatment. 

What are the results? 

This review found very low-certainty evidence of a diference between TENS compared to sham TENS on reducing neck pain. They include seven RTCs. Most of these studies used conventional TENS with a frequency between 600 Hz to 100 Hz, a pulse width of 40 Ts to 250 Ts and comfortable intensity. The study participants had daily TENS sessions that lasted 20 to 60 minutes and a total of one to 60 sessions. The máximum follow-up was six months. Electrodes were place on the mos painful región of the neck, including the upper trapezius muscle. 

At present, there is insuficiente evidence regarding the use of TENS in peopole with chronic neck pain. Due to very low-certainty evidence, heterogeneity between existing studies and the lack of data on important outcome, more research is needed on TENS for the treatment of people with chronic neck pain. 

Commented by María Soriano Micó