Whiplash occurs as the result of acceleration-deceleration mechanism of energy transfer to the neck. It is a symptom complex which has no pathological or radiological correlates2,11,13). The most common cause is a motor vehicle accident such as rear-end or side-impact collisions. The most common symptom is neck pain. In addition to neck pain, there may be pain in one or both arms and interscapular area and arm pain. The most common treatment options include physiotherapy, acupuncture, or a neck collar2,11,13). However, the recovery is often incomplete and 30% to 40% of people who get neck pain following motor vehicle accident continue to complain of constant severe pain even after 12 month13,15).

Electrotherapies such as transcutaneous electrical nerve stimulation (TENS) are one of popular treatment options for whiplash patients12). The Self-Controlled Energo-Neuro-Adaptive Regulator (SCENAR; ZAO, OKB RITM, Russia) standing for SCENAR is a hand held, battery powered, electrotherapy device. It was first invented in Russia in mid-80s under space and military research program. The SCENAR device combines Western electrical biofeedback with Eastern energy medicine14). This is the first time that SCENAR therapy is used in the treatment of whiplash. The aim of this study was to investigate the short-term efficacy of SCENAR therapy in patients with subacute neck pain after rear-end collision.

A total of 70 participants were included in the present trial. The clinical characteristics of all the subjects are summarized in Table 1. There was no statistically significant difference for age and gender. Additionally, the prevalence of hypertension and DM did not differ between SCENAR and TENS groups (Table 1). In the TENS group, 7 participants were lost during follow-up compared with 3 in the SCENAR group. No adverse affects were registered in any of intervention groups.

Pain and neck disability scores at each follow-up are shown in Table 2 and Table 3, respectively. The SCENAR group showed superior pain reduction compared with TENS group (SCENAR: initial mean VAS score; 6.3, final mean VAS score; 2.1, TENS: initial mean VAS score; 6.2, final mean VAS score; 3.7). Compared with the TENS group, the SCENAR group presents a reduction of mean VAS scores to the first follow-up measurement at four weeks. This improvement continued during the 16 week follow-up period. Similarly, the 16 week NDI score showed the disability level of the SCENAR group (9.5) was significantly lower than that of the TENS group (14.3).

Most patients who suffer neck pain following a rear-end collision will recover after a few weeks. However, approximately 30% of patients who have neck pain following a rearend collision continue to complain of constant severe pain and need active physical therapies including electrotherapy13). In the present study, we investigate whether largely untested electrotherapy (SCENAR therapy) can reduce subacute neck pain following whiplash.

It has been reported that TENS can be an important method of pain control because of its effect on large-diameter nerves. However, published reports on the effectiveness of TENS vary widely6). In this study, SCENAR therapy was used due to the similarity of its sensory stimulus compared to the TENS. The results of the present study show the possible therapeutic effects of SCENAR in the treatment of whiplash. In the TENS group, more participants were lost for follow-up than in the SCENAR group. This could be due to dissatisfaction with feeling of lacking treatment effect of the TENS.

The use of SCENAR for neck pain following whiplash is new. There are few reports investigating its mechanism of action5,14). The SCENAR is a hand held, electric stimulation therapeutic medical device. The device sends out electrical impulses similar to neural impulses of human body through the skin and measures the response. In respond to a SCENAR impulse, reflex biofeedback, which means the communication between the brain and the affected part, proceeds at real time and biological speed. It is able to instruct the brain and body to generate specific neuropeptides by our body to heal itself. By continuously using biofeedback, the SCENAR modifies each successive input signal to either amplify or dampen the form of the pathological signals that exist in the body.

The SCENAR is very different from other electrotherapy such as TENS. The feature of TENS impulse is asymmetrical biphasic square wave. TENS only stimulates A and B fibers and lack biofeedback capability. However, SCENAR device has a fixed and constant distance between cathode and anode (Fig. 1). The SCENAR impulse (Fig. 2) is high amplitude so it stimulates C-fibers, which make up about 85% of all nerves in the body. This explains the speed and effectiveness of SCENAR therapy. Moreover, SCENAR impulses contain numerous random features to prevent the body from adapting to the stimulation, compared to TENS1,4,7,10). The C-fibers react most readily to the electrical stimulation and are responsible for the production of neuropeptides and other regulatory peptides. The SCENAR catalyzes the process to produce regulatory peptides by stimulation of C-fibers in the body for it to use where necessary. It is these neuropeptides that are responsible for the healing process. As these peptides last up to several hr the healing process will continue even after treatment is over3). Pain is the most common complaint to be dealt with in the SCENAR therapy by block of transmission of the pain impulses in the nerve endings of the peripheral nerve fibers, pain focus suppression of brain cortex, and reduction of the edema around the nerve fibers leading to reduction of pressure effect. To summarize, the SCENAR impulse is similar to our own endogenous nerve impulses and the electrical impulse has a unique wave form that is almost identical to the body’s own nervous system.

There are several limitations to this study. (1) The study was conducted in small population. Thus, present findings need to be validated in lager populations. (2) We could not conclusively rule out some other potential confounders such as exposure to different environmental factors (such as smoking, vocational education, and occupation).

The present study demonstrates that SCENAR therapy is a more effective and safe method of treating patients with neck pain following whiplash compared with TENS. However, we should perform further research aimed at establishing the long-term effect of SCENAR therapy in the treatment of neck pain following whiplash.