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TREATMENT NOTE

TENS Relief of Discomfort ‘Like Worms Wriggling Under the Skin’

Jennifer Bending

Key Words TENS, electrotherapy, self-treatment.

Introduction Transcutaneous electrical nerve stimulation (TENS) is now widely accepted as having a role to play in the management of chronic pain. The following case histories demonstrate its use in two cases of dysaesthesia. Although this sensory disturbance is a problem encountered in a pain clinic, it is not defined by the patients as a ‘pain’ but as being a distressing and very unpleasant sensation. Both the following patients, referred as out-patients for a trial of TENS, described the sensations they were exeriencing as being ‘like worms wriggling under the skin’. The patients were instructed in the use of the TENS machine, electrode positions were discussed and evaluated and a trial programme established. Both patients used a Maxitens 6900 dual TENS machine and disposable self-adhesive electrodes. Contact for the duration of the trial was maintained by telephone.

Case Study 1 Mr P was an ex-wrestler and schoolteacher aged 48 years. He had had intermittent low back pain for many years. In 1987 he developed severe left-sided back pain which radiated down the anterior aspect of the thigh. After a month of bed-rest this pain eased. Subsequently he developed increasing sensory symptoms in the same distribution as that of his previous pain. He was diagnosed as having a femoral neuropathy probably as a result of trauma.

When seen in November 1992 to begin his trial of TENS, his main complaint was the abnormal sensation in the anterior aspect of his left thigh, which he described as being ‘like a bag of worms wriggling under the skin’. It was an uncomfortable deep sensation which was constantly present, very distressing, and for which he had found no means of relief.

Electrode Placement The first pair of electrodes was placed paraspinally in the lumbar region and the second pair with one on the anterior aspect of the top of the thigh and the other on the anterior aspect above the knee. He understood that he should try these positions first but that a certain amount of reasonable experimentation might be needed on his part to locate the optimum electrode positions.

The frequency was set a t 100 Hz and the pulse width at 100 microseconds. A modulated output was chosen. With modulation the frequency repeatedly ramps between the

selected frequency and 65% of it, and the pulse width repeatedly ramps between the selected pulse width and 50% of it, ie modulation constitutes a gradual decrease by a stated percentage from the selected setting and an abrupt rise back to the selected setting. The manufacturers of this particular machine state that there is a tolerance of plus or minus 10% on the marked settings and when accurately assessed it was found that the frequency being used ramped between 108.7 and 67.6 Hz and the pulse width ramped between 96 and 50 microseconds? The intensity was increased until the patient experienced a pleasant tingling sensation.

Results On being contacted four days later, Mr P was obtaining good relief from the dysaesthesia. Subsequently he settled into the pattern of using TENS each day for one hour in the morning with the electrodes still placed in their original positions. This provided almost immediate relief but the dysaesthesia gradually returned during the day. However it no longer disturbed his sleep and he could manage without using TENS again until next morning. Four months later he was still using it successfully.

Case Study 2 Mrs K was a 57-year-old woman who had presented with a history of brachalgia affecting the right arm in the distribution of the C5 nerve root. X-rays had revealed an instability a t C4/5 and she had had a Cloward fusion at the C4/5 level in 1987. Following this, most of her pain had resolved. However in 1992 she was referred to the pain management department having developed a persistent right-sided brachalgia which was resistant to analgesics. When seen to begin her trial of TENS her main complaint was a distressing sensation of ‘little worms wriggling under the skin’. This was present in both arms with the right arm more extensively affected than the left.

Electrode Placement Two electrodes were positioned on her right arm a t the proximal and distal limits of the dysaesthesia; one electrode was placed over the anterior fibres of deltoid and the other on the dorsal aspect of the hand at the base of the thumb. The other pair of electrodes was positioned on the left arm, closer together as the dysaesthesia was not so widespread; one was placed over the deltoid and the other just below the elbow on the extensor aspect of the forearm. The same machine settings as for the first case study were used. After a few minutes use

‘My thanks to G Bahlke, senior technician, The National Hospital for Neurology and Neurosurgery, for this information.

Physiotherapy, November 1993, vol79, no 11

the sensation of worms wriggling had disappeared. She continued to use the machine a t home, using the same electrode positions.

Results Two weeks later Mrs K reported that the dysaesthesia had completely resolved. She had used TENS four times only, .starting with four minutes, then three and then twice for two minutes. After each treatment the ‘wriggling worm’ sensation had disappeared and the benefit had lasted for approximately four days each time. After this the sensation had not returned and she felt there was no further need to continue with TENS.

Discussion This study demonstrates that it is possible to relieve the dysaesthesia described as worms wriggling under the skin and raises the possibility that TENS would be of benefit in other similar cases. It is not possible to extrapolate these results to other forms of dysaesthesia. The machine settings were determined by trial and error with the co-operation of the first patient. As they appeared to be successful with him they were the choice for the second patient. No firm conclusions can be drawn

from only two examples and more information is needed from a larger sample of patients before the electrical parameters can be established and the long-term benefits ascertained. However it does show that the use of TENS need not be directed solely towards the relief of pain.

For both these patients TENS was the only form of treatment which had relieved the discomfort and in doing so had relieved the distress associated with such a condition.

Conclusion These results demonstrate that TENS can have a beneficial effect on a specific type of dysaesthesia. These two case histories are presented for interest and in the hope that others may enlarge on this experience.

Author Jennifer Bending 6.9 MCSP is TENS physiotherapist, The National Hospital for Neurology and Neurosurgery, London.

Address for Cormspondence Mrs J Bending BSc MCSP, Elizabeth Cottage, Croft Road, Goring-on-Thames, Reading, Berks RG8 9ES.

in other journals Some of the following journals may be available in your hospital library, or photocopies of specific articles may be obtained using inter-library facilities (ask your librarian for details).

The CSP is also developing its own resource centre and special physlotherapy journals collection. in case of difficulty photocopies from physiotherapy journals may be supplied by the CSP on request (but please obtain them from libraries wherever possible). A charge will be made by the CSP for thls service. Contact: Maureen Muir, information Officer, Education Department, The Chartered Society of Physiotherapy.

Physiotherapy is a peer reviewed Journal which is indexed in Physiotherapy index, CINAHL and Exerpta Medlca. The figures at the end of each entry are the first and last page numbers.

Archives of Physical Medicine and Rehabilitation 1993, vol 74, no 4, April Ethical considerations in rehabilitation medicine. G R Scofield.

Technique to improve chronic motor deficit after stroke. E Taub, N E Miller, T A Novack 8t a/. 347-354. Patterns of visual spatial inattention and their functional significance in stroke patients. M J Chen Sea, A Henderson, S A Cermak. 355-360. The image of aphasia on marital satisfaction. S E Williams.

Traumatic brain injury as a risk factor for behavioural disorders in children. L J Michaud, F P Rivara, K M Jaffe et a/. 368-375.

341-346.

361 -367.

Performance comparison among children fitted with myoelectric and body-powered hands. J E Edelstein, N Berger. 376-380. Gait parameters of children with spastic diplegia: A comparison of effects of posterior and anterior walkers. B M Greiner, J M Czerniecki, J C Deitz. 381-385. Rehabilitation approaches to children with osteogenesis imperfecta: A ten-year experience. H Binder, A Conway, L H Gerber. 386-390. Preprogrammed reactions in individuals with Down sydrome: The effects of instruction and predictability of the perturbation. M L Latash, G L Atmeida, D M Corcos. 391-399. Exercise to improve gait velocity in older persons. J 0 Judge, M Underwood, T Gennosa. 400-406. Quadriceps angle and rearfoot motion: Relationships in walking. T W Kernozek, N L Greer. 407-410. Persistent facial myoclonus: A negative prognostic sign in patients with severe brain injury. M E Sandel, M W O’Dell. 411-415. A functional and psychosocial assessment of patients with post-Sudeck atrophy amputation. D SzeinbergArazi, M Heim, H Nadvorna et a/. 416-418. Baltimore therapeutic equipment work simulator: Energy expenditure of work activities in cardiac patients. N A Wilke, L M Sheldahl, S M Dougherty et at. 419-424. Active or passive physiotherapy for occupational cervicobrachial disorders? A comparison of two treatment methods with a 1-year follow-up. S Levoska, s Keinanen-Kiukaanniemi. 425-430. Increasing the wearing time of vinyl urinary drainage bags by decontamination with bleach. C A Dille, K T Kirchhoff, J J Sullivan, E Larson. 431-437.

Rebox: An adjunct in physical medicine? F Johanssen, A Gam, B Hauschild eta/ . 438-440. The Vannini-Rizzoli orthosis: A unique case of thoracic outlet syndrome. K L Dec, B R Vasquez. 441-444. Drug-induced dysphagia. J A Sliwa, S Lis. 445-447.

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