Biofeedback and Self-Regulation, Vol. 9, No. 4, 1984

Bringing the Feet in from the Cold: Thermal

Biofeedback Training of Foot-Warming in Raynaud's Syndrome I

David Crockett 2 and Danie l Bilsker

University of British Columbia

The biofeedback-assisted treatment o f a case o f Raynaud's syndrome was examined in order to determine the relationship between learning o f the hand- warming response and the subsequent ability to produce foot-warming responses. It was f o u n d that fluctuations in dermal hand and foo t tempera- tures were not significantly related, either within or across treatment sessions. The obtained hand-warming response was o f high magnitude and rapidly learned, while the foot-warming response was mote modest and took sub- stantially more trials to learn. These results indicate that an easy generaliza- tion o f the hand-warming response cannot be assumed.

Descriptor Key Words: Raynaud's syndrome; foot warming; biofeedback training.

Raynaud's syndrome involves a chronic cardiovascular insufficiency in the hands and feet, due to spasm of peripheral vaculature. This disorder often causes pain; without treatment it may lead to lesions. Onset of the vascular spasms has been related to such factors as physical trauma, cold, emotional stress, and scleroderma. A number of studies have shown that thermal bi- ofeedback may provide an effective treatment for this disorder (Freedman, Ianni, & Wenig, 1983; Freedman, Lynn, Ianni, & Hale, 1981; Surwit, Pilon, & Fenton, 1978; Blanchard & Haynes, 1975). Such treatment relies on the provision of precise information as to the temperature of the affected region.

~The authors would like to thank the subject of this experiment for volunteering her time, and R. Toren for her secretarial services,

2Address all correspondence to D. J. Crockett, Division of Psychology, Health Sciences Centre Hospital, 2255 Wesbrook Mail, Vancouver, B.C., Canada V6T 2A1.

431

0363-3586/84/1200-0431503.50/0 © 1984 Plenum Publishing Corporation

432 Crockett and Bilsker

The goal of the treatment is to allow the individual to dilate peripheral blood vessels voluntarily, thus raising the skin temperature.

What is striking about the various studies of thermal biofeedback in Raynaud's syndrome is that virtually all are concerned with training vasodi- lation of the hands. In a review of the literature, we were able to find only one study (Schwartz, 1973) that described the use of biofeedback to train foot warming. The source of this lacuna lies in the belief that the hand- warming response should generalize to the feet. Such generalization may take two forms. First, it may be that the specific skills or mediating processes learned to warm the hands will be readily applicable to foot warming as well. Second, it may be that hand warming is accomplished by elicitation of a gener- al relaxation response, among the concomitants of which is peripheral vasodi- lation. Thus, the learned response that leads to hand warming should have a corresponding effect on the feet.

In this paper, we will present some evidence to show that hand and foot warming in Raynaud's syndrome may be dissociated responses, with virtually no generalization f rom one to the other. In addition, we will con- sider the unique problems of training foot warming through biofeedback, and describe some techniques we have found useful.

C A S E H I S T O R Y

The patient is a 29-year-old woman who had definite signs of Raynaud's syndrome for the last 2 years, with some premonitory signs for the 4 years before that. At the beginning of treatment, she had an attack at least every day, with both her hands and her feet being affected. These attacks lasted between 1 and 2 hours, with long-standing redness of the feet after the at- tack. She had developed some painful ulcers underneath the toe pads, par- ticularly on her left foot. Her physical examination was generally asymptomatic. There were some dystrophic changes around her fingernails, with no infection but some increased flaking of the skin and a slight red- ness. No dilated capillaries were noted, nor was there any pulse-space wast- ing. At the time of the initial examination, her feet were of a bluish color, and the second toe of the left foot demonstrated a slight bluish-red spot. Labora tory investigations were uniformly negative.

M E T H O D

The patient was seen on a biweekly basis over the course of a year. In- strumentation included a J and J Thermal Biofeedback Unit (T-67), with

Training of Foot Warming 433

two thermistors attached to either her fingers, the soles of her feet, or her toes. This instrument was set to provide auditory feedback contingent upon thermal shifts greater than .28 ° C. The tone became progressively louder with increased magnitudes of changes. All data were accumulated with a J and J Digital integrator (D-200). Thermistors were located on the first finger- pad of her right and left middle finger, on the soles of her feet at approxi- mately the midpoint of her arch, or on the pad of the right and left big toe. All temperature readings were averages, calculated over a 4-minute record- ing period.

A typical session included a 10-minute adaptation period, during which the patient sat in a temperature-controlled environment as her weekly symp- tom history was taken. Following this, a baseline temperature reading was taken. Biofeedback-assisted thermal training was then carried out over the next seven 4-minute periods. This training involved the provision of continu- ous auditory feedback contingent upon positive thermal changes from specific sites in response to autogenic instructions. The autogenic instructions involved assuming a relaxed sitting posture while the patient concentrated on phrases conducive to skin warming (e.g., "My left hand is heavy and warm"). These phrases were supplemented with images of warmth such as imagining beach scenes, manipulating hot potatoes, removing objects from warm ovens, chang- ing light bulbs, and washing dishes. Thus, our autogenic procedures were con- sistent with the approaches outlined by Schultz and Luthe (1969) and Green and Green (1979). Following the training interval, a final temperature read- ing was obtained, once again using a 4-minute interval. Finally, home prac- tice was assigned, which consisted of listening to a 20-minute autogenic tape on a twice-a-day basis. In addition, the patient was instructed to rehearse the autogenic method at regular intervals throughout her day. To help moti- vate her, she was provided with a cholesteric liquid crystal strip to provide a rough estimate of her skin temperature before and after she engaged in her home practice (physiological trend indicator MDC-8010-5). Since it was impossible to standardize her application of this measurement device, this information was not included in this report.

It is interesting to note that the experimenters' suggested techniques for foot warming (e.g., concentrating on autogenic phrases and focusing on im- ages involving warming of the feet) were eventually augmented by the pa- tient with a technique she had found effective. Her technique began with producing the hand-warming response that she had learned through the bio- feedback technique. She then gradually moved the site of her concentra- tion down the body, warming successively her trunk, thighs, and calves, to her feet. Thus, the patient appeared to form spontaneously a method analo- gous to the progressive muscle relaxation method described by Jacobson

434 Crockett and Bilsker (1938). Perhaps her technique could be best described as progressive auto- genic relaxation.

Our posttreatment measure was the highest temperature reading ob- tained from each site following the determination of baseline levels. In most cases, this maximum reading was also the last reading, but in a few instances, skin temperature declined slightly after this high point was reached.

RESULTS

The first step in our analysis was to determine whether changes in hand and foot temperature across sessions were significantly correlated. Product- moment correlations were computed for baseline temperature readings at the three recording sites. There is no significant correlation, by two-tailed test, between baseline temperatures of hands and soles (r = .13, n = 22, p = n.s,) or hands and toes (r = .14, n = 20, p = n.s.). By contrast, readings from the soles and toes of the feet are much more consistent (r = .70, n

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Training of Foot Warming 435

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= 18, p < .01). A s imi lar analysis was car r ied out for pos t t r ea tmen t tem-

pe ra tu re readings . Once again , changes in hand t e m p e r a t u r e are not signifi- cant ly cor re la ted with changes in readings f rom the soles (r = .28, n = 22, p = n.s .) or f rom the toes (r = .13, n = 20, p = n.s .) , while soles and

toes are h ighly cor re la ted (r = .88, n = 18, p < .01). The next step was to determine the extent to which t empera tu re changes

within sessions were associated. P roduc t -momen t correlat ions were computed for wi th in-sess ion change scores (pos t t r ea tmen t t empe ra tu r e minus basel ine tempera ture) at the three recording sites. Change in hand tempera tu re showed

a nons ign i f ican t cor re la t ion with changes in s01e t e m p e r a t u r e (r = .41, n = 22, p = n.s .) and toe t empe ra tu r e (r -- - .38, n = 20, p = n.s .) ; changes

in soles and toes are not s igni f icant ly cor re la ted (r = . 14, n = 18, p = n.s .) . The changes in t empera tu re o f the hands , soles, and toes were also exa-

mined across sessions. These changes are presented in Figures 1, 2, and 3. A c o m p a r i s o n o f the p re t r ea tmen t basel ine and the pos t t r ea tmen t measures indicates that the changes observed for the hands were larger than the changes obtained for the soles or toes. Temperature change for the hands was + 5.99 ° C

436 Crockett and Bilsker

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Fig. 3. Changes in pretreatment baseline and posttreatment temperature read- ings for toes.

(n = 26 sessions, SD = 2.63); for the soles it was + .70 ° C (n = 23 sessions, SD = 1.38); and for the toes it was +1.61 ° C (n = 21 sessions, SD = 1.29). A l t h o u g h the magn i tude o f the d i f ference o f the pos t t r ea tmen t t empera tu re readings decreased over sessions, there was v i r tua l ly no over lap a m o n g the final t empera tu re readings f rom these sites.

It should be no ted tha t there was an enhancemen t o f basel ine skin tem- pe ra tu re over the course o f t r ea tmen t for the hands and soles. The corre la- t ion between basel ine t empe ra tu r e and session number for the hands is .45 (n = 26, p < .05); for the soles it is .53 (n = 23, p < .01). No such en- hancemen t was f o u n d for the toes (r = .26, n = 22, p = n.s .) . The evidence indicates that the foo t -warming response was gradual ly learned over sessions: The corre la t ion between within-session tempera ture change and session num- ber was .52 for the soles (n = 23, p < .01). However , the h a n d - w a r m i n g response shows no such enhancemen t over sessions, with a cor re la t ion o f - . 18 (n = 26, p = n.s .) be tween t empera tu re change of the hands and ses- sion number .

Training of Foot Warming 437

DISCUSSION

Our observations, based on extensive examination of one client, are as follows. First, fluctuations in hand and foot temperature were not cor- related, nor were the changes in temperature obtained through biofeedback training methods. Second, the temperature change obtained for the hands was strikingly larger than that for the feet, with virtually no overlap between the distributions of within-session change for hands and feet. Third, exami- nation of the data across sessions indicates that the hand-warming response was learned within several sessions, showing no significant enhancement over succeeding sessions, while the foot-warming response was learned gradually over the course of treatment. The thrust of these observations is that foot warming does not seem linked to hand warming as part of a general relaxa- tion response, nor do the skills acquired in hand warming generalize easily or "automatically" to the foot-warming response. The two responses must be examined and trained separately, with the latter requiring considerably more attention.

The reasons for the low level of association between the two are not clear. It may be that the lesser innervation of the foot than the hand, and the correspondingly smaller area of representation in the cortex reduce the degree of voluntary control that is possible. Also, it has been noted by Taub (1977) that maintenance of blood supply to the foot is of relatively low pri- ority in cardiovascular regulation: Under cold stress, foot temperature falls much more rapidly than hand temperature. Thus, foot warming would be a more difficult response to learn.

Whatever the factors responsible for the observed dissociation, the ther- apist using biofeedback in the treatment of Raynaud's syndrome must take it into account. The training of foot warming requires considerable patience on the part of therapist and client. There must be a willingness to experi- ment with alternate strategies (e.g., imagery, other autogenic techniques, different thermistor sites). Skillful arrangement of contingencies can be used to minimize discouragement in the early stages. This can include shifting at- tention to the feet after successful hand warming is achieved; providing "props" to self-control, such as heavy socks, unusually warm room temper- ature, or heating pads appliedto the feet; and adjusting the biofeedback sys- tem to deliver feedback for modest temperature increases.

R E F E R E N C E S

Blanchard, E., & Haynes, M. (1975). Biofeedback treatment of a case of Raynaud's disease. Journal o f Behavior Therapy and Experimental Psychiatry, 6, 230-234.

438 Crockett and Bilsker

Freedman, R., Ianni, P., & Wenig, P. (1983). Behavioral treatment of Raynaud's disease. Journal of Consulting and Clinical Psychology, 51, 539-549.

Freedman, R., Lynn, S., Ianni, P., & Hale, P. (1981). Biofeedback treatment of Raynaud's disease and phenomenon. Biofeedback and Self-Regulation, 6, 355-365.

Green, E., & Green, A. (1979). General and specific applications of thermal biofeedback. In J. Basmijian (Ed.), Biofeedback: Priniciples and practice for clinicians. Baltimore: Wil- liams and Wilkins.

Jacobson, E. (1938). Progressive relaxation. Chicago: University of Chicago Press. Schultz, J., & Luthe, W. (1969). Autogenic therapy (Vol. I). New York: Grune and Stratton. Schwartz, G. E. (1973). Biofeedback as therapy: Some theoretical and practical issues. Ameri-

can Psychologist, 28, 666-670. Surwit, R. S., Pilon, R. N., & Fenton, C. H. (1978). Behavioral treatment of Raynaud's dis-

ease. Journal of Behavioral Medicine, 1, 323-335. Taub, E. (1977). Self-regulation of human tissue temperature. In G. E. Schwartz, & J. Beatty,

(Eds.), Biofeedback: Theory and practice (pp. 265-300). New York: Academic Press.