Acrocyanosis in a spinal cord injured patient - effects of computer-controlled neuromuscular electrical stimulation: a case report.

Acrocyanosis is a circulatory disorder of the hands or feet. The term acrocyanosis is derived from the Greek words akron (extremity) and kyanos (blue). The arterioles (the smaller precapillary vessels) of the acrocyanotic patient's involved hands or feet are abnormally constricted, causing a reduction in blood flow and accounting for the cyanosis. In the non-spinal cord injured individual, the veins are secondarily dilated, perhaps because of the effects of ischemia. In the spinal cord injured individual, however, the veins are dilated because of the loss of normal vasomotor tone in the abdomen and the lower extremities; this condition is especially common after a midthoracic or cervical cord lesion. [1] in addition, peripheral edema and a high incidence of deep vein thrombosis (DVT) have been reported soon after the injury because of circulatory stasis in the lower extremities. [2,3]

Recently, researchers and clinicians have begun to investigate computerized neuromuscular electrical stimulation (NMES) of weakened or paralyzed muscles as a means of preventing or reversing some of the circulatory problems that occur following traumatic spinal cord injury (SCI). [4] The aim of using NMES in the individual with SCI is to elicit muscular contractions that are no longer under the patient's voluntary control by using direct electrical current via surface or implanted electrodes. Sophisticated computer technology and bioengineering have made it possible to use microprocessor-controlled electrical stimulators, which are capable of stimulating numerous different muscle groups at one time, depending on the number of channels of surface electrodes. Computer-controlled NMES systems also enable patients to receive constant, preprogrammed stimulation of muscle groups for potentially lengthy periods of time.

Research to date, however, about the effects of computerized NMES in the patient with SCI has focused mainly on exercise training effects based on structural and biochemical changes that occur within the muscles. [5] Literature regarding the effects of the clinically available NMES units on blood flow in healthy individuals appears to be aimed mainly at determining the effects of different intensities of electrical current or various pulsed frequencies on blood flow in the extremities. [6] The purpose of this case report is to document empirical observations of improved circulation and wound healing and decreased edema in the feet of a spinal cord injured patient following the application of computerized NMES over a period of six weeks.

Patient Data and Treatment

The 37-year-old white male patient in this case report sustained a traumatic SCI at the age of 16 years, which resulted in an incomplete vertebral fracture at the C5-C6 level. The patient functioned at a level of C6-C7. Currently, his full-time job and daily activities keep him confined to his wheelchair for approximately 10 to 15 hours per day. Since his initial injury, there has been no formal rehabilitation. His family assists with his activities of daily living and provides assistance for standing in parallel bars with short leg braces for 10 to 15 minutes, two times per week.

About eight months prior to referral for physical therapy, the patient noticed "spotty blue areas" on both feet. The condition worsened until both feet and toes remained a blue-black color for six months with ulcers on all toes. The patient complained of swelling in both feet and of discomfort while wearing his shoes. A vascular surgeon was seen for pharmacological and possible surgical intervention. The vascular surgeon performed no angiographic studies upon initial consultation to verify possible obstruction; however, the results of a clinical evaluation verified weak pedal pulses bilaterally. Pulses in the popliteal and femoral regions were normal bilaterally. The patient was instructed to elevate both feet, note any swelling and coloration changes, and begin a program of computerized NMES-induced bicycle ergometry. The goal of the NMES-induced ergometry was to reduce the amount of noticeable cyanosis and to promote wound healing.

Prior to treatment, roentgenograms of the patient's hips, knees, and ankles were taken bilaterally to rule out any old fractures and to detect any significant osteoporosis that might he present. Physical therapy evaluation revealed passive range of motion to be minimally limited in straight leg raising, hip extension, and ankle dorsiflexion, bilaterally. Manual muscle testing revealed voluntary muscle control in the Trace to Poor range about the hips, knees, and toes. The patient's muscle strength on knee extension was Fair-plus bilaterally. Sensation, including proprioception, was preserved below the level of the lesion.

Following the medical screening and physical therapy evaluation, the patient was prepared for computerized NMES-induced bicycle ergometry. The treatment protocol consisted of two phases: 1) a leg-training phase, which consisted of quadriceps femoris muscle training, and 2) a lower extremity bicycle ergometry phase, which consisted of quadriceps femoris, hamstring, and gluteus maximus muscle training.

Phase 1-Leg Training

The patient was positioned in 90 degrees of hip and knee flexion in the specially designed chair of the REGYS I Clinical Rehabilitation System (Fig. 1). Three carbon surface electrodes measuring 4.5 X 10 cm and prepared with hypoallergenic electrode gel were positioned over the anterior surface of the thigh. In addition, the electrodes were secured to the surface of the thigh with a hypoallergenic tape. A monophasic, constant-current waveform with a pulse frequency of 30 Hz was applied to the two active electrodes (anodes). The reference electrode (cathode) was positioned between both active electrodes (Fig. 2). Each stimulus pulse on the REGYS I system has a duration of 350 [micro]sec and an amplitude range of 0 to 132 mA. The amplitude is determined by the system's microprocessor computer in accordance with the demands programmed into the computer by the operator (eg, rate of repetition, knee extension ROM).

The rise-fall time of the stimulation envelope was set for a three-second rise, a two-second hold, and a three-second fall. A 12-second relaxation time interval was programmed between contractions to prevent fatigue and a sensation of cramping between successive stimulations. The goal of the leg-strengthening phase of the treatment program was for the patient to lift (with 30 degrees -45 degrees of knee extension) an external load of 6 to 11 kg placed on each ankle 15 consecutive times. The patient successfully completed Phase 1 in six weeks in the following manner: Week 1-one session, no weight; Week 2-two sessions, 2 kg of weight; Week 3-two sessions, 4 kg of weight; Week 4-two sessions, 6 kg of weight; Week 5-two sessions, 8 kg of weight; Week 6-three sessions, 11 kg of weight. Each treatment session lasted for about 30 to 40 minutes. No changes in blood pressure, heart rate, or body temperature (by oral thermometer) were noted during any of the treatment sessions.

Improvements in the color of the patient's feet and subjective reports by the patient of less discomfort and swelling while wearing his shoes were noted during Week 2 of Phase 1. After the fifth week of Phase 1, the patient's feet had returned to their normal color and size and the toe ulcers were nearly healed. The patient was referred back to his physician for a reevaluation. The physician performed a clinical evaluation, which confirmed the improvements in skin color, swelling, and toe ulceration. Pedal pulses were stronger bilaterally. Upon the completion of Phase 1, the patient commenced Phase 2 of the treatment program.

Phase 2-Lower Extremity Bicycle Ergometry

The patient was again positioned in the specially designed chair of the REGYS 1 system. In Phase 2, the patient's quadriceps femoris, hamstring, and gluteus maximus muscles were stimulated, respectively. Three carbon electrodes were positioned over the anterior surface of the quadriceps femoris muscle (as in Phase 1), on the dorsal aspect of the upper thigh over the hamstring muscle group, and on each gluteus maximus muscle. The electrodes used for the hamstring and gluteus maximus muscles measured 4.5 x 4 cm. The reference electrode was positioned between the active electrodes (Fig. 2). Electrodes were prepared with gel and secured with tape (as in Phase 1). Wire leads attached to each electrode fed back into a unit, which controlled the succession of stimulation to the six channels.

The patient was secured in the chair with a shoulder harness and waist belt. His feet were secured in plastic boots that were affixed to the pedals of the bicycle. Woolen booties were worn inside the plastic boots to further protect the skin of the feet. The sequence of the stimulation (ie, quadriceps femoris, hamstring, and gluteus maximus muscles), which simulated the motions of bicycle riding, was controlled via position sensors in the bicycle pedals that fed back information to potentiometers in the stimulus-control unit. These potentiometers measured the rate and range of limb motion during successive stimulation and allowed the computer to make appropriate adjustments in amplitude intensity) of stimulation to the muscles for safety and efficacy of treatment (Fig. 3).

Discussion

The patient in this case report was a subject in a larger study analyzing the physiological and psychological consequences" of a computerized NMES program. Thus, no objective measurements changes in blood flow or pictorial verification of the condition of this patient's feet before and following leg strengthening or bicycle ergometry were available for this case report. The subjective improvements in the patient's skin color, swelling, and complaints of discomfort, however, should be reported. A personal communication (G Zemke, personal communication, 1988) during a yearly conference of physical therapists who use computerized NMES systems revealed a second patient (TI2 paraplegic as result of SCI sustained two years previously) with cyanosis of both lower extremities from the knees to the toes whose skin color also improved after about six weeks of use of the REGYS I system.

Although this case report did not attempt to establish a correlation between blood flow response and the use of computerized NMES, empirical observations of improved circulation and wound healing were noted. Future studies max, attempt to establish correlations between the use of computerized NMES and increased blood flow, decreased edema, and improved wound healing in the lower extremities of spinal cord injured patients with acrocyanosis. For example, future studies might be aimed at obtaining quantitative measurements of arterial blood flow velocity via Doppler ultrasound flowmetry [7,8] or at using venous plethysmography [9,11], to determine venous hemodynamics before and after computerized NMES treatment. Future analysis should also include control groups to study the effects of various intervening variables on dependent measures.

Conclusion

The empirical clinical findings noted in this case report should alert clinicians that a potential might exist for improving lower extremity circulation using computerized NMES in the spinal cord injured individual with acrocyanosis.

Further study, however, is needed to determine whether a significant relationship may exist.

Acknowledgments

I thank David Fiorini, Stephen Papp, and Dawn Scaramuzza, Norwalk Hospital, Norwalk, Conn, for their contributions to patient care.

References

1 Guttman L: Disturbances of vasomotor control. In Guttman L (ed): Spinal Cord Injuries: Comprehensive Management and Research. oxford, England, Blackwell Scientific Publications Ltd, 1976, pp 295-330

2 Walsh JJ, Tribe C: Phlebo-thrombosis and pulmonary embolism in paraplegia. Paraplegia 3:209-213, 1965

3 Green D, Rossi EC, Yao JS, et al: Deep venous thrombosis in spinal cord injury: Effect of prophylaxis with calf compression, aspirin, and dipyridamole. Paraplegia 20:227-234, 1982

4 Petrofsky JS, Phillips CA: Active physical therapy: A modern approach for rehabilitation of the disabled. journal of Neurological and Orthopedic Surgery 4:165-173, 1983

5 Glaser RM: Physiologic aspects of spinal cord injury and functional neuromuscular stimulation. Cent Nerv Syst Trauma 3:49-62, 1986

6 Tracy JE, Currier DP, Threlkeld AJ: Comparison of selected pulse frequencies from two different electrical stimulators on blood flow in healthy subjects. Phys Ther 68:1526-1532, 1988

7 Fisher DC, Altobelli SA: Physical principles of Doppler ultrasound: Measuring movement with sound. Postgrad Med 78:118-130, 1985

8 Halpern N: Ultrasound in cerebral and peripheral vascular disease: Clinical applications. Postgrad Med 78:137-148, 1985

9 Frieden RA, Ahn JH, Pineda HD, et al: Venous plethysmography values in patient with spinal cord injury. Arch Phys Med Rehabil 68:427-429, 1986

10 Dresler CM, Jeevandam M, Brennan MF: Extremity blood flow in man: Comparison between strain-gauge and capacitance plethysmography. Surgery 1:35-39, 1986

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