FES and spasticity

Abstract

A model of hemiplegic spasticity based on electromyographical and biomechanical parameters measured during passive muscle stretching is presented. Two components of spasticity can be distinguished--phasic and tonic. This classification depends on the pattern of stretch reflex activity which can be either phasic or tonic as well as on the muscle stretch/tension characteristic. Stretch reflex, as a control loop, is in phasic spasticity characterized by increased sensitivity to velocity of stretching. In tonic spasticity, sensitivity to length of stretching is increased. After the injury, phasic spasticity appears first and invokes monosynaptic reflex pathways. The intensity of tonic spasticity increases with the duration of disability and hence causes changes in muscle fiber biomechanical properties. The model mentioned above has been used to evaluate the effects of FES on spasticity. Hemiplegic patients with implanted peroneal nerve stimulator for gait correction were followed up for one year starting a week before implantation. Long-term use of FES resulted in decrease of tonic spasticity in both ankle joint antagonistic muscle groups. In stimulated tibialis anterior muscle, the phasic type of spasticity increased. To obtain the correlation between changes in spasticity and functional abilities of patients, the maximal voluntary isometric contraction of both muscle groups was also measured. An improvement in voluntary strength was also observed. This can be taken as additional evidence that tonic spasticity is of greater physiological and clinical significance than phasic spasticity. It may be concluded that use of FES can decrease tonic spasticity and, if applied early after the injury, can prevent the appearance of tonic spasticity.

Functional electrical stimulation as a safe and effective treatment for equine epaxial muscle spasms: Clinical evaluations and histochemical morphometry of mitochondria in muscle biopsies

“…used extensively over several decades as an effective means to reduce or reverse muscle atrophy and to obtain some functional recovery by rehabilitation strategies for spinal cord injury patients, [1][2][3][4][5] including those paraplegics with permanent and complete denervation of the legs (complete Conus and Cauda Equina Syndrome). [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23] The benefits of this technology are being expanded into other areas, and FES has been recently utilized for injury rehabilitation and performance enhancement in horses.…”

Review of electrical stimulation, botulinum toxin, and their combination for spastic drop foot

“…Spasticity of spinal origin can be similar but tends to involve more flexor spasms of the lower limbs. Stefanovska et al divided spasticity into "tonic" and "phasic" components [20][21], depending on whether sensitivity to velocity or length of stretch increased. Study of spasticity in general is also complicated by the fact that both involvement of different descending tracts [22] and the amount of time after an upper motor neuron lesion [11] can influence the nature of the deficit and the response to therapy.…”

“…PNS in paraplegia from SCI has also been shown to aid gait by generating a knee/hip withdrawal reflex [37], although the effects on these joints in MS seem less clear [39]. Although there has been some investigation into percutaneous and implanted systems [20][21]40], surface FES systems are widely available and have fewer contraindications. PNS has been investigated both for its potential gait improvement while the patient is actively using the device, the "orthotic effect," [41] and for its rehabilitation benefit after the device is no longer in use, the "therapeutic effect."…”

Cycle-to-cycle control of swing phase of paraplegic gait induced by surface electrical stimulation

“…It has been reported that warming up prior to, for example, standing up or ambulation prevents the occurrence of spasticity (STEFANOVSKA et aL, 1989). (ii) Stimulation onset and burst duration were optimized (Section 3.3).…”