Repetitive Peripheral Magnetic Nerve Stimulation (rPMS) as Adjuvant Therapy Reduces Skeletal Muscle Reflex Activity

Abstract

Background: The reduction of muscle hypertonia and spasticity, as well as an increase in mobility, is an essential prerequisite for the amelioration of physiotherapeutical treatments. Repetitive peripheral magnetic nerve stimulation (rPMS) is a putative adjuvant therapy that improves the mobility of patients, but the underlying mechanism is not entirely clear. Methods: Thirty-eight participants underwent either an rPMS treatment ( N = 19) with a 5 Hz stimulation protocol in the posterior tibial nerve or sham stimulation ( N = 19). The stimulation took place over 5 min. The study was conducted in a pre-test post-test design with matched groups. Outcome measures were taken at the baseline and after following intervention. Results: The primary outcome was a significant reduction of the reflex activity of the soleus muscle, triggered by a computer-aided tendon-reflex impact. The pre-post differences of the tendon reflex response activity were −23.7% ( P < 0.001) for the treatment group. No significant effects showed in the sham stimulation group. Conclusion: Low-frequency magnetic stimulation (5 Hz rPMS) shows a substantial reduction of the tendon reflex amplitude. It seems to be an effective procedure to reduce muscular stiffness, increase mobility, and thus, makes the therapeutic effect of neuro-rehabilitation more effective. For this reason, the 5 Hz rPMS treatment might have the potential to be used as an adjuvant therapy in the rehabilitation of gait and posture control in patients suffering from limited mobility due to spasticity. The effect observed in this study should be investigated conjoined with the presented method in patients with impaired mobility due to spasticity.

A study of flex miniaturized coils for focal nerve magnetic stimulation

“…[22][23][24][25][26][27] MS uses similar TMS devices to target the peripheral nervous system (PNS) or peripheral magnetic stimulation (PMS) for investigational nerve conduction studies, [28][29][30][31] to treat different neurological [32][33][34] and musculoskeletal impairments. [34][35][36][37][38][39][40][41] In a typical PMS session, a standard figure-of -eight or a circular coil is applied over specific muscles or nerves, such as the trapezius and the deltoid, to treat migraine, 34,42,43 or the sacral nerve to treat urinary and fecal incontinence. [44][45][46] Furthermore, PMS is increasingly being studied for stimulating both the spinal root and the peripheral nerve levels in treating neuropathic pain.…”

“…[44][45][46] Furthermore, PMS is increasingly being studied for stimulating both the spinal root and the peripheral nerve levels in treating neuropathic pain. 33,47 Besides already existing TMS devices, other coil geometries have been proposed, such as the parabolic coil, used to administer PMS as an adjuvant therapy to reduce skeletal muscle reflex activity 35 or the elliptical coil as a monotherapy for the treatment of lumbar radiculopathy. 48 Newly approved devices developed explicitly for PMS are also available to treat particular conditions, such as stress urinary incontinence (SUI), neuropathic pain, and peripheral neuropathy.…”

Controversies and Clinical Applications of Non-Invasive Transspinal Magnetic Stimulation: A Critical Review and Exploratory Trial in Hereditary Spastic Paraplegia

“…Another possibility would be that the intense direct muscle recruitment and peripheral nerve stimulation at the stimulation sites, undoubtedly a limited form of peripheral magnetic stimulation, would indirectly modulate spinal tissue. When performed on limbs, it has been documented as being able to reduce spasticity scores and alter tendon reflexes with several inhibitory protocols, including 5 Hz, 20 Hz, 50 Hz, and continuous theta burst [ 50 ]. While this could be initially attributed to a proprioceptive modulation of upper spinal circuitry, H-reflex and F-wave were left unchanged in two studies that included neurophysiological testing [ 51 , 52 ].…”

Checklist on the Quality of the Repetitive Peripheral Magnetic Stimulation (rPMS) Methods in Research: An International Delphi Study

“…It is non-invasive and painless with negligible side effects. Over the two last decades, this technique has gained popularity to reduce chronic pain or improve sensorimotor function in physiopathology and its clinical potential is currently being tested in several population ( 1 , 5 – 24 ).…”