Impact of Direct Current Electrical Stimulation on Spasticity Levels and Functional Muscle Use in MS

In an individual with MS the central nervous system (CNS) is over-protective and causes the threshold for stretch reflex and muscle tightness to be set lower than normal. This inhibits normal movement and causes abnormalities in posture, stiffness and at times joint contractures. In this pilot study we hope to assess the ability for the direct current of Neubie, which creates mechanoreceptor inputs and lengthening at the sarcomere level of muscle and joints in the spine and lower extremity, to alter the proprioceptive peripheral nervous system (PNS) at muscle spindle and GTO level with a change in CNS over-guarding during the treatment and after the treatment. If the investigators are able to create normalized stretch and muscle tension at the PNS level, it may be possible to create temporary or sustained CNS level changes. This would allow the amount of stretch and tension at the PNS level to be normalized and possibly reduce spasticity. If this theory is accurate, the investigators may be able to increase access to normalized movement, strength and functional ability in individuals with neuro-compromise.

Approximately 66%6 to 84% of individuals with multiple sclerosis experience various levels of debilitating spasticity limiting freedom of movement at ankles, knees and hips causing deficits in ambulation, weakness from disuse of muscles not accessible due to spasticity. Per the North American Research Committee on Multiple Sclerosis, a survey was conducted on spasticity prevalence and results show 84% have some degree of spasticity from mild to incapacitating. Spasticity pathophysiology is complex and not completely understood with higher levels of incapacitating spasticity reported in this survey by those who were male, disabled and unemployed, indicating that psychosocial and subjective variables are significant. The pathophysiology currently best understood demonstrates an imbalance between inhibitory dorsal reticulospinal tract (RST) fibers and excitatory bulbopontine tegmentum. RST neurons receive direct somatic, vestibular, tectal, cerebellar and motor excitatory input and are scattered in the ventral and lateral spinal cord columns intermingled with propriospinal fibers. The peripheral Golgi tendon organ of muscle tendon and muscle spindle intrafusal fibers ubiquitous throughout the musculoskeletal system have direct monosynaptic connection to these central nervous system propriospinal fibers and heavily influence the degree of spasticity and overactive stretch reflexes.

Those who deal with all levels of spasticity use compensatory movement strategies causing altered arthrokinematics and have loss of strength, balance and efficient muscle use with postural changes. Spasticity management has been studied and treated from a pharmaceutical standpoint with some improvements but often side effects including fatigue, muscle weakness and cognition limit dosing in oral Baclofen, Dantrolene Sodium, Tizanidine and Benzodiazepines. Marijuana especially in form of cannabinoids shows mixed evidence for spasticity improvement and is a growing area of interest. There is a growing CBD interest in the MS population due to known reduction of CNS neurodegeneration in animal MS studies and no significant negative side effects with possible mild to moderate improvement in spasticity levels. Therapy interventions offered include frequent stretching especially of muscles that cross two joints including lumbricals, hamstrings, gastrocnemius and iliopsoas; light stroking over lower limbs demonstrated a 30% decrease in H-reflex amplitude lasting even 30 minutes after treatment; muscle cooling was shown to reduce muscle stretch activity and clonus; Armutlu et al. Reported significant reduction in plantar flexor spasticity in 10 patients with MS using high-frequency (100Hz) TENS for 20min daily for 4 weeks. Reduction noted on Modified Ashworth Scale (MAS), electrophysiologic measurements and the AI; and serial casting performed over a 9-day period with cast changes every 3 days demonstrated reduced spasticity levels.

The NeuFit company offers a Neubie EMS product with a direct current using high fidelity audio equipment to decrease intensity of the treatment noxious stimulus and protect skin integrity from burns or intolerable pain. This system uses an exponential wave pattern to mimic the natural pattern neurologically to lengthen fibers of the sarcomere and engage force velocity of muscle with minimized protective co-contraction of nearby muscle groups9. The golgi tendon and muscle spindles code for joint position and muscle/tendon stretch with 66% of fibers being intrafusal. Impacting these structures has direct impact on reticulospinal tract (RST) fibers and proprioceptive central fibers modulation of levels of spasticity. However, finding effective means to impact these areas is difficult. The Neubie direct current is designed to improve positioning of these stretch receptors. As discussed within the paper hypothesis, the theory is that this may improve spasticity levels as well as agonist strength enough to create long term, significant functional improvement.

Dr. Terry Wahls who has MS and has studied and marketed a protocol for MS treatment, promotes this product and has a home unit she uses daily to control her own MS symptoms and gain strength. Currently there is no research study conducted on the effects of the Neubie direct current treatment combined with exercise and ramifications of spasticity in multiple sclerosis. There have been only a few studies conducted with quantitative spasticity measures mostly with FES and NMES targeting tibialis anterior and quadriceps to lessen plantar flexor spasticity in spinal cord injury (SCI) and hemiplegia. In the SCI study Mirbagheri et al. observed decreases in intrinsic and reflex dynamic stiffness in all 4 subjects studied over a 16-month period. Robinson et al. stimulated quadriceps muscle pulse duration 500, 20 Hz and amplitude of 100 with spasticity quantitatively reduced immediately after stimulation but return of baseline spasticity level when measured 24 hours later. Levin and Hui-Chan assessed sensory level stimulation of the common peroneal nerve for a total of 15, 60 min sessions for 3 weeks in people with hemiplegia using pulse duration 125 continuously at 99Hz and observed inhibition of H-reflex at soleus, increase in dorsiflexion voluntary force and reductions in stretch reflex at triceps surae. The NeuFit method of treatment allows the recipient to voluntarily concentrically or eccentrically activate muscles while receiving the direct current passive eccentric input. In order to assess the feasibility of this papers' hypothesis the investigators will perform a pilot study of 4-6 individuals with MS in the greater Denver metro area.

Eligibility Criteria:
Inclusion Criteria:

1. Greater than 18 years old (no upper age limit)
2. Physician diagnosed MS (As stated in Rooney S, et al. Disabil Rehabil. 2019, stage of MS did not impact individuals from making neuromuscular or functional gains. All stages of MS will be eligible)
3. Physician clearance to participate
4. Unable to ambulate more than 70 feet at a time and unable to ambulate outside the home, with use of manual chair or power chair as mobility source \>= 50% of the time.
5. BLE MMT in hips, knees and ankles \<=3/5
6. Modified Ashworth assessed spasticity levels 1-4

Exclusion Criteria:

1. Co-morbidities in cardiovascular disease (myocardial infarction in past 1-year, unstable angina, CHF, h/o arrythmia, h/o CVA or TIA in past year, uncontrolled hypertension)
2. History of epileptic seizures
3. Lower Motor Neuron disease
4. Existing pacemaker, defibrillator or other implanted device (other than baclofen pump)
5. Unstable long bone fractures of lower limb or trunk
6. Allergies to surface electrodes or conductive gel
7. Pregnancy or actively seeking to become pregnant