Spinal Cord Stimulation Assisted by Motor Rehabilitation Training for Restoring Motor Function After Spinal Cord Injury

The Medical Research Council's (MRC) scale of muscle power will be used to evaluate motor weakness. The MRC scale of muscle strength uses a score from Grade 5 (normal) to Grade 0 (no visible contraction) to assess the power of a particular muscle group in relation to the movement of a single joint.

The Lower Extremity Functional Scale (LEFS) will be used by clinicians as a measure of lower extremity function. It is a questionnaire containing 20 questions about a person's ability to perform everyday tasks (minimum score 0, maximum score 80).

Quantitative assessment of maximal voluntary isometric muscle force. Measurements were performed only in muscles reaching MRC grade ≥3, corresponding to active movement against gravity. The measured outcome was the maximal force generated during isometric contraction.

Quantitative kinematic assessment of isolated lower-limb movements using wearable inertial measurement units (IMUs). The measured outcomes were the peak hip flexion angle and peak knee extension angle during stimulation-assisted single-joint movements.

Functional evaluation of upright standing ability. Standing performance was quantified by:

• duration of maintained standing (minutes);
• percentage of body weight supported through the lower limbs, measured using a stabilometric platform.

10-Meter Walking Test (10MWT). Standardized assessment of walking speed over a 10-meter distance. The measured outcome was the time required to complete the test, from which walking speed can be derived. In motor-incomplete participants the test was performed in the OFF condition whenever feasible, whereas motor-complete participants were assessed during active stimulation.

Six-minute walk test (6MWT). Standardized assessment of walking endurance. The measured outcome was the total distance walked over six minutes. Motor-incomplete participants were assessed in the OFF condition whenever feasible, whereas motor-complete participants performed the test during active stimulation.

The Modified Ashworth scale will be used to evaluate spasticity. This scale grades the muscle tone from 0 (normal) to 4 (severe spasticity).

Electromyography will be used to evaluate muscle response or electrical activity in response to a nerve's stimulation.

Motor evoked potentials will be used to evaluate electrical signals recorded from the descending motor pathways or from muscles following stimulation of motor pathways within the brain.

Sensory evoked potentials will be used to assess electrical activity in the brain in response to sensory stimulation.

Structural and functional brain and spine MRI analysis.

The McGill Pain Questionnaire (MPQ) can be used to evaluate a person experiencing significant pain. It consists of 15 descriptors (11 sensory; 4 affective) which are rated on an intensity scale as 0 = none, 1 = mild, 2 = moderate or 3 = severe.

The Pain Catastrophizing Scale (PCS) assesses the extent of catastrophic thinking. It assesses the extent of catastrophic thinking due to low back pain according to 3 components: rumination, magnification, and helplessness. It is a 13-item scale, with a total range of 0 to 52. Higher scores are associated with higher amounts of pain catastrophizing.

12-item Allodynia Symptom Checklist (ASC-12) evaluates presence of allodynia and hypoesthesia.

The WISCI II is used to assess functional status in patients with lower-limb disability; the SCIM to evaluate independence in activities of daily living; and the SF-36 to assess overall health-related quality of life. Mood and emotional status is assessed using the BDI for depressive symptoms and the STAI for anxiety. Apathy was assessed using the IDAS.