Improving SCI Rehabilitation Interventions by Retraining the Brain

UEMS is used in Spinal Cord injury to identify strength (muscle power) in patients with spinal cord injury. It involves a manual muscle test of five key muscles in each arm graded from 0 (no contraction) to 5 (normal strength). Each Arm can have a max score of 25 and the total score for the test is 50 points. The higher the value the more muscle strength the participant has and a higher change score means more improvement. The sum of scores for both arms is reported here.

Graded and Redefined Assessment of Strength, Sensibility and Prehension (GRASSP) is a functional measure which identifies the functional ability of the upper limbs and is widely used in studies recruiting Spinal Cord Injury patients. It has subsets including strength (100 points total, 50 per arm), palmar and dorsal sensation (48 points total, 24 per arm), prehension ability (24 points total, 12 per arm), and prehension performance (60 points total, 30 per arm). The higher the score the better the performance. The greater the change in score the more the participant improved. The sum of scores for both arms is reported here.

The Canadian Occupational Performance Measure (COPM) is an evidence-based outcome measure designed to capture the participants self-perception of everyday issues that restrict their participation in everyday living, measuring both their performance in completing the identified task and their satisfaction in their performance of the task. Here we report the performance scale of the assessment. The score range is from minimum 1 (not able to do it at all) and maximum 10 (able to do it extremely well). A larger change score indicates more subjective improvement in performance of activies of daily living.

The Canadian Occupational Performance Measure (COPM) is an evidence-based outcome measure designed to capture the participants self-perception of everyday issues that restrict their participation in everyday living, measuring both their performance in completing the identified task and their satisfaction in their performance of the task. Here we report the satisfaction scale of the assessment. The score range is from minimum 1 (not satisfied at all) and maximum 10 (extremely satisfied). A larger change score indicates more subjective improvement in satisfaction of completing activies of daily living.

The Spinal Cord Indepence Measure (SCIM) is a participant subjective spinal cord injury measure that identifies daily acitivity indepence. The Self-care subscore of the SCIM looks at independence in performing daily activies and ranges from minimum 0 (total dependence in self-care) to maximum 20 (complete independence in self-care). A higher change score indicates improved levels of independece for the participant.

The Capabilities of Upper Extremity Test (CUE-T) is a performance based functional measure that evaluates upper extremity function in poeple with cervical spinal cord injury. It consists of 32 items, each item is scored from 0 (unable to complete task) to 4 (no difficulty to complete task). The minimum score of the scale is 0 (unable to performe any of the tasks) to maximum 128 (able to complete every task with no difficulty). A higher change score indicates and improvement in ability to complete upper limb functional tasks.

Transcranial magnetic stimulation was used to test cortical and corticospinal physiology. The active motor threshold (AMT) is the lowest intensity of stimulation needed to produce a motor evoked potential during a voluntary contraction in the biceps muscle. The criteria for defining a motor evoked potential is 6 out of 10 trials in which the response signal is larger peak-to-peak than the background muscle activity by 100µV. The AMT can have a value ranging from 0-100, an indicator of the percentage of the maximum stimulator output (MSO). The higher the value the more stimulation intensity needed to get a criterion motor evoked potential in the target muscle; lower AMT values indicate higher excitability in the muscle. A change score that is negative indicates increased excitability in the biceps muscle.

Transcranial magnetic stimulation was used to test cortical and corticospinal physiology. The active motor threshold (AMT) is the lowest intensity of stimulation needed to produce a motor evoked potential during a voluntary contraction in the triceps muscle. The criteria for defining a motor evoked potential is 6 out of 10 trials in which the response signal is larger peak-to-peak than the background muscle activity by 100µV. The AMT can have a value ranging from 0-100, an indicator of the percentage of the maximum stimulator output (MSO). The higher the value, the more stimulation intensity needed to get a criterion motor evoked potential in the target muscle; lower AMT values indicate higher excitability in the muscle. A change score that is negative indicates increased excitability in the triceps muscle.

Spinal pathways were tested using peripheral nerve stimulation to median nerve to collect responses in the Flexor Carpi Radialis muscle of the weaker arm. This stimulation stimulates both the sensory and motor nerves to produce a evoked potential for each pathway. The evoked potential produced for the sensory pathway is considered the Hoffman reflex (H-reflex) and the evoked potential produced for the motor pathway is considered the muscle compund action potential (M-wave). To get an understanding of the motor neuron pool of exitability we use the H/M ratio which compares the peak amplitude of the maximum H-reflex to the maximum M-wave (H-reflex/M-wave). This ratio reflects the proportion of the motor neruon pool activated by the reflex or motor neuron excitability. A lower H/M ratio generally indicates lower excitability while a higher ratio indicates higher excitability.

In line with this phase I/II clinical trial, safety and feasibility will be tested throughout this study. Vital signs (blood pressure, heart rate, respirations, blood oxygen saturation) will be recorded for each study session. During Intervention sessions we will ask a tDCS adverse effects questionnaire at the end of each session.

A TMS safety questionnaire will be asked at the end of the preintervention tests and the post intervention testing visit.