Corticospinal Excitability After rTMS in Spinal Cord Injury Patients
Condition: Spinal Cord Injury
MeSH terms: Spinal Cord Injuries
Study type: Interventional

Summary: 
      A crossover trial with spinal cord injury volunteers will be conducted. Three sessions will
      be performed once a week in a counterbalanced order and at least with seven days washout
      period to minimize carry-over effects. In each session, volunteers will be submitted to
      quantity and quality of sleep, type of eating, fatigue and motivation level, Ashworth scale
      spasticity, cortical brain activity measures through simple pulse transcranial magnetic
      stimulation (pTMS), spinal cord activity measures through electrical stimulation and
      non-invasive brain stimulation (rTMS)
    

Detailed description: 
      After given prior informed consent, volunteers will be submitted to three randomized and
      counterbalanced sessions using a website (randomization.com) by a non-involved researcher. At
      study beginning, volunteers will be evaluated through structured questionnaire and each
      session, will comprise the following experimental sequence:

        1. Quantity and quality of sleep: It will be enquired how many hours the volunteer slept in
           the last night. The quality of the sleep will be measured through an analogue scale
           graded from 0 (worst quality of sleep) to 10 points (best quality of sleep).

        2. Type of eating: All the individuals will be asked about ingestion of food and drinks
           that could change the cortical excitability (e. g.; coffee, chocolate, energetic, soda e
           etcc). If positive, researchers will record the time since of ingestion and quantify the
           amount of food.

        3. Fatigue and motivation level: It will be measured through an analogue scale graded from
           0 (lower fatigue or motivation levels) to 10 points (greater fatigue or motivation
           levels).

        4. Spasticity: It will be assessed by the modified Ashworth scale ranging from 0 to 4.
           Performs the passive drive member to be measured and observing the time it arises the
           resistance difficult the passive movement. This scale will be tested bilaterally in the
           muscles of the lower limbs, the tested muscles are the quadriceps, adductors, hamstring,
           dorsiflexors, hip flexors and flexors plant. The scale always applies by the same
           evaluator.

        5. Spinal cord activity: the level of excitability of spinal cord will be measured through
           the following outcomes:

           • Hoffman reflex (H reflex): the H reflex will be elicited by a percutaneous electrical
           stimulation on tibial nerve delivered on popliteal fossa and recorded the
           electromyographic responses from the soleus muscle. The values of maximal H reflex, M
           wave and maximal H reflex and maximal M wave ratio (H/M ratio) will be obtained through
           a recruitment curve.

           The recruitment curve will start with a stimulus intensity delivered from 2 milliampere
           (mA) and increasing on steps of 1 mA until to M wave curve stabilization (no increasing
           of the M wave amplitude).

           • Homosynaptic depression (HD): the HD will be obtained through a serie of two
           consecutive stimuli separated by a interstimulus interval (from 30 ms until 10.000 ms).
           The stimuli will be delivered on popliteal fossa and the electromyographic responses
           from soleus muscle will be recorded. The stimuli will be delivered with the intensity
           necessary to produce the maximal H reflex (this information will be available in the
           recruitment curve as stated before). The difference between the first and the second
           stimuli for each interstimulus interval will give rise to the recovery curve.

        6. Cortical excitability: the cortical excitability will be measured through the motor
           evoked potential (MEP) through simple pulse transcranial magnetic stimulation (BiStim2,
           Magstim, UK) Initially, the higher cortical representation area (hotspot) of first right
           dorsal interosseous (FDI) muscle will be determined through a figure-eight coil
           connected to the magnetic stimulator held manually at 45 degrees from the midline, will
           be placed over the right primary motor cortex (C3 - 10/20 System). Then, will be
           determined the rest motor threshold (RMT) by finding the lowest stimulator output that
           elicit motor evoked potential (MEP) at least 50 microvolts (μV). After determined the
           RMT, the MEP value will be obtained through twenty suprathreshold (130% of RMT) stimuli
           that will be delivered on primary motor cortex (C3).

        7. rTMS: Initially, the higher cortical representation area (hotspot) of first right dorsal
           interosseous (FDI) muscle will be determined through a figure-eight coil connected to
           the magnetic stimulator (Rapid2, Magstim, UK) held manually at 45 degrees from the
           midline, will be placed over the right primary motor cortex (C3 - 10/20 System). Then,
           will be determined the rest motor threshold (RMT) by finding the lowest stimulator
           output that elicit motor evoked potential (MEP) at least 50 microvolts (μV). After
           determined the RMT, the coil will be positioned over the scalp (Cz - 10/20 System) and
           based on previous studies will be performed rTMS protocols. Low frequency protocol: 1
           hertz (Hz), 90% RMT, 1500 stimuli (1 train). High frequency protocol: 10 Hz, 90% RMT, 45
           trains, 40 stimuli per train, inter interval of 28 seconds, 1800 stimuli. Sham rTMS will
           be performed with low frequency protocol using two coils. The first one - connected to
           the stimulator - will be positioned on a coil support close to the volunteer but not
           visible. Therefore, characteristic stimulation noises will be audible. The second -
           disconnected to the stimulator - will be placed over left primary motor area. After each
           rTMS session, presence of adverse effects will be computed.

        8. Spasticity: this evaluation will be performed immediately after (T0), thirty minutes
           after (T1) and 1 hour after (T2) the rTMS. The procedures will be conducted following
           the same protocol.

        9. Spinal cord activity: this evaluation will be performed immediately after (T0), thirty
           minutes after (T1) and 1 hour after (T2) the rTMS. The procedures will be conducted
           following the same protocol.

       10. Cortical brain activity: this evaluation will be performed after each revaluation of
           spinal cord activity (T0, T1 and T2). The procedures will be conducted following the
           same protocol.
    

Intervention name(s): High frequency rTMS (repetitive Transcranial Magnetic Stimulation); Low frequency rTMS (repetitive Transcranial Magnetic Stimulation); sham rTMS (repetitive Transcranial Magnetic Stimulation)
Intervention type(s): Device; Device; Device
Intervention description(s): Higher cortical representation area of first right dorsal interosseous muscle will be determined through a figure-eight coil connected to the magnetic stimulator (Rapid2, Magstim, UK) held manually and at 45 degrees from the midline over the right primary motor cortex (C3 - 10/20 System). Then, will be determined the rest motor threshold by finding the lowest stimulator output that elicit motor evoked potential at least 50μV. After determined the RMT, the coil will be positioned over the scalp (Cz - 10/20 System). Thereafter, RMT will be measure. rTMS protocols was based on previous studies. High frequency protocol: 10Hz, 90% RMT, 45 trains, 40 stimuli per train, inter interval of 28s, 1800 stimuli. After each rTMS session, presence of adverse effects will be computed.; Initially, the higher cortical representation area (hotspot) of first right dorsal interosseous (FDI) muscle will be determined through a figure-eight coil connected to the magnetic stimulator (Rapid2, Magstim, UK) held manually and at 45 degrees from the midline, will be placed over the right primary motor cortex (C3 - 10/20 System). Then, will be determined the rest motor threshold (RMT) by finding the lowest stimulator output that elicit motor evoked potential (MEP) at least 50 microvolts (μV). After determined the RMT, the coil will be positioned over the scalp (Cz - 10/20 System). Thereafter, RMT will be measure. Low frequency protocol: 1Hz, 90% RMT, 1500 stimuli (1 train). After each rTMS session, presence of adverse effects will be computed; The hotspot of first right dorsal interosseous (FDI) muscle will be determinate through a figure-eight coil connected to the magnetic stimulator positioned over the motor primary cortex (C3). Then, the motor threshold (RMT) of FDI will be measure. Sham rTMS will be performed with low frequency (1Hz, 90% RMT, 1500 stimuli) protocol using two coils. The first one - connected to the stimulator - will be positioned on a coil support close to the volunteer but not visible. Therefore, characteristic stimulation noises will be audible. The second - disconnected to the stimulator - will be placed over primary motor area Cz. After each rTMS session, presence of adverse effects will be computed.
Other intervention name(s): High frequency rTMS; Low frequency rTMS; sham rTMS
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary purpose: Other
Keywords: Transcranial Magnetic Stimulation; Spinal Cord Injury; Humans