Non-invasive Neuromodulation Guided Through Biomarkers in Patients With Stroke Sequels

Project NEUROMOD: Non-invasive Neuromodulation Guided Through Biomarkers in Patients With Stroke Sequels

This study aims to investigate if the size effect of repetitive magnetic transcranial stimulation in the paretic upper limb in patients after stroke is influenced by the therapeutic decision.

After the patients and volunteers signed an informed consent form they will be classified and randomized using a website (randomization.com) by a non-involved researcher. All patients and volunteers will be assigned to groups (arms) after being tried: (i) rTMS-DIR: in which the patients will be submitted to a customized treatment with repetitive transcranial magnetic stimulation (rTMS) based in neurophysiological assessments; (ii) rTMS: patients will be submitted to standard treatment in the lesioned or non-lesioned hemisphere based in neurophysiological assessments; (iii) rTMS sham: each patient will receive a sham intervention that emits the same sound as the real stimulation; In each group, the patients will be submitted to 10 sessions for two weeks, five days a week in which will receive the rTMS followed by 45 minutes of neurofunctional physiotherapy. All outcomes will be assessed before and after the 10 sessions.

A conventional high-frequency rTMS (rTMSc) will be applied over the lesioned hemisphere over the motor cortex. After rTMSc, patients will be submitted to 45 minutes of neurofunctional physiotherapy. Experimental sessions will be repeated five times per week for two weeks.

A personalized high or low-frequency rTMS (rTMSp) will be applied to the lesioned or non-lesioned hemisphere depending on cortical biomarkers assessment guide a personalized stimulation for each patient in this group. After rTMSp, patients will be submitted to 45 minutes of neurofunctional physiotherapy. Experimental sessions will be repeated five times per week for two weeks.

The sham protocol will be delivered to each patient of this arm imitating the exat sound of the equipment and structure of the experimental arms. After rTMS sham, patients will be submitted to 45 minutes of neurofunctional physiotherapy. Experimental sessions will be repeated five times per week for two weeks.

In all rTMS protocols the patient will remain seated in a comfortable chair with adjustable arms and head rests. Before the start of the conventional rTMS (rTMSc), the resting motor threshold (RMT) of the first dorsal interosseous muscle contralateral to the lesioned hemisphere will be determined. The RMT will be defined as the lowest RMT intensity necessary to produce a motor evoked potential amplitude greater than or equal to 50 µV in at least 5 out of 10 attempts.

All patients will be submitted to a protocol of exercise with different levels according to motor learning, neuroplasticity principles and motor impairment. All physiotherapists will be trained prior to the study.

During the rTMS sham sessions the same procedures will be used as the rTMSc protocols, however, the magnetic stimulator and its coil will be turned off.

Accessed with: Quantitative electroencephalogram (qEEG) through the power spectral density (PSD) for each channel considering each band frequency: delta (0,5 a ≤ 4 Hz); theta (> 4 a ≤ 8 Hz); alpha (> 8 a ≤13 Hz); beta (> 13 a ≤ 30 Hz); gama (< 30 a ≤ 45 Hz) and the relative power for each band. . The Brain Symmetry Index (BSI) will be used to assess the absolute value of the difference in mean hemispheric power in the frequency range of 1 to 45Hz. All of these measures derive from each qEEG band frequency.

Accessed with: Quantitative electroencephalogram (qEEG) through the power spectral density (PSD) for each channel considering each band frequency: delta (0,5 a ≤ 4 Hz); theta (> 4 a ≤ 8 Hz); alpha (> 8 a ≤13 Hz); beta (> 13 a ≤ 30 Hz); gama (< 30 a ≤ 45 Hz) and the relative power for each band. . The Brain Symmetry Index (BSI) will be used to assess the absolute value of the difference in mean hemispheric power in the frequency range of 1 to 45Hz. All of these measures derive from each qEEG band frequency.

Accessed with: Low-Resolution Brain Electromagnetic Tomography (LORETA) software. All data from qEEG will also be computed to the LORETA software to generate a tridimensional image of the patient's brain.

Accessed with: Low-Resolution Brain Electromagnetic Tomography (LORETA) software. All data from qEEG will also be computed to the LORETA software to generate a tridimensional image of the patient's brain.

Fugl Meyer assesment is used to measure motor control recovery. It is a 226 point scoring system that includes the following sessions: range of motion, pain, sensation,motor function of upper and lower limbs, balance, coordination and velocity. We will apply only two sessions: upper limb motor function and coordination/velocity, these sessions totalize 66 points. Higher scores indicates better outcomes

The modified Ashworth scale is a 6-point rating scale that is used to measure muscle tone and it will be used to determine the spasticity wrist flexor muscles in the affected hand by stroke. It evaluates the antagonist muscles that limits the force of agonist muscled during a intended motion.

This scale will determine the severity and disability level of the post-stroke patient; which consists of 15 items that assess the domains: level of consciousness, eye movements, visual field, facial movements, motor function and ataxia of upper and lower limbs, as well as sensitivity, language, presence of dysarthria and spatial neglect. Each domain punctuates a specific skill from 0 (zero) to 4 points that may vary until a maximum of 42 points.

Inclusion Criteria: More than 3 months after stroke; Ischemic or hemorrhagic stroke with upper limb motor impairment; Exclusion Criteria: Any contraindication for application of transcranial magnetic stimulation; Peripheral lesions in the assessed upper limb; Score ≤ 18 at Folstein Mini Mental State Examination; Alteration of drugs that alter the excitability of the cortex (in less than 3 months); Application of botulinum toxin in less than 6 months.