Cortical Inhibition in Patients With Multiple Sclerosis

"1. Expanded Disability Status Scale (EDSS) (Kurtzke, 1983): This scale will be used for neurological disability assessment~2. Multiple Sclerosis Functional Composite (MSFC): This composite will be used for the assessment of functional performance in patients with MS. It includes: a) Timed 25-foot walk (T25FW), b) Nine-hole peg test (9HPT) for both hands, and c) Paced auditory serial addition test (PASAT).~3. Toronto Alexithymia Scale (TAS-20): This scale reports Alexithymia. It is a 20-item self-report questionnaire measuring three domains: Difficulty identifying feelings (DIF), Difficulty describing feelings (DDF), and externally oriented thinking (EOT). A score ≥ 61 indicates alexithymia (Bagby, Parker \& Taylor, 1994).~4. Montreal Cognitive Assessment (MoCA), (Nasreddine ZS et al, 2005): a 30-point tool that investigates visuospatial abilities, language, attention, memory, abstraction, and orientation, with scores \<26 suggestive of mild cognitive impairment"

"Corticospinal inhibition will be evaluated using Transcranial Magnetic Stimulation (TMS) (Ayache et al., 2022; Chalah et al., 2018). All TMS assessments will be conducted according to international safety guidelines. The following parameters will be measured:~1. Motor Evoked Potentials (MEPs) will be recorded from the abductor pollicis brevis muscle.~2. Cortical silent period (CSP) will be assessed to measure corticospinal excitability and inhibition.~3. The interhemispheric inhibition (IHI) is a parameter reflecting the transcallosal GABA-mediated inhibitory activity. It will be obtained at complete muscle rest using figure-of-eight coils (MC-B70; MagVenture), connected with a MagPro\_R20 (Medtronic Inc., USA) generator connected to a butterfly coil."

"All patients will undergo brain and spinal cord Magnetic Resonance Imaging (MRI) using a 1.5T scanner. Brain MRI sequences include: T1-weighted, T2-weighted, FLAIR, and post-contrast sequences. Spinal MRI (cervical and thoracic) includes T2-weighted and STIR sequences. Radiological assessment focused on:~* Number and location of T2/FLAIR lesions~* Presence of contrast-enhancing lesions~* Degree of brain atrophy (qualitatively)~* Spinal cord lesion load A neuroradiologist will review MRI findings, blinded to the clinical and neuropsychological data"