This study will be conducted to investigate the following:

1. The impact of implementing GVS in MS rehabilitation on cortical excitability.
2. The influence of GVS on upper limb function in patients diagnosed with MS. Patients will be randomly assigned to a control group (Conventional Physical Therapy program = CPT) and a study group (Galvanic Vestibular Stimulation = GVS in addition to the conventional program) subsequently. CPT will perform moderate intensity aerobic training (arm ergometer) and task oriented hand manipulation training, while GVS will receive Galvanic Vestibular Stimulation will be added to the conventional physical Therapy program.

Inclusion Criteria:

1. Patients with ataxic RRMS type of both genders will be recruited. The last MS relapse occurred at least 3 months prior to the study.
2. Patients' age will range from 20 to 45 years old.
3. Ambulant Patients who meet the level less than or equal to 5 on EDSS will be recruited.
4. Patients' score on Mini Mental State Examination should be > 26.
5. Mild or no spasticity (grade 1 or 1+) according to Modified Ashworth Scale.
6. All patients must at least hold Primary stage certificate of education from one of the Egyptian educational authorities.
7. All patients can independently sign consent form

Exclusion Criteria:

• Patients will be excluded if they have:

  1. Moderate to severe auditory or visual or cognitive impairment.
  2. Coexistence of other neurological diagnoses of Central or Peripheral Nervous system (e.g. cerebrovascular stroke, vestibulopathy or polyneuropathy).
  3. History of any problems that hinder conduction of aerobic training or magnetic stimulation (e.g. deep venous thrombosis, shunts and pacemakers).