hi thank-you for providing the brief history of you. a thorough clinical neuromuscular assessment is advised. As you mentioned of facing issue with shoulder pain, neck pain , balance issues etc I will recommend first to take the detailed clinical assessment. Based on this we can understand as what MRI needs to be performed. But on a safer side taking and MRI of the cervical spine and brain in contrast will make some insight. The pain in the neck and shoulder - this looks more of the Neuromuscular issue. Like if there is any pinch of the nerve root in the cervical spine then there is a possibility of the radiating symptoms and pain. For which physical therapy is a choice to get solution for. Evidence of research has a good support. For the balance issue - it should be assessed in detail as this can occur due to two issues. One any vestibular related issue or any cerebellar related issue. Understanding the proper clinical examination and the MRI should help assist further by which the help can be initiated. For anything more you can surely ask me I will be happy to assist you. Regards. Jay Indravadan Patel