Hi Kike,
I'm sorry for what you are going through. You mention you have syrinx of the spinal cord, but you sound as if you have not been advised as to all the complications you can experience due to this, as you also mention if you could have MS.
If I were in your position -- unable to walk and experiencing seizures, I would be sure to write down some questions for the doctor and schedule an appointment asap.
Begin with:
What can you prescribe to reduce the instance of seizure?
Will you prescribe as physical therapy for mobility?
Are the lesions the cause of the syrinx? This question so you can understand what a syrinx is, and can and is likely doing to you :(
What is important to know is that as MSers we understand some of what you are going through, as we may share some similar symptoms to a garden variety of diagnoses, but it's equally important to not just "know" what you are dealing with by name, but that you "understand" thoroughly what your specific condition causes you to experience.
Please plan a doctor visit when you can, and I hope we were able to help you a bit.
A positive EMG actually points away from MS as it measures issues with the peripheral nervous system, not the central nervous system. Has the cause of your seizures been identified? Is that being treated?
MRI results can be caused by many different things, so it's more a case of it being a part of the overall diagnostic picture. Have you been given a neurological exam? (it's similar to a field sobriety test: close your eyes and touch your nose, etc)