Brain lesions are a common condition. Unfortunately, they can also represent severe conditions that require medical attention. I strongly recommend you discuss this with your doctor
. A neurologist
(brain specialist) could also be of assistance if you have further questions.
In general, it is possible for a sports injury
to cause lasting damage on cerebral imaging--although most do not. For example, concussions are not seen on normal MRIs. More severe types of trauma, such as a brain contusion or hemorrhage, do cause changes that are seen on MRI. However, these changes will often resolve. They may persist, however the appearance of these should be consistent with prior damage. Damage to the cranium (skull bone) can last, however this would unlikely to be confused with multiple sclerosis. It would be unusual for a sports injury to be confused with MS. If you had an MRI or CT at the time of the injury--it would be helpful in determining the cause.
MRI findings of multiple sclerosis should normally show areas of demylelination (which looks like inflammation). That being said, by definition, MS can only be diagnosed if there are two lesions that are found in two different locations at two different points in time. Therefore, one MRI cannot itself diagnose MS.
Other causes are possible. Infections, strokes or cancer can also be seen as lesions. These should be ruled out.
However if you are having symptoms and have the appropriate imaging--a lesion consistent with MS is concerning for the diagnosis. It is possible, but unlikely that it is caused by an old brain trauma. I recommend discussing this with your doctor.