When patients diagnosed with Multiple Sclerosis show symptoms while the MR images show no lesions in the brain, it could be because the lesions are so tiny and located in the cerebral cortex.  

These are not revealed on any regular MR images, but in a new Danish study, a connection between the lesions and a patient's physical symptoms is made. 

You can read the interview (IN DANISH) in MS Tidskrift or on their homepage by clicking HERE.