http://www.medhelp.org/health_pages/Multiple-Sclerosis/Diagnostic-Guidelines-Chart---The-McDonald-Criteria-2001---2005---2006-proposed-/show/448?cid=36
The above is a chart of what is needed to dx MS, time and space to give a basic example, brain MRI locates a number of T2 lesions in MS locations indicating first recorded attack, follow up MRI's locates additional lesions indicating second attack which would fullfil time and if the new lesions are in a different area of the brain or spine it would fullfil space.
Physical signs: one example would be a positive Romberg
"The Romberg test is a test of the body's sense of positioning (proprioception), which requires healthy functioning of the dorsal columns of the spinal cord.
The Romberg test is used to investigate the cause of loss of motor coordination (ataxia). If a patient is ataxic and Romberg's test is not positive, it suggests that ataxia is cerebellar in nature, that is, depending on localized cerebellar dysfunction instead." (wiki)
hope this helps..........JJ