For example, any of the following can indicate separation in time: A history of exacerbations and remissions MRI that shows simultaneous enhancing and nonenhancing lesions, even if patients are asymptomatic A new lesion on a subsequent MRI in patients with a previous lesion Separation (dissemination) in space can be established by finding lesions in ≥ 2 of the 5 following CNS areas typically affected by MS (1): Periventricular: ≥ 3 lesions Cortical / juxtacortical (white matter next to cortex and / or cortex): ≥ 1 lesions Infratentorial: ≥ 1 lesions Spinal cord: ≥ 1 lesions Optic nerve: ≥ 1 lesions (either by MRI or clinical evaluation) Additional testing If MRI plus clinical findings are not diagnostic, additional testing may be necessary to objectively demonstrate separate neurologic abnormalities.