Clinical attack vs Clinical evidence lesion

I have trying to master the McDonald Criteria for Diagnosis of MS ....but there is this little confusion that is killing me.

the criteria says : clinical attack and clinical evidence lesion. What is the difference ?
I could understand that there would be 2 clinical attacks and one clinical evidence .... but how can it be explained to have one clinical attack and two clinical evidence lesion.

I understood "clinical evidence lesion" as a lesion proved by clinical exam (MRI not included) is it right ?

Hi,
clinical attack is deficit on clinical examination - like visual loss, sensory loss, spasticity, that is a sign of neural dysfunction on clinical examination,
BUT, clinical evidence is a lesion(pathology) noted on investigations like MRI, CSF study etc, but not yet showing any patient discomfort overtly.
mostly in MS you can have 1 attack but more than one clinical evidence of lesion as they are either in the area of CNS which does not show signs, or they are so small to produce clinical symptoms/signs.

regards