people can have minor strokes that their unaware of completley - and then theres the more obvious versions you see on those NHS tv adverts which mention the F.A.S.T test - which, if you dialed 999 and the paramedics attended, thats what theyd do.
Facial - drooping on the mouth or eyes, ability to smile normally.
Speach - can you speak normally or understand simple requests
Arms - can you raise both arms above your head
im not medically qualified at all but the loss of use in a finger i wouldnt say is an indication of a stroke - to be honest im only 27 and i suffered a lot of numbness in my hands arms and face which lasted a good year but after an MRI scan nothing was ever found and i was left to literally wait for it to stop!
someones the body does random stuff for god knows what reason! anyways - i wouldnt worry personally, this happened 19 months ago! if you went to a GP id expect them to just reassure you :)