Can a stroke cause a seizure without losing consciousness?

Simple vs complex. Complex seizures are ones that impair one's level of consciousness. Simple ones do not. Different strokes could cause one or the other, depending on how large and where the stroke is.
Yes, it can. A seizure following a stroke occurs because there was damaged to the underlying brain. Depending on the lobe of the brain involved and whether dominant or non-dominant sides, a seizure can occur without loss of consciousness but with focal motor or sensory signs.