That's right. Brain ischemia comes in two flavors...more or less.
Focal brain ischemia is your basic stroke.
In focal ischemia, something has occluded a cerebral vessel, like a
blood clot, gas bubble, or the wire you let go of when you tried to hit
that guy's internal jugular but cannulated his carotid instead. Such an
arterial occlusion results in brain ischemia distal to the site of the
obstruction, characterized by a central core of dense ischemia (which
is almost certainly going to die) and a penumbra of less-densely ischemic tissue (which may be salvageable).
This is an ex-rat. Section
of rat brain subjected to focal ischemia stroke. Pale area on the left
indicates necrotic brain. Immediately after the occlusion that led to
the stroke, much of this area may have been salvageable (penumbra). But
it's too late now.