The major arteries give off small, penetrating vessels, which supply areas deep in the brain (sub-cortical areas) such as the internal capsule, thalamus and basal ganglia.
Strokes involving these small end arteries are called lacunar strokes. Lacunar strokes involving the posterior limb of the internal capsule are typically associated with only motor signs, whereas those affecting the thalamus produce pure sensory signs.
It is important to distinguish between patients who have evidence of cortical involvement and those who do not. Symptoms indicating cortical involvement include: