Aphasia is most common if the stroke occurred in which hemisphere of the brain?

Aphasia typically occurs when there is damage to the dominant hemisphere of the brain, which is responsible for language processing. In most individuals, the left hemisphere is dominant for language, so a stroke affecting this area would likely result in aphasia. This condition illustrates the connection between language function and specific areas of the brain, particularly Broca's area and Wernicke's area, both found in the left hemisphere.

The non-dominant hemisphere primarily governs functions related to spatial awareness, creativity, and emotional content of speech rather than language itself. Consequently, while strokes affecting the non-dominant hemisphere can lead to other cognitive or communication difficulties, they are less likely to result in classic aphasia. Strokes affecting both hemispheres would generally lead to broader cognitive deficits rather than isolated language deficits characteristic of aphasia. Thus, aphasia is most commonly associated with a stroke in the dominant hemisphere where the main language centers are located.