[8][9] It is most common for the onset of global aphasia to occur after a thrombotic stroke (at the trunk of the middle cerebral artery), with varying severity.

[17] Global aphasia typically results from an occlusion to the trunk of the middle cerebral artery (MCA),[2] which affects a large portion of the perisylvian region of the left cortex.

[16][2] In addition to stroke, global aphasia can also be caused by traumatic brain injury (TBI), tumors, and progressive neurological disorders.

However, a study by Kumar et al. (1996) suggests that lesions to the subcortical regions of the cortex such as the thalamus, basal ganglia, internal capsule, and paraventricular white matter can also cause speech and language deficits.

[21] After the diagnosis of a brain injury, a speech and language pathologist will perform a variety of tests to determine the classification of aphasia.

[11] BASA is used to determine treatment plans after strokes lead to symptoms of aphasia and tests both gestural and verbal responses.

The goal of speech and language therapy is to increase the person’s communication abilities to a level functional for daily life.

In 2016, Wallace et al. found the following outcomes were commonly prioritized in therapy: communication, life participation, physical and emotional well-being, normalcy, and health and support services.

[16] Group therapy sessions typically revolve around simple, preplanned activities or games, and aim to facilitate social communication.

[27] One important therapy technique includes teaching family members and caregivers strategies for more effectively communicating with their loved ones.

Research offers such strategies including, simplifying sentences and using common words, gaining the person's attention before speaking, using pointing and visual cues, allowing for adequate response time, and creating a quiet environment free of distractions.

[25] When evaluating the prognosis of a patient, the main contributing participant factors that influence the extent of neuroplasticity, or the brain's ability to change are: age, lesion location, pre-existing cognitive status, motivation, overall health, and interaction amongst these.

[29] Research has shown that the prognosis of long-term language abilities is determined by the initial severity level of aphasia within the first four weeks after a stroke.

[29] As a result, there is a poor prognosis for persons who retain a diagnosis of aphasia after one month due to limited initial language abilities.

For example, in 1992, Ferro performed research in which he studied the recovery of individuals with acute global aphasia, resulting from the five different lesion sites.

[2] Communication of basic needs and the comprehension of simple conversations on highly familiar topics, are examples of common functional language use for this population.