What is the number one cause of Broca's aphasia?
Expressive aphasia
In most cases, expressive aphasia is caused by a stroke in Broca's area or the surrounding vicinity. Broca's area is in the lower part of the premotor cortex in the language dominant hemisphere and is responsible for planning motor speech movements. However, cases of expressive aphasia have been seen in patients with strokes in other areas of the brain. Patients with classic symptoms of expressive aphasia in general have more acute brain lesions, whereas patients with larger, widespread lesions exhibit a variety of symptoms that may be classified as global aphasia or left unclassified.
Paul Broca
Broca also spent many of his earlier years researching cancer. His wife had a known family history of carcinoma, and it is possible that this piqued his interest in exploring possible hereditary causes of cancer. In his investigations, he accumulated evidence supporting the hereditary nature of some cancers while also discovering that cancer cells can run through the blood. Many scientists were skeptical of Broca’s hereditary hypothesis, with most believing that it is merely coincidental. He stated two hypotheses for the cause of cancer, diathesis and infection. He believed that the cause may lie somewhere between the two. He then hypothesized that (1) diathesis produces the first cancer (2) cancer produces infection, and (3) infection produces secondary multiple tumors, cachexia, and death.”