Guillermo was eventually unable to speak because he lost the ability to control the muscles around his vocal cords. a stroke patient sometimes loses the ability to speak because of the loss of blood flow to the brain. what is this called

The condition of not being able to speak is called aphasia. Aphasia is an inability to comprehend language because of damage brain caused by the low supply of blood to the brain. People having this may not just lose their ability to speak but also the ability to read and write.