The loss of the ability to speak is associated with damage to

The loss of ability to speak is known as Aphasia

caused by damage to the related regions of the brain. It is mainly caused by a stroke or brain injury with damage to one or more parts of the brain.

people who survive a stroke have highly chances to get aphasia.

Aphasia may also be caused by a brain tumor, brain infection, or dementia auch as Alzheimer's disease In some cases, aphasia is a symptom of epilpsy or other neurological disorder.