With improvements in medicine, more patients survive severe traumatic brain injuries, even in cases where the brain injury led to a minimally conscious or vegetative state. An increase in survival means that there is a chance that the brain injury patient can emerge from unconsciousness. Subsequently, this has led to an increase in opportunities to observe the effects of such injuries.
One of the effects noted in patients who emerge from a brain injury-related minimally conscious or vegetative state is a unique speech disturbance known as mixed speech apraxia and dysarthria syndrome.
Patients with this speech disturbance can typically comprehend verbally, read silently, and write words using a word board or talking aid implement. However, these patients suffer from facio-oral apraxia- a diminished ability to purposefully control the muscles in their faces and mouths. They also typically have difficulty swallowing (dysphagia), other motor control issues, and cognitive and emotional impairments.
Researchers found that brain injury patients with this speech disturbance showed damage to the arcuate fasciculus (AF) and to fibers in the white matter related to dysarthria. Additionally, diffuse damage to the cingulum, fornix, white matter, and basal ganglia may be related.
Toyoshima, Y, Asano, Y, Shinoda, J, et al. A speech expression disorder in patients with severe diffuse brain injury who emerged from a vegetative or minimally conscious state. Brain Injury. (November 2011).