Acquired Brain Injury

An ABI is an injury to the brain that is not hereditary, congenital, degenerative, or induced by birth trauma. Occurs after birth with presumed normal brain development preceding the injury. Results in a change in neuronal activity affecting physical integrity, the metabolic activity, or the functional ability of nerve cells

Acquired brain injury is an umbrella definition as it includes injuries caused by external physical forces applied to the head, as well as internal insults to the brain. All of the injury causes and pathologies you see in this chart are included as Acquired Brain Injuries.

Traumatic Brain Injury

A TBI is an alteration in brain function, or other evidence of brain pathology, caused by an external force. With traumatic impact injuries the head is struck by an object or an object strikes the head resulting in either a: Closed injury Open (penetrating) injury

An open head injury is a penetrating brain injury involving a breach of the skull or breach of the meninges (so that an object penetrates the skull and enters the brain). This type of injury often results in focal injuries. Infection can be a secondary factor.

A closed head injury means you received a hard blow to the head from striking an object, but the object did not break the skull

Non-traumatic brain injuries include stroke, neurotoxic poisoning, hypoxia and anoxia, among others. Hypoxia and anoxia include a lack of oxygen that causes brain cells to die. When they die, they release chemicals that can cause further damage to the brain.

APHASIA

Aphasia is a language disorder that happens when you have brain damage. Your brain has two halves. Language skills are in the left half of the brain in most people. Damage on that side of your brain may lead to language problems. Damage on the right side of your brain may cause other problems, like poor attention or memory.

Aphasia may make it hard for you to understand, speak, read, or write. It does not make you less smart or cause problems with the way you think. Brain damage can also cause other problems along with aphasia. You may have muscle weakness in your mouth, called dysarthria. You may have trouble getting the muscles of your mouth to move the right way to say words, called apraxia. You can also have swallowing problems, called dysphagia.

• Aphasia is a neurologic communication disorder, commonly acquired after a stroke that leads impairments in receptive and expressive language skills.

• In addition to linguistic deficits, people with aphasia (PWA) often exhibit deficits in executive functions, which play an important role in communication.

• Understanding deficits of executive functions in PWA is important in terms of theoretical implications as well as implications for clinical assessment and treatment.

Dysarthria

Refers to a group of neurologic speech disorders that are characterized by “impaired execution of the movements of speech production” (Yorkston, Beukelman, Strand,&Hakel, 2010, pg. 4). These impairments are caused by damage to parts of the central or peripheral nervous system that control motor movements for speech. Dysarthria classification depends on the location of damage within the nervous system. For example, peripheral nervous system damage results in different symptoms than central nervous system damage. Generally, neurological damage can cause the muscles that underlie speech subsystems to have impairment in tone, strength, range of motion, speed, steadiness, and/or accuracy.

Apraxia of Speech

Like dysarthria, is a motor speech disorder caused by neurological damage. However, unlike dysarthria, apraxia of speech (AOS) is a disorder of the planning or programming stage of speech production and does not affect muscle characteristics like tone and strength. Deficits in speech motor programming/planning result in difficulty or inconsistency in selecting and/or sequencing commands for muscle execution.

Generally, the articulatory system is the most affected, including rate, prosody, and fluency.

These definitions are intended to familiarize you with the terms associated with MSDs and to provide context for the rest of the chapter. This chapter will introduce the neuromotor control of speech production, expand on the characteristics of both dysarthria and apraxia, and touch on assessment and treatment for MSDs.

Dysphagia

• Dys-: Bad/difficult/abnormal-phagien (Gr.): Eat

• Dysphagia refers to difficulty swallowing Can occur at any location from the mouth to lower

• esophageal sphincter (near the stomach)

• Not a disease on its own, but occurs secondarily to (as a symptom of) diseases and disorders

There are numerous conditions that can impact any or all stages of the swallow process. Disabilities that affect motor control mechanisms in the brain can impact oral preparatory, oral, pharyngeal, and esophageal stages, resulting in impaired bolus formation and propulsion from the oral cavity to the stomach. Conditions that impact respiratory function can impair the ability to coordinate breathing and swallowing, increasing the risk for aspiration. In addition, structural abnormalities can restrict passage of the bolus through the pharynx and/or esophagus.

Consider for a moment that on average we spend 1.17 hours per day eating and drinking (ADL, 2015). From a biological standpoint, eating and drinking are a necessity for our growth, development, and overall health and well being. But eating and drinking are also an important social activity that brings family and friends together. We hardly stop to think about the act, but it plays a very important role in our lives.

Now consider what your life would be like if you had to think about swallowing every time you took a bite of food or a sip of liquid; or worse, if you were unable to swallow at all. Your health and well-being would be compromised, and you might require a modified diet—one where your liquids were thickened and/or your food needed to be ground up—or you may require an alternative method for meeting your nutritional needs such as a feeding tube. These modifications may cause embarrassment or anxiety, resulting in isolation from friends and family.

RHD Communication Impairments

The language behaviors and deficits associated with right hemisphere brain damage can be subtle and difficult to identify, measure, and treat. It has been estimated that at least 50% of adults with right hemisphere damage experience one or more cognitive-communication deficits (Blake, 2018; Tompkins, 2012). Specifically, impairments may be evident in topic maintenance (Myers, 1993), discourse coherence and cohesion (Marini, Carlomagno, Caltagirone & Nocentini, 2005), inference generation (Blake, 2009), turn-taking, question use (Minga, 2014), and integration of contextual nuance (McDonald, 2000). Discourse in some adults with RHD has been described as content-deprived (Joanette & Goulet, 1994), disinhibited, tangential (Brownell & Martino, 1998), and plagued with inappropriate comments and humor (Klonoff, Sheperd, O’Brien, Chiapello, & Hodak, 1990).