Plain-English definitions of not-so-plain words.
These definitions are clear but not intended to be precise. They are are intended for laypeople such as caregivers and patients who just need a rough idea of what the words mean.
Apraxia or Apraxia of Speech (AOS) - Apraxia of speech, also known as verbal apraxia or dyspraxia, is a speech disorder in which a person has difficulty saying what he or she wants to say correctly and consistently due to difficulty with making purposeful movements of the muscles used for speech. It is not due to weakness or paralysis of the speech muscles (the muscles of the face, tongue, and lips). The severity of apraxia of speech can range from mild to severe.
Dysarthric errors result from a disruption of muscular control due to lesions of either the central or peripheral nervous systems. In this way, the transmission of messages controlling the motor movements for speech is interrupted. Because it involves problems with the transfer of information from the nervous system to the muscles, dysarthria is classified as a neuromotor disorder.
In dysarthria, errors are consistent and predictable. There are no islands of clear speech; no matter what the speaking task or materials used, the patient will exhibit the same amount and types of errors. Errors are mainly distortions and omissions. Distortions are the most common type of error in dysarthria.
Apraxia results from an impaired ability to generate the motor programs for speech movements rather than from the disordered transmission of controlling messages to the speech musculature. Apraxia is a planning/programming problem, not a movement problem like dysarthria. Apraxia occurs following damage to Broca's Area, or Brodmann's area 44, which is located on the third gyrus of the left frontal lobe. Thus, apraxia is always the result of a central nervous system lesion. It is a cortical problem, not a motor impulse transmission problem like dysarthria.
In apraxia, errors are inconsistent and unpredictable. Different error patterns occur in spontaneous speech versus repetition. Patients' spontaneous speech contains fewer errors than does his/her speech in repetition tasks. There are islands of clear speech; when producing over-learned material or material that has become automatic, the patient will speak clearly.
More on this from Dr. Patrick McCaffrey, PhD at California State University
Anomia or word-retrieval difficulty (often due to Expressive Aphasia) -Difficulty retrieving the word for something. They know what the something is but just can't retrieve the word. It's a language problem not a recognition problem.
Analogy: If you show the survivor a frying pan and spatula, they can't name either one, but they could easily fry an egg with them. It's like being in a foreign country that you previously spoke the language ... in high school. You know what an egg is but don't quite recall the word for egg. This is obviously an oversimplification, but I think it's good enough for a caregiver.
Aphasia - there are many different types of Aphasia. The most basic two types are Expressive and Receptive. Expressive Aphasia impairs your ability to express yourself in speech and/or writing. See Anomia above.
Primary Progressive Aphasia (PPA) - a neurological condition where language ability slowly becomes impaired. It is different from standard Aphasia: PPA is usually caused by neurodengenerative diseases such as Alzhheimers. And, as the name suggests, it is unfortunately Progressive, meaning it gets worse over time. Read more from the National Aphasia Association.
PT - Physical Therapy - Therapy focused on physical recovery. Usually involves movement, muscles, joints, etc.
OT - Occupational Therapy - This is sort of between Speech and Physical Therapy. It involves physical an mental therapy but is focused on so-called Activities of Daily Living - i.e., everyday skills.
SLP - Speech & Language Pathology - treatment for speech production (the language, the physical articulation of the sounds, the word retrieval) and language (word retrieval, etc.). It applies to both expressive language (speech and writing) and receptive (listening and reading)
TBI - Traumatic Brain Injury is injury to the brain caused by external force such as a blow to the head, accident, etc. It's different from a stroke, which is due to internal injury ( a bleed or blockage of a blood vessel in the brain)