Disorders of communication and swallowing occur across the lifespan and may result from disruption of neurologic function and anatomical abnormalities of the head, neck, and respiratory system. Effective assessment and treatment involves collaboration across medical and rehabilitation disciplines. A discussion of normal function, incidence and prevalence, etiology, categories of impairment and treatment options is provided for each group of disorders.
Speech refers to motor acts that result in the production of sounds through the coordination of respiration, phonation, resonance, articulation, and prosody. Language is the symbolic organization of sounds into purposeful words and sentences to represent thought and includes linguistic elements such as morphology and syntax and paralinguistic elements of prosody.1 Cognition refers to mental processes and systems, such as attention, perception, memory, organization, and executive function.2
Successful communication requires intact neural pathways and peripheral structures to plan, modify, and process speech, language, and cognition. Neural activation patterns of communication and cognition are widespread and include structures and circuits of the cerebrum, the brainstem, the limbic system, and the cerebellum (Table 57–1).
Table 57–1Key Functions of the Lobes of the Brain ||Download (.pdf) Table 57–1 Key Functions of the Lobes of the Brain
|Lobe ||Location ||Function ||Impairment |
|Frontal ||Most anterior part of the brain || |
Planning and initiation
Judgment and reasoning
Adaption to change
Loss of flexible thinking
Poor focus or attention
Inability to express language (Broca's aphasia)
Difficulty in problem solving
|Temporal ||Laterally in cerebral hemispheres || |
Auditory sensation and perception
Categorization of objects
Difficulty comprehending language (Wernicke's aphasia)
Disturbance with selective attention to what is seen and heard
|Parietal ||Between occipital lobe and central sulcus || |
Sensory integration: touch, pressure, pain, temperature, taste
Poor divided attention
Poor kinesthetic awareness
|Occipital ||Most posterior part of the brain || |
Visual field cuts
Difficulty locating objects in environment
Difficulty reading or writing
For example, in spoken language, humans require the temporal lobe for comprehension, the frontal lobe for production, the occipital lobe to visualize gestures and facial expression, and the parietal lobe for sensorimotor integration.3 The cerebellum and basal ganglia refine and coordinate speech movements, and the brainstem relays and receives the neural signals to and from the anatomy of speech and hearing4,5 (Table 57–2).
Table 57–2Key Functions of the Subcortical Structures of the Brain ||Download (.pdf) Table 57–2 Key Functions of the Subcortical Structures of the Brain
|Structure ||Location ||Function ||Impairment |
|Thalamus ||Center of forebrain || |
Relay of sensorimotor input to other areas of the brain
Contributes to cortically ...