Cognitive-linguistic processes
The combination of thoughts, feelings, and emotions generate an intent to communicate verbally is organized and converted into a code that abides by the rules of language
Motor speech planning, programming, and control
The selection, sequencing, and regulation of sensorimotor “programs” that activate speech muscles at appropriate times, durations, and intensities. Organizes an intended verbal message for neuromuscular execution
Neuromuscular execution
The neural and neuromuscular transmission and subsequent muscle contractions and movements of speech structures. The central and peripheral nervous system activity combines to execute speech motor programs by innervating breathing, phonatory, resonatory, and articulatory muscles.
Motor speech processes
The combined processes of speech motor planning, programming, control, and execution
Motor Speech Disorders
Dysarthria and Apraxia of Speech
THE DYSARTHRIAS
Abnormalities in the strength, speed, range, steadiness, tone, or accuracy of movements required for the breathing, phonatory, resonatory, articulatory, or prosodic aspects of speech production.
Neuropathophysiologic disturbances of control or execution
* Due to one or more sensorimotor abnormalities,
* weakness, spasticity, incoordination, involuntary movements, or excessive
or variable muscle tone
THE DYSARTHRIAS pt 2
- Dysarthria is neurologic in origin.
- It is a disorder of movement.
- It can be categorized into different types characterized by distinguishable perceptual characteristics and underlying neuropathophysiologic factors. The ability to categorize the dysarthrias therefore has implications for the localization of the causal disorder
Factors involved when identifying dysarthria
Age of onset
Cause
Natural course
Site of lesion
Neurological diagnosis of disease
Pathophysiology
Speech subsystem involved
Perceptual characteristics
Severity
APRAXIA OF SPEECH (AOS)
- “A motor speech disorder caused by a disturbance in motor planning, or programming of sequential movement for volitional speech production.”
- Characteristics include impaired articulation, rate, and prosody, or in the rhythm of the spoken utterance”
- Typically co-exists with aphasia or language delay
- Less likely to occur concomitantly with dysarthria
CHILDHOOD APRAXIA OF SPEECH (CAS)
- “Term used or the developmental counterpart of acquired apraxia
of speech” - Development of expressive phonological skills are affected
SPEECH DISTURBANCES THAT ARE DISTINGUISHABLE FROM MOTOR SPEECH DISORDERS
Other Neurologic Disorders
Cognitive, Linguistic, and Cognitive-Linguistic Disturbances
Sensory Deficits
Non-neurologic Disturbances (musculoskeletal defects)
Non-neurologic and non-psychogenic voice disorders
Functional (psychogenic) and related non-organic speech disorders
Age related changes in speech
Gender
Variations in Style
Other Neurologic Speech Disturbances
Deficits include, but may not be limited to, acquired neurogenic stuttering, palilalia, echolalia, foreign accent syndrome, aprosodia associated with right hemisphere dysfunction, and some
forms of mutism.
Cognitive, Linguistic, and Cognitive-Linguistic Disturbances
Changes in verbal expression resulting from language and other cognitive deficits (e.g.,
aphasia, akinetic mutism, and other cognitive and affective disturbances that attenuate or
inhibit speech) are sometimes difficult to distinguish from MSDs. Often co-occur with MSDs
Sensory Deficits
- Deafness acquired in adulthood can result in some degradation of speech.
- Tactile, kinesthetic, and proprioceptive sensations are also important to the development and maintenance of normal speech, and their malfunction.
Musculoskeletal Defects
laryngectomy, cleft lip and palate, fractures, abnormal variants of cavity size and shape
Non-neurologic and Non-psychogenic Voice Disorder
dysphonias associated with head or neck neoplasms, vocal abuse, or hormonal disturbances
Functional (Psychogenic) and Related Non-organic Speech Disorders
schizophrenia, depression, conversion disorder
Dysarthria is present in
- 25% of patients with small strokes,
- 90% of persons with Parkinson’s Disease
- 25% of people with amyotrophic lateral sclerosis. Dysarthria is one of the first symptoms in about
- 50% of people with multiple sclerosis
- One-third of those with traumatic brain injury (TBI)
- 90% of individuals with cerebral palsy
NERVOUS SYSTEM
Divided into:
* Central Nervous System (Brain and Spinal Cord)
* Peripheral Nervous System (Cranial and spinal nerves)
THE NEURON
Neurons - The function of neurons is to
transmit neural impulses from:
* one neuron to another
* from neuron to muscle
* from sensory receptors to other neural
structures (e.g. muscles, brain).
* Motor Neuron
* Sensory
* Internuncial
Neuron Disorders
MS and ALS
Glial Cells
Another type of cell found in the NS are glial cells which serve as supportive cells for neurons and form the blood brain barrier
Oligodendroglia and Schwann Cells
Cells that form myelin in the CNS and PNS
Astrocytes
Star-shaped cells that assist in neural migration
