Lectures 11-16 Flashcards
~The Nervous System~
Consists of:
Neuron:
Nerve:
Electrochemical impulses:
Consists of: the brain, spinal cord, and all associated nerves and sense organs
Neuron:
* Basic unit of the nervous system
* Contains: Cell body, axon, dendrites
Nerve:
* A collection of neurons
Electrochemical impulses: generally pass between the axon of one neuron to the dendrites of another across the synapse
~Central Nervous System~
Brain and Spinal Cord:
Made up of-
Lobes-
Left hemisphere-
Cerebrum:
Brain and spinal cord: Communicates with the rest of the body through nerves
Made up of- Cerebrum, cerebellum, brainstem
Four lobes:
* Frontal, temporal, parietal, occipital
- Generalized areas of the brain for particular operations
- Left hemisphere is dominant for most aspects of language and motor speech
production in 98% of people
Cerebrum: has left and right hemispheres
* Sensory and motor functions are mostly contralateral
* Each hemisphere consists of white fibrous connective tracts running below the surface and
covered by a gray cortex of cell bodies
* The cortex is wrinkled due to presence of gyri and fissures
~Central Nervous System~
Cerebellum:
Cerebellum:
* Consists of right and left hemispheres and a central vermis
* Coordinates control of fine, complex motor activities, maintains muscle tone, and participates in motor learning
* Influences language processing and higher level cognitive and affective functions
~Language Processing~
-Processed in ____ hemisphere for most people
In the right hemisphere:
Broca’s area:
Wernicke’s area:
Motor Cortex:
-Language is processed in the left hemisphere in most people
-Nonlinguistic and paralinguistic information are primarily processed in the right hemisphere
Broca’s area: Incoming auditory information is held in working memory in Broca’s area
Wernicke’s area: Most incoming linguistic processing occurs in Wernicke’s area, concepts are formed and supported by the angular gyrus (for words) and supramarginal gyrus (for grammar)
Motor Cortex: Broca’s area sends programming information to the motor cortex, which sends signals to motor neurons for speech
~Aphasia~
# of Americans that have aphasia=
Problems in=
Impaired=
Aphasia may affect=
-Over 1 million Americans have aphasia
-Problems in auditory comprehension and word retrieval are common to all aphasias to some degree
-Memory may also be impaired
Aphasia may affect:
◦ Listening
◦ Speaking
◦ Reading
◦ Writing
◦ Specific language functions such as naming
~Aphasia~
Severity=
Severity related to=
Other neurogenic disorders=
Common mental health issue=
-Severity can range from few intelligible words and little comprehension to those with subtle deficits
-Severity is related to the cause, location, extent, and age of brain injury
◦ Also the age and general health of the individual
-Patterns of behavior exist that allow categorization of aphasia syndromes
-Other neurogenic disorders often exist with aphasia
-Depression is common
~Types of Aphasia~
Fluent Aphasia:
Wernicke’s aphasia:
Fluent Aphasias:
◦ Characterized by word substitutions, neologisms, and often verbose verbal output
◦ Lesions tend to be in posterior portions of the left hemisphere
◦ Wernicke’s aphasia
◦ Rapid-fire strings of sentences with little pause for acknowledgement or turn taking
◦ Often unaware of difficulties
◦ Content may be jumbled, incoherent, or incomprehensible but fluent and well articulated
~Anomic Aphasia~
-Most aspects of speech are normal with the exception of word retrieval
~Types of Aphasia~
Nonfluent Aphasias:
Broca’s Aphasia:
Transcortical motor aphasia (nonfluent):
NonFluent Aphasias:
◦ Characterized by slow, labored speech and struggle to retrieve words/form sentences
◦ Site of lesion is in or near the frontal lobe
Broca’s aphasia:
◦ Short sentences with agrammatism
◦ Slow, labored speech and writing
◦ Articulation and phonological errors
Transcortical motor aphasia (nonfluent):
◦ Difficulty initiating speech or writing
◦ Severely impaired speech (damage to motor cortex
~Global Aphasia~
-Profound language impairment in all modalities
~Causes of Aphasia~
Most common cause=
Types of stroke=
Most common cause= stroke/cerebrovascular accident (CVA)
◦Strokes affect half a million Americans annually
◦Onset is rapid
Types of stroke=
◦ Ischemic
◦ Hemorrhagic
Other conditions that may have aphasia symptoms:
◦ Head injury
◦ Neural infections
◦Degenerative neurological disorders
◦Tumors
~Primary Progressive Aphasia~
◦Degenerative disorder of language with preservation of other mental functions and of activities of daily living
◦Progresses to a near-total inability to speak
Risks of Aphasia:
-Smoking
-Alcohol use
-Poor diet
-Lack of exercise
-High blood pressure
-High cholesterol
-Diabetes
-Obesity
-TIAs
Signs of Occurrence in Aphasia
-Loss of consciousness
-Sudden numbness weakness on one side of body
-Difficulty understanding speech
-Loss of balance/coordination
-Trouble seeing in one or both eyes
-Weak/immobile limbs
-Slurred speech
~Spontaneous Recovery~
◦A natural restorative process
◦Maximum spontaneous recovery for language occurs in the
first 3 months
◦Assessment and intervention begin as soon as the client’s
condition permits
◦The earlier the treatment, the better the rate of recovery
What to expect
◦ Following acute care, the individual may require rehabilitative hospitalization, outpatient rehabilitation, or nursing home care
◦ Most individuals receive services for at least the first several months
◦ Course and extent of recovery is difficult to predict
◦ Loss of language ability changes social roles and can lead to isolation
◦ Families are frightened and confused
◦ Individual with aphasia may become dependent on others for daily tasks
◦ Economic burden can be enormous
◦ Individual may focus on physical and language complications, leading to frustration and depression
Procedures (assessment)
-Occurs in several stages as the client stabilizes
-Observations inform nature and extent of the disorder
Formal testing is postponed until the patient is stable; informal testing allows treatment to begin as soon as possible
-Medical history, interview with client and family, oral peripheral exam, hearing testing, direct speech and language testing
◦ Should address overall communication skills, as well as receptive and expressive language in all modalities
◦ Standardized tests are available
-May exhibit perseveration, disinhibition, and emotional problems
◦ Note client behavior during testing
Evidence- Based Practice:
Overall goal:
-Intervention methods vary; must be determined individually
-Failure to participate in intervention has an adverse effect on recovery
Overall goal= is to aid in the recovery of language and provide strategies to compensate for persistent language deficits
◦ Goals are determined by assessment results and the desires of the client and family
◦ Decide whether to work on underlying skills or skill deficits
◦ Cross-modality generalization
◦ Skills trained in one modality generalize to another
◦ Using semantic associations increases naming accuracy in patients with anomic aphasia
◦ Conversational techniques provide language therapy and therapeutic support
Assessment of RHBD
◦ Special Areas
◦ Visual scanning/tracking
◦ Auditory/visual comprehension of words and sentences
◦ Direction following
◦ Response to emotion
◦ Naming/describing pictures
◦ Writing
◦ Sampling and observation are essential for pragmatics
◦ Portions of aphasia batteries, standardized tests for RHBD, and non- standardized procedures can be used
Intervention for RHBD
-Often begins with visual and auditory recognition
◦ Expressive aprosodia (a deficit in comprehending or expressing variations in tone of voice)
◦ Imitate a sentence in unison with the SLP or used cognitive-linguistic treatment in which there are cues to modify prosody
◦ Interpretation of nonliteral or figurative meaning
◦ Word meaning and connotations can be mapped and diagrammed
◦ Intervention for activating meanings and suppression of non-contextual meanings
◦ Contextual pre-stimulation often begins with visual and auditory recognition
Brain Damage:
May result from:
-Closed head injuries that include swelling of the brain result in diffuse injury
-Open head injury may accommodate swelling, resulting in less damage that is more focused
Brain damage may result from:
◦ Bruising and laceration of the brain from coming into contact with the rough inner surface of the skull
◦ Secondary edema, which can lead to increased pressure
◦ Infection
◦ Hypoxia
◦ Intracranial pressure from tissue swelling
◦ Infarction: Death of tissue deprived of oxygen supply
◦ Hematoma: Focal bleeding
TBI Characteristics:
-May have sensory, motor, behavioral, and affective disabilities
-Seizures, hemisensory impairment, and hemiparesis or hemiplegia may occur
-Inability to resume interests and daily living tasks to the level that existed before the injury
-Affects orientation, memory, attention, reasoning/problem solving, and executive function
-Language may be affected in 3 out of 4 individuals with TBI
-Most disturbed language area is pragmatics
Pragmatic deficits include
◦ Inability to inhibit behavior
◦ Inappropriate laughter and swearing
-Psychosocial and personality changes
CI- Umbrella Term
Irreversible cognitive impairment:
A group of pathological conditions and syndromes that result in declining memory and at least one other cognitive ability
◦ Significant enough to interfere with daily life
◦ Acquired
◦ Characterized by intellectual decline due to neurogenic causes
-Fewer than 15% of the elderly experience dementia or cognitive impairment
-Up to 20% respond to treatment
Irreversible cognitive impairment:
◦ Alzheimer’s disease (AD), vascular cognitive impairment (VCI), multi-infarct dementia, or mixed causes
~Subdivided into cortical and subcortical types~
Cortical cognitive impairments:
Subcortical cognitive impairments:
Cortical cognitive impairments:
◦ Include Alzheimer’s and Pick’s diseases (Frontotemporal dementia (FTD) symptoms include personality & behavior changes)
◦Resemble focal impairments such as aphasia and RHBD
Subcortical cognitive impairments:
◦ May accompany Multiple Sclerosis (MS), A I D S-related encephalopathy, and Parkinson’s and Huntington’s diseases
◦ Slow, progressive deterioration of cognitive functioning
Frontal Lobes house the primary motor cortex:
Direct activation pathway, or pyramidal tract:
Indirect activation pathway, or extrapyramidal tract:
Frontal lobes house the primary motor cortex:
-Descending pathways from primary motor cortex are important for initiating voluntary motor movements
Direct activation pathway, or pyramidal tract:
* Originates in the primary motor cortex
* Rapid, discrete, volitional movement of
limbs and articulators
Indirect activation pathway, or extrapyramidal tract:
* Regulates reflexes and maintains posture and muscle tone
* Provides the necessary framework to facilitate movement
Parts of the brain diagram: LABEL
Look up picture from google docs
Cranial nerves diagram:
Look up picture from google docs
~Cranial Nerves~
Peripheral nervous system:
Cranial Nerves:
Spinal Nerves:
Brain stem:
Peripheral nervous system:
-12 pairs of cranial nerves
-31 pairs od spinal nerves
Cranial Nerves:
-especially important for speech production
Spinal Nerves:
-important for breathing purposes of speech production
Brain stem:
-control centers in brainstem, govern breathing for life
~Apraxia-Neurology~
Speech disorder that…..
Damace to:
Usually occurs after:
-Speech disorder that impairs the ability to plan or program the sensory and motor commands needed for speech production
-Damage to the left cerebral hemisphere, particularly motor and premotor areas
-Usually occurs after a left hemisphere stroke in Broca’s area
~Dysarthria Definition~
Group of:
Affect:
Motor Movements:
Group of: neuromotor impairments resulting from disturbances in the CNS and PNS that control the muscles of speech production
Affect: speed, range, direction, strength, and timing of motor movement
* Result of weakness, spasticity, discoordination, or involuntary movement
- Respiration, phonation,
resonation, and articulation may all be affected - Motor movements may be lost or modified in some way
~Spastic Dysarthria~
Typically results from:
Weakness and loss of:
Reflexes:
Spasticity in the larynx=
Typically results from: bilateral upper motor neuron lesions in the cerebral hemispheres or a single lesion in the brainstem
-Weakness and loss of inhibitory motor control
- Reflexes are hyperactive, muscle tone is increased at rest, and individuals exhibit spasticity (increased resistance to passive stretch)
- Movements of the articulators are slow and reduced in force and range of motion
- Spasticity in the larynx results in a strain-strangled voice quality
~Flaccid Dysarthria~
Usually results from:
Usually results from lesions in the cranial and spinal nerves (lower motor neurons) or the motor unit
~Hypotonia~
Weak, soft, low muscle tone
- Reduced respiratory drive for speech breathing, continuously breathy voice, reduced pitch and loudness levels, monopitch, hypernasality, and imprecise
articulation
-Flaccid Dysarthria
~Bell’s palsy~
- Idiopathic condition that results in unilateral damage to the facial nerve
- Occurs suddenly and resolves in most cases
- Mild articulatory imprecision
-Flaccid Dysarthria
~Progressive Bulbar Palsy~
-Degeneration of lower motor neurons
- Flaccid paralysis and eventual muscle atrophy
- Fasciculations
- Visible, isolated twitches in resting muscle
- Due to spontaneous firing of nerve impulses in response to nerve degeneration
- Speech sounds weak, hypernasal, monopitched, and articulation is imprecise
-Flaccid Dysarthria
~Myasthenia Gravis~
-Autoimmune disease that affects the neuromuscular junction
- Rapid weakening due to inadequate transmission of nerve impulses to the muscles
- Muscles become progressively weak with repeated use but regain strength with a short rest
- Imprecise articulation and hypernasality
- Gets worse with prolonged speaking
- Dramatically improves with 1-2 minutes’ rest
-Flaccid Dysarthria
~Hypokinetic Dysarthrias~
Movements are:
Reduced:
Speech rate:
Loudness levels:
-Degeneration of dopaminergic neurons in the brainstem prevents proper function of the Basal Ganglia
- Movements are slow and reduced in range due to rigidity
- Individuals with hypokinesia feel stiff and find it hard to get movement started
- Once started, they struggle to stop
- Reduced ROM is a hallmark feature
- Speech rate becomes very fast, and disfluencies are common
- Loudness levels gradually diminish
~Parkinson Disease~
- Idiopathic degenerative neurological
disease - Affect 1-2% of individuals over age 50
- Genetic and environmental factors play a role
- Hypokinetic dysarthria is eventually present in 90% of cases
- Reduced loudness, accelerated rate of speech, disfluencies, imprecise articulation
- Voice quality may be breathy and harsh or hoarse
- Pitch and loudness variability is significantly reduced, resulting in monopitch and monoloudness
-Hypokinetic Dysarthrias
~Hyperkinetic Dysarthrias~
Production of:
Tremor:
Tics:
Indirect pathway or structures of the Basal Ganglia that help inhibit unwanted movements are damaged
- Production of motorically normal speech that is interrupted by abnormal involuntary movements
- Tremor: Rhythmic movement of a body part
- Tics: Rapid, patterned movements that are not completely involuntary and can be briefly suppressed
~Hyperkinetic Dysarthrias~
Dystonia:
Chorea:
- Dystonia: Slow hyperkinesia that may involve the entire body or may be localized.
- Excessive pitch and loudness variations, irregular articulatory breakdowns, variable rate, inappropriate silences
- Chorea: Rapid and unpredictable movements of the limbs, face, and tongue
- Variable speech rate, irregular articulatory breakdowns, significant prosodic abnormalities
~Ataxic Dysarthria~
Results in:
Irregular breakdowns in:
Movements are:
-Damage to the cerebellum or cerebellar control circuitry
- Results in incoordination and reduced muscle tone (ataxia)
- Irregular breakdowns in articulation and abnormalities of prosody
- Due to incoordination and improper timing
- Movements are inaccurate, jerky, and lacking smoothness
~Mixed Dysarthrias~
-When two or more Dysarthrias are present
-Can occur in neurodegenerative diseases that cause damage to multiple areas of the CNS
Amyotrophic lateral sclerosis (ALS):
Traumatic Brain Injury (TBI):
Amyotrophic lateral sclerosis (ALS):
* Both upper and lower motor neurons degenerate
* Causes both spastic and flaccid paralysis
* 75% are unable to speak at the time of death
Traumatic Brain Injury (TBI):
* causes mixed dysarthria, usually spastic-ataxic
* Axonal shearing in TBI causes diffuse damage
-Mixed Dysarthrias
~Cerebral Palsy~
CP in prediatric population:
Causes:
Type of CP:
-CP is the most common etiology of chronic physical disability in the pediatric population
-Causes abnormal muscle tone, loss of selective motor control, muscles weakness, and impaired balance
-Type of CP varies with the areas of the CNS that are damaged
~Spastic Cerebral Palsy~
Damaged….
60% of individuals with CP:
Limbs may be:
-Damaged upper motor neurons are unable to inhibit signals that increase muscle tone
-60% of individuals with C P have characteristics of spasticity and increased muscle tone
-Exaggerated stretch reflex
-Movement is jerky, stiff, labored, and slow
Limbs may be rotated inward, with arms drawn upward and head turned to the side
~Athetoid Cerebral Palsy~
Damage to:
30% of individuals with CP:
Feet may:
-Damage to Basal Ganglia structures and pathways that inhibit involuntary movements
-30% of individuals with CP have athetosis – slow, involuntary writhing
-Movement is disorganized and uncoordinated
-Speech breathing problems are more severe than in other types
-Feet may turn inward, back and neck arch, and arms and hands overextend above the head
-Severity varies
~Ataxic Cerebral Palsy~
Injury to:
Impairs:
In extreme cases:
Injury to the cerebellum
* Impairs monitoring of information about balance from the inner ears and proprioceptive information from the muscles
-Uncoordinated movement
-Disturbed balance
-In extreme cases, walking is characterized by a wide stance with the head pushed forward and arms back
~Procedures for Dysarthria Evaluation~
-Oral Peripheral mechanism evaluation-
- Thorough case history is necessary
- SLP evaluates structure and function of the oral mechanism, connected speech, and speech in special tasks
-Oral peripheral mechanism evaluation-
* Symmetry, configuration, color, and general appearance of the face, jaw, lips, tongue, teeth, and hard and soft palate at rest
* Movement of the jaw, tongue, lips, and soft palate
* Range, force, speed, and direction of the jaw, lips, and tongue during movement
* Lung capacity, respiratory driving pressure, control during speech production
* Phonatory initiation, maintenance, and cessation
* Pitch and pitch variability
* Loudness and loudness variability
* Volitional pitch-loudness variations
* Velopharyngeal function
~Basic principles of treatment Dysarthrias~
- Must address respiration, phonation, resonation, articulation, and prosody
- Increasing respiratory drive might be accomplished via pausing/phrasing
- If respiratory muscle weakness is too great, an abdominal binder can be used
- Voice amplifiers can be used
~Basic principles of treatment Dysarthrias~
~Evidence based practice~
LSVT:
CPAP:
Intensive:
EPG:
Augmentative and alternate communication:
- LSVT can be used to increase phonatory competence in adults with Parkinson disease and for respiratory and phonatory deficits in children with spastic CP
- Continuous positive airway pressure (CPAP) and palatal lift can be used for velopharyngeal function
- Intensive, repetitive speech production drill practice with meaningful words and phrases can increase articulatory accuracy
- Slowing speech rate is effective
- Electropalatography (EPG) may be helpful
- Augmentative and alternative communication
~Basic Principles of Treatment Apraxia~
-Evidence based practice-
Integral Stimulation:
Melodic Intonation Therapy:
Integral stimulation:
* “Watch me, listen to me, do what I do”
* Involve an 8-step continuum for cueing that is used to help a client retrain motor
planning/programming
* Core set of functional vocabulary words or phrases
*Incorporates principles of motor learning
Melodic Intonation Therapy:
* Focuses on prosody, emphasizing the melody, rhythm, and stress patterns of the utterances
* Believed to facilitate motor planning/programming for speech by accessing the right
hemisphere
* Most effective for clients with mild-moderate apraxia of speech who have prosodic abnormalities but otherwise adequate articulation
~SYMBOLS ARE CENTRAL TO THE PROCESS OF CLASSIFYING AAC SYSTEMS~
Unaided systems:
Aided systems:
Unaided systems do not involve external equipment
Aided systems involve the use of equipment
-Can be No-tech, low-tech, mid-tech, and high-tech
~Unaided AAC~
Gestures and Vocalizations:
Iconic:
Transparent:
Opaque:
Fingerspelling:
Gestures and Vocalizations:
* Use of gesture, body movement, or observable signal with a partner
* (manual sign systems) ASL, Signed English, Signing Exact English, Tactile Signing, Amer-Ind
- Iconic: signs look like what they represent
- Transparent: signs are easily guessable, explainable, and memorable
- Opaque: signs are difficult to interpret
- Finger spelling: refers to the manual alphabet
~Aided ACC, Symbol types~
Tangible:
Pictorial:
Orthographic:
Tangible:
* Visual schedules can use tangible symbols
* Organized according to daily activities
Pictorial:
-Pictures, drawings, or other representations
-Some are designed specifically for A A C use
-Relatively rule-governed and generative
Orthographic:
* Braille
* Fingerspelling
* Writing
~Selection Types~
Direct:
Indirect:
Scanning-
Auditory Scanning-
Direct:
* Select an item directly by pointing with a finger, hand, head pointer, optical head pointer, joystick, or eye gaze
* Can be difficult for those with severe motor problems
Indirect:
▪ Scanning and partner-assisted selection/scanning
▪ Scanning involves assembling a message through a series of switch activations in which choices are presented sequentially
▪ In partner-assisted scanning, options are presented by another person
▪In auditory scanning, auditory cues are present
▪Scanning can be slow and laborious
▪Efficiency can be enhanced by placing the most
frequently used symbols in locations where they are scanned more often, or by changing scanning method
~Voice Output on AAC Devices~
-Intelligibility can be increased through training
-Voice output communication (VO C) can be recorded or digitized, synthesized, or both
-Comprehension of synthesized speech requires increased focused attention by the communication partner
-Partners tend to respond more slowly to synthesized speech
~Considerations with AAC~
Linguistic Competence:
Operational Competence:
Social Competence:
Strategic Competence:
Linguistic Competence: Individual’s language ability across all dimensions of language
Operational Competence: How a person uses an AAC system
Social Competence: How well a person manages the social aspects of communication
Turn taking, topic maintenance, reciprocal interactions
Strategic Competence: ability to solve problems
~Intervention, Symbol Selection~
-Select vocabulary that reflects the user’s needs, desires, likes, and preferences
-Functional or useful
-Several lists of potential vocabulary are available
-Order of teaching signs or symbols must be guided by a client’s immediate need
~Intervention Considerations~
-Intervention will be most effective if caregivers also use AAC with speech (augmented input)
-Establish a positive AAC culture
-Understand AAC as critical to literacy development
-Individualize the content
-Teach partners to modify their interaction style
-Classroom integration requires collaboration between the teacher and SLP
-AAC training for the educational team is a key element in success
-Abandonment of AAC is usually related to loss of facilitator/partner support
~AAC evidence based practice~
-AAC does not impede speech production
-Many individuals who use AAC produce shorter utterances when they use graphic symbol-based AAC systems
-Few studies have investigated the effectiveness of AAC-specific aspects of intervention in a family context
-Improved speech intelligibility coming from high- tech systems doesn’t necessarily lead to a persons’ social participation
~Incidence, prevalence, and classification of hearing loss~
% of Americans with hearing loss:
Worldwide # of people with hearing loss:
of people older than 65 with hearing loss:
Hearing loss undetected in more than:
~20% of Americans report some degree of hearing loss
-Worldwide 360 million people have disabling hearing loss
~1/3 Hearing Loss 5 of individuals older than 65 year os age have
Hearing loss goes undetected or untreated in more than 75% of adults with hearing loss
~How with hearing loss~
Sound travels from:
Hearing loss results from:
Conductive hearing loss:
Sensorineural loss:
Sound travels from:
outer ear–> middle ear –> inner –> auditory nerve –> brain
A hearing loss results from a change somewhere in this path.
Disorder that affects the outer or middle ear = conductive disorder
Outer or inner hair cell damage in the cochlea or damage to the auditory nerve, which travels from
Conductive system made up of:
Sensorineural system made up of:
Conductive Hearing loss (results from, usually prevents, impacts):
Sensorineural Hearing loss:
The outer and middle ears comprise the conductive system
The cochlea and auditory nerve make up the sensorineural system
Conductive Hearing Loss:
-Results from deformation, malfunction, or obstruction of the outer or middle ear
-Usually prevents low- to moderate-intensity sounds from being heard at all and higher-intensity sounds being
perceived as softer
-Impacts audibility
-Most are not permanent
Sensorineural Hearing Loss:
-Absence, malformation, or damage to structures of the inner ear
-may be present at brith or develop over time
-usually permanent
-hearing loss is predominantly in the higher frequency range
-sounds that are audible are perceives as being distorted
Causes and risk factors for conductive and sensorineural loss:
SENSORINEURAL LOSS Noise exposure due to
* The intensity of the noise
* The length of exposure
* No hearing protection
- Cerumen blockage, particularly due to the use of cotton swabs.
- Foreign objects inappropriately
put into the ear canals or
inflammation of canals - Otosclerosis, abnormal bone growth which develops around
the ossicles compromising the transmission of sound. * Otitis media, although it occurs
far less frequently than it does
with children (due to structural
changes in the ear mechanism-
lengthening and curving of the
Eustachian tube & an improved
immune system)
SENSORINEURAL LOSS Noise exposure due to:
* The intensity of the noise
* The length of exposure
* No hearing protection
* recovery time between exposures
Ototoxicity
Ototoxicity Another common cause of inner-ear damage and sensorineural hearing loss
Labyrinthitis
-a short-term infection that is treated medically
Meniere’s Disease:
-a long term disorder caused by an overproduction or under absorption of endolymph, a fluid that circulated in the inner ear, resulting in a progressive hearing loss
Acoustic Neuromas:
-tumors can be hard to identify and are usually noticed by a decrease in hearing in one ear, followed by a feeling of fullness or pressure
~Hearing loss Procedures~
Screening:
Referral and case history:
Otoscopic exam:
Screening:
Can be initiated with an audiometric screening, but it more often begins
with a complete hearing evaluation
Referral and case history:
-Why the client has come in for an evaluation
-Has he/she been exposed to noise
-Is there a history of ear
infections or surgery
-How is communication difficult
Otoscopic Exam:
-Conducted with an otoscope
-Allows visual inspection of the canal and eardrum
-A video otoscope projects the image of the ear on a monitor
Range for hearing loss:
-expressed in decibels (dB)
-the greater the dB value required to reach a person’s threshold, the greater the hearing loss
-the severity of hearing loss ranges from mild to profound and is typically defined using decibels
-range of normal is different for children and adults
Helping people who have hearing loss:
Amplification Hearing Aids:
Cochlear Implants:
AMPLIFICATION HEARING AIDS
* Every hearing aid contains a microphone, amplifier, receiver, and some type of computer processor
* Most incorporate sophisticated digital signal processing
* Signal can be manipulated to improve audibility while maintaining comfort, reducing unwanted background noise, and eliminating feedback
* Primary goal is to make speech audible to improve intelligibility
* Will not return hearing to normal
* Must be counseled so expectations are realistic
COCHLEAR IMPLANTS
* Prosthesis that bypasses damaged hair cells in the cochlea
* Directly stimulates the surviving auditory nerve fibers with electrical energy
* External components
* Microphone, speech processor, external transmitter
* Internal components
* Receiver-stimulatorthatissurgicallyattached to the skull, and the electrode array that is inserted into the cochlea
* Bilateral implantation is becoming more common
* Signal is transmitted across the skin via F M waves to the internal receiver-stimulator and finally to the electrodes in the cochlea
~Cochlear Implant~
Auditory Training and Auditory Communication Modality
Auditory Verbal Therapy (AVT)
Goal of auditory training is to maximize a person’s use of residual hearing
Neural plasticity:
Physiological and functional changes within the central nervous system in response to auditory stimulation
By providing certain types of auditory input, hope is to change the way the central auditory system works and improve effective use of speech and language information
~Fundamentals of Sound~
- There must be an energy source, an object capable of vibrating, a medium, and a receptor
- Sound is a series of compressions and rarefactions that move outward from the vibrating source
- Amplitude is the distance the vibrating object travels in either direction
*Determines intensity, measured in decibels (dB) - Frequency refers to the number of cycles of vibration per
second - MeasuredinHertz(Hz)
~Anatomy and physiology of the auditory system~
The outer ear
The Outer Ear
*Consists of the pinna and the external auditory meatus
* Pinna enhances sound and facilitates localization
*External auditory meatus is an elliptical tube lined with skin that extends from the concha to the tympanic membrane
* Outer external auditory meatus has hair follicles and glands that produce cerumen
*External auditory meatus can enhance high frequency sounds
~Anatomy and physiology of the auditory system~
The middle ear
- Tympanic membrane vibrates in response to sound waves
- Tympanic membrane is composed of three layers of tissue and is a semitransparent pearl gray in color
- The middle ear space is air-filled, lined with mucous membranes,
and includes the opening to the Eustachian tube 7 - The Eustachian tube connects the middle ear with the nasopharynx
- It is normally closed but opens to provide ventilation and equalize pressure
- The malleus, incus, and stapes are the bones (ossicles) of the ossicular chain
- The malleus is embedded in the fibrous layer of the eardrum
- The footplate of the stapes rests against the oval window
~Anatomy & Physiology of
the auditory system~
The inner ear
The cochlea is responsible for providing auditory input to the central auditory system
* The vestibular system is responsible for supplying information about balance
* The cochlea contains auditory sensory receptor cells that respond to auditory stimuli
* Composed of two labyrinths
* Outer labyrinth is composed of bone and is filled
with perilymph
* Inner labyrinth is composed of membranous material and contains endolymph
~Hearing loss severity~
-Hearing loss is classified according to its severity, using the decibel (dB) system.
Decibels
* Standard unit of sound intensity – how loud it is
Threshold
* represent the differences in loudness available to human hearing, from the threshold of sound at 0 dB (the drop of a pin) to the threshold of pain between 120 dB and 140 dB (a fire alarm close to your ear).
Audiogram
* The graphic representation of what a person can hear
Infant Screening (ABR)
AUDITORY BRAINSTEM RESPONSE (ABR)
* Measures neuroelectric activity of the auditory nerve and structures of the lower brainstem
* Can be used to identify neurological issues such as tumor or cranial nerve VIII or auditory neuropathy/dys- synchrony disorder
Comprehensive Audiological Evaluation
Behavioral Testing
Audiometer
*Equipment used for selection, manipulation, and presentation of stimuli during hearing assessment
*Testing is usually carried out in a specifically treated sound booth
Behavioral Observation Audiometry (BOA)
*Audiologist presents a stimulus through a loud speaker and observes a child’s reaction
*Reliability and validity has been questioned
*Electroacoustic and electrophysiological measures are
preferred when assessing children younger than 5 months
Bimodal Hearing:
Cochlear implant on one ear and a hearing aid on the other
- Hybrid device that houses both hearing aid and cochlear implant technology in the same unit
- Children as young as 12 months can undergo cochlear implant surgery
- Post-lingually deafened adults tend to benefit extensively
- Children implanted at an early age who receive intensive auditory therapy demonstrate significant gains in speech perception, language acquisition, speech production, and literacy development
Central Auditory Processing Disorders
-Interfere with the ability to efficiently and effectively use and interpret acoustic information
-May have difficulty hearing subtle differences between similar sounding words and misunderstanding of speech when presented in noise
-Normal peripheral hearing
