Chapter 3: Medical and Scientific Disciplines

Question 1

What three health bodies are involved with SLT?

Answer 1

1. Royal College of Speech and Language Therapists.
2. Quality Assurance Agency for Higher Education.
3. Health and Care Professions Council.

Question 2

What does a prevalence of a disorder mean?

Answer 2

The number of individuals in a population who have the disorder at a specific period of time.
E.g. percentage of the population.

Question 3

What does the incidence of a disorder mean?

Answer 3

The number of individuals who develop a disease/disorder during a particular time period, usually a month/year.

Question 4

What variables affect the distribution of diseases/disorders? 4

Answer 4

1. Sex.
2. Race.
3. Ethnicity.
4. Socioeconomic status.

Question 5

What is the study of aetiology?

Answer 5

Study of medical causes of diseases/disorders.

Medical cause of a communication disorder can often be identified e.g. Down syndrome.

Question 6

What does functional disorder mean?

Answer 6

Disorder that lacks medical aetiology.
Functional voice disorder label used when there is impairment of the use/function of the vocal apparatus.
Can relate to psychogenic origins (e.g. stuttering) - psychogenic voice disorder label used.

Question 7

What is the study of epidemiology?

Answer 7

Study of distribution and determinants of diseases/disorders in populations.
Key concepts - prevalence and incidence.

Question 8

What is the difference between proximal aetiology and distal aetiology?

Answer 8

Proximal - direct causes of a disorder.

Distal - cause via an intermediary factor.

Question 9

What is the difference between anatomy and physiology?

Answer 9

Anatomy - structure of the organs.

Physiology - function of the organs.

Question 10

Why would the knowledge of cell biology be useful?

Answer 10

Includes the structure and function of hair cells of the cochlea and how these cells may be degraded via illness e.g. meningitis and injury e.g. noise exposure.

Question 11

Why would the study of histology be useful?

Answer 11

Study of tissues - can help understand vocal fold structure and function.
Lamina propria lies deep in the squamous epithelium vocal fold.
Three layers - superficial, intermediate and deep.

Question 12

Why would the knowledge of genetics be useful?

Answer 12

To understand genetic syndromes e.g. fragile X syndrome and autism - can explain higher male ratio.
4-5:1 imprinted X-liability threshold model.

Question 13

Why is knowledge of respiration useful?

Answer 13

Reduced breath speech support can affect intelligibility e.g. cerebal palsy.
Reduced vocal volume e.g. Parkinson’s disease.

Question 14

Why is knowledge of the cardiovascular systems useful?

Answer 14

Children with congenital heart disease are at risk of brain injury.
Relationship between cardiovascular disease and cerebrovascular accidents.
E.g. blood clots (atherosclerosis) can travel to the brain and prevent oxygenated blood from reaching brain tissue - stroke.

Question 15

Why is knowledge of the central nervous system useful?

Answer 15

Relates to the brain and spinal cord.
Brain contains neuroanatomical areas related to speech and language e.g. primary motor context, Broca’s area and Wernicke’s area.

Question 16

Why is knowledge of the peripheral nervous system useful?

Answer 16

31 spinal nerves and 12 cranial nerves.
Cranial nerves control a lot of facial muscles.
E.g. orbicularis oris (sphincter muscle which encircles the lips).
Spinal nerves e.g. pherenic nerve controls diaphragm and intercostal muscles.

Question 17

Why is knowledge of the sensory systems useful?

Answer 17

Hearing, vision and olfaction are vital for communication and swallowing.
Visual - facial expressions and gestures.

Question 18

What are some examples of congenital malformations?

Answer 18

Cleft lip and palate.
Micrognathia (undeveloped mandible - jaw) e.g. Pierre Robin syndrome.
Macroglossia (large tongue).

Question 19

What happens to the body growing up?

Answer 19

During preschool period - brain enlarges x4.
Puberty - larynx descends and dimensions of the infraglottic sagittal and transverse planes increase.
Changes in mass and size is greater for males.
Male average frequency - 130 Hz at 18 years old.
Female average frequency - 220-225 Hz at 18 years old.

Question 20

CASE STUDY - Cleft Palate.

Prevalence? How is speech affected and why?

Answer 20

9.92 per 10,000 (2011) - higher in boys.
Highest rates in the white population of California.
Hypernasal speech due to velopharyngeal incompetence.
Closure of the velopharyngeal port is often not possible due to anatomical and physiological reasons.

Question 21

What happens to the lungs as an adult?

Answer 21

Lungs mature by 20-25 years age.

Decrease in maximum inspiratory pressure can lead to inadequate ventilation and impaired clearance of airway secretions.

Question 22

What can happen to the ears as an adult?

Answer 22

Ossicular chain in the middle ear may be impaired - onset of otosclerosis.
E.g. new bone growth on the anterior stapes footplate, leading to the fixation of the stapes - hearing loss.
Treated by stapedectomy surgery.
Mean age for surgery - 43.57 years old.

Question 23

What are some examples of anatomy not developing properly in the pre-natal period? 3

Answer 23

Cleft lip and palate.
Micrognathia (undersized jaw).
Atresia (absence) of the ear canal.

Question 24

Cerebral Palsy CASE STUDY

Prevalence? Causes (4)? Detectable stat? How is it classified?

Answer 24

Motor disability - prevalence 1.5-2.5 per 1,000 live births.
Number of aetiologies (causes) e.g. abnormal neurodevelopment in pre-natal period, hypoxia (reduced oxygen supply), infections such as congenital cytomegalovirus and neonatal meningitis.
17% cases - undetectable via MR/CT scanning.
Classified via motor impairment (e.g. spasticity hemiplegia - tight muscle tone on one half of the body) and impairment distribution (e.g. hemiplegia).

Question 25

What is an example of acquired neurological impairment?

Answer 25

Strokes - affecting cortical and sub-cortical areas.
Can cause aphasia, dysarthria, speech apraxia and dysphagia.
Undamaged brain areas can experience activity increase.
Parkinson’s disease, MS, dementias - rapidly or slowly progressive.
Can also onset in developmental period e.g. Duchenne muscular dystrophy in children.

Question 26

What will an SLT want to establish in a neurological assessment?

Answer 26

Establish if client has neurological impairment.
Which components of nervous system are affected.
Location of any dysfunction.

Question 27

What is Cholesteatoma?

Answer 27

3 - 1,000 children. 9.2 - 1,000 adults.
Skin cyst - grows in the middle ear and mastoid bone.
Arise from Eustachian tube dysfunction.
Inadequate opening of the tube leads to negative middle ear pressure and retraction of the tympanic membrane.
Epithelial cells that are shed may accumulate and get trapped under the membrane - causing cholesteatoma.
Progressive hearing loss - from erosion of incus.

Question 28

Noise-induced hearing loss? (NIHL)

Answer 28

20-69 year olds - 15% prevalence.
21.8% males and 8.5% females.
Morphological changes to outer hair cells in the cochlea.
Sterocilia of cells become bent - first and third row most sensitive to noise.
Second row most resistant.
Loss of 30% hair cells causes shift in frequencies.
Tinnitus - sound in absence of acoustic stimulus is also featured.

Question 29

What is laryngomalacia?

Answer 29

Supraglottic structures collapse during inspiration.
Results in poor air flow - feeding problems.
Generally resolves within 2 years of life.
5-20% - supraglottoplasty.

Question 30

What is vocal fold paralysis?

Answer 30

Unknown exact cause.
Arnold-Chiari malformation is the most common abnormality resulting in it.
Stridor (high pitched wheezing) - common symptom.
Tracheotomy is sometimes needed to protect the airway.
Feeding difficulties.

Question 31

What is Subglottic Stenosis?

Answer 31

Larynx ring abnormal in size/shape.
Case - 18% children had a normal voice.
82% - mild to severe dysphonia.
Common form - as a result of endotracheal intubation in neonates.
Partial cricotracheal resection - popular surgery.

Question 32

What are some common adult-onset neck injuries?

Answer 32

Road accidents, sports injuries and violent assaults.
Laryngeal injuries - dislocation of cricothyroid joint, hyoid bone fractures.
Recurrent laryngeal nerve can be damaged during thyroidectomy and oesophagectomy.
Tumours may require glossectomy (removal of part of tongue), pharynx or oesophagus.

Question 33

How does sound mature after the post-natal months?

Answer 33

Several years - maturation of certain auditory processing skills.
Related to axon myelination (fatty substance surrounding cells) and maturation of synaptic mechanisms.

Question 34

What happens regarding age-related hearing loss?

Answer 34

Presbycusis.
High-frequency hearing loss.
Loss of hair cells at the basal end of the cochlea.
Neural presbycusis - loss of cochlear neurons - gradual curve from low to high frequency.
Metabolic presbycusis - deterioration of the stria vascularis.

Question 35

What tests are included in audiometric assessment?

Answer 35

Mechnical sound transmission (middle ear function).
Neural sound transmission (cochlear function).
Speech discrimination ability (central auditory processing).
Pure bone audiometry - pure tone presented through earphone.

Question 36

What is immittance audiometry?

Answer 36

Used to determine ear pressure, mobility of the tympanic membrane, Eustachian tube function, continuity and mobility of the middle ear ossicles, and acoustic reflex thresholds.

Question 37

What is tympanometry?

Answer 37

Airtight seal is formed by inserting a probe tip into the ear canal.
Pressure in the enclosed cavity is varied and change in sound pressure level of a probe tone is graphed.
Shows the movement of the middle ear under various pressure.

Question 38

What does a contraction of the stapedius muscle mean?

Answer 38

In response to loud sound can be measured (acoustic reflex test) - can be seen in 70 to 90 dB above pure tone threshold.
Contraction - sustained for 10 seconds at 10-15 dB above the reflex threshold at 500-1,000 Hz.
Reflex delay/failure - early sign of retrocochlear disease.

Question 39

What does auditory brainstem response (ABR) audiometry measure?

Answer 39

Electrical activity of the auditory nervous system.
Electrodes placed on vertex (crown), earlobes and forehead.
Display of five waves.
Normal - wave I-V is 4.00 milliseconds.
Acoustic tumour (acoustic neruoma) when travel time is delayed by 0.5 milliseconds.

Question 40

What can help manage hearing loss?

Answer 40

Hearing aids.
Electronic prosthetic devices (cochlear implants).
Basic electronic components including microphone that detects sound.
Amplifier circuitry - amplifies sound.
Receiver - delivers amplified sound into ear canal.
Batteries - power electronic parts.

Question 41

What do cochlear implants involve?

Answer 41

Sound processor (external portion) and internal receiver-simulator (internal portion).
Sound processor contains a magnet and a microphone - radiofrequency coil which connects to implanted portion.
An active electrode is placed into the scala tympani of the cochlea through a cochleostomy.
Widespread under-utilisation of implant technology - between 2006-2011 - only 74% children 0-3 years and 5% adults actually received the cochlear implant.

Question 42

What is Psychiatry?

Answer 42

Medical discipline that is involved with the assessment, diagnosis and treatment of children and adults with mental health conditions.

Question 43

What are some examples of psychiatric disorders that can affect SALT?

Answer 43

Schizophrenia - negative symptoms e.g. alogia (poverty of speech) and disorganised speech.
Conversational anomalies in ADHD.

Question 44

What approaches to psychiatry must SALT students be aware of?

Answer 44

CBT
Pharmacotherapy - drugs can affect motor speech production. E.g. Olanzipine (long-acting injection) for schizophrenia is associated with post-injection delirium syndrome (PDSS).
Case found 54% PDSS patients had dysarthria (unclear articulation of speech).
Psychotherapy.

Question 45

How is Gerontology (study of ageing and older adults) relevant to SALT?

Answer 45

Ageing impacts communication skills.
20% dysphonia (muscle spasms in voice box/larynx) in geriatric population.
50% of these incurred significant reduction in quality-of-life impairment as a result.
End-of-life care - older person’s competence to communicate decisions.

Question 46

How is Gastroenterology (disorders of the gastrointestinal tract) relevant to SALT?

Answer 46

Dysphagia (swallowing problems) management.
Achalasia (condition where lower oesophageal muscles do not relax enough to let food enter the stomach).
Oesophageal stricture (narrowed oesphagus traps large pieces of food).
Throat cancers - oesophagectomy may be required.
Ensures safe oral and non-oral feeding for clients.

Question 47

How is Endrocrinology (studies of the endocrine (hormone) system) relevant to SALT?

Answer 47

Must understand effects of hormones and imbalances on vocal fold function/quality.
Lowered speaking frequency during menopause.
Increased jitter in women with premenstrual syndrome.
Long-term androgen therapy can result in acceptable male to female voice - 10% experience difficulties.