Sensory Flashcards
semicircular canals
- receptors detect mvmt of the head by sensing the motion of endolymph
– 3 hollow rings perpendicular to each other – opens into utricle – swelling called ampulla, containing a crista which consists of supporting cells & sensory hair cells – embedded in gelatinous mass (cupula) & bending of cupula & hair cells sensitive to rotational acceleration/decel
Otolith organs
– utricle & saccule – membranous sacs within the vestibular apparatus
– respond to head position relative to gravity & to linear acceleration/deceleration
- Inside is membranous labyrinth – endolymph – bending of hair cells determines signals – CN 8
Hair cells
sensitive to rotation
Semicircular canals
– acceleration/deceleration – linear
Cochlea
– organ of hearing
Lateral Vestibulospinal Tract
Activate postural muscles
Medial Vestibulospinal Tract
- To lower motor neurons – influence posture
- Positioning of head, neck, eyes in response to postural changes
Medial Longitudinal Fasciculus
- Bilateral connections w/ the extraocular nuclei (CN III, IV, & VI) & superior colliculus, influencing eye & head mvmts
- Descending from vestibular nuclei out ot motor neurons
- Ascending to vestibular nuclei & cranial nerves
- Eyes positioning – CN 3,4,6
Benign Paroxysmal Positional Vertigo
- Rapid head change results in vertigo and nystagmus which subsides in approx. 2 minutes
- Caused by Otoconia (crystals) from the macula getting into semicircular canals and disrupting endolymph flow
- inner ear disorder – acute speed of onset - <2 min – if untreated, improves in weeks or months; if treated w/ particle repositioning maneuver, often cured immediately – elicited by change of head position – getting out of bed quickly – displacement of otoconia (crystals of calcium carbonate in ear) – confuses brain, start feeling dizzy
Vestibular neuritis
- Inflammation of vestibular nerve
- Loss of balance, nystagmus, nausea, and vertigo
– infection – acute onset – severe symptoms 2-3 days, gradual improvement over 2 weeks – clears as virus clears – no unique signs
Meniere’s Disease
- Abnormal fluid pressure in inner ear
- Sensation of full ear, tinnitus, vertigo, nausea, vomiting, and hearing loss
– unknown etiology – chronic – duration of typical incident is 0.5 – 24 hours – some pts have only mild hearing loss & few episodes of vertigo. Most have multiple episodes of vertigo & progressive loss of hearing. – associated with hearing loss, tinnitus, & feeling of fullness in ear. (pop ears when yawn or swallow to relieve pressure)
Bilateral lesions of vestibular nerve (CN 8)
- Oscillopsia (visual objects bouncing when moving)
– interfere with reflexive eye mvmts in response to head mvmt – oscillopsia – over time, adapts & less difficulty w/ visual field – certain antibiotics/strept may damage both the cochlea & vestibular apparatus – hearing loss, disequilibrium, oscillopsia – vertigo infrequent
Ataxia - tremor
-Voluntary, normal-strength, jerky, & inaccurate movements Three types -Sensory -Vestibular -Cerebellar
Peripheral Neuropathy
- Destruction of myelination of large sensory fibers carrying proprioceptive information
- Guillian-Barre, autioimmune disorders
Multiple Sclerosis
- Impaired sensory transmission due to plaques and demyelination of CNS (brain & spinal cord)
Nystagmus testing
Post-rotary Caloric Optokinetic Electronystagmography Nystagmus is normal response to rotary movement
Romberg test
- Stand feet together arms in front flexed to 90 degrees
- Close eyes
- Observe postural sway and maintenance of arm position
- CAUTION – client may fall to affected side
- Arms may drift to affected side
Functional Reach Test
-Measure of balance
the difference, in inches, between arm’s length & maximal forward reach, using fixed base of support.
-Used to detect balance impairment, change in balance performance over time
-Test utilizes a force platform (electronic system for measuring functional reach) or a 48-inch measuring device or “yardstick”.
-Reach of < or = 6 inches predict fall risk
Treatment of body awareness and balance issues
Activities that:
- increase proprioceptive input
- increase vestibular input
- require utilization of proprioceptive information
- challenge balance
Olfaction
- CN 1
- Sickness decreases smell
- Smoking decreases smell
- Terminate in olfactory cortex
- Cingulate gyrus – emotional response to smells
- Memory also associated with smells
- Can’t smell, can’t taste
- Brain injury, strokes also can affect
Gustation
- CN 7, 9, & 10
- Food restrictions, swallowing problems
- Precautions
- Sitting up
- Taste buds –
- Sensory nerve fibers – CN 7, 9. 10 – project to solitary nucleus (gustatory nucleus) – to thalamus, through cortex into frontal lobe – insular cortex (autnomic responses)
Dysphagia
- difficulty swallowing
- Enzymes in saliva breakdown food
- Bolus – what end up swallowing
Stages of Swallowing
- Preoral stage
- Oral Preparatory stage
- Oral Stage
- Pharyngeal Stage
- Esophageal Stage
Preoral stage
-See food, smell food = salivate & grab spoon
Oral Preparatory Stage
- Food enters mouth and is mixed w/ saliva
- Chewed, contained by cheeks, and retrieved by tongue cupped by the tongue to form bolus in center of tongue
Oral Stage
-Tongue squeezes bolus against hard palate moving it back
Pharyngeal Stage
- Soft palate elevates and retracts minimizing the opening to the esophagus and the epiglottis tips back to cover the opening
- Vocal cords close
- Pharyngeal constrictor muscles contract to propel bolus past the pharynx
- Elevation of larynx causes the upper esophageal sphincter to relax so bolus can go through
Esophageal Stage
- Upper esophageal sphincter returns to normal
- Bolus passes through esophagus with peristalsis and gravity
- Lower esophageal sphincter relaxes to allow bolus to pass into stomach
Effects of Dysphagia
- Choking
- Aspiration
- Dehydration
- Weight loss
- Pulmonary complications
- Drooling
- Social exclusion
TBI (dysphagia)
– Pseudobubar, Paralytic
- Behavioral and cognitive problems
- Abnormal pathological reflexes
- Increased muscle tone
- Open mouth and poor lip closure
- Drooling
- Decreased tongue control
- Pocketing of bolus in cheek
- Delayed swallow
- Nasal regurgitation
- Decreased base of tongue movement and laryngeal elevation
- Takes longer to eat
Pseudobulbar
– UMN – neurological – poorly coordinated swallow
Paralytic
– LMN – neurologic – decreased swallow reflex
CVA (dysphagia)
– Pseudobulbar Paralytic
- Occur in R and L hemisphere and subcortical
- R HEMISPHERE
- Oral transit delays
- Delay in pharyngeal trigger and laryngeal elevation
- Pharyngeal stage lasts longer resulting in aspiration
- May be neglect or denial of swallowing problems
- May be apraxic for eating and swallowing
- SUBCORTICAL
- Oral transit delays and delay in triggering swallow
- Overall weakness in swallow
- May be reduced upper esophageal sphincter opening
Cerebral Palsy
- Pseudobulbar, Paralytic
- Difficulty with bolus formation and transit
- Delayed swallow reflex
- Pharyngeal dysmotility
- Diseases of the esophagus
- Aspiration
- Abnormal oral reflexes
- Hypo or hypersensitivity of oral structures
- Decreased laryngeal elevation
- Proper positioning important
Head and Neck Cancer
– Mechanical
- Depends on size and location of lesion
- Removal of parts create unique problems
Psychiatric Disorders
– Pseudobulbar
- Tardive dyskinesia (neuroleptic drugs)
- Dystonia of tongue and larynx
- Hyperkinesis of face jaw, tongue and UES
- Difficulty pacing eating
Alzheimer’s
– Pseudobulbar
- Decreased attention span and apraxia
- Need cueing
Multiple Sclerosis
– Pseudobulbar, Paralytic
- Weakness of oral structures and neck muscles
- Delayed pharyngeal swallow
- Weak pharyngeal contractions
Parkinson’s Disease
– Pseudobulbar
- Impulsiveness and poor judgment (late stages)
- Jaw rigidity
- Abnormal head and neck posture
- Impaired coordination of tongue and chewing
- Retention of food in mouth
- Delayed oral transit
- Impaired pharyngeal motility aspiration
Assessment of Dysphagia
- Observation of controlled feeding
- Technological tests
- Electromyography
- Fiberoptic Endoscopic Swallowing Study
- Manometry
- Scintigraphy
- Ultrasonography
- Videofluoroscopy
- Box 48-3, p. 1333, Radomski & Trombly Latham (2008)
- Treatment: p. 1335-1342 Radomski & Trombly Latham (2008)
Auditory Receptor
- Transmits soundwaves into energy
- Unit of measurement = decibel
- Outer, inner & middle ear
Soundwaves
- pass through ear canal & cause to vibrate
- Transmit into electrical impulses & travel along nerve fibers
Tempanic membrane
eardrum
Osicles
– mallous, incus & stapes
Auditory Pathway
- Vestibular cochlear nerve (CN 8) – 2 branches – vestibular branch & cochlear branch
- Tubes connect inner ear to pharynx – closed off when swallow – Eustachian tubes
Primary auditory cortex
– awareness of sound – intensity of sound
Secondary cortex
– memory (determine if language, music, loud noise)
Wernicke’s area
– language comprehension
Superior colliculus
– vision
Inferior colliculus
– auditory
Cochlea
– organ of hearing
Hearing Impairment
SENSORINEURAL -Inner ear (cochlea) -Vestibulocochlear nerve -Central nervous system CONDUCTIVE -Outer ear -Middle ear (tympanic membrane, malleus, incus, stapes)
Resultant Hearing Impairment
Hearing distortion -Tinnitus (ringing) Hearing loss -Loss of certain frequencies -Reduction of all frequencies -Excessive fluid -Presbycusis Inability to interpret -Aphasia -Central auditory processing disorder
Hearing Distortion - Tinnitus
-“ringing” or other head noises
-Can be due to damage anywhere in system (ear canal to CNS)
Etiology
-Allergic reactions
-Diseases/infections/increased blood pressure
-Tumors
-Wax/fluid buildup
-Stress
-Traumatic head injury
-Medication side effect
-Noise exposure
-Temporal mandibular joint syndrome
Hearing loss
- Mild- difficulty hearing speech at 26-45 db
- Moderate – difficulty hearing speech at 46-65 db
- Severe – a lot of difficulty hearing speech even at 66-85 db
- Profound – loss over 85 db. Hearing aids may or may not help.
- Generally higher frequencies lost first
- Infections with resultant fluid can cause temporary hearing loss
- Presbycusis – with age cochlear hair cells may become damaged
- May be 50% of people over 75 years
Hearing interpretation – central auditory processing disorder
-Difficulty processing auditory information though the hearing mechanism is intact
-figure-ground – can’t pay attention with background noise
-memory – immediate or delayed recall
discrimination – difficulty differentiating between similar words
-attention – cannot sustain attention
-cohesion – higher level listening requiring inferences and comprehension
-May be suspected by OT. Referral to SLP & audiologist for confirmation and treatment.
Techniques for working with client with central auditory processing disorder
- Reduce background noise
- Have person look at you when you’re speaking
- Use simple, expressive sentences
- Speak slower rate & mildly increased volume
- Ask person to repeat directions or paraphrase back to you to ensure understanding
- Use notes, a watch, and routines
Graphesthesia
– recognizing writing on your skin
Double simultaneous stimulation
– i.e. touch arm & leg at same time
Barognosis
– being able to determine which one is heavier if holding two objects (abarognosis)
Topognosia
– recognizing a sitmulus on your skin – localizing it
Merkel cell
– sensitive to fine touch pressure
Pacinian corpuscle
– deep pressure (lets brain know that the arm actually moved & where)
-can also respond to vibration
Meissner’s corpuscle
– light touch and vibration
Hair cells
- also respond to light touch & vibration
Free nerve endings
- pain
End-bulb of Krause
- Cold
Ruffini end organ
- heat
