Test 3 - Vestibular

Question 1

Function of vestibular system?

Answer 1

maintain equilibrium and balance

Question 2

Common clinical S & S of vestibular dysfunction?

Answer 2

Nystagmus – abnormal beating of eyes
     Torsional
      Side to side
Tinnitus – abnormal sounds in ears
Vertigo
Hearing loss 
Loss of balance & possible falls
Compensatory movements such as a broad-based stance          (to accommodate for imbalance)
Sweating, nausea, and vomiting (due to ANS involvement)

Question 3

Vestibular ocular reflex

Answer 3

(VOR)
Stabilizes Vision When Head Moves
Follows objects when head moves
Fastest reflex in body
Inner ear sends signals

Question 4

Vestibular spinal reflex

Answer 4

(VSR)
Balance Control
Reflexes
Signal to motor system
Try to keep person upright
Protective fx with autonomic reflexes

Question 5

Semicircle canals

Answer 5

anterior - neck flex/ext
posterior - lateral neck flexion
horizontal - neck rotation

Question 6

otolithic organs

Answer 6

saccule and utricle
Linear movements, acceleration and orientation of the head in respect to earths gravity

saccule - moving up and down on an elevator

utricle - moving forward and backward like in a car or side to side

Question 7

vertigo

Answer 7

Vertigo: The feeling of movement when there isn’t any. Spinning sensation, swimmy head, floating sensation, lightheadedness

Question 8

otoconia

Answer 8

Rocks or crystals that are embedded in a gelatinous layer that covers the hair cells (sterocillium and kinocillium)

Question 9

crista ampullaris

Answer 9

The function of thecrista ampullarisis to sense angular acceleration and deceleration.

Question 10

BPPV

Answer 10

BPPV:Benign paroxysmal positional vertigo. Otoconia get displaced in either one of the 3 semi-circular canals (most common) or in the cupula (hair cells) located in the ampula, utricle or saccual

Question 11

Labyrinth

Answer 11

Bony: 3 semicircular canals, the cochlea and the vestibule. It is filled with perilymphatic fluid (similar to cerebral spinal fluid) on the outside or the membrane.

Membranous: is suspended within the bony section and contains membranous portions of the canals and utricle and saccule. It is filled with endolymphatic fluid (similar to intracellular fluid)

Question 12

What are the motion sensory of the inner ear?

Answer 12

Ampulla: contain the cupula (hair cells) which convert displacement into neuro firing thru bending of hair cells to detect linear/angular motion

Otolith Organ (Utricle and Saccule): contain calcium carbonate crystals called otoconia. Shift in these crystals set off neuro firing detecting gravity and acceleration

Question 13

What are the 3 motor outputs? - reflexes

Answer 13

VOR (Vestibular Ocular Reflex): generates eye movements, which enables clear vision while head is in motion

VSR (Vestibular Spinal Reflex): generates compensatory body movement in order to maintain head and postural stability, thereby preventing falls

VCR (Vestibular Collic Reflex): stabilizes the head in space

Question 14

Peripheral structures and function

Answer 14

Peripheral Functions:
Stabilization of visual images on the fovea of the retina during head movement to allow clear vision

Maintain postural stability especially during movement of the head

Provide information used for spatial orientation

Involves the vestibular apparatus in the inner ear: 
Semicircular canals (3)
Utricle 
Saccule
CN VII: Vestibulocochlear nerve

Question 15

Central structure and function

Answer 15

Vestibular reflexes are controlled by processes primarily in the brainstem
Connections between the vestibular nuclei, reticular formation, thalamus & cerebellum
Semicircular canals (angular) & otolith (linear) input is sent to the vestibular nuclei (extremely important)
Info travels to the ocular motor nuclei (III, IV , VI) for mediation of the vestibular ocular reflex
Then to the thalamus & cortex for arousal & conscious awareness of the head & body in space
Maintenance of postural control – peripheral vestibular input is sent distally to the Medial & Lateral Vestibulo-Spinal tracts

Question 16

Common peripheral dysfunction

Answer 16

Peripheral Disorders
Vestibular Neuritis/labryinthitis
Viruses (Ramsay Hunt)
Acoustic Neuroma
Meniere’s Disease
BPPV  - crystals out of wack
Toxicity (medication, alcohol)
Water in the ear
Sinus infection

Question 17

Common central dysfunction

Answer 17

Central Disorders
Disequilibrium of Aging
CVA
Migraine
Head Trauma (TBI/Concussion)
Tumors
Multiple Sclerosis

Question 18

Vestibular neutritis

Answer 18

2nd most common cause of vertigo - inflammation of vestibular Nn

Key Features: Vestibular crisis (vertigo, imbalance, nausea) improving over 1-4 days, absence of associated auditory symptoms, left with head movement sensitivity

Gradual and complete recovery is expected
Prognosis is excellent with compensation, vestibular and balance rehab

Question 19

Viral Endolymphatic Labryinthitis

Answer 19

inflamed labyrinth

Key feature is a sudden hearing loss accompanied with vertigo. Hearing loss within a few hours before or after the onset of vertigo

Hearing loss may recover or persist.
If no vertigo reported suspect bilateral loss
Prognosis: excellent for dizziness with compensation and vestibular balance rehab, need immediate steroid tx to prevent hearing loss

Question 20

Acoustic neuroma

Answer 20

3rd most common intracranial tumor
Nerve sheath benign tumors arise from Schwann cells lining the axons of the cochleovestibular n.
Causes progressive unilateral hearing loss or tinnitus without vestibular symptoms. Balance issues (if present) tend to be mild and intermittent
Rarely cause acute vestibular crises but may produce syndromes that mimic other vestibular diagnoses.
3 therapeutic options: watchful waiting, radiosurgery and surgical resection

Question 21

Menieres Dx

Answer 21

A disorder of the inner ear function resulting in devastating hearing loss and vestibular symptoms

Key Features: recurrent, spontaneous spells intense rotational vertigo lasting several hours, postural imbalance, nystagmus, nausea, vomiting, hearing loss, tinnitus and aural fullness. Vertigo will persist anywhere from 30 mins to 24 hours.

Symptoms gradually abate, usually ambulatory within 3 days. Some sensation of unsteadiness will persist but then normal balance returns between spells
Hearing may return to baseline or may have residual permanent sensorineural hearing loss, most common in lower frequencies.

Vestibular exercises are not appropriate unless there is permanent loss of vestibular function

Question 22

Benign Paroxysmal Positional Vertigo (BPPV)

Answer 22

Most common cause of vertigo
Key features: brief episodes of vertigo when head is moved in certain positions
Report of symptoms: triggered by lying down, rolling over in bed, bending over, and looking up. Women may report problems in hair salon, men while changing oil under car.

Canalithiasis: Debris floating freely in the endolymph in the long arm of the semi circular canal ( SCC)
Cupulolithiasis: Debris, probably fragments of otoconia from the utricle, adhere to the cupula

No hearing loss

Dix-Hallpike (anterior and posterior)
Epley

Question 23

Nystagmus and what they mean.

Answer 23

R Posterior control
Cupulolithiasis – Persistent UBN & R Torsion
Canalithiasis – Transient UBN & R Torsion

L Posterior Canal
Cupulolithiasis – Persistent UBN & L Torsion
Canalithiasis – Transient UBN & L Torsion

Question 24

Vertebrobasilar Vascular insufficiency

Answer 24

Blockages of one or more of the following aa;
Posterior Inferior Cerebellar (PICA)
Vertebral aa.
Anterior Inferior Cerebellar (AICA)
Basilar a
Superior Cerebellar (SCA)
Can involve episodic vertigo with imbalance with other brainstem signs and symptoms, loss of coordination, ocular motor control deficits as well as postural control and gait abnormalities, speech etc
Treatment: neurology + balance and gait therapy and fall prevention, habituation if symptoms present

Question 25

Ramsay Hunt Syndrome

Answer 25

Herpetic infection of the VII and VIII cn
Sudden onset of pain with open sores, loss of hearing with a vestibular crisis event, facial mm weakness
Treatment: medical antiviral with steroids
Prognosis: usually left with hearing loss and needs vestibular balance rehab

Question 26

Arnold Chiari

Answer 26

Episodic to continuous imbalance and lightheadedness exacerbated by hyperextension of neck, double vision on lateral gaze
Down beating nystagmus in primary gaze usually exacerbated with lateral gaze
Treatment: neurology/neurosurgery
Prognosis: post surgery gait and balance therapy