Auditory System Clinical Application Flashcards
The auditory pathway begins with first-order neurons with cell bodies in __________ and axons in ___________ nerve. They synapse in the _________ nuclei
spiral ganglia, vetibulocochlear nerve, ipsilateral cochlear nuclei
Second order neurons in the auditory pathway have their cell bodies in the _______ nuclei and their axons in the ________ and _______ of the pons. These axons eventually reach the ________ in the midbrain.
cochlear nuclei, trapezoid, lateral lemniscus, inferior colliculus
The step in the auditory pathway just before the information reaches the thalamus is axons in the ________ of the caudal midbrain travel to their cell bodies in the same structre. Axons from these neurons then travel through the ________ of the _________ and synapse finally in the ______ of the thalamus.
inferior colliculus, brachium, inferior colliculus, MGN
Thalamic neurons of the auditory pathway have their cell bodies in the ______ of the thalamus and their axons travel in the ________ to synapse in the __________
MGN, auditory radiation, primary auditory cortex
The _________ decussates but does not contribute to bilateralism of the auditory pathway
posterior acoustic stria
The 3 structures which contribute to bilateralism in the auditory pathway are:
commissure of inferior colliculus, commissure of lateral lemniscus, trapezoid body
The 3 structures that contribute to bilateralism in the auditory pathway and prevent loss of hearing with lesions _______ to ________ nuclei are found in the _______ pons, and the commissure of inferior colliculus is found in the _______ midbrain
proximal, cochlear nuclei, middle, posterior
The ________ artery from the _______ artery supplies the inner ear and cochlear nuclei
labyrinthine artery, AICA
The _________ branch of the ________ artery supplies the inferior colliculus
quadrigeminal, superior cerebellar artery (SCA)
The thalamogeniculate artery supplies the _____.
The _________ artery supplies the primary auditory cortex and auditory radiation.
MGN, MCA (inferior trunk)
A patient presents to the clinic with tinnitus in the right ear and almost total deafness in that ear. Neither air or bone conduction of sound is effected.
What kind of deafness is this?
sensorineural deafness
________ deafness can be caused by a lesion to the hair cells, organ of corti, spiral ganglion, CN VIII, cochlear nuclei, or the cochlea itself.
sensorineural deafness
A patient presents with otitis media in the left ear, an infection and inflammation of the cochlea. She has some form of deafness. What kind of deafness is this?
sensorineural deafness
A patient has damage to the superior olivary nuclei. What kind of deafness do they likely have?
central deafness
A patient presents with difficulty localizing or interpreting sounds with no loss of hearing. Air and bone conduction of sound is unaffected. What kind of deafness is this?
central deafness
________ deafness is caused by lesion to one of the following:
lateral lemniscus, inferior colliculus, MGN, auditory radiation, auditory cortex
central deafness
A patient presents with partial left-sided deafness. Bone conduction of sound is unaffected but air conduction is diminished to the left side. No other neurological signs are found. What is the type of deafness?
conduction deafness
________ deafness is caused by one of the following:
inflammation/infection of EAM (otitis externa), excessive ear wax in EAM, inflammation or trauma of tympanic membrane, inflammation/infection of middle ear (otitis media), damage to middle ear bones, tissue overgrowth and fixation of stapes to oval window (otosclerosis)
conduction deafness
Tissue overgrowth that results in the fixation of the stapes to the oval window is referred to as _______, and is a cause of ______ deafness
otosclerosis, conduction deafness
If the neural pathway of auditory conduction is disrupted at or before the cochlear nuclei, this is _________ deafness.
sensorineural deafness
With _______ deafness, the vibration during the Weber test is perceived best on the normal side since the other side has damaged hair cells, CN VIII, or cochlear nuclei.
sensorineural deafness
With conduction deafness the vibration during Weber test is perceived best on the side with _________________ since this decreases the phase interference of air and bone conduction.
diminished air conduction
During the rinne test, a person with _______ deafness will be unable to perceive any sound waves
sensorineural deafness
During the Rinne test, a person with ________ deafness will perceive bone conduction time as equal to or greater than air conduction time.
conduction deafness
With __________, a patient will perceive air conduction time as twice as long as bone conduction time during the rinne test
central deafness
A patient presents with a form of hearing loss. The Weber test reveals that the patient perceives sounds as louder on the right, and the Rinne test finds that air conduction is greater than bone conduction on the right. What is the diagnosis?
left side nerve deafness
A patient has a Weber test that is left-sided, and a Rinne test that shows AC>BC on the left. What is the diagnosis?
right side nerve deafness
A patient presents with almost complete hearing loss to the left side with a Weber test that is greater on the right and a Rinne test that shows AC>BC on the right. An angiogram shows occlusion of an artery. What artery is occluded?
labyrinthine artery from AICA —> damaged inner ear and cochlear nuclei
Central deafness can be caused by occlusion of any of the following 4 arteries:
circumferential basilar branches, quadrigeminal branches of SCA, MCA inferior trunk, thalamogeniculate artery
Occlusion of the labyrinthine artery causes ________ and affects the following 7 structures in the lateral caudal pons:
ALS, spinal trigeminal nucleus and tract, vestibular nuclei, MCP and lateral cerebellum, hypothalamospinal tract, facial nucleus and nerve, cochlear nuclei
A patient presents with left-sided hemianalgesia, right-sided hemianalgesia of the face, left-sided nystagmus, nausea, vomiting, vertigo, ataxia, right-sided Horner syndrome, right-sided facial hemiparesis, and right-sided nerve deafness. What artery is occluded?
AICA (including labyrinthine artery)
A patient presents to the emergency department complaining of ptosis, myosis, and anhydrosis of the left face. He also has left-sided hemianalgesia of the body and right-sided hemianalgesia of the face. Further evaluation determines he has right-sided nerve deafness as well as left-sided nystagmus. What artery is occluded?
AICA (including labyrinthine artery)
They key structures damaged in occlusion of the _______ artery are facial nucleus and nerve, as well as cochlear nuclei. The key findings are ipsilateral facial hemiparesis and ipsilateral nerve deafness.
AICA
The key findings in lateral medullary syndrome are _____________ and _________.
The key structure damaged is the _________.
contralateral deviation of the uvula, hoarseness, nucleus ambiguous
Occlusion of _______ affects these 5 structures:
trapezoid, medial lemniscus, corticospinal tract axons, corticonuclear tract axons, abducens nucleus and nerve
paramedian branches of basilar artery
Occlusion of the ________ artery results in difficulty localizing and interpreting sounds, contralateral loss of vibration sense, contralateral hemiplegia or hemiparesis, UMN signs for corticonuclear tract in medulla, contralateral gaze palsy
paramedian branches of basilar artery
Occlusion of the _______ artery results in damage to these 6 structures:
Inferior colliculus, ALS, medial lemniscus, anterior trigeminothalamic tract, crus cerebri, substantia nigra
quadrigeminal branch of superior cerebellar artery
Occlusion of the _______ artery results in these 4 clinical signs:
difficulty localizing and interpreting sounds; contralateral hemianesthesia of UE, LE, and face; possible contralateral plegia or paresis of LE; contralateral tremor
quadrigeminal branch of the superior cerebellar artery
Occlusion of the _____ artery results in damage to these 3 structures:
MGN, LGN, VPL/VPM
thalamogeniculate artery
Occlusion of the _______ artery results in these 4 clinical signs:
difficulty localizing and interpreting sounds; contralateral homonymous hemianopia; contralateral hemianesthesia of UE, LE, and face; may develop thalamic pain syndrome
thalamogeniculate artery
Occlusion of the _______ artery results in contralateral hemiparesis or hemiplegia of the UE, LE, and lower face; contralateral hemianesthesia of the UE, LE, and face; and difficulty localizing and interpreting sounds
lenticulostriate arteries of the MCA
Occlusion of the _______ artery results in contralateral paresis or plegia of the UE and lower face; contralateral anesthesia of the UE and face; and contralateral gaze palsy
MCA superior trunk
Occlusion of the _____ artery results in contralateral superior quadrantanopia and difficulty localizing and interpreting sounds
MCA inferior trunk
Occlusion of _______ artery results in contralateral paresis or plegia of UE, LE, and lower face; contralateral anesthesia of UE and face; contralateral gaze palsy; contralateral superior quadrantanopia; difficulty localizing and interpreting sounds
MCA distal stem
Occlusion of _____ artery results in contralateral hemiparesis or hemiplegia of UE, LE, and lower face; contralateral hemianesthesia of UE, LE, and face; contralateral gaze palsy; contralateral homonymous hemianopia; difficulty localizing and interpreting sounds
MCA proximal stem
