Tinnitus Flashcards
How might central auditory processing explain tinnitus?
- There is a change in spontaneous neural activity with hearing loss
- The brain identifies the change and interprets it as sound
- The brain interprets this new sound as tinnitus
What do results from animal studies suggest about tinnitus?
-What neurons do in the hearing loss region causes tinnitus and stopping what they’re doing suppresses tinnitus
In what structures does cochlear damage lead to increased spontaneous firing rates?
- Cochlear nucleus (ventral and dorsal)
- Inferior colliculus
- Auditory cortex
What is spatial synchrony?
- Correlated firing between nerve fibers
- Noise trauma results in increased spontaneous firing rates and increases cross-correlation activity between nerve fibers
- Increased neural synchrony in the deafferent (not working) hearing loss areas underlies the spectrum of tinnitus
Describe SNHL-related changes in FFR.
- Increased firing rate in the inferior colliculus
- Increased excitatory transmission
- Conclusion: sensory deprivation associated with hearing loss may disrupt the balance of excitation/inhibition, resulting in larger but less precise responses
Describe the click-ABR differences between older patients with tinnitus and older patients without tinnitus.
- Tinnitus patients had changes in waves I and V
- Decreased activity in the auditory nerve, which is perceived as tinnitus
- Higher Wave V/I and Wave III/I ratios in tinnitus patients
What is the role of the somatosensory system in the generation and modulation of tinnitus?
- 2/3 of people with tinnitus are able to alter the loudness and pitch of their tinnitus via somatic maneuvers (i.e. jaw clenching, tensing neck muscles)
- Stimulation of CN V (trigeminal) leads to increased activity in dorsal cochlear nucleus
What non-auditory structures are involved in tinnitus management?
- Limbic system
- Nucleus accumbens
- Ventromedial prefrontal cortex
Describe the limbic system.
- Collection of structures supporting a variety of functions, including emotion, behavior, motivation, long-term memory, and olfaction
- Primarily responsible for emotional life, formation of memories
Describe the nucleus accumbens.
-Plays a role in positive emotions (i.e. laughter, reinforcement, learning) and negative emotions (i.e. fear, aggression, impulsivity)
Describe the ventromedial prefrontal cortex.
- Location: frontal lobe at the bottom of the cerebral hemispheres
- Implicated in the processing of risk and fear
- Greater activation in tinnitus patients
What does hearing loss lead to?
- Cortcial re-organization
- Increased spontaneous firing rates
- Increased synchronization of neural oscillations
What are the levels of tinnitus assessment?
- Level 1: Triage
- Level 2: Audiologic evaluation
- Level 3: Group education
- Level 4: Tinnitus evaluation
- Level 5: Individualized management
When should you refer a tinnitus patient to an audiologist?
-Tinnitus plus ALL of the following:
- Symptoms suggesting neural origin of tinnitus
- No ear pain, drainage, or malodor
- No vestibular symptoms
- No unexpected sudden hearing loss or facial palsy
When should you refer a tinnitus patient to an ENT?
-Tinnitus plus ANY of the following:
- Symptoms suggesting somatic origin of tinnitus
- Ear pain, drainage, or malodor
- Vestibular symptoms
