HL w/ Neurologic Disorders Flashcards
How does ANSD manifest
issues with speech recoginition in noise
acoustic reflexes are abnormal
WRS would show abnormal
what is meant by ANSD being a spectrum disorder
meaning that the clinical presentation will not be the same
see variability in its presentation
are OHC present and in tact in ANSD
YES
where does cochlear microphonic come from
OHC
what is affected in ANSD
neuralsynchrony
where is ANSD
sensory hair cells are in tact
issue with the synapses of the IHCs with CN VIII N
why are OAEs normal in ANSD
because they come from the OHCs and these are still in tact
what kind of tests will show as abs in ansd
any test related to the 8th nerve
ABRs, electrochochleaography, acoustic reflexes
why do we see issues with wrs in ANSD
if not firing in synchronous, tonotopic organization the information will not go to the brain in the correct way it should and brain gets garbled info and cannot understand the speech and when noise is introduced the test is now harder
how was ANSD discovered
becasue of OAEs
could a deaf baby with no ANSD pass the new born hearing screening with OAEs?
no because their outer and inner hair cells are affected
could they pass a screening with ANSD
YES
ANSD can be
genetic or environmental
what is aANSD mode of inheritance
it has different modes
what environmental based disorders can act like ANSD
mumps and measles
can you determine ANSD based on the audiogram
NOOO because it is based on the hair cells and ANSD is not a dysfunction of the hiar cells
how can you detect ansd?
ABR
Reflexes
OAEs
what is the most successful treatment for ANSD
CIs
what is the only condition where an audiogram is not used for determining a condition?
ANSD
why do CIs work for ANSD?
because you can bypass the synapse with the CI and if the CN VIII and sensory cells are working this is why it workds
what is myelin
important for conduction of nerve impulses
an insulating layer, or sheath that forms around nerves, including those in the brain and spinal cord. It is made up of protein and fatty substances
what is the transmission of charcot-marie-tooth disease
AD, AR, or x linked recessive
what is PMP22
gene that encodes for peripheral myelin protein-22
what is charcot-marie-tooth disease
one of the most common inherited neurological disorders
peripheral neuropathy
Chronic degeneration of peripheral nerves causing muscular atrophy
what is peripheral neuropathy
any condition that affects the nerves outside of the brain and spinal cord
progressive neurodegenerative disease characterized by polyneuropathy
charcot-marie-tooth disease
what is polyneuropathy
multiple peripheral nerves are damaged
what are the clinical features of charcot marie tooth disease
absent limb reflexes
motor and sensory nerves affected
muscle wasting up to the knees and elbows
progressive HL
what is the inheritance of friedreich’s ataxia
Autosomal recessive neurodegenerative disorder
what is ataxia
the inability to control voluntary movements
what is friedrich’s ataxia
rare inherited disease that causes progressive damage to your nervous system and movement problems
what is an intron
a segment of a DNA or RNA molecule which does not code for proteins and interrupts the sequence of genes.
what is an extron
part of the gene that is expressed
what happens with more repeats in the GAA trinucleotide in friedreichs ataxia
the more repeats you have the worse the condition is
larger the number of GAA copies the earlier the onset of the disease and faster the decline of the PT
what are the characteristics of friedrich’s
incoordination of limb movements
dysarthria
nystagmis
what are the triad clinical manifestations sufficient for a friedreichs diagnosis
hypoactive knee and ankle reflex
progressive cerebellar dysfunction
preadolescent onset
what is hereditary sensory and autonomic neuropathy type I (HSAN1)
autosomal dom transmission
rare
neurodegenerative disorder
adult onset progressive SNHL to deafness
early onset dementia
sensory neuropathy in toes and ulceration
what is the peripheral form of neurofibromatosis
NF-1
what is the central form of neurofibromatosis
NF-2
what is the inheritance for NF
AD
high penetrance and variable expressivity
characteristics of neurofibromatosis I
cafe au lait spots
pigment in the eyes
tumors on or under the skin
characteristics of neurofibromatosis II
tumors
progressive visual loss
acoustic neuromas
devastating communication disorder
how do you manage NF-2
auditory brainstem implant
how does an abi work
bypasses the damaged auditory nerve and connects directly to the brainstem to detect sound
It is placed on or near the surface of the cochlear nucleus
does abi provide speech understanding
no more sound awareness with limited speech understanding
what are the 3 main parts of an ABI
microphone and sound processor behind the ear
decoding chip under the skin
electrodes connected directly to the BS
