Friday, November 18, 2016
Friday, January 10, 2014
1/10/2013
1/10/2014
Answers:
Answers:
What percentage of vestibular schwannoma patients have neurofibromatosis type 2?
A)3%
B) 15%
C) 50%
D) 85%
E) 97%
MC Questions:
Which of the following is not characteristic of the Wishart subtype of NF2?
A) Larger tumors
B) Faster growing tumors
C) Multiple tumors
D) Hearing loss is related to tumor size
E) Later age of onset of disease
A)3%
B) 15%
C) 50%
D) 85%
E) 97%
Patients w/ NF2 represent about 2-4% of VS cases.
The NF2 gene encodes what protein? What is the function of this protein?
NF2 encodes for the protein "merlin" which has functions involved with linking cytoskeletal components in the plasma membrane and in contact inhibition.
Which of the following is not characteristic of the Wishart subtype of NF2?
A) Larger tumors
B) Faster growing tumors
C) Multiple tumors
D) Hearing loss is related to tumor size
E) Later age of onset of disease
Free Response Question:
Describe the difference in the presence of skin neurofibromas between NF1 and NF2.
Quick Facts:
Describe the difference in the presence of skin neurofibromas between NF1 and NF2.
Quick Facts:
Thursday, January 9, 2014
1/9/2014
1/9/2014
Answers:
Answers:
What is the most common extra-axial malignant neoplasm of the CPA?
A) Astrocytoma
B) Chordoma
C) Glomus Jugulare
D) Chondrosarcoma
E) Metastases
MC Questions:
What percentage of vestibular schwannoma patients have neurofibromatosis type 2?
A)3%
B) 15%
C) 50%
D) 85%
E) 97%
A) Astrocytoma
B) Chordoma
C) Glomus Jugulare
D) Chondrosarcoma
E) Metastases
Mets are the most common extra-axial malignant neoplasm of the CPA.
What is "Meckel's Cave"?
Meckel's Cave, aka trigeminal cave, is an arachnoid pouch w/ CSF in it. It is formed by two layers of dura which are part of an evagination of the tentorium cerebelli near the apex of the petrous part of the temporal bone and envelops CN V. Its boundaries are: the cerebellar tentorium, the lateral wall of the cavernous sinus, the clivus and the posterior petrous face.
What percentage of vestibular schwannoma patients have neurofibromatosis type 2?
A)3%
B) 15%
C) 50%
D) 85%
E) 97%
Free Response Question:
The NF2 gene encodes what protein? What is the function of this protein?
Quick Facts:
Clinical Findings
Gardner Subtype:
-early onset
-smaller tumors
-few tumors
-slower growing tumors
-hearing loss related to tumor size
Wishart Subtype:
-Later onset
-Larger tumors
-Multiple tumors
-Faster growing tumors
-Hearing loss not related to tumor size
-Usually present in 20-30s, rarely after 60.
-50% of patients present with hearing loss, it is usually progressive and associated
w/ poor speech discrimination scores.
-10% have tinnitus
-acute vertigo is uncommon due to slow growth pattern
-Skin tumors present in 2/3rds of patient as are Cafe-au-lait spots however there are
fewer than six of these (unlike in NF1)
-Juvenile posterior subcapsular lenticular opacities are common (up to 51%). Some are congenital and can be useful in diagnosis.
The NF2 gene encodes what protein? What is the function of this protein?
Quick Facts:
Clinical Findings
Gardner Subtype:
-early onset
-smaller tumors
-few tumors
-slower growing tumors
-hearing loss related to tumor size
Wishart Subtype:
-Later onset
-Larger tumors
-Multiple tumors
-Faster growing tumors
-Hearing loss not related to tumor size
-Usually present in 20-30s, rarely after 60.
-50% of patients present with hearing loss, it is usually progressive and associated
w/ poor speech discrimination scores.
-10% have tinnitus
-acute vertigo is uncommon due to slow growth pattern
-Skin tumors present in 2/3rds of patient as are Cafe-au-lait spots however there are
fewer than six of these (unlike in NF1)
-Juvenile posterior subcapsular lenticular opacities are common (up to 51%). Some are congenital and can be useful in diagnosis.
Wednesday, January 8, 2014
1/8/2013
1/8/2014
Answers:
Answers:
What percentage of CPA tumors are not vestibular schwannomas?
A) 5%
B) 20%
C) 50%
D) 80%
E) 95%
MC Questions:
What is the most common extra-axial malignant neoplasm of the CPA?
A) Astrocytoma
B) Chordoma
C) Glomus Jugulare
D) Chondrosarcoma
E) Metastases
A) 5%
B) 20%
C) 50%
D) 80%
E) 95%
20% of CPA tumors are not schwannomas. Of these ~50% are meningiomas.
What factors should prompt testing for NF2 in a patient who presents w/ a CPA tumor?
If meningiomas are present in a young patient or there are multiple meningiomas, then NF2 testing should be considered.
What is the most common extra-axial malignant neoplasm of the CPA?
A) Astrocytoma
B) Chordoma
C) Glomus Jugulare
D) Chondrosarcoma
E) Metastases
Free Response Question:
What is "Meckel's Cave"?
Quick Facts:
Neurofibromatosis Type 2
-Hallmark is b/l vestibular schwannomas.
-often confused with von Recklinghausen syndrome, however this is peripheral
neurofibromatosis and is designated NF1.
-NF2 is much more rare compared to NF1 (1:50,000)
-NF2 is autosomal dominant w/ 95% gene penetrance.
-presents in 2-3rd decade.
-Pts w/ NF2 represent 2-4% of VS.
-NF2 gene encodes for protein called merlin which functions as a membrane-organizing protein.
Pathogenesis
-from inheritance of mutation in merlin protein on chromosome 22.
-Merlin involved in linking cytoskeletal components w/ plasma membrane.
-Loss of this protein could lead to loss of contact inhibition.
-50% of patients have no family hx and are likely new germ line mutations.
-NF2 mutations associated w/ protein truncation are more severe = Wishart
type
-NF2 mutations associated w/ protein missense or splicing are milder = Gardner
type
What is "Meckel's Cave"?
Quick Facts:
Neurofibromatosis Type 2
-Hallmark is b/l vestibular schwannomas.
-often confused with von Recklinghausen syndrome, however this is peripheral
neurofibromatosis and is designated NF1.
-NF2 is much more rare compared to NF1 (1:50,000)
-NF2 is autosomal dominant w/ 95% gene penetrance.
-presents in 2-3rd decade.
-Pts w/ NF2 represent 2-4% of VS.
-NF2 gene encodes for protein called merlin which functions as a membrane-organizing protein.
Pathogenesis
-from inheritance of mutation in merlin protein on chromosome 22.
-Merlin involved in linking cytoskeletal components w/ plasma membrane.
-Loss of this protein could lead to loss of contact inhibition.
-50% of patients have no family hx and are likely new germ line mutations.
-NF2 mutations associated w/ protein truncation are more severe = Wishart
type
-NF2 mutations associated w/ protein missense or splicing are milder = Gardner
type
Tuesday, January 7, 2014
1/7/2013
1/7/2014
Answers:
Answers:
Which of the following approaches to a CPA tumor is hearing ablative?
A) Retrosigmoid
B) Middle Fossa
C) Translabyrinthine
D) They can all be hearing preserving as long as care is taken not to damage vital hearing structures
E) They are all hearing ablative
MC Questions:
What percentage of CPA tumors are not vestibular schwannomas?
A) 5%
B) 20%
C) 50%
D) 80%
E) 95%
A) Retrosigmoid
B) Middle Fossa
C) Translabyrinthine
D) They can all be hearing preserving as long as care is taken not to damage vital hearing structures
E) They are all hearing ablative
The translabyrinthine approach is hearing ablative whereas the retrosigmoid and middle fossa approaches can keep hearing intact.
When is observation an adequate management strategy for vestibular schwannomas?
Observation is reasonable in older patients or in pts where the tumor does not appear to be growing significantly.
What percentage of CPA tumors are not vestibular schwannomas?
A) 5%
B) 20%
C) 50%
D) 80%
E) 95%
Free Response Question:
What factors should prompt testing for NF2 in a patient who presents w/ a CPA tumor?
Quick Facts:
Treatment of CPA meningiomas
-can observe or use stereotactic radiotherapy if pt has limited life expectancy or not surgical candidate, otherwise treat w/ surgery.
-ideal surgery consists of total meningioma removal and excision of surrounding dura w/ drilling of underlying bone.
-Surgical approach depends on location of tumor and pts hearing.
-Meningiomas medial to the IAC are more common.
-arise along inferior petrosal sinus and involve petrous apex, lateral clivus and meckel cave.
-Meningiomas lateral to IAC involve the sigmoid sinus, jugular bulb and superior petrosal sinus.
-Approach these via retrosigmoidal approach as facial nerve is often displaced anteriorly so a retro sigmoid approach does not place the nerve between the surgeon dn the tumor. Also allows for hearing preservation.
-Limited intracanalicular meningiomas can be managed by middle cranial fossa approach to preserve hearing or translabyrinthine if pt has poor/no hearing.
-If meningioma invades cochlear or extends to clivus or meckle cave than transcochlear approach is warranted.
-60% of CPA meningiomas involve middle fossa and may need craniotomy of combine middle/posterior fossae.
Prognosis
-Total tumor removal achieved in 70-85% of cases.
-Non total removal often due to adherence to brainstem or cavernous sinus involvement.
-Long term recurrence is 10-30% if all removed, 50% if some left behind.
-Hearing preservation is ~70% (more than schwannomas)
What factors should prompt testing for NF2 in a patient who presents w/ a CPA tumor?
Quick Facts:
Treatment of CPA meningiomas
-can observe or use stereotactic radiotherapy if pt has limited life expectancy or not surgical candidate, otherwise treat w/ surgery.
-ideal surgery consists of total meningioma removal and excision of surrounding dura w/ drilling of underlying bone.
-Surgical approach depends on location of tumor and pts hearing.
-Meningiomas medial to the IAC are more common.
-arise along inferior petrosal sinus and involve petrous apex, lateral clivus and meckel cave.
-Meningiomas lateral to IAC involve the sigmoid sinus, jugular bulb and superior petrosal sinus.
-Approach these via retrosigmoidal approach as facial nerve is often displaced anteriorly so a retro sigmoid approach does not place the nerve between the surgeon dn the tumor. Also allows for hearing preservation.
-Limited intracanalicular meningiomas can be managed by middle cranial fossa approach to preserve hearing or translabyrinthine if pt has poor/no hearing.
-If meningioma invades cochlear or extends to clivus or meckle cave than transcochlear approach is warranted.
-60% of CPA meningiomas involve middle fossa and may need craniotomy of combine middle/posterior fossae.
Prognosis
-Total tumor removal achieved in 70-85% of cases.
-Non total removal often due to adherence to brainstem or cavernous sinus involvement.
-Long term recurrence is 10-30% if all removed, 50% if some left behind.
-Hearing preservation is ~70% (more than schwannomas)
Monday, January 6, 2014
1/6/2014
1/6/2014
Answers:
Answers:
What is the average growth rate of vestibular schwannomas?
A) 0.5 mm/yr
B) 1mm/yr
C) 1.2 mm/yr
D) 1.5 mm/yr
E) 1.8mm/yr
The average growth of VS is 1.8/yr. However, this can vary widely and a repeat scan should be performed 6 months after initial diagnoses to assess the growth pattern of each particular tumor.
Typically, how large must a CPA tumor be to cause cerebellar symptoms?
MC Questions:
Which of the following approaches to a CPA tumor is hearing ablative?
A) Retrosigmoid
B) Middle Fossa
C) Translabyrinthine
D) They can all be hearing preserving as long as care is taken not to damage vital hearing structures
E) They are all hearing ablative
A) 0.5 mm/yr
B) 1mm/yr
C) 1.2 mm/yr
D) 1.5 mm/yr
E) 1.8mm/yr
The average growth of VS is 1.8/yr. However, this can vary widely and a repeat scan should be performed 6 months after initial diagnoses to assess the growth pattern of each particular tumor.
Typically, how large must a CPA tumor be to cause cerebellar symptoms?
To cause cerebellar symptoms a VS usually has to fill the CPA which requires it to be ~ 3cm.
Which of the following approaches to a CPA tumor is hearing ablative?
A) Retrosigmoid
B) Middle Fossa
C) Translabyrinthine
D) They can all be hearing preserving as long as care is taken not to damage vital hearing structures
E) They are all hearing ablative
Free Response Question:
When is observation an adequate management strategy for vestibular schwannomas?
Quick Facts:
Vestibular Schwannomas = 80% of CPA tumors.
-Of the other 20%, most are distinguished be imaging characteristics
-CPA: Bounded be temporal bone, cerebellum and brainstem
-CPA is traversed be CN V-XI.
-90% of CPA tumors are schwannomas and meningiomas, the other 10% include congenital rest lesions, intra-axial tumors, metastases and vascular lesions and lesions from skull base.
-Classic symptoms of CPA tumors include : unilateral hearing loss, vertigo, altered facial sensation, facial pain progressing to nystagmus, facial palsy, vocal cord palsy, dysphagia, diplopia, respiratory compromise and death.
When is observation an adequate management strategy for vestibular schwannomas?
Quick Facts:
Vestibular Schwannomas = 80% of CPA tumors.
-Of the other 20%, most are distinguished be imaging characteristics
-CPA: Bounded be temporal bone, cerebellum and brainstem
-CPA is traversed be CN V-XI.
-90% of CPA tumors are schwannomas and meningiomas, the other 10% include congenital rest lesions, intra-axial tumors, metastases and vascular lesions and lesions from skull base.
-Classic symptoms of CPA tumors include : unilateral hearing loss, vertigo, altered facial sensation, facial pain progressing to nystagmus, facial palsy, vocal cord palsy, dysphagia, diplopia, respiratory compromise and death.
Friday, January 3, 2014
1/3/2014
1/3/2014
Answers:
Answers:
What is the best study to diagnose a vestibular schwannoma.
A) MRI w/o contrast
B) MRI w/ contrast
C) CT w/ contrast
D) CT w/o contrast
E) Angiogram
The gold standard for VS diagnosis is MRI w/ gadolinium contrast
What is the definition of "rollover"?
Rollover = Retrocochlear
pathology causes WRS to be lower than expected based on pure-tones. Often this WRS gets worse with increasing intensity of sound.
MC Questions:
What is the average growth rate of vestibular schwannomas?
A) 0.5 mm/yr
B) 1mm/yr
C) 1.2 mm/yr
D) 1.5 mm/yr
E) 1.8mm/yr
A) MRI w/o contrast
B) MRI w/ contrast
C) CT w/ contrast
D) CT w/o contrast
E) Angiogram
The gold standard for VS diagnosis is MRI w/ gadolinium contrast
What is the definition of "rollover"?
Rollover = Retrocochlear
pathology causes WRS to be lower than expected based on pure-tones. Often this WRS gets worse with increasing intensity of sound.
What is the average growth rate of vestibular schwannomas?
A) 0.5 mm/yr
B) 1mm/yr
C) 1.2 mm/yr
D) 1.5 mm/yr
E) 1.8mm/yr
Free Response Question:
Typically, how large must a CPA tumor be to cause cerebellar symptoms?
Quick Facts:
Surgical Measures for vestibular schwannomas
-Approach is based on hearing status, size of tumor and extent of IAC
involvement.
-Can be hearing preserving(retrosigmoid/middle fossa) or ablative
(translabyrinthine).
-Middle fossa = good hearing pt and tumor <1.5cm in CPA.
-Retrosigmoid = good hearing pt w/ tumor <4 cm not involving lateral IAC.
Typically, how large must a CPA tumor be to cause cerebellar symptoms?
Quick Facts:
Surgical Measures for vestibular schwannomas
-Approach is based on hearing status, size of tumor and extent of IAC
involvement.
-Can be hearing preserving(retrosigmoid/middle fossa) or ablative
(translabyrinthine).
-Middle fossa = good hearing pt and tumor <1.5cm in CPA.
-Retrosigmoid = good hearing pt w/ tumor <4 cm not involving lateral IAC.
Thursday, January 2, 2014
1/2/2014
1/2/2014
Answers:
Answers:
Rank the following complaints on presentation of vestibular schwannoma from most common to least common.
A) V2 Dysfunction > Hearing Loss > Tinnitus > Diplopia
B) Tinnitus > Hearing Loss > Diplopia > V2 Dysfunction
C) Hearing Loss > Tinnitus > Diplopia > V2 Dysfunction
D) Tinnitus > Hearing Loss > V2 Dysfunction > Diplopia
E) Hearing Loss > Tinnitus > V2 dysfunction > Diplopia
95% of VS present w/ unilateral hearing loss. 65% will present with tinnitus. Facial/Trigeminal dysfunction is another common presentation for VS. Diplopia is an unusual in early VS and is not a common presenting symptom.
The IAC is divided into 4 quadrants by what two structures?
MC Questions:
What is the best study to diagnose a vestibular schwannoma.
A) MRI w/o contrast
B) MRI w/ contrast
C) CT w/ contrast
D) CT w/o contrast
E) Angiogram
A) V2 Dysfunction > Hearing Loss > Tinnitus > Diplopia
B) Tinnitus > Hearing Loss > Diplopia > V2 Dysfunction
C) Hearing Loss > Tinnitus > Diplopia > V2 Dysfunction
D) Tinnitus > Hearing Loss > V2 Dysfunction > Diplopia
E) Hearing Loss > Tinnitus > V2 dysfunction > Diplopia
95% of VS present w/ unilateral hearing loss. 65% will present with tinnitus. Facial/Trigeminal dysfunction is another common presentation for VS. Diplopia is an unusual in early VS and is not a common presenting symptom.
The IAC is divided into 4 quadrants by what two structures?
The "transverse crest" and the "vertical crest" (aka Bill's bar)
What is the best study to diagnose a vestibular schwannoma.
A) MRI w/o contrast
B) MRI w/ contrast
C) CT w/ contrast
D) CT w/o contrast
E) Angiogram
Free Response Question:
What is the definition of "rollover"?
Quick Facts:
-Natural hx of VS includes a slow growth in the IAC and then into the cisterna of the
CPA.
-Average growth rate is 1.8 mm/yr.
-Symptom onset is often slow/insidious but predictable.
-Occasional rapid progression can occur due to cystic degeneration or bleeding.
-Initial growth often affects vestibulocochlear nerve in rigid IAC causing unilateral
hearing loss, tinnitus and vertigo.
-Tumor then progresses to CPA cistern and grows freely w/o symptoms until it reaches 3 cm.
-At this point corneal/mid face numbness, further hearing loss, vertigo and facial
weakness/spasms can occur.
-Further growth causes cerebellar signs including ocular changes, headache, AMS, n/v and eventually death.
What is the definition of "rollover"?
Quick Facts:
-Natural hx of VS includes a slow growth in the IAC and then into the cisterna of the
CPA.
-Average growth rate is 1.8 mm/yr.
-Symptom onset is often slow/insidious but predictable.
-Occasional rapid progression can occur due to cystic degeneration or bleeding.
-Initial growth often affects vestibulocochlear nerve in rigid IAC causing unilateral
hearing loss, tinnitus and vertigo.
-Tumor then progresses to CPA cistern and grows freely w/o symptoms until it reaches 3 cm.
-At this point corneal/mid face numbness, further hearing loss, vertigo and facial
weakness/spasms can occur.
-Further growth causes cerebellar signs including ocular changes, headache, AMS, n/v and eventually death.
Wednesday, January 1, 2014
1/1/2014
1/1/2014
Answers:
Answers:
What is the most common type of CPA tumor?
A) Epidermoid
B) Glomus
C) Meningioma
D) Astrocytoma
E) Schwannoma
MC Questions:
Rank the following complaints on presentation of vestibular schwannoma from most common to least common.
A) V2 Dysfunction > Hearing Loss > Tinnitus > Diplopia
B) Tinnitus > Hearing Loss > Diplopia > V2 Dysfunction
C) Hearing Loss > Tinnitus > Diplopia > V2 Dysfunction
D) Tinnitus > Hearing Loss > V2 Dysfunction > Diplopia
E) Hearing Loss > Tinnitus > V2 dysfunction > Diplopia
A) Epidermoid
B) Glomus
C) Meningioma
D) Astrocytoma
E) Schwannoma
80% of CPA tumors are vestibular schwannomas (aka acoustic neuromas)
Describe the boundaries of the CPA.
-Superior boundary = tentorium
-inferior boundary = cerebellar tonsil / medullary olives
-anterior border = posterior dural surface of petrous bone and clivus
-posterior border = ventral surface of pons/cerebellum
-medial border = cisterns of pons and medulla
-apex = region of the lateral recess of the fourth ventricle.
Rank the following complaints on presentation of vestibular schwannoma from most common to least common.
A) V2 Dysfunction > Hearing Loss > Tinnitus > Diplopia
B) Tinnitus > Hearing Loss > Diplopia > V2 Dysfunction
C) Hearing Loss > Tinnitus > Diplopia > V2 Dysfunction
D) Tinnitus > Hearing Loss > V2 Dysfunction > Diplopia
E) Hearing Loss > Tinnitus > V2 dysfunction > Diplopia
Free Response Question:
The IAC is divided into 4 quadrants by what two structures?
Quick Facts:
Imaging for Vestibular Schwannomas
-gold standard is MRI w/ gadolinium contrast
-can differentiate various CPA tumors on MRI.
-VS are hypointense globular mass centered over IAC on T1 w/ enhancement w/
gadolinium. They are iso-to hypointense on T2.
Special Tests
-Average pt requires 4 years from onset of symptoms to diagnosis of VS.
-Pts w/ unilateral auditory, vestibular and facial complaints need to undergo eval to
r/o retrocochlear disease.
-Pure-tone audiograms in VSD patients show asymmetric, downsloping, high frequency SNHL in 70%.
-Retrocochlear pathology causes WRS to be lower than expected based on pure-tones. Often this WRS gets worse with increasing intensity of sound = Rollover.
-Abnormal WRs should prompt imaging.
The IAC is divided into 4 quadrants by what two structures?
Quick Facts:
Imaging for Vestibular Schwannomas
-gold standard is MRI w/ gadolinium contrast
-can differentiate various CPA tumors on MRI.
-VS are hypointense globular mass centered over IAC on T1 w/ enhancement w/
gadolinium. They are iso-to hypointense on T2.
Special Tests
-Average pt requires 4 years from onset of symptoms to diagnosis of VS.
-Pts w/ unilateral auditory, vestibular and facial complaints need to undergo eval to
r/o retrocochlear disease.
-Pure-tone audiograms in VSD patients show asymmetric, downsloping, high frequency SNHL in 70%.
-Retrocochlear pathology causes WRS to be lower than expected based on pure-tones. Often this WRS gets worse with increasing intensity of sound = Rollover.
-Abnormal WRs should prompt imaging.
Tuesday, December 31, 2013
12/31/2013
12/31/2013
Answers:
Answers:
What percentage of traumatic TM perforations heal within 30 days?
A) 20%
B) 50%
C) 70%
D) 90%
E) 100%
MC Questions:
What is the most common type of CPA tumor?
A) Epidermoid
B) Glomus
C) Meningioma
D) Astrocytoma
E) Schwannoma
A) 20%
B) 50%
C) 70%
D) 90%
E) 100%
~70% of traumatic TM perfs heal on their own in one month. ~95% will heal within 3 months. If a TM perf is still not healed on its own after this time consider performing a paper-patch myringoplasty.
After what length of time dose persistence of a posttraumatic CSF leak significantly raise the chance of developing meningitis?
80% of CSF leaks will close on their own within a week and the risk of meningitis is low, however, CSF leaks that persist longer than 7-10 days the risk of developing meningitis increases dramatically to >20%.
What is the most common type of CPA tumor?
A) Epidermoid
B) Glomus
C) Meningioma
D) Astrocytoma
E) Schwannoma
Free Response Question:
Describe the boundaries of the CPA.
Quick Facts:
Clinical
Findings Of Vestibular Schwannoma -Hearing
loss present in 95% of patients.-Mostly
slowly progressive hearing loss w/ noise distortion.-20%
have episodes of sudden hearing loss.-Level
of hearing loss does not predict tumor size.
-Tinnitus
present in 65% of patient, often constant high pitch buzzing.-Pts
often adapt to disequilibrium well because it occurs so slowly but it is present
in 60% of patients.
-Facial/Trigeminal
nerve dysfunction-most
common to see V2 numbness/absent corneal reflex.-can
also see numbness of posterior EAC (Hitselberger sign-Facial
weakness only present in 17%
-Other
complaints include visual complaints, diplopia, headache, AMS, n/v and increased
ICP w/ papilledema however these occur only during rapid expansion.
Describe the boundaries of the CPA.
Quick Facts:
Clinical
Findings Of Vestibular Schwannoma -Hearing
loss present in 95% of patients.-Mostly
slowly progressive hearing loss w/ noise distortion.-20%
have episodes of sudden hearing loss.-Level
of hearing loss does not predict tumor size.
-Tinnitus
present in 65% of patient, often constant high pitch buzzing.-Pts
often adapt to disequilibrium well because it occurs so slowly but it is present
in 60% of patients.
-Facial/Trigeminal
nerve dysfunction-most
common to see V2 numbness/absent corneal reflex.-can
also see numbness of posterior EAC (Hitselberger sign-Facial
weakness only present in 17%
-Other
complaints include visual complaints, diplopia, headache, AMS, n/v and increased
ICP w/ papilledema however these occur only during rapid expansion.
Monday, December 30, 2013
12/30/2013
12/30/2013
Answers:
Answers:
What percentage of transverse temporal bone fractures cause a facial nerve injury?
A) 10%
B) 25%
C) 50%
D) 75%
E) 90%
Facial nerve injury is present in 50% of transverse tbone fractures. Facial nerve injury is present in only 20% of longitudinal t bone fractures. It is always import to delineate whether facial nerve injuries are immediate or delayed as immediate are almost always operative, wheres delayed is usually not.
What test can be done to determine whether clear fluid draining from the ear is CSF or simply rhinorrhea from rhinitis?
MC Questions:
What percentage of traumatic TM perforations heal within 30 days?
A) 20%
B) 50%
C) 70%
D) 90%
E) 100%
A) 10%
B) 25%
C) 50%
D) 75%
E) 90%
Facial nerve injury is present in 50% of transverse tbone fractures. Facial nerve injury is present in only 20% of longitudinal t bone fractures. It is always import to delineate whether facial nerve injuries are immediate or delayed as immediate are almost always operative, wheres delayed is usually not.
What test can be done to determine whether clear fluid draining from the ear is CSF or simply rhinorrhea from rhinitis?
B2 Transferrin is the test of choice to confirm the presence of CSF. B2 transferring is a protein found exclusively in CSF.
What percentage of traumatic TM perforations heal within 30 days?
A) 20%
B) 50%
C) 70%
D) 90%
E) 100%
Free Response Question:
After what length of time dose persistence of a posttraumatic CSF leak significantly raise the chance of developing meningitis?
Quick Facts:
-CPA = potential CSF filled space in posterior cranial fossa bounded be temporal
bone, cerebellum and brainstem.-triangle
shaped,-Superior
boundary = tentorium-inferior
boundary = cerebellar tonsil / medullary olives-anterior
border = posterior dural surface of petrous bone and clivus-posterior
border = ventral surface of pons/cerebellum-medial
border = cisterns of pons and medulla-apex
= region of the lateral recess of the fourth ventricle.-The
lateral opening of the fourth ventricle (foramen of luschka) opens into
CPA.-CN
V-XI traverse cephalic and caudal extent of CPA.-Transition
to peripheral myelin (made by schwann cells) occurs at the medial opening of the
IAC.
After what length of time dose persistence of a posttraumatic CSF leak significantly raise the chance of developing meningitis?
Quick Facts:
-CPA = potential CSF filled space in posterior cranial fossa bounded be temporal
bone, cerebellum and brainstem.-triangle
shaped,-Superior
boundary = tentorium-inferior
boundary = cerebellar tonsil / medullary olives-anterior
border = posterior dural surface of petrous bone and clivus-posterior
border = ventral surface of pons/cerebellum-medial
border = cisterns of pons and medulla-apex
= region of the lateral recess of the fourth ventricle.-The
lateral opening of the fourth ventricle (foramen of luschka) opens into
CPA.-CN
V-XI traverse cephalic and caudal extent of CPA.-Transition
to peripheral myelin (made by schwann cells) occurs at the medial opening of the
IAC.
Friday, December 27, 2013
12/27/2013
12/27/2013
Answers:
Answers:
Diagnose this fracture.
A) Mastoid fracture
B) Transverse Temporal bone fracture
C) Longitudinal Temporal Bone Fracture
D) Occipital Bone fracture
MC Questions:
What percentage of transverse temporal bone fractures cause a facial nerve injury?
A) 10%
B) 25%
C) 50%
D) 75%
E) 90%
B) Transverse Temporal bone fracture
C) Longitudinal Temporal Bone Fracture
D) Occipital Bone fracture
This is a classic longitudinal temporal bone fracture extending along the EAC and ending near the foramen lacerum.
After a temporal bone fracture, what degree of delayed facial nerve degeneration is required in order to benefit from surgical decompression.
Patients with delayed facial nerve paralysis who are found to have > 90% degeneration of the nerve on nerve excitability or electroneuronography testing (which cannot be done until at least 3 days post injury) may benefit from surgical decompression. This is controversial however. Patients with <90% degeneration should not be operated on as they are likely to have full and spontaneous recoveries.
What percentage of transverse temporal bone fractures cause a facial nerve injury?
A) 10%
B) 25%
C) 50%
D) 75%
E) 90%
Free Response Question:
What test can be done to determine whether clear fluid draining from the ear is CSF or simply rhinorrhea from rhinitis?
Quick Facts:
Treatment of Temporal Bone Fracture Complications
-Conductive Hearing Loss:
-Hemotympanum resolves on its own within 3-4 weeks of the injury.
-Traumatic TM perfs heal well on their own, 68% in 1 months, 94% in 3 months. If
not healed be 3 months can perform paper-patch myringoplasty. (can only do if TM
is <25% and does not involve margin and middle ear mucosa
uninfected/dry)
-Freshen edges of perf w/ Rosen needle (Husseman dose this w/ TCA (some type of
acid) then place paper over hole and bacitracin over paper.
-If perf is large or paper-patch has failed then pt can go to OR for standard
tympanoplasty.
-Facial Nerve Paralysis:
-Mostly conservative treatment for delayed onset palsy (94% recover
fully).
-If pt has >90% degeneration of facial nerve function then recovery is much
worse, likely due to nerve swelling within bony fallopian canal. Management is
controversial.
-Some recommend watchful waiting, other recommend decompression.
-Immediate onset facial nerve palsy should undergo nerve exploration
ASAP.
-If pt has normal hearing a combined middle fossa/transmastoid facial nerve
exploration can be done including subtemporal craniotomy w/ delineation of the
facial nerve within IAC from porus acusticus internus to geniculate ganglion.
-If patient has complete SNHL then translabyrinthine facial nerve exploration
can be done, allows for complete exposure to facial nerve from porus acousticus
to stylomastoid foramen.
-Injuries are most commonly located in the area of the geniculate ganglion.
-If intraneural hematoma appreciated then epineurium should be carefully opened
and hematoma evacuated.
-Remove any bony fragments.
-If obvious fracture of nerve then freshen both ends an anastomosis. If to long
to anastomose w/o tension then interposition nerve graft from greater auricular
or sural nerve can by done.
-CSF Leak and Encephalocele
-80% of posttraumatic CSF leaks close spontaneously after 7 days and risk of
meningitis is low so treat medically at first.
-Med treatment = HOB elevated, stool softeners, acetazolamide (decreases CSF
production) and lumbar drain. Short to abx can decrease meningitis rates.
-Most common organisms for meningitis in these cases are pneumococcus, staph,
strep and H. flu.
-If CSF leak persists 7-10 dys risk of meningitis increases to >20% and surgical repair is needed.
-Most common after transverse tbone fx involving otic capsule as otic capsule
does not heal w/ new bone formation but be fibrous union which is not strong
enough to contain CSF.
-An encephalocele should always be surgically repaired.
What test can be done to determine whether clear fluid draining from the ear is CSF or simply rhinorrhea from rhinitis?
Quick Facts:
Treatment of Temporal Bone Fracture Complications
-Conductive Hearing Loss:
-Hemotympanum resolves on its own within 3-4 weeks of the injury.
-Traumatic TM perfs heal well on their own, 68% in 1 months, 94% in 3 months. If
not healed be 3 months can perform paper-patch myringoplasty. (can only do if TM
is <25% and does not involve margin and middle ear mucosa
uninfected/dry)
-Freshen edges of perf w/ Rosen needle (Husseman dose this w/ TCA (some type of
acid) then place paper over hole and bacitracin over paper.
-If perf is large or paper-patch has failed then pt can go to OR for standard
tympanoplasty.
-Facial Nerve Paralysis:
-Mostly conservative treatment for delayed onset palsy (94% recover
fully).
-If pt has >90% degeneration of facial nerve function then recovery is much
worse, likely due to nerve swelling within bony fallopian canal. Management is
controversial.
-Some recommend watchful waiting, other recommend decompression.
-Immediate onset facial nerve palsy should undergo nerve exploration
ASAP.
-If pt has normal hearing a combined middle fossa/transmastoid facial nerve
exploration can be done including subtemporal craniotomy w/ delineation of the
facial nerve within IAC from porus acusticus internus to geniculate ganglion.
-If patient has complete SNHL then translabyrinthine facial nerve exploration
can be done, allows for complete exposure to facial nerve from porus acousticus
to stylomastoid foramen.
-Injuries are most commonly located in the area of the geniculate ganglion.
-If intraneural hematoma appreciated then epineurium should be carefully opened
and hematoma evacuated.
-Remove any bony fragments.
-If obvious fracture of nerve then freshen both ends an anastomosis. If to long
to anastomose w/o tension then interposition nerve graft from greater auricular
or sural nerve can by done.
-CSF Leak and Encephalocele
-80% of posttraumatic CSF leaks close spontaneously after 7 days and risk of
meningitis is low so treat medically at first.
-Med treatment = HOB elevated, stool softeners, acetazolamide (decreases CSF
production) and lumbar drain. Short to abx can decrease meningitis rates.
-Most common organisms for meningitis in these cases are pneumococcus, staph,
strep and H. flu.
-If CSF leak persists 7-10 dys risk of meningitis increases to >20% and surgical repair is needed.
-Most common after transverse tbone fx involving otic capsule as otic capsule
does not heal w/ new bone formation but be fibrous union which is not strong
enough to contain CSF.
-An encephalocele should always be surgically repaired.
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