Ear and temporal bone

Question 1

Facial nerve segments

Answer 1

intracranial/cistenal
intracanalicular (do not enhances)
labyrinthic (do not enhances, mild enhancement)
genculate ganglion (Enhances)
tympanic (enhances)
mastoidien (enhances)
Extra-cranial parotidien

Question 2

Treacher Collins syndrome

Answer 2

mandibulofacial dysostosis, ilateral malformations of 1st and 2nd branchial arches

• dental and mandibular
• zygomatic arch
• otic
• nasal
• ocular

Question 3

Inner ear annomaly classification

Answer 3

1 complete labyrinthine aplasia (Michel malf)
2 cochlear aplasia
3- common cavity
4- incomplete partition type I: absent modiolus, cystic appearance
5- cochlear hypoplasia: less than 4 mm and less than 2 and 1/2 turns
6- Incomplete partition type II: (classic Mondini) normal basal turn of cochlea with apical structures in cystic. DiGeorge, Waardenburg, Alagille, Klippel-Feil, Pendred, trisomies
7- Incomplete partition type III

Question 4

SNHL

Answer 4

non syndromic 70%
-enlarged endolymphatic duct
syndromic 30%
-Pendred: enlarged vestibular aqueduct, thyroid dysphunction
-Usher
-Waardenburg
-Branchio-oto0rebal

Question 5

Congenital SNHL

Answer 5

cmv
hypoxia
ototoxic drugs
kernicterus
tumor

Question 6

External otitis

Answer 6

acute: swimming. Otomycosis in post-operative
Malignant: secondary to pseudomonas in diabetics. Hyper T2FS and enhancement. Ct with possible osseus destruction

Question 7

Otitis media

Answer 7

the most common infection treated with ATB
fever, ear pain and red thympanic membrane
10% complications

Question 8

Mastoiditis

Answer 8

most common complication of acute otitis media
complications in 25% (children)
-coalescent mastoiditis: bone destruction
-subperiosteal absces: in postauricular recion (Macewen triangle)
-Bezold abscess inferior to the mastoid tip
-Luc abscess: beneath the temporalis muscle
-Retropharyngeal abscess: trough eustachian tube
-petrous apicitis: Gradenigo triad: purulent otorrhea, pain in distribution of V and VI ipsilateral palsy
-Empyema, trombophlebitis

Question 9

Chronic otomastoiditis

Answer 9

Pars tensa tympanic membrane perforation
erosion of the long process of the incus
retraction of membrane

Question 10

Cholesteatoma

Answer 10

-Congenital: embryonic epithelial rests
located everywhere in the temporal bone: middle ear, mastoid, petrous apex, in the squama of the temporal bone, within the TM, or in the EAC
-Acquired only in middle ear
+Primary acquired cholesteatomas (80%), intact tympanic membrane (dysfunction of Eustachian tube), pars flacida (Prussak space)
+Secondary acquired cholesteatomas: come in trough perforated tympanic membrane, trought pars tensa (medial to ossicles and to oval window)
IRM: hyper in difussion, peripheral enhancement

Question 11

Cholesteatoma complication

Answer 11

labyrinthine fistula 5-10%
episodic vertigo
SNHL
tinnitus
dehiscent lateral semicircular canal

Question 12

Labyrithitis

Answer 12

most commonly complication of meningitis
others: viral, syphilitic, posttraumatic
sicle cell: SNHL and labyrinthine hemorrhage
MRI: hyper t1 in hemorraghe, hyper FLAIR

Question 13

Labyrithitis ossificans

Answer 13

result of labyrinthine infection, hemorrhage or toxic insult
Acute: hyper FLAIR
Subacute: loss of normal high T2
Chronic:isolated involvement of scala tymani is common, inferior basal turb

Question 14

Cholesterol granuloma

Answer 14

Secondary to inflammation and obstruction, with granulation tissue
Middle ear, petrous apex and EAC
Expansile, non agressive, nonenhancing
High T1 and T2, low DWI

Question 15

Facial nerve enhancement

Answer 15

Lyme: suggestive when bilateral
Bell’s palsy
Ramsay Hunt: facial nerve palsy, SNHL, tinnitus, vertigo, ataxia, vesicular eruptions
Miller-Fisher syndrome:ataxia, areflexia, ophtamoplegia, with multiple cranial neves enhancement
Neoplastic

Question 16

Tumors

Answer 16

Not frequent
rhabdomyosarcoma
LCH
Lymphoma
Endolymphatic sac tumor: von Hippel Lindau
Schwannomas
Meningioma
Hemangiopericytoma