Vertigo D/D😊

Vertigo D/D

Meniere's

• Vertigo: Few minutes to hours.

• Associated hearing loss:
• SNHL (Low frequency).
• Diplacusis (double hearing).

• IOC: Electrocochleography (SP/AP > 30% > 45%).

• Treatment:
• Intra tympanic steroids.
• Intratympanic gentamicin.
• Surgery.

BPPV

• Vertigo: Few seconds to few minutes.

• Associated hearing loss: None.
• Only semicircular canals involved.

• IOC: Dix Hallpike test.

• Treatment:
• Epley's maneuver (5 steps).
• Rehabilitating maneuver.

Labyrinthitis

• Vertigo: Single long episode.
• Lasts for days to weeks.

• Associated hearing loss:
• SNHL (high frequency).

• Treatment:
• Steroids.
• Antibiotics.
• Antiviral therapy.

Vestibular neuronitis

• Vertigo: Single long episode.
• Lasts for days to weeks.

• No Associated hearing loss
• Cochlear nerve not involved.

• Treatment:
• Steroids.
• Antibiotics.
• Antiviral therapy.

Glomus tumors

• Nature: Benign tumor of middle ear.

Glomus tympanicum:

• From tympanic plexus.

• Made of glossopharyngeal nerve.

• Rising sun appearance:
• Reddish hue on otoscopy.

• Browns sign:
• Siegel speculum → Blanching
• Tumor vibrates then pales with increased EAC pressure.

• Salt and pepper appearance:
• On contrast enhanced MRI.

Glomus jugulare:

• From plexus on internal jugular vein.

• Floor of middle ear

• Phelps sign:
• Glomus jugulare invades into jugular foramen
• On CT scan, tumor eroding bone.

Origin:

• From paraganglionic cells / ncc
• Cells of sympathetic nervous system.
• Secrete catecholamines.
• Present across major blood vessels.
• Internal carotid artery.
• Internal jugular vein.

Characteristics:

• Benign.

• Locally invasive.

• Slow growing.

HPE:

• Zellballen pattern.

• Pre operative Biopsy in contraindicated

Symptoms:

• Sweating, flushing, headache, tachycardia.

• Conductive hearing loss (gradually progressive).

• Pulsatile tinnitus.

• Probe test, biopsy, FNAC should not be done.
• Pain + bleeding → D/t lack of tunica media/ smooth muscle

• Jugular foramen involvement:
• 9th, 10th, 11th nerve palsies.

• Can cause Horner's syndrome.

IOC: CECT.

• MRI for intracranial spread.

• Angiography for feeding vessel.

Classification:

• FISCH classification

Treatment:

• Angiography and embolization.

• Followed by surgical excision.

Mnemonic:

• Ballenu ()
• Globe (), Brown sugar (), Salt and pepper (), Fish () while rising in the morning ()

NOTE: Glomus tumor in nail

• Location: Always on nail beds (subungual).

• Symptom: Excruciating pain (pain to the power infinity).

• Origin: Arises from glomus bodies (arteriovenous anastomoses at fingertips).
• Regulate temperature (thermoregulation).

Anatomy of facial nerve

• 7th cranial nerve.

Basic Features

• Mixed nerve
• Sensory root (nerve of Wrisberg).
• Motor root.
• Secretomotor root.

• Derived from the 2nd pharyngeal arch

• Exits from pons.

Nuclei

• Located in the pons

• Facial motor nucleus
• deep to the floor of the fourth ventricle

• Supranuclear palsy:
• UMN
• Lesion above pons.
• Forehead spared
• Innervation from bilateral cerebral cortex.

• Infranuclear palsy:
• LMN
• Lesion below pons.

Components and Functions

Col.	Nucleus	Function
SVE	Facial motor nucleus in pons	Muscles from 2nd pharyngeal arch – facial expression
GVE	SSN	Parasympathetic to submandibular, sublingual, and lacrimal glands
SVA	NTS	Taste from anterior 2/3 of tongue (via chorda tympani)
GVA	NTS	General visceral sensation
GSA	Trigeminal sensory nucleus	Sensation from auricle, nasal, lacrimal regions

Course and Exit

• Loops around abducent nucleus forming internal genu
• → elevation in floor of 4th ventricle = Facial colliculus

• Exits brainstem at pontomedullary junction

• Enters internal acoustic meatus

• Longest interosseous course

• Exits skull via stylomastoid foramen

Course has 3 parts:

• Intracranial.

• Intratemporal.

• Extracranial.

Intracranial route:

• Exits nucleus.

• Turns around 6th nerve nucleus → Facial Colliculus

• Enters internal auditory canal.

Intratemporal route:

• Longest portion.

• Runs in bony canal (Fallopian canal).
• Absent in 50% of population.

• Most common dehiscence site:
• horizontal part.

Segments:

Meatal Segment (8–10mm):

• In internal acoustic meatus.

• Falciform crest:
• vertical Y-shaped crest.

• Bills bar:
• crest of bone.

Quadrant of Internal Acoustic Meatus	Nerve Present
Anterosuperior	Facial nerve
Anteroinferior	Cochlear nerve
Posterosuperior	Superior vestibular nerve
Posteroinferior	Inferior vestibular nerve

Labyrinthine segment:

• Travels above vestibule.

• Anterior: Cochlea.

• Posterior: Semicircular canals.

• Shortest and narrowest segment.

• Most prone to ischemia and edema [Bell’s Palsy]

Tympanic segment:

• 1st genu/Geniculate ganglion:
• Landmark: Cochleariform process.

• Runs horizontally on medial wall.
• Above oval window
• below LSC

• 2nd genu:
• Landmark: Pyramid

Mastoid segment:

• Vertical segment.

• In mastoid bone.

• Exits from stylomastoid foramen.

• Iatrogenic facial palsy during mastoidectomy

Extracranial route:

• Enters parotid gland.

• Gives five terminal branches.

Branches

Before 1st genu	ㅤ
↳ Greater Petrosal Nerve	• First branch • Preganglionic parasympathetic • from before 1st genu ↳ Joins with deep petrosal nerve ↳ Forms Nerve of pterygoid canal (Vidian nerve) ↳ Lacrimation # Affected if injury above 1st genu # Great Superficial People make us cry
Branches before Stylomastoid Foramen	ㅤ
↳ Nerve to stapedius	• At second genu • If Affected → Hyperacusis
↳ Chorda Tympani	• from vertical segment • Functional nerve of submandibular ganglion • Taste from anterior 2/3 of tongue • Secretomotor fibers to submandibular and sublingual glands • If Affected if mastoid segment involved
↳ Sensory auricular branch	ㅤ
Branches after Stylomastoid Foramen	ㅤ
↳ To posterior belly of digastric ↳ To stylohyoid ↳ To auricular muscles ↳ To occipitalis ↳ To platysma	ㅤ

Terminal Branches in Parotid Gland

• Facial nerve divides into 5 branches in Patey's plane:
• Temporal
• Zygomatic
• Buccal
• Pierces buccinator muscle
• Marginal mandibular
• Cervical

• Supplies muscles of facial expression
• except LPS

Identification of Facial Nerve Trunk

• Cartilaginous Pointer
• It is a sharp triangular cartilage of the pinna.
• Facial nerve lies 1 cm deep, slightly anterior and inferior to this pointer.
• Acts as a landmark — it “points” to the nerve.

• Posterior Belly of Digastric Muscle
• Upper border (anterior border) is used for tracing.
• When traced posteriorly to its attachment at digastric groove,
→ Facial nerve lies between posterior belly and styloid process.

• Retrograde Dissection
• Identification method by tracing from distal branch backward.

Topodiagnosis

• Identifying lesions via clinical tests.

• Suprageniculate lesion:
• Affects lacrimation, stapedial reflex, taste, motor fibers.

• Infrageniculate lesion:
• Affects stapedial reflex, taste, motor fibers.

Clinical Points

• Testing:
• Ask patient to smile → observe angle of mouth deviation

• Rule of 17:
• CN VII lesion causes contralateral deviation of face
• Right CN VII lesion → deviation to left

• UMNL:
• Contralateral lower face paralysis

• LMNL:
• Ipsilateral complete hemifacial paralysis

• Facial colliculus lesion:
• LMNL + ipsilateral paralysis

Facial Palsy causes summary

• Most common cause:
• Idiopathic > Traumatic

• Iatrogenic facial palsy:
• Occurs during mastoidectomy
• Mastoid segment affected

Causes of B/L facial Nerve (diplegia):

Condition	Features
Sarcoidosis	ㅤ
Melkersson Rosenthal Syndrome	Triad: • Recurrent facial nerve palsy • Swelling of lips • Fissured tongue Melkerson → Rose koduthitt french kiss cheyth (lips - tongue)
GBS	• Albumino-cytological dissociation • Earliest sign: Distal areflexia. • Bladder and bowel spared. • Bilateral ascending symmetrical flaccid paralysis. • Brighton Criteria for GBS

Causes of U/L facial Nerve (Monoplegia)

Herpes zoster oticus / Ramsay hunt syndrome

• Involves reactivation of herpes zoster virus.

• Virus remains latent in
• Geniculate ganglion, CN 7

• Presents with
• Vesicles in facial nerve distribution (EAM)
• LMN type of facial palsy.
• SNHL due to 8th nerve involvement.
• Otalgia
• Loss of taste in anterior 2/3 tongue

Treatment:

• Antiviral therapy: Acyclovir, Valacyclovir.

• Topical agents and lotions for vesicles.

• Steroids (+/-).

Facial nerve palsy is seen in

• Malignant otitis externa

• Ramsay Hunt syndrome

• Keratosis obturans

• Bell’s Palsy

• MRK facial N palsy

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NOTE: Referred Otalgia

Lesion Site	Nerve involved in referred pain
Oral lesions /dental caries	5th nerve (V3)
Oropharyngeal lesions / Tonsil	9th nerve (Glossopharyngeal)
Hypopharyngeal & Laryngeal lesions	10th nerve (Vagus)

---

Bell’s palsy

• Idiopathic facial nerve palsy.

• Seen in pregnancy, diabetics.

• Associated with EBV and HSV.

• Clinical features:
• Deviation of angle of mouth.
• Loss of nasolabial fold.
• Sagging of eyebrow.
• Hyperacusis

Fractures of temporal bone

• Temple il uchaykk ponam (Uhrlich classification )

Longitudinal fracture	Transverse fracture
Parallel to long axis of petrous bone	Perpendicular to long axis of petrous bone
More common	Less common
TM perforation ++	Not common
Less	High risk of facial nerve palsy
CHL ↑↑	SNHL risk ↑↑
CSF otorrhea common	Paradoxical CSF rhinorrhea
Less	Otic capsule involvement common

Electrophysiological Tests in Facial Palsy

• Purpose:
• Understand extent of nerve damage.
• Determine need for treatment.

• Measures
• nerve conduction capacity.
• muscle potentials.

• Compares normal vs paralyzed side.

• Interpretation:

Finding	Interpretation / Next Step
Motor unit potentials present	Nerve regenerating
90% decrease in CMAP (Compound Muscle Action Potential) within 14 days	Consider surgical decompression
Fibrillation potential present	Consider surgical decompression
No electric output	Consider facial reanimation

Faulty Reinnervation

Frey’s Syndrome:

• Gustatory sweating.

• Parasympathetic fibers of Parotid gland (ATN)
• communicates with GAN (most common)

• Stimulus to ATN → sweating in parotid region

• Investigation: Starch iodine test.
• Sprinkle starch and Paint iodine

• ATN fuses with:
• Ettan (Atn) likes gan
• GAN > Buccal nerve > Lesser occipital nerve

• Mx:
• First line: Botox and anti-perspirants
• TOC: Tympanic neurectomy.

• Prevention: 
• SCM flap/digastric muscle flap to cover parotid bed.

Facial Synkinesis

• Facial nerve anomalous regeneration

• Examples
• Crocodile tears (Bogorad syndrome):
• Facial N Injury before geniculate ganglion.
• Fibers anastomose with chorda tympani.
• Lacrimation when patient eats.
• Mouth retraction on eye closure
• orbicularis oculi aberrantly innervate orbicularis oris

Vestibular schwannoma /Acoustic neuroma

• Nerve tumor
• Originates from inferior vestibular nerve.
• In internal auditory canal.

• Grows towards cerebellopontine region.

• Most common: Unilateral.

• Associated with: NF2 syndrome.
• Bilateral seen in neurofibromatosis type 2.

Symptoms:

• Transient vertigo.

• Earliest
• Absent corneal reflex
• 5th nerve affected 1st

• M/c
• Unilateral SNHL.
• Retro cochlear hearing loss.

• Tinnitus is absent.

• Hitzelberger sign:
• Vestibular schawannoma → Sensory fibers of 7th nerve
• loss of sensation in concha and along posterior meatal wall
• Mnemonic: HitZel → Hit Zeven → 7th CN → Hit Antony

• 9th, 10th, 11th nerves
• Dysphagia, palatal paralysis, speech difficulty

• Brunss nystagmus
• Suggests large CPA tumor
• Different nystagmus on right vs left gaze
• Gaze toward lesion side
• Coarse
• Low frequency
• High amplitude
• Vestibular type
• Gaze away from lesion
• Fine
• High frequency
• Low amplitude
• Gaze-evoked (central) type

Microscopically:

• Antony A areas: 
• Hypercellular (lot of cells).

• Antony B areas: 
• Hypocellular/blank (hardly any cells).

• Verocay bodies: 
• Two rows of palisading nuclei with cytoplasm in the center.

• Mnemonic:
• Antony A → ahankaram kuduthal (↑cellularity) and show (shauman) karanam → veruthu (verucay) pallu (palisading) adichilakki
• apo show ahankaram kurach (↓ cells) antony b () ayi

Diagnosis:

• MRI with contrast (IOC)

• B/L ice cream cone appearance in cerebellopontine angle.
• B/L Vestibular schwannoma.

• Chromosome no. 22.

• Mnemonic: Show man () eating Ice cream () with 22 (Chr 22) year old

Treatment:

• <3cm: Radio surgery.

• >3cm: Surgical excision/Gamma knife

Cochlear implant

• For bilateral severe to profound SNHL

• Has external and internal device.

• Implant in scala tympani via round window.

• Approach: Facial recess.

Pre requisite

1. Confirm sensorineural hearing loss (SNHL)

2. Confirm defect of organ of Corti
• Oto acoustic emission (OAE): Test effectiveness of outer hair cells
• Brainstem Evoked Response Audiometry (BERA): Differentiate cochlear vs retrocochlear defect

3. Confirm functionality of Cochlear nerve

Indication

• B/L severe to profound SNHL
• 70 dB hearing loss in all frequencies
• 90 dB hearing loss at 2000 & 4000 Hz

• No result from hearing aid trial after at least 3 months

• Mentally and physically stable patient

• Deafness
• Prelingual:
• Born deaf
• Cochlear implant placed b/w 1 year to <7 years
• Neural integration of speech develops by 7 years
• Postlingual:
• People who have developed speech & then become deaf
• Cochlear implant placed as early as possible
• (Auditory deprivation → Nerve becoming dysfunctional)

• Mondini’s aplasia:
• Cochlea has 1.5 turns instead of 2.75 turns
• Mnemonic: Mandelathe turne ullu

Note

• Michel aplasia
• Absence of bony and membranous labyrinth
• Cochlear implant can’t be placed

Components of a Cochlear Implant

Stenver’s view

A. External Component

• Located outside the body, behind ear

• Functions to capture and process sound
• Microphone:
• Picks up environmental sounds
• Speech Processor:
• Converts sound → digital signal
• Transmitter Coil:
• Sends processed signal wirelessly to internal part

B. Internal Component

• Implanted under skin and inside ear
• Receiver Stimulator:
• Receives digital signal from external transmitter coil
• Converts signal → electrical impulses
• Electrodes:
• Thin wire array attached to receiver stimulator
• Inserted into cochlea → (via round window → scala tympani)
• Deliver impulses directly to auditory nerve
1. Electrodes deliver impulses → cochlear nerve
2. This bypasses damaged hair cells of organ of Corti
3. Directly stimulates auditory nerve → brain interprets as sound

D. Pathway of Electrode Placement

• Passed via mastoid bone

• Through facial recess (surgical corridor)

• Into middle ear

• Via Round window (membrane-covered opening)

• Into scala tympani of cochlea

BAHA (Bone Anchored Hearing Aid)

• Prerequisites
• Age > 5 yrs
• SNHL ≤ 45 dB

• Indications:
• Unilateral severe to profound SNHL.
• Cannot use normal hearing aid
• Congenital deformities of external ear
• Microtia
• Anotia
• EAC atresia
• Discharging ears → pus
• Following MRM → Big mastoid cavity

• Insertion
• Screw placed in temporal bone.
• Screw integrates with bone.
• Abutment and processor placed over it.
• Conducts sound to inner ear through bone.

Bone anchored hearing aid (BAHA) can be used in which of the following:

1. A 40 years old male with bilateral profound hearing loss

2. A 6 years old male with bilateral hearing loss

3. A 7 years old male with bilateral microtia, canal atresia and congenital hearing loss

4. A 50 years old male with bilateral acoustic neuroma, planned for surgery
ANS
A 7 years old male with bilateral microtia, canal atresia and congenital hearing loss

Auditory brainstem implant

• For 8th nerve palsy.

• Bypasses external, middle, inner ear.

• Electrode placed in
• brainstem
• Lateral recess of 4th ventricle.

• Stimulates cochlear nucleus directly

Hearing aid

• For mild to moderate hearing loss.

One-liners

Q. Cochlear implant is contraindicated in which of the following?

• A. Scheibe dysplasia

• B. Mondini's dysplasia

• C. Alexanders dysplasia

• D. Michel aplasias
Ans.
Michel aplasia