Optic Nerve Decompression

Definition and Overview

• Cummings Otolaryngology Head and Neck Surgery, p. 974-975

Indications

1. Traumatic Optic Neuropathy (TON)

• Seen in 1.5-4% of all head trauma patients (up to 8% with TBI by some estimates)
• Mechanism: indirect transmission of blunt force to the optic canal -> nerve edema -> compartment-type syndrome -> apoptosis of retinal ganglion cells
• The role of surgical decompression in TON remains controversial (see below)
• Surgery is generally undertaken within 72 hours of injury if indicated

2. Compressive Optic Neuropathy (non-traumatic)

• Fibro-osseous lesions of the sphenoid (e.g., fibrous dysplasia)
• Skull base tumors compressing the orbital apex (meningioma - causes hyperostotic reaction with soft tissue mass effect)
• Sinonasal tumors
• Inflammatory conditions: orbital pseudotumor, Graves' orbitopathy (thyroid eye disease)
• Intra-sheath tumors (e.g., cavernous hemangioma of the optic canal)
• The majority of patients with compressive optic neuropathy derive significant visual improvement from decompression - in contrast to the controversial results in TON

3. Other

• Worsening vision in idiopathic intracranial hypertension (papilledema not responding to medical management)
• Orbital compartment syndrome (a distinct emergency requiring urgent intervention)

Surgical Approaches

Surgical Technique (Endoscopic - Standard Steps)

• Expose the ethmoid roof and lamina papyracea
• Maximally open the sphenoid face to the planum sphenoidale superiorly and orbital apex laterally
• If an Onodi cell is present, remove the partition between the sphenoid sinus and Onodi cell

• Bony prominences of the optic canal and carotid artery on the lateral sphenoid wall
• The opticocarotid recess (OCR) between them
• Image-guided surgery is recommended at this stage
• Note: the ophthalmic artery courses inferior/inferomedial to the optic nerve in ~20% of orbits - an important anatomical variant

• Fracture and remove lamina papyracea ~1-1.5 cm anterior to the sphenoid face (eggshell technique)
• Avoid penetrating the periorbita - herniated orbital fat will obstruct the operative view

• Use a high-speed diamond burr with copious irrigation (prevent thermal injury)
• Drill along the nerve, not across it
• Once bone is thinned, use a microcurette or elevator to gently flake fragments inferomedially away from the nerve
• Decompress 1 cm posterior to the face of the sphenoid for TON and thyroid eye disease

• Performed after bony decompression is complete
• Use a disposable sickle knife along the entire exposed nerve length, posterior to anterior, incorporating the annulus of Zinn
• CSF egress is expected
• If done, a mucosal onlay graft should be considered to prevent postoperative rhinorrhea
• Sheath incision is required for intra-sheath tumors; remains debated for indirect TON

Preoperative Workup

• Complete ophthalmologic examination: visual acuity, color vision (dyschromatopsia), relative afferent pupillary defect (RAPD), visual fields
• CT of sinuses and orbit: optic canal fracture/compression, bony anatomy, sinus anatomy
• MRI orbits with/without contrast: evaluate the full course of the optic nerve and orbital contents (preferred for compressive optic neuropathy)
• Visual evoked potentials: occasionally useful in obtunded/unresponsive patients (impractical in acute trauma)

Controversies: Traumatic Optic Neuropathy

1. Expectant management - spontaneous recovery is possible
2. Corticosteroids (high-dose IV methylprednisolone) - earlier meta-analyses showed benefit; however, the International Optic Nerve Trauma Study (IONTS) failed to show a difference between groups. High-dose steroids carry increased mortality risk in acute TBI
3. Surgical decompression - similarly shown in IONTS to offer no statistically significant benefit over observation

Current Consensus: No treatment (including surgery) has demonstrated clear benefit over observation in indirect TON. There is strong evidence of harm from megadose IVMP in TBI patients (increased mortality). Treatment must be individualized. - Blanch et al., Eye, 2024 [PMID: 38862644, Systematic Review]

Optic Nerve Sheath Incision: Debated in TON

• Not shown to be superior to bony decompression alone
• Theoretical advantage: allows more maximal decompression, especially with intra-sheath hematoma
• Risk: potential injury to optic nerve or ophthalmic artery; increased CSF leak risk
• Required for intra-sheath tumors (direct removal and decompression)

Outcomes

Complications

• Direct injury to the optic nerve (rare but devastating - permanent visual loss)
• Injury to the ophthalmic artery
• CSF leak (especially after nerve sheath incision - manage with mucosal onlay graft)
• Complications shared with endoscopic sinus surgery: bleeding, orbital hematoma, orbital fat herniation
• Postoperative rhinorrhea
• Diplopia (more relevant in combined orbital + optic nerve decompression for GO)

Key Points

• The intracanalicular segment is most vulnerable due to fixed bony confinement
• Endoscopic endonasal approach is now the standard, with open approaches reserved for failures or contraindications
• Decompression in TON is controversial with no high-level evidence of benefit; compressive optic neuropathy responds much better
• Diamond burr drilling with copious irrigation is the standard technique to avoid thermal nerve injury
• The ophthalmic artery has an anatomical variant (inferomedial course) in ~20% of orbits - vigilance required
• Multidisciplinary collaboration between otolaryngology and ophthalmology is essential

• Cummings Otolaryngology Head and Neck Surgery, pp. 974-979 (Endoscopic Optic Nerve Decompression chapter)
• Scott-Brown's Otorhinolaryngology Head & Neck Surgery Vol. 1, pp. 1297-1232 (Endoscopic optic nerve decompression)
• Blanch RJ et al. "Traumatic optic neuropathy management: a systematic review." Eye (Lond), 2024 Aug. [PMID: 38862644]

Bullous Myringitis

Definition

Pathology

Otoscopic Appearance

Aetiology

• Bacterial: Streptococcus pneumoniae (consistently the predominant organism), Haemophilus influenzae, Moraxella catarrhalis, beta-haemolytic streptococci
• Viral: Rhinovirus, enterovirus, RSV, influenza A, parainfluenza virus

Epidemiology

• True incidence is unknown, but reported in 5.7% of children under 2 years in a 1-year follow-up period
• Occurs in 1 in every 20 episodes of AOM
• Most prevalent in children aged 2-8 years (unlike AOM which peaks under 2 years)
• More common in winter months
• Usually unilateral

Clinical Features

Symptoms

• Severe, sudden-onset otalgia - typically disproportionate to the findings on examination; often the most prominent symptom
• Pain usually lasts 1-2 days, though discomfort may persist even after bulla rupture
• Compared with AOM alone, BM children show higher rates of earache (58% vs 29%), fever (62% vs 41%), and excessive crying (80% vs 65%)
• Associated upper respiratory tract infection is common

Signs

• Bullae on the TM and medial canal - serous or serosanguinous, may be single or multiple
• Scanty serosanguinous otorrhoea upon rupture (short-lived; no TM perforation)
• Middle ear effusion present in 30-40% of cases (serous OM)
• Hearing loss (see below)

Hearing Loss - A Key Complication

• The cochlea is implicated as the site of lesion (stapedial reflex and ABR data)
• Pathogenesis of SNHL in BM is unknown
• Complete recovery of hearing occurs in 57-100% of cases regardless of treatment, though pre-existing audiological baselines are rarely available
• History and physical examination alone cannot exclude SNHL - formal audiometry is mandatory

A 2021 systematic review (Ungar et al., Otol Neurotol, PMID: 33883520) found that of 81 BM patients, 62% had confirmed hearing loss on audiometry despite only 48% reporting it subjectively. SNHL or mixed HL was present in the vast majority of those with hearing loss - pure CHL was very uncommon. This has important implications: do not wait for formal audiometry before initiating steroid treatment.

Vertigo

Differential Diagnosis

Treatment

Symptomatic

• Analgesics - oral analgesia is the mainstay (pain can be severe)
• Warm compresses
• Incision/lancing of bullae - for pain relief; benefit is unproven and carries risk of secondary infection; no definitive evidence of superiority over analgesia alone

Topical

• Antibiotic/steroid drops - to prevent bacterial superinfection of the ruptured bulla

Systemic Antibiotics

• Treat as for AOM given the comparable pathogen profile
• Broad-spectrum oral antibiotics are favoured, particularly when SNHL is present

Systemic Corticosteroids (Controversial)

• Used by some authors for SNHL component, analogous to treatment of sudden sensorineural hearing loss
• Typical regimen: prednisone 1 mg/kg/day for 7 days, then tapered
• Evidence is weak: only one small comparative study (n=23) - systemic antibiotics alone vs. antibiotics + steroids - showed no improved hearing outcomes with steroids, but was likely underpowered (type II error risk)
• Eliashar et al. treated SNHL with admission + oral steroids + carbogen: 86% complete hearing recovery
• Randomized trials are lacking

Current practice guidance (Ungar et al., 2021): Because pure CHL is uncommon in BM and SNHL is frequently present (even when not subjectively reported), steroid treatment should not be delayed pending formal audiometry. Early empirical steroids are recommended when BM is diagnosed.

Myringotomy

• Indicated if middle ear effusion accompanies bullae formation

Prognosis

• Generally good and self-limiting
• Hearing loss in the majority recovers fully
• Persistent SNHL is possible - emphasizing the importance of follow-up audiometry
• No TM perforation expected from bullae rupture

• Shambaugh Surgery of the Ear, pp. 2103-2126
• Cummings Otolaryngology Head and Neck Surgery, p. 2654
• Scott-Brown's Otorhinolaryngology Head & Neck Surgery Vol. 2, pp. 979-980
• K.J. Lee's Essential Otolaryngology, p. 436
• Textbook of Family Medicine 9e, p. 660
• Ungar OJ et al. "The Actual Incidence and Types of Hearing Losses in Bullous Myringitis." Otol Neurotol, 2021. [PMID: 33883520 - Systematic Review]

Prosthesis After Maxillectomy

Overview

Multidisciplinary Team (MDT)

• Head and neck surgeon
• Oncologist/radiation oncologist
• Speech and language therapist
• Dental hygienist
• Specialist dental/facial prosthetic technicians
• The patient's primary dental practitioner (in dentate patients)

Classification of Maxillectomy Defects

• Brown's classification - surgery-based; widely used to decide between surgical reconstruction and obturation. When the defect extends beyond level 2, obturation yields increasingly poor results and surgical reconstruction is preferred
• Okay's classification - more directed at the maxillofacial prosthodontist; guides obturator design based on the remaining dental configuration following surgery

Pre-surgical Assessment

• Screening panoramic dental radiograph + detailed oral examination
• Decision-making on dental extractions, restorations, and pre-prosthetic preparation
• Impressions and dental models taken pre-operatively (mandatory for dentate patients; may not be required for edentulous patients already wearing a well-extended prosthesis)
• Planning for osseointegrated implant placement (primary at time of surgery or secondary)
• A clear explanation to the patient of the staged prosthetic process and follow-up requirements

The Three Stages of Obturator Provision

Stage 1: Surgical Obturator (Immediate)

• Separates oral and nasal/antral cavities immediately
• Supports cheek soft tissues
• Assists haemostasis
• Enables early speech and swallowing

• Pre-operative dental models allow fabrication of a tooth-bearing obturator; alternatively a simple clear acrylic cover plate is used when time is limited
• Obturating material options: addition-cured silicone putty (preferred - engages undercuts, supports cheek, assists haemostasis), black gutta percha, foam products

• Small defects with sufficient remaining teeth: dental clasps suffice
• Larger defects: bone screws and/or circum-zygomatic wires

• Requires regular removal and modification as the defect heals and shrinks
• Small defects: managed in outpatient clinic
• Large defects (especially with circum-zygomatic wires): may require return to the operating room
• Generally left in situ for 6-8 weeks post-operatively

Stage 2: Interim Obturator

• Provided after wound healing, typically at ~6-8 weeks
• The defect continues to change shape during this phase; the interim obturator is adjusted as required
• Allows the patient to resume eating, speech rehabilitation continues
• Transition period lasting several months while the defect matures

Stage 3: Definitive Obturator

• Constructed once the defect has fully healed and stabilized (typically 3-6+ months post-surgery, longer if radiotherapy is given)
• A bespoke, carefully crafted prosthesis that restores form and function optimally

Surgical Modifications to Facilitate Obturator Provision

1. Bone cuts through edentulous areas or extraction sockets - preserves periodontal bone support of remaining abutment teeth, which are vital for obturator retention
2. Palatal mucosal incisions made lateral to bone cuts - creates a keratinized mucosal flap that folds over the cut bone edge, cushioning the prosthesis during masticatory function
3. Split-skin graft to the cheek defect - produces a scar band within the cheek that assists retention of the obturator (one of the few retentive surfaces available in conventional obturation)
4. Removal of the inferior turbinate(s) - creates more vertical space for the obturator and prevents future trauma to prolapsed turbinate tissue
5. Smoothing of sharp bony margins - essential for all prosthetic rehabilitation

Obturator Design

Simple Obturator

• For low-level partial maxillectomy defects
• A soft silicone bung engages natural undercuts in the defect for retention

Multi-Part Obturator

• Used when trismus limits access for impressions or prosthesis insertion/removal
  • Trismus is common post-maxillectomy, especially after radiotherapy
• Impressions are taken in several parts using a multi-part technique
• The definitive obturator has a separate obturator component that inserts directly into the defect and attaches to the overlying dental component via magnet linkage

Osseointegrated Implants in Maxillary Obturation

• Extensive maxillary defects
• Edentulous patients
• Patients with severe trismus
• Patients with few or no remaining teeth

Zygomatic Implants

• Particularly useful for large maxillary defects where there is insufficient alveolar bone for standard implants
• Achieve very high initial stability and can support the obturator at an early stage
• Multiple zygomatic implants are typically splinted together with a retentive bar, and the obturator clips or screws onto this bar
• Should ideally be placed at the time of primary resection if post-operative radiotherapy is planned, to allow osseointegration before radiotherapy-induced changes compromise implant success
• When implant-retained, the need for the prosthesis to deeply engage the defect undercuts is greatly reduced

Standard Dental Implants

• Placed in residual alveolar bone or in reconstructed bone (e.g., fibula flap)
• Can provide excellent retention in partially dentate patients with smaller defects

Facial Prostheses (Midfacial/Orbital Defects)

• Traditionally: skin adhesives, spectacle frames, mechanical undercuts
• Modern standard: osseointegrated craniofacial implants (last 30 years)
• Conventional adhesive-retained prostheses remain useful but are difficult to locate accurately, prone to dislodgement, and cause skin irritation

• Remove small areas of unsupported tissue to provide a solid margin
• Keep bulk of vascularized flaps in this area minimal (or debulk before prosthesis construction)
• Smooth sharp bony margins
• Use split-skin grafts within the orbit: provide a stable, hair-free, drier surface
• For rhinectomy: preserve nasal bones when oncologically safe - assists prosthesis retention

Obturator vs. Free Flap Reconstruction

Complications and Challenges

• Trismus - limits access for impressions, insertion/removal; may necessitate extraction of additional teeth and multi-part obturator design
• Radiotherapy effects - xerostomia, trismus, mucositis, compromised implant osseointegration, increased risk of osteoradionecrosis with implants placed post-radiotherapy
• Retention difficulties - especially in edentulous patients and large defects; addressed with implants
• Globe displacement - inferior drop of globe if orbital floor not reconstructed
• Lip contracture - can occur after level 2 maxillectomy and obturation
• Speech and swallowing - incompletely restored by obturation in large defects; multidisciplinary support needed

• Scott-Brown's Otorhinolaryngology Head & Neck Surgery Vol. 3, pp. 543-547 (Prosthodontic Rehabilitation chapter)
• Scott-Brown's Otorhinolaryngology Head & Neck Surgery Vol. 2, pp. 979 (HRQoL after maxillectomy)
• K.J. Lee's Essential Otolaryngology, p. 436
• Cummings Otolaryngology Head and Neck Surgery, pp. 1945, 2437

Superior Semicircular Canal Dehiscence Syndrome (SCDS)

Background and Discovery

Pathophysiology: The "Third Mobile Window"

1. Auditory effects

• Air-conducted sound energy is dissipated away from the cochlea through the dehiscence → reduced cochlear stimulation by air conduction → apparent conductive hearing loss
• Bone-conducted stimuli are enhanced or thresholds unchanged → bone conduction thresholds may be supra-normal (better than 0 dB)
• Net result: air-bone gap, predominantly in low frequencies (<2,000 Hz), with bone conduction thresholds sometimes reaching -20 dB or better
• Additionally, the abnormal third window alters hydrodynamic forces within the cochlea, biasing the basilar membrane toward the scala tympani - analogous to endolymphatic hydrops - which explains elevated SP/AP ratios on electrocochleography (ECochG)

2. Vestibular effects

• Sound pressure and intracranial/middle ear pressure changes are transmitted to the SSC via the dehiscence
• Loud sounds and positive pressure in the external canal → ampullofugal deflection of the superior canal → excitation of SSC afferents
• Negative pressure or Valsalva against closed glottis → ampullopetal deflection → inhibition of SSC afferents
• The eye movements evoked are strictly in the plane of the superior canal regardless of direction of gaze

Clinical Features

Auditory Symptoms

Vestibular Symptoms

Characteristic Eye Movement

• Slow phase: upward + torsional rotation of the superior pole away from the affected ear (with SSC excitation)
• Opposite direction (downward + torsion toward affected ear) with SSC inhibition

Diagnosis

Audiometry

• Air-bone gap in low frequencies (typically below 2,000 Hz)
• Supra-normal bone conduction thresholds (e.g., -10 to -20 dB)
• Acoustic reflexes present in the affected ear - this is the critical distinguishing point from otosclerosis, which also shows low-frequency CHL but with absent reflexes
• Patients with intact acoustic reflexes + air-bone gap must be investigated for SCDS before any middle ear surgery is contemplated - some have undergone unnecessary stapedectomy which does not close the air-bone gap

Key rule: Air-bone gap + present acoustic reflexes = investigate for SSCD before stapedectomy

Vestibular Evoked Myogenic Potentials (VEMP)

• Cervical VEMP (cVEMP): Lowered threshold + elevated amplitude in the affected ear - highly useful screening test. Normal cVEMP threshold is ~90-100 dB nHL; in SSCD it may drop to 60-70 dB
• Ocular VEMP (oVEMP): May be more sensitive and specific than cVEMP for this diagnosis; amplitudes are elevated on the ipsilateral side
• Both reflect the enhanced responsiveness of the otolith organs through the dehiscence

Electrocochleography (ECochG)

• Elevated SP/AP (summating potential/action potential) ratio in the symptomatic ear, similar to Meniere disease (mean 0.62 in affected ears vs. 0.29 in unaffected ears)
• Useful as a sensitive adjunct and as an intraoperative monitoring tool: the SP/AP ratio increases when the dehiscence is surgically exposed and normalizes immediately upon satisfactory plugging of the canal
• Criterion for abnormality: SP/AP >0.4

High-Resolution CT of the Temporal Bone

• Images must be reconstructed in two dedicated planes:
  • Pöschl plane - parallel to the superior canal (best demonstrates dehiscence)
  • Stenver plane - perpendicular to the superior canal
• Conventional 1-mm axial/coronal CT has low specificity (high false-positive rate) due to partial volume averaging
• In cases of near-dehiscence (very thin bone that is not truly absent), CT may fail to confirm the diagnosis even with thin cuts - clinical and physiologic findings must then carry greater diagnostic weight
• CT is essential to plan the surgical approach (defect location, angle subtended, middle fossa anatomy)

Differential Diagnosis

Note: SCDS is frequently misdiagnosed as a patulous Eustachian tube due to prominent autophony.

Third Window Lesions - Differential

• Semicircular canals: superior, posterior, or lateral canal dehiscence
• Vestibule: large vestibular aqueduct syndrome, inner ear malformations
• Cochlea: dehiscence between carotid canal and scala vestibuli; DFN-3 (X-linked deafness with stapes gusher)

• Paget disease of bone

Management

Conservative

• Many patients with incidentally discovered dehiscence and mild symptoms can be managed conservatively
• Avoidance of triggering stimuli (loud sounds, straining)
• Careful counseling about the risks of middle fossa craniotomy before considering surgery
• Vestibular rehabilitation for chronic disequilibrium

Surgical Indications

Surgical Approaches

1. Middle Cranial Fossa (MCF) Craniotomy

• The original and most established approach (Minor, 2000)
• Allows direct visualization and confirmation of the dehiscence
• The SP/AP ratio actually rises when the dehiscence is surgically exposed, then normalizes immediately upon satisfactory plugging - confirming adequacy of repair intraoperatively
• ECochG intraoperative monitoring is used routinely
• Plugging reliably relieves vestibular symptoms and reduces aVOR gain for the superior canal by ~44% (with a modest 10% reduction of the ipsilateral posterior canal)
• Resolves many auditory symptoms; hearing loss improvement is less predictable
• Disadvantage: Requires craniotomy + temporal lobe retraction

2. Transmastoid Approach

• More recently described alternative
• Advantages: Avoids craniotomy; no temporal lobe retraction; surgeons more familiar with mastoidectomy
• Disadvantages: Does not permit direct confirmation of dehiscence (transmastoid plugging of an intact canal has been described); plug is placed closer to the sensory epithelia (ampulla and utricle), risking disturbance; not feasible with low-hanging dura or extensive tegmen dehiscence
• Initial reports included one case of significant SNHL post-operatively; more recent series report minimal morbidity

3. Round Window Reinforcement (Third Window Occlusion)

• Controversial alternative approach: does not directly address the third window at the superior canal
• Some patients developed worse symptoms - not widely recommended

Plugging Materials and Technique

• Materials used: bone wax, bone dust, fascia/periosteum, surgical glue - applied in multiple layers
• Care must be taken to avoid suctioning perilymph from the dehiscence intraoperatively

• Cummings Otolaryngology Head and Neck Surgery, pp. 2574-2576 (ECochG in SSCD); pp. 3249-3250 (Surgery for SSCD)
• Shambaugh Surgery of the Ear, pp. 86-88 (Third window lesions); pp. 600-601 (SCDS pathophysiology and surgery)
• K.J. Lee's Essential Otolaryngology, pp. 63-64 (SSCS syndrome)
• Scott-Brown's Otorhinolaryngology Head & Neck Surgery Vol. 2, p. 1236 (CT imaging of SSCD)

Epstein-Barr Virus (EBV) in ENT

Virology and Epidemiology

• In lower-income settings with less hygiene: EBV infection in early childhood is nearly universal; usually asymptomatic
• In higher-income settings: infection is delayed until adolescence/young adulthood; symptomatic disease is much more common
• Only ~20% of seropositive persons in high-income countries shed virus; ~50% of those exposed acquire infection
• More than half of infected individuals continue to shed virus in saliva, usually for life

EBV's Role in ENT - Overview

1. Infectious Mononucleosis (IM) / Glandular Fever

Pathogenesis

• EBV infects oropharyngeal epithelial cells initially, then spreads to underlying lymphoid tissue (tonsils, adenoids), where B cells are infected via CD21
• Infected B cells disseminate in circulation, secreting antibodies with unusual specificities (including heterophile antibodies against sheep/horse/bovine erythrocytes - the basis of diagnostic tests)
• Host CD8+ T-cell response controls B-cell proliferation and viral spread - the "atypical lymphocytes" on peripheral blood smear are activated CD8+ T cells, not infected B cells

Clinical Features (ENT Focus)

• Incubation period: 4-7 weeks
• Classical triad: sore throat + cervical lymphadenopathy + fever
• Tonsil enlargement: can be massive; may cause airway compromise and dysphagia
• Palatal petechiae: more common in younger patients
• Periorbital oedema (especially lower lids) - Hoagland sign
• Hepatomegaly and jaundice: more common in older patients
• Splenomegaly: late sign, resolves in 3-4 weeks
• Nasopharyngeal lymphoid hyperplasia: present in 92% of IM patients on flexible nasendoscopy - helps distinguish IM from acute tonsillitis

Investigations

• FBC: lymphocytosis >50% of WBC with >10% atypical lymphocytes (Hoagland criteria), or >20% atypical lymphocytes alone
• Liver and renal function tests
• Monospot test (heterophile antibody): latex agglutination using horse RBCs; sensitivity 63-95%, specificity 84-100%
  • Positivity increases over the first 6 weeks (heterophile antibody titres peak)
  • Approximately 10% never develop a positive test (higher rate in children)
  • False positives: mumps, SLE, Mediterranean spotted fever, diabetes, sarcoidosis
• Paul-Bunnell test: based on sheep RBC agglutination (older method)
• Gold standard: IgM antibody to EBV viral capsid antigen (VCA-IgM) during acute primary infection
• EBV viral load by PCR: useful in inconclusive serology
• L/WBC ratio >0.35: suggested as a screening tool but sensitivity 72%/specificity 84% - insufficient alone; use only with Hoagland criteria

If Monospot is repeatedly negative, consider: CMV, HIV, Toxoplasmosis, Rubella

Management

• Supportive: fluids, analgesia, rest
• Treat superimposed streptococcal infection if present (confirmed by throat culture)
• AVOID aminopenicillins (ampicillin/amoxicillin): virtually 100% develop a maculopapular/rubelliform rash due to transient immunostimulation (amoxicillin: 30%; ampicillin: 90%)
• Use penicillin V or cephalosporins if antibiotic needed; IV penicillin or cephalosporins for those admitted

• Cochrane review: insufficient evidence to recommend steroids for routine symptom control in IM
• Indicated for: significant tonsillar swelling causing airway compromise/swallowing difficulty (short course)
• Corticosteroids improve pain scores and time to resolution, especially when combined with antibiotics
• When airway is unsafe: intubation or tracheostomy required

• Acyclovir: meta-analysis of 5 RCTs (n=339) - clinical data do not justify use for mild-moderate IM
• May benefit patients with severe manifestations, especially as an adjunct to corticosteroids

• Patients must avoid sport/vigorous activity due to risk of splenic rupture (usually following minor trauma; rate <1 in 500)

Complications

2. Nasopharyngeal Carcinoma (NPC)

EBV Link

• EBV infects nasopharyngeal epithelium
• In susceptible individuals → epithelial cell transformation
• Tumor cells contain EBV genomes and express latent membrane protein-1 (LMP1), which activates the NF-κB pathway generating oncogenic signals
• Tumors are often heavily infiltrated by T cells responding to viral antigens

Histological Types

Epidemiology

• Common among Southern Chinese; rare in the West (<1% of US cancers)
• Strong germline genetic susceptibility in endemic populations
• EBV is a cofactor (not sole cause) - dietary carcinogens (salted fish) and genetic factors also contribute

Clinical Use of EBV in NPC

• Plasma EBV DNA can be used to monitor treatment response and predict prognosis
• EBV serology (anti-VCA IgA, anti-EA IgA) used for screening in endemic areas

Treatment

• Early stage (T1-T2): definitive radiotherapy (RT) alone; local control 64-95%
• Locally advanced: concurrent chemoradiotherapy (CRT), with or without induction/adjuvant chemotherapy
• IMRT is now standard: preserves parotid glands, reduces xerostomia, protects brainstem/chiasm in skull base involvement
• Intergroup 00-99 study: CRT + adjuvant chemo vs. RT alone → 3-year OS 78% vs. 47% (p=0.005)
• Distant metastases remain the dominant mode of failure (up to 30%)
• Immune checkpoint inhibitors: responses reported - new strategy for refractory tumors (leveraging T-cell response to viral antigens)

3. NK/T-Cell Lymphoma, Nasal Type (ENKL)

Key Features

• Virtually all cases are EBV-associated - one of the strongest EBV-tumor associations
• Predominantly affects young to middle-aged adults with male predilection
• Common in East Asia and Latin America

Presentation

• Nasal mass, obstruction, epistaxis
• Palatal destruction
• Erythema and swelling of the face
• Perivascular infiltration → vascular occlusion → massive tissue necrosis (the hallmark)
• Due to necrosis: multiple biopsies often needed to make diagnosis

Diagnosis

• IHC: CD56 positive; EBV positive (in situ hybridization with EBER-1 or EBER-2 probes)
• Plasma EBV DNA level: monitors disease status, predicts prognosis
• LMP1 deletion (del-LMP1): predominant EBV strain in this tumor
• CD56+ EBV+ lymphocytes are rarely seen in normal/inflammatory nasal mucosa - important diagnostic clue

Treatment

• Historically RT was mainstay; high response rate (60-80%) but high relapse rate (~50%)
• Modern regimens incorporate chemotherapy: SMILE (dexamethasone, methotrexate, ifosfamide, L-asparaginase, etoposide)
• More than 80% present with stage I-IIE disease

4. Other EBV-Associated ENT/Head and Neck Malignancies

Hodgkin Lymphoma

• EBV is present in Reed-Sternberg cells in a subset of HL (30-50% in Western series)
• Commonly presents with cervical lymphadenopathy in ENT practice
• EBV genome-positive Burkitt lymphoma: endemic form (African) is virtually 100% EBV+

EBV+ DLBCL (Diffuse Large B-Cell Lymphoma)

• Can occur in paranasal sinuses
• EBV association particularly strong in HIV/immunosuppressed patients and in elderly (EBV+ DLBCL of the elderly)
• Paranasal sinus DLBCL: usually maxillary sinus, often extends to orbit

Post-Transplant Lymphoproliferative Disorder (PTLD)

• EBV-associated lymphoproliferative disorders are a major complication in immunodeficient/post-transplant patients
• Head and neck (tonsils, adenoids) is a common primary site

Chronic Active EBV Infection (T/NK-cell type)

• Systemic EBV+ T-cell and/or NK-cell proliferation; no morphologic features of neoplasm
• Most commonly reported in East Asia
• Can progress to overt NK/T-cell lymphoma

5. Oral Hairy Leukoplakia (OHL)

• White, corrugated, hyperkeratotic lesion on the lateral tongue
• Caused by EBV (lytic infection) of oral epithelial cells
• Diagnosis confirmed by identifying EBV on biopsy
• Typically asymptomatic
• Strongly associated with HIV infection - its presence in a previously healthy individual should prompt HIV workup
• No malignant transformation potential
• Differential diagnosis: lichen planus, idiopathic leukoplakia, carcinoma in situ

EBV Serology Summary

Third-Window EBV Oncological Risk Summary

• Nasopharyngeal carcinoma (cofactor)
• Hodgkin disease (Reed-Sternberg cells EBV+)
• Burkitt lymphoma (genome-positive; endemic form ~100% EBV+)
• NK/T-cell lymphoma (nasal type; ~100% EBV+)
• EBV+ DLBCL
• Post-transplant lymphoproliferative disorders
• Gastric carcinoma (non-ENT but EBV-associated)
• Multiple sclerosis (recent evidence of association)

• Scott-Brown's Otorhinolaryngology Head & Neck Surgery Vol. 3, pp. 843-845 (IM in adults - systemic manifestations, diagnosis, treatment)
• Scott-Brown's Otorhinolaryngology Head & Neck Surgery Vol. 3, pp. 1050-1051 (IM in laryngology context)
• Scott-Brown's Otorhinolaryngology Head & Neck Surgery Vol. 2, pp. 8907-8912 (IM as acute tonsillitis)
• Cummings Otolaryngology Head and Neck Surgery, pp. 2278-2280 (NPC treatment, IMRT)
• Cummings Otolaryngology Head and Neck Surgery, pp. 1553-1574 (ENKL, DLBCL of paranasal sinuses)
• Robbins & Kumar Basic Pathology, pp. 398-400 (EBV pathogenesis, IM, NPC)
• K.J. Lee's Essential Otolaryngology, pp. 63, 215-221 (SSCD; OHL; Lymphoma)

Parotid Gland Anatomy

Embryology

• The parotid develops first among the major salivary glands (weeks 6-8 of gestation), as an outpouching of oral ectoderm growing posteriorly toward the ear
• As the gland develops, the facial nerve advances anteriorly, and the gland grows around it - this is why the facial nerve is embedded within the parotid
• Uniquely, the parotid is the last gland to be encapsulated, after lymphatics have already developed. This results in lymphatics becoming trapped within the gland parenchyma and salivary epithelial cells being included within intraparotid lymph nodes
• This embryological quirk explains the development of Warthin's tumors and lymphoepithelial cysts within the parotid (conditions not seen in submandibular or sublingual glands, which encapsulate before lymphogenesis)

General Features

• Largest of the major salivary glands
• Weight: ~25 g, irregularly lobulated
• Shape: wedge-shaped on coronal section
• Secretion type: predominantly serous (only a few mucous acini) - produces watery saliva and salivary amylase
• Unique feature: only salivary gland containing intraglandular lymph nodes (the majority in the superficial lobe)

Extent and Surface Anatomy

Surface Layers (Superficial to Deep)

1. Skin
2. Platysma (posterior border)
3. Parotid fascia
4. Superficial lymph nodes (on or deep to fascia)
5. Parotid gland parenchyma

Capsule and Fascia

• The deep cervical fascia splits to enclose the gland - this investment is the parotid fascia (also called parotidomasseteric fascia)
• Continuous anteriorly with the fascia over the masseter
• Extends up to the zygomatic arch superiorly
• The SMAS (superficial musculoaponeurotic system) overlies the gland, adherent to the parotidomasseteric fascia in the pretragal area, becoming separate in the cheek
• The deep part of the fascia extends to the base of skull and is thickened between the styloid process and the angle of the mandible forming the stylomandibular ligament
• The fascia is largely tough and inelastic but thins anteriorly
• Clinical implication: inflammatory oedema and rapidly growing tumours cause the capsule to stretch and become painful before overt enlargement is visible
• The relatively thin fascia over the apex can allow spread of sepsis into the parapharyngeal space

Lobes: Superficial vs. Deep

• The majority of intraglandular lymph nodes are in the superficial lobe
• Deep lobe tumours can extend into the prestyloid compartment of the parapharyngeal space, causing a medial oropharyngeal bulge
• Deep lobe tumours limited by the stylomandibular ligament may expand both superficially and into the parapharyngeal space forming a dumbbell-shaped mass
• Most parotid tumours arise from the superficial lobe

Accessory Parotid Gland

• A separate portion of parotid tissue typically lying on the masseter muscle, between the parotid duct (below) and the zygomatic arch (above)
• Has its own excretory ductule that joins the Stensen duct
• Subject to the same pathologies as the main parotid gland

Parotid Duct (Stensen's Duct)

• Lined by low cuboidal epithelium with a smooth muscle and fibrous tissue wall
• Length: ~5 cm; internal calibre: ~0.6 mm
• Originates within the gland, enveloped by the deep lobe; only small ductules connect the superficial lobe to the duct
• Exits from the anterior border of the gland
• Travels across the masseter muscle (superficially)
• Turns medially at the anterior border of the masseter
• Pierces the buccinator and runs obliquely between buccinator and oral mucosa
• Opens at the parotid papilla on the oral mucosa opposite the second upper molar tooth
• Surface marking: the middle of a line from the intertragal notch of the auricle to the midpoint of the philtrum
• Key relationship: the facial nerve and its branches are always lateral to the parotid duct

Facial Nerve - The Most Important Surgical Structure

Entry into the parotid

• Exits the stylomastoid foramen just deep to the junction of the cartilaginous and bony parts of the external auditory meatus
• Usually a single trunk (rarely double - estimated 3-26.7%)
• The main trunk lies approximately 1 cm above the posterior belly of digastric
• Passes downwards and forwards over the styloid process and attached muscles
• Enters the gland high on the posteromedial surface, between the mastoid and styloid processes
• Before entering the gland, gives off:
  • Posterior auricular branch - supplies occipital belly of occipitofrontalis
  • Muscular branch - supplies posterior belly of digastric and stylohyoid

Division within the parotid

• Upper: zygomaticotemporal (upper) division
• Lower: cervicofacial (lower) division

Branching patterns

Cross-innervation

• Most pronounced between zygomatic and buccal branches (extensive anastomoses)
• Least for the marginal mandibular branch (few anastomoses)
• Clinical implication: midfacial movement defects are rare after zygomatic/buccal branch injury due to cross-innervation; marginal mandibular injuries cause predictable lower lip weakness

Spatial relationship to vascular structures

• The facial nerve lies superficial to the retromandibular vein
• The retromandibular vein lies superficial to the external carotid artery
• The retromandibular vein is therefore a useful radiological landmark for localizing the facial nerve on MRI

Blood Supply

Arterial

• External carotid artery courses medial to the parotid and divides within the gland into:
  • Maxillary artery - exits the anteromedial surface
  • Superficial temporal artery - continues superiorly, exits from the superior surface; gives off the transverse facial artery

Venous

• The maxillary vein and superficial temporal vein unite to form the retromandibular vein within the gland
• The retromandibular vein emerges from the lower pole of the gland and divides into:
  • Anterior branch - joins the facial vein → internal jugular vein (lies just deep to the marginal mandibular branch of facial nerve)
  • Posterior branch - joins the posterior auricular vein → external jugular vein

Nerve Supply (Innervation)

Parasympathetic (secretomotor)

1. Preganglionic fibres: inferior salivatory nucleus (medulla)
2. → Glossopharyngeal nerve (CN IX)
3. → Tympanic branch (Jacobson's nerve) → enters middle ear via tympanic canaliculus → tympanic plexus
4. → Lesser superficial petrosal nerve (LSPN)
5. → Exits skull base via foramen ovale (or nearby canaliculus)
6. → Otic ganglion (ganglion associated with V3, just inferior to foramen ovale) - synapse here
7. → Postganglionic fibres travel with the auriculotemporal nerve (branch of V3/mandibular nerve)
8. → Parotid gland

Sympathetic (vasoconstrictor)

1. Superior cervical ganglion → postganglionic fibres
2. Follow the external carotid artery plexus and middle meningeal artery plexus
3. → Parotid gland

Sensory

• Auriculotemporal nerve (V3): sensory to the gland
• Great auricular nerve (C2/C3): sensory to the parotid fascia and lower two-thirds of the pinna; divides into anterior and posterior branches. The posterior branch can often be preserved during parotidectomy, reducing post-operative auricular numbness

Clinical correlation - Frey's syndrome (auriculotemporal nerve syndrome)

Lymphatics

• Intraparotid lymph nodes are present (unique to the parotid among salivary glands - due to late encapsulation after lymphogenesis)
• Superficial lymph nodes lie on or deep to the parotid fascia
• The majority of intraparotid nodes are in the superficial lobe
• Parotid nodes receive drainage from the scalp, external auditory canal, pinna, eyelids, and lacrimal gland
• Drain ultimately to upper deep cervical nodes (level II)
• Clinical implication: cutaneous malignancies of the scalp/pinna/face can metastasize to intraparotid nodes; lymphomas can present as parotid masses

Microscopic Anatomy

• Parotid is predominantly serous (small granules, secretes proteins and enzymes including amylase)
• Acinar organization:
  • Secretory acini → intercalated ducts (lined by simple low cuboidal epithelium; surrounded by myoepithelial cells) → striated ducts (columnar cells with basal folding; actively transport water and electrolytes) → main excretory duct (lined by tall columnar epithelium)
• Lobules are connected by dense fibrous tissue containing excretory ducts, vessels, lymphatics, nerve fibres and ganglia

Parapharyngeal Extension

• The deep lobe of the parotid extends directly into the prestyloid compartment of the parapharyngeal space (which contains fat, deep lobe tissue, lymph nodes, and branches of V3)
• Deep lobe tumours expanding into this space present as a medial oropharyngeal bulge or a neck mass
• This anatomical extension explains why the oropharynx must always be examined when assessing the parotid gland

• Scott-Brown's Otorhinolaryngology Head & Neck Surgery Vol. 3, pp. 721-724 (Parotid gland - clinical anatomy, microscopy, embryology, duct, facial nerve, vessels, nerve supply)
• Cummings Otolaryngology Head and Neck Surgery, pp. 1525, 3787-3789 (Parotid gland; innervation)
• K.J. Lee's Essential Otolaryngology, pp. 641-642 (Parotid anatomy)
• Gray's Anatomy for Students, p. 1052 (Innervation)

Sialendoscopy

Definition and Concept

Historical Context

Indications

Contraindications

• Active infection (sialendoscopy is contraindicated in the presence of active infection - risk of spreading infection along the ductal system)
• Trismus limiting access
• Very young/uncooperative patients unable to tolerate local anaesthesia (general anaesthesia required)

Background: Sialolithiasis (Context for Sialendoscopy)

Epidemiology and Distribution

• Sialolithiasis is the most common cause of salivary gland inflammation
• Submandibular gland: most commonly affected (80-90% of stones occur in the Wharton duct)
• Parotid (Stensen) duct: 10-20% of cases
• Sublingual duct: ~1%

Why stones prefer the submandibular gland

• Wharton duct is longer, wider, more tortuous, and angulated against gravity as it courses around the mylohyoid → slower flow, poorer egress
• Submandibular saliva is more viscous with higher calcium and phosphorous concentration
• In the submandibular gland: sialolith formation is often the primary event → stasis → retrograde bacterial migration → sialadenitis
• In the parotid gland: chronic sialadenitis precedes stone formation (inverse relationship)

Stone location

• Parotid: stones most commonly at the hilum or parenchyma
• Submandibular: stones most commonly in the duct

Pre-endoscopy management

• Initial: sialagogues (sour candy, lemon drops, pickles), hydration, local heat, gland massage
• Transoral milking/incision for palpable submandibular stones within 2 cm of the duct orifice

The Sialendoscope: Instrumentation

Types by Rigidity

• Flexible endoscopes - good for navigating curves; smaller working channels
• Semirigid endoscopes - most commonly used; balance between maneuverability and instrument channel capacity
• Rigid endoscopes - limited to straight segments

Types by Function

• Diagnostic endoscopes: fiberoptic light + image transmission; may include irrigation channel; no working channel for instruments
• Therapeutic endoscopes:
  • Compact: single integrated unit combining fiberoptic light, image transmission, working channel, and irrigation channel (cannot be disassembled)
  • Modular (semirigid): optical fibers combined as a separate probe inserted into sheaths of various sizes; the space between optical system and sheath wall serves as the irrigation channel

Standard Sizes (Erlangen/Karl Storz system)

• 0.8 mm: light + image + irrigation; no working channel
• 1.1 mm: light + image + irrigation + working channel
• 1.6 mm: light + image + irrigation + working channel (may be too large for some paediatric patients)

• Microdrill - for stone fragmentation
• Holmium laser fiber - for larger stone fragmentation
• Balloon dilator - for ductal stenosis
• Wire basket - for stone fragment extraction

Surgical Technique

Anaesthesia

• General anaesthesia is standard
• Local anaesthesia feasible in cooperative children ≥8 years
• For adults: increasingly performed under local anaesthesia in an office-based setting

Steps

• Appropriate bite block placed on the contralateral side
• Topical mucosal anaesthesia to the papilla (if local anaesthesia)

• Identify the salivary duct papilla (Stensen duct: opposite second upper molar; Wharton duct: floor of mouth)
• Serial dilation using salivary duct probes and dilators
• Note: Wharton duct is more difficult to cannulate than Stensen duct

• Sialendoscope introduced via the dilated orifice through an introducer sheath
• Attached to camera and monitor for real-time visualisation

• Under continuous saline irrigation (maintains lumen patency and clears secretions/debris)
• Advanced to the first branching point; each branch explored as far as the scope can comfortably pass
• Ductal system assessed for:
  • Sialoliths (size, location, mobility)
  • Stenoses / strictures
  • Mucosal changes (polyps, sialodochitis, erythema)
  • Ductal kinks

• Temporary ductal stent may be placed (especially in Stensen duct after manipulation, to prevent stricture)

Approaches: Pure Endoscopic vs. Combined

Pure Endoscopic

• Stone visualised and retrieved entirely through the working channel
• Limited to stones that can be captured in the wire basket or fragmented to basket-retrievable size

Combined (Hybrid) Approach

• Endoscope localises the stone (or ultrasound used for localisation)
• A small external or intraoral incision is made over the stone location to extract it
• Success rate for endoscope-assisted transoral removal: 86.3% (meta-analysis)
• Particularly useful for large or impacted stones
• Combined approach for parotid gland: 78.2% success rate

Lithrotripsy Modalities

Intracorporeal Lithotripsy

• Holmium laser: delivers laser energy through a fiberoptic cable passed through the working channel; can fragment most stones safely including large ones; preferred modality
• Pneumatic lithotripsy (microdrill): intraductal compressive fragmentation; gaining experience in recent years

Extracorporeal Lithotripsy (ESWL)

• Compressive shock waves focused via acoustic lenses → stone fragmentation
• Not FDA-approved in the United States
• Residual stone fragments can be subsequently removed by sialendoscopy

Specific Conditions and Sialendoscopy

Ductal Stenosis

• Balloon dilatation is the primary therapeutic manoeuvre
• May be primary (inflammatory) or secondary to irradiation (RAIS)
• Success rate for stenoses: 56.3% (lower than for stone disease - more variable outcomes)

Juvenile Recurrent Parotitis (JRP)

• Sialendoscopy is both diagnostic (confirms ductal ectasia) and therapeutic
• Treatment: irrigation + corticosteroid instillation through the working channel
• Success rate: 67.0%

Sjögren Syndrome / Chronic Inflammatory Disease

• Sialendoscopy + intraductal steroid irrigation used to manage ductal stenosis
• Post-irradiation salivary gland stenosis (RAIS): lowest success rate (45.8%)

Diagnostic Role

• Locates stones not detected by ultrasound, CT, or MRI
• Identifies ductal pathology that explains unexplained salivary gland swelling
• Reveals ductal polyps, sialodochitis, kinks

Outcomes: Evidence-Based

• 91 studies, 8,218 patients, 9,043 procedures
• Weighted pooled success rate: 80.9% overall

Complications

• Ductal perforation: most common complication (especially in paediatric series)
• Ductal avulsion
• Temporary ductal swelling / post-procedural sialadenitis
• Transient pain
• Ductal stenosis (particularly after Stensen duct incision/manipulation - hence stenting is important)
• Nerve injury: rare

Paediatric Sialendoscopy

• Effective and feasible in children
• General anaesthesia typically required (local anaesthesia possible in cooperative children ≥8 years)
• The 1.6-mm telescope may occasionally be too large for some paediatric patients → smaller scopes (0.8-1.1 mm) preferred
• Indications: JRP (most common - 68.9%), sialolithiasis (14.7%)
• Long-term results are excellent: children treated for sialolithiasis remained free of recurrent swelling at 4-8 year follow-up

Advantages over Traditional Surgery

Office-Based Sialendoscopy

• Reduces costs and avoidance of general anaesthesia
• Enables repeat procedures if needed
• Suitable for diagnostic procedures and small stone retrieval

• Cummings Otolaryngology Head and Neck Surgery, pp. 1487-1488 (Sialolithiasis and sialendoscopy); pp. 3880-3883 (Paediatric sialendoscopy chapter)
• K.J. Lee's Essential Otolaryngology, pp. 650-651 (Sialadenitis and sialendoscopy)
• Beumer LJ et al. "Success rate of sialendoscopy. A systematic review and meta-analysis." Oral Dis, 2024. [PMID: 37486613 - 91 studies, n=8218]
• Rahmati RW. "Office-Based Sialendoscopy." Otolaryngol Clin North Am, 2025. [PMID: 40133106]
• Teng TZJ et al. "Steroid Use in Sialendoscopy - A Systematic Review." Clin Otolaryngol, 2026. [PMID: 41501981]