Arab Board ENT Part 1 cheat sheet

Branchial arches: 1st (trigeminal), 2nd (facial), 3rd (glossopharyngeal), 4th-6th (vagus); each arch gives cartilage, muscle, nerve, and aortic derivative.

Pharyngeal pouch derivatives: 1st tympanic cavity/eustachian tube, 2nd palatine tonsil, 3rd inferior parathyroid and thymus, 4th superior parathyroid and ultimobranchial body.

Larynx develops from the laryngotracheal groove; the cricoid and arytenoids derive from the 4th-6th arches, recurrent laryngeal nerve innervates all intrinsic muscles except cricothyroid.

Cochlea: 2.5 turns, organ of Corti on basilar membrane; high frequencies at base, low frequencies at apex (tonotopic organization).

Olfaction: bipolar receptor neurons in olfactory epithelium project through cribriform plate to glomeruli; only sensory pathway not relaying through thalamus.

Taste: CN VII (anterior 2/3 tongue), IX (posterior 1/3), X (epiglottis); all relay via nucleus of tractus solitarius to thalamus then insula.

Mucociliary clearance rate approximates 5-10 mm/min; nasal cilia beat 10-20 Hz in a periciliary fluid layer.

Middle ear transformer ratio: tympanic membrane to stapes footplate area ratio ~17:1 plus ossicular lever ~1.3:1, giving ~25 dB gain.

Rinne positive = air conduction better than bone (normal or sensorineural); Rinne negative = bone better than air (conductive loss).

Weber lateralizes to the ear with conductive loss or the better ear in sensorineural loss.

Schwartze sign (reddish blush over promontory) suggests active otosclerosis; Carhart notch is an artifactual bone-conduction dip at 2 kHz.

Cholesteatoma: keratinizing squamous epithelium in middle ear; congenital type arises from epidermoid rest, often behind intact tympanic membrane.

Acoustic neuroma: most common at cerebellopontine angle; MRI with gadolinium is gold standard; arises from vestibular (superior) division of CN VIII.

BPPV: posterior canal most common; Dix-Hallpike provokes torsional upbeating nystagmus; Epley canalith repositioning is first-line.

Meniere disease: episodic vertigo, fluctuating sensorineural hearing loss, tinnitus, aural fullness; endolymphatic hydrops on histology.

Facial nerve: geniculate ganglion, then nerve to stapedius, chorda tympani, then exits stylomastoid foramen; topognostic testing localizes lesion.

Ostiomeatal complex drains maxillary, anterior ethmoid, and frontal sinuses; sphenoid drains separately via sphenoethmoidal recess.

Maxillary sinus is largest paranasal sinus; ostium is superiorly located, predisposing to poor gravitational drainage.

Frontal sinus drains via frontal recess into middle meatus; frontal sinus aplasia is common and asymmetric.

Allergic rhinitis: type I IgE-mediated; early-phase histamine, late-phase eosinophils; intranasal corticosteroids are most effective single agent.

Epistaxis: Kiesselbach plexus (anterior, Little area) vs. sphenopalatine artery (posterior); posterior bleeds more often need packing or ligation.

Nasal polyps arise from middle meatus; associated with asthma, aspirin sensitivity (Samter triad), and cystic fibrosis in children.

CSF rhinorrhea: beta-2 transferrin is confirmatory; cribriform plate/fovea ethmoidalis are common leak sites.

Inverted papilloma: lateral nasal wall, unilateral, risk of malignant transformation; endoscopic medial maxillectomy is treatment.

Recurrent laryngeal nerve injury causes vocal fold paresis in paramedian position; superior laryngeal nerve injury causes pitch and register loss.

Vocal fold nodules: bilateral, at junction of anterior 1/3 and posterior 2/3; related to phonotrauma; treatment is voice therapy.

Leukoplakia is a clinical white plaque; dysplasia on biopsy determines malignant potential; excision recommended for high-grade dysplasia.

Spasmodic dysphonia: adductor type most common; treated with botulinum toxin injection into thyroarytenoid.

Laryngomalacia is most common cause of stridor in infants; omega-shaped epiglottis with prolapse of arytenoids on inspiration.

Paradoxical vocal fold motion mimics asthma; diagnosis by flexible laryngoscopy during symptomatic episode.

Glottic carcinoma: hoarseness is early symptom; true vocal fold has sparse lymphatics, so nodal spread is late compared with supraglottis.

Presbyphonia: age-related vocal fold atrophy with bowing; treatment includes voice therapy and augmentation.

Oral cavity SCC: nodal levels I-III at risk; supraomohyoid neck dissection for N0.

Oropharynx: HPV-positive SCC has better prognosis; nodes often cystic level II; tonsil and base of tongue are common sites.

Nasopharyngeal carcinoma: associated with EBV; presents with neck mass or eustachian tube dysfunction; treated primarily with radiotherapy.

Thyroid papillary carcinoma spreads via lymphatics; follicular carcinoma spreads hematogenously; medullary arises from parafollicular C cells.

Salivary gland: pleomorphic adenoma most common benign; mucoepidermoid is most common malignant; facial nerve preservation is key.

Supraglottic larynx has rich lymphatic drainage to levels II-IV; glottic has sparse drainage; subglottic drains to paratracheal nodes.

Neck levels: I submental/submandibular, II upper jugular, III mid jugular, IV lower jugular, V posterior triangle, VI anterior compartment.

Radiotherapy for head and neck cancer may cause xerostomia, osteoradionecrosis, and hypothyroidism; dental evaluation before treatment.

Acute otitis media: bulging tympanic membrane is the most specific sign; Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis are common.

Tympanostomy tube indications: recurrent AOM (3 in 6 months or 4 in 12 months), chronic OME with hearing loss, or speech delay.

Croup (laryngotracheobronchitis): barking cough, steeple sign; parainfluenza virus; treated with dexamethasone and nebulized epinephrine.

Epiglottitis: drooling, tripod position, thumb sign; Haemophilus influenzae type b; avoid throat examination until airway secured.

Juvenile nasopharyngeal angiofibroma: adolescent males, recurrent epistaxis, nasal mass; highly vascular, avoid biopsy.

Subglottic stenosis grading (Myer-Cotton): grade I <50%, II 51-70%, III 71-99%, IV no lumen.

Branchial cleft cyst: second branchial cleft most common, anterior to sternocleidomastoid; thyroglossal duct cyst moves with tongue protrusion.

Choanal atresia: bilateral causes respiratory distress relieved by crying; CHARGE association; computed tomography confirms bony vs. membranous.

Aging face: brow ptosis, midface descent, jowl formation; superficial musculoaponeurotic system (SMAS) suspension in rhytidectomy.

Rhinoplasty: nasal tip support from lower lateral cartilages, septal angle, and medial crura; dorsal reduction may require spreader grafts.

Skin flaps: random flaps rely on subdermal plexus; axial flaps have named vessels; length-to-width ratio limits random flap viability.

Local flaps: bilobed for nasal defects, rhomboid for cheek, advancement for forehead; match color and texture.

Cleft lip: repair at 3 months (rule of 10s: 10 lb, 10 g/dL, 10 weeks); cleft palate repair at 9-12 months for speech.

Mohs micrographic surgery for basal cell carcinoma of the nose; preserves tissue with margin control.

Facial nerve branches: temporal (frontalis), zygomatic, buccal, marginal mandibular, cervical; marginal mandibular injury causes asymmetric smile.

Bone grafts: calvarial, rib, iliac crest; resorbable fixation preferred in pediatric craniofacial surgery.

Pure tone audiometry: conductive loss has air-bone gap; sensorineural loss has no gap; mixed loss has gap plus elevated bone thresholds.

Tympanometry: type A normal, type B flat (effusion or perforation), type C negative pressure (eustachian tube dysfunction).

Acoustic reflex: stapedius contraction at 70-100 dB above threshold; absent reflex suggests conductive loss or retrocochlear lesion.

Otoacoustic emissions reflect outer hair cell function; absent in sensorineural loss >30 dB; used for newborn screening.

Auditory brainstem response: waves I-V; wave V latency prolongation suggests retrocochlear pathology; used for newborn hearing screening.

Vestibular testing: caloric test assesses horizontal canal; head impulse test assesses vestibulo-ocular reflex; Dix-Hallpike for posterior canal BPPV.

Hearing loss severity: mild 26-40 dB, moderate 41-55, moderately severe 56-70, severe 71-90, profound >90 dB HL.

Cochlear implant candidacy: severe-to-profound bilateral sensorineural loss with limited benefit from hearing aids.

Shock types: hypovolemic, cardiogenic, distributive (septic, neurogenic), obstructive; treat cause and restore perfusion.

ATLS primary survey: airway, breathing, circulation, disability, exposure; cervical spine immobilization in trauma.

Wound healing phases: hemostasis, inflammation, proliferation, remodeling; collagen type III replaced by type I.

Anastomotic leak risk factors: tension, ischemia, malnutrition, steroids, diabetes; presentation may be subtle.

Thyroidectomy complications: recurrent laryngeal nerve injury, hypocalcemia from parathyroid injury, hematoma causing airway compromise.

Tracheostomy: indications include prolonged ventilation, upper airway obstruction, and airway protection; complications include bleeding, stenosis, and fistula.

Fluid resuscitation: crystalloid first-line; blood products in massive hemorrhage; monitor urine output and lactate.

Surgical site infection prevention: preoperative antibiotics within 60 minutes of incision, normothermia, glycemic control.

Asthma: reversible airflow obstruction; beta-2 agonists for rescue, inhaled corticosteroids for control; consider aspirin-exacerbated respiratory disease with nasal polyps.

Gastroesophageal reflux disease: may cause laryngopharyngeal symptoms; lifestyle modification and proton pump inhibitors.

Diabetes mellitus: perioperative hyperglycemia increases infection and anastomotic complications; target glucose control.

Hypertension: end-organ damage assessment; avoid abrupt withdrawal of beta-blockers perioperatively.

Anticoagulation: warfarin reversal with vitamin K and prothrombin complex concentrate; direct oral anticoagulants require specific reversal agents.

Anemia: iron deficiency most common; evaluate for gastrointestinal blood loss in older adults; transfusion thresholds individualized.

Antibiotic stewardship: culture-directed therapy; avoid unnecessary broad-spectrum agents to reduce resistance.

Perioperative cardiac risk: revised cardiac risk index; stress testing only if it will change management.

Acute respiratory distress syndrome (ARDS): Berlin criteria include acute onset, bilateral opacities, PaO2/FiO2 <=300, not explained by cardiac failure; low tidal volume ventilation 6 mL/kg.

Sepsis: life-threatening organ dysfunction from infection; sepsis bundle includes cultures, antibiotics within 1 hour, fluids, lactate measurement.

Vasopressors: norepinephrine first-line in septic shock; target mean arterial pressure >=65 mmHg.

Mechanical ventilation: lung-protective strategies reduce barotrauma; permissive hypercapnia may be tolerated.

Airway management: rapid sequence intubation with preoxygenation; anticipate difficult airway; surgical airway backup.

Tracheostomy timing: considered after prolonged intubation; percutaneous vs. open based on anatomy and expertise.

Nutrition in critical illness: enteral feeding preferred when gut functional; monitor for aspiration and ileus.

Delirium prevention: early mobilization, sleep hygiene, minimizing sedatives; assess with confusion assessment method.

Vestibular neuritis: acute prolonged vertigo without hearing loss; positive head impulse test; supportive care and vestibular rehabilitation.

Labyrinthitis: vertigo with hearing loss; may follow viral infection; treat symptomatically and monitor hearing.

Superior semicircular canal dehiscence: Tullio phenomenon (sound-induced vertigo); high-resolution CT confirms.

Vestibular schwannoma: unilateral sensorineural hearing loss and tinnitus; MRI with gadolinium is diagnostic.

Central vertigo: direction-changing nystagmus, skew deviation, normal head impulse; consider stroke and obtain imaging.

Hearing aid fitting: real-ear measurement improves verification; consider cochlear implant if inadequate benefit.

Tinnitus: evaluate for underlying cause; sound therapy and cognitive behavioral therapy are mainstays; avoid ototoxic medications.

Vestibular rehabilitation: habituation, gaze stabilization, and balance training for chronic vestibular dysfunction.

Cranial nerves: VII facial has motor, parasympathetic, and taste fibers; X vagus provides motor to pharynx and larynx.

Sympathetic chain: Horner syndrome (ptosis, miosis, anhidrosis) suggests apical lung or carotid pathology.

Parathyroid glands: superior from 4th pouch, inferior from 3rd pouch; blood supply from inferior thyroid artery.

Thyroid embryology: descends from foramen cecum along thyroglossal duct; thyroglossal duct cyst is midline and moves with swallowing.

Nasal septum: perpendicular plate of ethmoid, vomer, and quadrangular cartilage; Little area is common site of epistaxis.

Temporomandibular joint: innervated by auriculotemporal nerve; dysfunction may cause otalgia.

Lymph node levels: level I submental/submandibular; level II upper jugular; level III mid jugular; level IV lower jugular; level V posterior triangle.

Cochlear blood supply: labyrinthine artery from anterior inferior cerebellar artery; ischemia causes sudden sensorineural hearing loss.

Sudden sensorineural hearing loss: >30 dB across 3 contiguous frequencies within 72 hours; treat with corticosteroids; MRI to exclude retrocochlear lesion.

Otitis externa: Pseudomonas and Staphylococcus aureus; treat with topical antibiotics; malignant otitis externa in diabetics requires systemic therapy.

Chronic suppurative otitis media: persistent perforation with drainage; cholesteatoma may complicate; surgery for cholesteatoma.

Tympanic membrane perforation: central perforation usually safe; marginal perforation with keratinizing epithelium suggests cholesteatoma.

Mastoiditis: postauricular swelling, tenderness, and fever; computed tomography shows coalescent mastoiditis; IV antibiotics and surgery.

Facial nerve decompression: consider in acute facial paralysis with severe degeneration and no recovery.

Otosclerosis: progressive conductive hearing loss; stapes fixation; treatment with hearing aid or stapedotomy.

Vestibular migraine: recurrent vertigo with migrainous features; treat with migraine prophylaxis.

Chronic rhinosinusitis: symptoms >12 weeks with endoscopic or CT evidence; medical therapy includes saline irrigation and intranasal corticosteroids.

Fungal sinusitis: allergic fungal sinusitis with eosinophilic mucin and polyps; invasive fungal sinusitis in immunocompromised patients is emergent.

Orbital complications of sinusitis: preseptal cellulitis vs. orbital cellulitis; orbital abscess requires drainage.

Endoscopic sinus surgery: removes ostiomeatal obstruction; complications include CSF leak, orbital injury, and bleeding.

Septoplasty: corrects septal deviation; complications include septal hematoma, perforation, and saddle nose.

Nasal fractures: reduce within 7-10 days; assess for septal hematoma.

Allergic rhinitis: skin prick or specific IgE testing; avoidance and pharmacotherapy.

Epistaxis management: pressure, topical vasoconstrictors, cautery, packing, and arterial ligation for refractory cases.

Vocal fold paralysis: unilateral may cause weak breathy voice; bilateral may cause stridor; evaluate with laryngoscopy and imaging.

Laryngeal papillomatosis: recurrent respiratory papillomatosis caused by HPV 6 and 11; surgical debulking; adjuvant therapy for aggressive disease.

Laryngeal cancer: glottic most common; risk factors include smoking and alcohol; treatment options include surgery and radiation.

Tracheostomy: indications include airway obstruction, prolonged ventilation, and pulmonary toilet; complications include bleeding and stenosis.

Dysphagia: evaluate with modified barium swallow; aspiration risk; speech-language pathology involvement.

Laryngopharyngeal reflux: symptoms include hoarseness, throat clearing, and globus; treat with lifestyle and proton pump inhibitors.

Vocal fold leukoplakia: biopsy to rule out dysplasia or carcinoma; smoking cessation.

Airway stenosis: may be congenital or acquired; endoscopic dilation or resection with reconstruction.

Neck mass evaluation: fine needle aspiration is first-line; open biopsy avoided if possible.

Lymphoma: may present as neck mass; excisional biopsy preferred for diagnosis.

Thyroid nodules: ultrasound features and fine needle aspiration guide management; Bethesda categories guide surgery.

Parotid tumors: superficial parotidectomy with facial nerve preservation; avoid enucleation.

Oral cavity cancer: surgical resection with margins; adjuvant radiation for positive margins or extracapsular spread.

Laryngeal cancer: early glottic cancer may be treated with radiation or surgery; advanced disease requires multimodality therapy.

Head and neck reconstruction: free flaps (radial forearm, fibula) for complex defects; local flaps for smaller defects.

Chemoradiation: may cause mucositis, xerostomia, and dysphagia; supportive care important.

Tonsillectomy indications: recurrent throat infections, obstructive sleep apnea; bleeding is a complication.

Adenoid hypertrophy: causes nasal obstruction, mouth breathing, and otitis media with effusion; adenoidectomy may be indicated.

Cleft palate: may cause velopharyngeal insufficiency and otitis media with effusion; repair before speech development.

Laryngomalacia: most common cause of stridor in infants; usually resolves by 12-18 months; surgery for severe cases.

Subglottic hemangioma: biphasic stridor; treat with propranolol.

Foreign body aspiration: sudden choking and cough; bronchoscopy for removal.

Kawasaki disease: fever, rash, conjunctivitis, and cervical lymphadenopathy; risk of coronary aneurysms; treat with IVIG and aspirin.

Peritonsillar abscess: uvular deviation and trismus; treat with drainage and antibiotics.

Skin cancer reconstruction: basal cell carcinoma most common; Mohs surgery for head and neck lesions.

Scar revision: timing after maturation; techniques include Z-plasty and W-plasty.

Otoplasty: prominent ear correction; complications include hematoma and infection.

Blepharoplasty: removes excess eyelid skin; assess for dry eye and ptosis.

Rhinoplasty: functional and aesthetic; septal surgery may be combined.

Facial fractures: mandible most common; assess airway and cervical spine; treat with fixation.

Cleft lip and palate: multidisciplinary care; speech therapy and orthodontics.

Burns: assess airway; fluid resuscitation with Parkland formula; wound care and grafting.

Audiogram interpretation: air conduction thresholds; bone conduction thresholds; gap indicates conductive component.

Speech audiometry: speech reception threshold and word recognition score; helps assess functional hearing.

Immittance testing: tympanometry and acoustic reflexes; assesses middle ear function.

Otoacoustic emissions: screening tool; absent in sensorineural hearing loss.

Auditory brainstem response: assesses retrocochlear pathway; used in newborn screening.

Vestibular testing: electronystagmography and videonystagmography; caloric testing.

Hearing loss prevention: noise exposure and ototoxic medications.

Hearing rehabilitation: hearing aids, cochlear implants, and assistive devices.

Trauma: primary survey; airway, breathing, circulation; FAST exam for abdominal trauma.

Burns: Parkland formula for fluid resuscitation; assess airway.

Wound care: clean and debride; tetanus prophylaxis.

Hernia: inguinal most common; repair with mesh.

Appendicitis: pain migrating to right lower quadrant; McBurney point tenderness; surgery.

Bowel obstruction: nausea, vomiting, distension; imaging; surgery if strangulation.

Thyroid surgery: complications include recurrent laryngeal nerve injury and hypocalcemia.

Postoperative fever: consider atelectasis, infection, and deep vein thrombosis.

Diabetes: perioperative glucose control; monitor for hypoglycemia.

Hypertension: assess end-organ damage; continue medications perioperatively.

Asthma: optimize before surgery; avoid triggers.

Anticoagulation: bridge therapy for high-risk patients; reversal agents for bleeding.

Anemia: evaluate cause; transfuse if symptomatic.

Infection: source control and antibiotics.

Renal failure: adjust medications; monitor electrolytes.

Cardiac risk: assess with history and testing if indicated.

Mechanical ventilation: lung-protective strategies; monitor for barotrauma.

Sepsis: early antibiotics and fluids; vasopressors if needed.

ARDS: low tidal volume; prone positioning for severe cases.

Airway management: anticipate difficult airway; backup plan.

Tracheostomy: timing and technique; complications.

Nutrition: enteral feeding preferred; monitor tolerance.

Delirium: prevention and management.

Sedation: minimize; assess with sedation scales.

Embryology: branchial arches give rise to head and neck structures; pouches give glands.

Anatomy: cranial nerves; vascular supply.

Physiology: hearing and balance; olfaction and taste.

Histology: respiratory epithelium; squamous epithelium.

Pharmacology: antibiotics and steroids.

Microbiology: common pathogens.

Immunology: allergic rhinitis.

Genetics: hearing loss.

Hearing loss: conductive vs. sensorineural; mixed.

Vertigo: peripheral vs. central.

Tinnitus: evaluation and management.

Facial nerve: anatomy and disorders.

Otitis media: acute and chronic.

Cholesteatoma: diagnosis and surgery.

Otosclerosis: stapes fixation.

Vestibular disorders: BPPV, Meniere, vestibular neuritis.

Rhinosinusitis: acute and chronic.

Nasal polyps: medical and surgical management.

Epistaxis: anterior vs. posterior.

Septoplasty: indications and complications.

Fungal sinusitis: types and treatment.

Orbital complications: cellulitis and abscess.

CSF leak: diagnosis and repair.

Allergic rhinitis: testing and treatment.

Hoarseness: evaluation with laryngoscopy.

Vocal fold nodules: phonotrauma; voice therapy.

Laryngeal cancer: risk factors and treatment.

Vocal fold paralysis: unilateral vs. bilateral.

Spasmodic dysphonia: botulinum toxin.

Laryngopharyngeal reflux: lifestyle and medication.

Airway stenosis: diagnosis and treatment.

Tracheostomy: indications and complications.

Neck mass: fine needle aspiration.

Thyroid nodules: ultrasound and biopsy.

Salivary gland tumors: surgery.

Oral cavity cancer: resection and neck dissection.

Laryngeal cancer: treatment options.

Nasopharyngeal carcinoma: radiotherapy.

Reconstruction: local and free flaps.

Chemoradiation: side effects.

Otitis media: antibiotics and tubes.

Tonsillectomy: indications and complications.

Adenoidectomy: indications.

Cleft palate: repair timing.

Laryngomalacia: stridor.

Foreign body: bronchoscopy.

Kawasaki disease: IVIG and aspirin.

Peritonsillar abscess: drainage.

Skin cancer: Mohs surgery.

Scar revision: techniques.

Otoplasty: prominent ear.

Blepharoplasty: indications.

Rhinoplasty: functional and aesthetic.

Facial fractures: fixation.

Cleft lip and palate: multidisciplinary care.

Burns: fluid resuscitation.

Audiogram: air and bone conduction.

Speech audiometry: SRT and WRS.

Tympanometry: types A, B, C.

Otoacoustic emissions: screening.

Auditory brainstem response: retrocochlear.

Vestibular testing: caloric and head impulse.

Hearing rehabilitation: aids and implants.

Tinnitus: sound therapy and CBT.

Trauma: primary survey.

Burns: Parkland formula.

Wound care: debridement and tetanus.

Hernia: mesh repair.

Appendicitis: surgery.

Bowel obstruction: imaging and surgery.

Thyroid surgery: complications.

Postoperative fever: evaluate causes.