MBBS ENT Flashcards

24 sample cards from the ENT deck

Sampled from the end of the deck, so these are different cards from the ones shown on the syllabus page.

1. Differentiate vestibular neuritis from labyrinthitis.

   Vestibular neuritis is inflammation of the vestibular nerve causing acute prolonged vertigo WITHOUT hearing loss. Labyrinthitis involves the whole labyrinth, causing vertigo WITH hearing loss and sometimes tinnitus.

2. What is presbycusis and its typical audiometric pattern?

   Age-related, bilateral, symmetrical sensorineural hearing loss from degeneration of cochlear hair cells. The audiogram classically shows a high-frequency sloping loss, with difficulty understanding speech especially in background noise.

3. Define the decibel severity grades of hearing loss commonly used.

   Normal $\leq 25\,\text{dB HL}$; mild $26$-$40\,\text{dB}$; moderate $41$-$55\,\text{dB}$; moderately severe $56$-$70\,\text{dB}$; severe $71$-$90\,\text{dB}$; profound $> 90\,\text{dB}$.

4. What is the characteristic audiogram finding of noise-induced hearing loss?

   A sensorineural notch (dip) in the audiogram at $4000\,\text{Hz}$ (the '4 kHz notch'), often with later recovery at higher frequencies, due to damage of outer hair cells from chronic loud noise exposure.

5. What are ototoxic drugs and give three examples of drug classes.

   Drugs that damage the cochlea and/or vestibular system causing sensorineural hearing loss, tinnitus or vertigo. Examples: aminoglycoside antibiotics (e.g. gentamicin), loop diuretics (furosemide), platinum chemotherapy (cisplatin), and high-dose salicylates/quinine.

6. Compare conductive and sensorineural hearing loss in terms of lesion site.

   Conductive loss arises from the external or middle ear (canal, eardrum, ossicles) impairing sound transmission. Sensorineural loss arises from the cochlea (hair cells) or the auditory nerve/central pathway impairing transduction or neural conduction.

7. Name the three turbinates (conchae) of the lateral nasal wall and what drains beneath the middle turbinate.

   Superior, middle and inferior turbinates. The middle meatus (under the middle turbinate) receives drainage from the frontal, maxillary, and anterior ethmoid sinuses via the osteomeatal complex; the nasolacrimal duct drains into the inferior meatus.

8. What is the blood supply forming Little's area (Kiesselbach's plexus) on the nasal septum?

   An anastomosis of the anterior ethmoidal artery, sphenopalatine artery, greater palatine artery, and superior labial artery on the antero-inferior nasal septum. It is the commonest site of anterior epistaxis.

9. What instrument and view are used in anterior nasal examination?

   A Thudichum's (or Vienna) nasal speculum with a headlight allows anterior rhinoscopy to inspect the nasal septum, turbinates, and floor; nasal endoscopy gives a more complete view of posterior structures and the postnasal space.

10. List four common causes of nasal obstruction.

    Deviated nasal septum, hypertrophied (inferior) turbinates, nasal polyps, allergic/non-allergic rhinitis, adenoid hypertrophy (in children), and foreign bodies or tumours.

11. What are nasal polyps and a key association to remember in adults and children?

    Benign oedematous swellings of inflamed nasal/sinus mucosa, appearing as pale grey mobile insensate masses. In adults associated with chronic rhinosinusitis, asthma and aspirin sensitivity (Samter's triad). In children, unilateral polyp warrants exclusion of cystic fibrosis.

12. Define acute versus chronic rhinosinusitis by duration.

    Acute rhinosinusitis: symptoms (nasal blockage, discharge, facial pain/pressure, reduced smell) lasting < 4 weeks (often < 12 weeks with complete resolution). Chronic rhinosinusitis: symptoms persisting $\geq 12$ weeks.

13. Which sinus is most commonly affected in sinusitis and which bacteria are typical?

    The maxillary sinus is most commonly affected (poor dependent drainage). Typical bacteria: Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis - the same as acute otitis media.

14. List dangerous complications of acute sinusitis.

    Orbital cellulitis/abscess (especially from ethmoid sinusitis), cavernous sinus thrombosis, osteomyelitis (Pott's puffy tumour from frontal sinusitis), meningitis, and intracranial abscess.

15. Differentiate anterior from posterior epistaxis in terms of source and severity.

    Anterior epistaxis arises from Little's area (Kiesselbach's plexus), is common, usually mild and visible/controllable. Posterior epistaxis arises from the sphenopalatine artery branches, is more common in elderly/hypertensive patients, heavier, harder to control and risks airway compromise.

16. Outline the stepwise management of acute epistaxis.

    First aid: sit forward, pinch the soft part of the nose for 10-15 minutes, ice. If continuing: identify the bleeding point and apply topical vasoconstrictor; cautery (silver nitrate or electrocautery) for visible anterior point; anterior nasal packing; posterior packing/balloon for posterior bleeds; arterial ligation or embolisation (e.g. sphenopalatine artery) if refractory.

17. What instrument provides the standard examination of the larynx and what does it visualise?

    Indirect laryngoscopy with a laryngeal mirror, or more commonly flexible fibreoptic nasendoscopy/videostroboscopy. It visualises the vocal cords (folds), arytenoids, epiglottis, vallecula and piriform fossae, and assesses cord mobility.

18. Describe the sensory and motor innervation of the larynx by branches of the vagus.

    Superior laryngeal nerve: external branch motor to cricothyroid muscle, internal branch sensory above the vocal cords. Recurrent laryngeal nerve: motor to all other intrinsic laryngeal muscles and sensory below the vocal cords.

19. What happens to the voice with unilateral versus bilateral recurrent laryngeal nerve palsy?

    Unilateral palsy: hoarse, breathy voice (cord lies in paramedian position); usually voice compensates. Bilateral palsy: cords lie close to midline causing stridor and airway obstruction (may need tracheostomy), but voice may be relatively preserved.

20. What are vocal cord nodules and how do they differ from polyps?

    Nodules are bilateral, symmetric, callus-like lesions at the junction of the anterior one-third and posterior two-thirds of the vocal cords from chronic voice overuse ('singer's nodules'); managed with voice therapy. Polyps are usually unilateral, often related to a single phonotrauma event or smoking, and frequently need surgical removal.

21. What is laryngopharyngeal reflux (LPR) and how does it differ from classic GERD?

    LPR ('silent reflux') is retrograde flow of gastric contents reaching the larynx/pharynx, causing hoarseness, chronic throat clearing, globus sensation, cough and posterior laryngeal inflammation. Unlike GERD, heartburn is often absent and symptoms are predominantly upright/daytime; managed with PPIs, diet and lifestyle.

22. Define stridor and distinguish inspiratory, expiratory, and biphasic stridor by site of obstruction.

    Stridor is a high-pitched noise from turbulent airflow through a narrowed airway. Inspiratory stridor = obstruction above the glottis (supraglottic/laryngeal). Expiratory stridor = lower tracheal/bronchial obstruction. Biphasic stridor = obstruction at the glottis or subglottis/trachea (fixed narrowing).

23. List a differential of neck masses by location and a useful rule about midline versus lateral masses.

    Midline: thyroglossal cyst (moves with tongue protrusion), thyroid swelling (moves with swallowing), dermoid. Lateral: lymphadenopathy (commonest), branchial cyst (upper anterior triangle), carotid body tumour, salivary gland tumour. Rule of thumb: a neck lump persisting > 3 weeks in an adult, especially > 40 or a smoker, is metastatic squamous carcinoma until proven otherwise.

24. What are the key post-operative complications of thyroidectomy and the role of parathyroid glands?

    Complications: recurrent laryngeal nerve injury (hoarseness/airway), external superior laryngeal nerve injury (voice fatigue), hypocalcaemia from inadvertent removal/devascularisation of the four parathyroid glands, haematoma (airway emergency), and thyroid storm. The parathyroids secrete PTH which raises serum calcium; their damage causes hypocalcaemia with tetany (Chvostek's and Trousseau's signs).

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