Diseases of the Larynx — MCQs

Diseases of the Larynx Indian Medical PG Practice Questions and MCQs

Question 71: Cadeveric position of vocal cords after thyroidectomy is typically due to which of the following?

A. Unilateral recurrent laryngeal nerve paralysis.
B. Bilateral recurrent laryngeal nerve paralysis. (Correct Answer)
C. Unilateral external laryngeal nerve paralysis.
D. Bilateral external laryngeal nerve paralysis.

Explanation: **Explanation:** The position of the vocal cords is determined by the balance of intrinsic laryngeal muscles. In **Bilateral Recurrent Laryngeal Nerve (RLN) paralysis**, all intrinsic muscles of the larynx are paralyzed except for the cricothyroid (supplied by the external laryngeal nerve). The cricothyroid acts as a tensor and slight adductor. When both RLNs are severed (often during extensive thyroid surgery), the cords lose their motor supply and assume the **cadaveric position**—a neutral, mid-abducted position (approx. 3.5mm from the midline) where they are neither fully open nor closed. **Analysis of Options:** * **Option A (Unilateral RLN paralysis):** The affected cord typically assumes a **paramedian position** (1.5mm from midline) because the intact cricothyroid muscle on the same side adducts it slightly. The patient presents with hoarseness but a safe airway. * **Option C & D (External Laryngeal Nerve paralysis):** This nerve supplies the cricothyroid muscle. Paralysis leads to a loss of tension in the vocal cords, resulting in a **wavy/zigzag appearance** and inability to produce high-pitched sounds, but does not result in a cadaveric position. **NEET-PG High-Yield Pearls:** 1. **Semon’s Law:** States that in progressive RLN lesions, abductor fibers (posterior cricoarytenoid) are more vulnerable and paralyzed before adductor fibers. 2. **Wagner and Grossman Hypothesis:** Explains that if the Superior Laryngeal Nerve is intact, the cricothyroid muscle keeps the paralyzed cord in a paramedian position; if both SLN and RLN are gone, the cord moves to the cadaveric position. 3. **Clinical Emergency:** Bilateral RLN injury is a surgical emergency because the cords may eventually fall into a paramedian position, causing acute airway obstruction (stridor) requiring tracheostomy.

Question 72: Rienke's edema in the vocal cord is a condition affecting which layer?

A. Mucosal
B. Submucosal (Correct Answer)
C. Muscular layer
D. All layers

Explanation: **Explanation:** Reinke’s edema is a clinical condition characterized by the accumulation of gelatinous fluid in the **Reinke’s space**. To understand why the correct answer is the **submucosal layer**, one must look at the microanatomy of the vocal fold (Hirano’s Layer Structure). The vocal fold consists of five layers. The outermost is the stratified squamous epithelium (Mucosa). Immediately beneath this lies the **Lamina Propria**, which is divided into three parts: 1. **Superficial Layer (Reinke’s Space):** This is a potential space composed of loose areolar tissue. 2. **Intermediate Layer** 3. **Deep Layer** Reinke’s edema specifically involves the **Superficial Lamina Propria**, which is histologically part of the **submucosal** structure of the vocal cord. **Analysis of Options:** * **A. Mucosal:** While the epithelium covers the edema, the pathology (fluid accumulation) occurs beneath the basement membrane, not within the epithelial cells themselves. * **C. Muscular layer:** The Thyroarytenoid (vocalis) muscle lies deep to the lamina propria and is not involved in the edematous process of Reinke’s. * **D. All layers:** The condition is localized to the superficial lamina propria; it does not infiltrate the vocal ligament or the muscle. **High-Yield Clinical Pearls for NEET-PG:** * **Etiology:** Strongly associated with **chronic smoking** and vocal abuse (often seen in middle-aged women). * **Clinical Feature:** Presents with a characteristic **low-pitched, "husky" voice**. * **Appearance:** Bilateral, diffuse, "bag-like" swelling of the vocal cords. * **Treatment:** Smoking cessation is mandatory. Surgical management involves a "stringing" procedure or **decortication** (stripping of the vocal cord mucosa).

Question 73: A one-day-old neonate presents with a weak cry since birth and biphasic stridor, suggestive of incomplete canalisation. What is the most common site of this defect?

A. Supraglottic
B. Subglottic
C. Glottic (Correct Answer)
D. Hypopharynx

Explanation: ### Explanation The clinical presentation of a neonate with a **weak cry** and **biphasic stridor** since birth, specifically mentioning **incomplete canalisation**, points towards a **Laryngeal Web**. **1. Why Glottic is Correct:** Laryngeal webs result from the failure of the larynx to recanalize during the 10th week of intrauterine life. The **glottis (vocal cords)** is the most common site for this defect, accounting for approximately **75% of cases**. Because the web involves the vocal cords, it interferes with phonation (leading to a weak or muffled cry) and narrows the airway (causing stridor). **2. Analysis of Incorrect Options:** * **Supraglottic:** While congenital anomalies like laryngomalacia occur here, webs are rare in this region. Supraglottic lesions typically present with inspiratory stridor and a normal cry. * **Subglottic:** This is the second most common site for congenital narrowing (e.g., Subglottic Stenosis), but it is not the primary site for defects of "incomplete canalisation" (webs). Subglottic lesions usually present with a normal cry but significant biphasic stridor. * **Hypopharynx:** This area is part of the pharynx, not the larynx. Obstructions here usually present with feeding difficulties or muffled voice (hot potato voice) rather than true laryngeal stridor. **3. Clinical Pearls for NEET-PG:** * **Most common congenital anomaly of larynx:** Laryngomalacia (presents with inspiratory stridor). * **Most common site of Laryngeal Web:** Glottis (specifically the anterior commissure). * **Triad of Laryngeal Web:** Weak cry/hoarseness, croup-like cough, and varying degrees of respiratory obstruction (stridor). * **Association:** Large glottic webs may be associated with **Shprintzen syndrome (22q11.2 deletion)**. * **Management:** Small webs may require no treatment; thick webs require endoscopic laser excision or placement of a Silastic keel.

Question 74: In a case of glottic carcinoma with fully mobile cords, what is the treatment of choice?

A. Total laryngectomy
B. Radiotherapy (Correct Answer)
C. Hemilaryngectomy
D. Chemotherapy

Explanation: ### Explanation **1. Why Radiotherapy is the Correct Answer:** Glottic carcinoma with **fully mobile vocal cords** corresponds to **Stage T1** (limited to vocal cords) or **T2** (extension to supraglottis/subglottis with normal mobility). For early-stage glottic cancer (T1 and T2), the primary goal is **cure with organ preservation**. Radiotherapy (RT) is the treatment of choice because it offers excellent local control rates (85-95% for T1) while providing a **superior functional voice quality** compared to surgical options. In modern practice, Transoral Laser Microsurgery (TLM) is also an equivalent alternative, but RT remains the classic gold standard for preserving the mucosal wave of the vocal cord. **2. Why Other Options are Incorrect:** * **A. Total Laryngectomy:** This is reserved for advanced stages (T3 with fixed cords or T4a with cartilage destruction). It is far too radical for early disease where the larynx can be saved. * **C. Hemilaryngectomy:** This is a type of partial laryngectomy. While oncologically sound, it results in a poorer voice quality compared to RT and involves a more invasive surgical recovery. It is usually reserved for RT failures or specific anatomical contraindications. * **D. Chemotherapy:** Chemotherapy is not used as a standalone curative treatment for glottic cancer. It is typically used as "induction" or "concurrent" therapy with RT for organ preservation in advanced (Stage III/IV) cases. **3. High-Yield Clinical Pearls for NEET-PG:** * **Staging Key:** Mobile cords = T1/T2; Fixed cords = T3. * **Most Common Site:** The glottis is the most common site for laryngeal cancer (60-65%). * **Lymphatic Spread:** Glottic cancers have a **low rate of nodal metastasis** due to the sparse lymphatic drainage of the true vocal cords (Reinke’s space). * **Prognosis:** Glottic cancer has the best prognosis among all laryngeal cancers because it presents early with hoarseness.

Question 75: Which of the following is the gold standard test for Laryngopharyngeal Reflux?

A. 24 hour double probe pH monitoring (Correct Answer)
B. Esophageal biopsy
C. Abnormal esophageal radiography (Barium Swallow)
D. Esophageal motility studies

Explanation: **Explanation:** **Laryngopharyngeal Reflux (LPR)**, often called "silent reflux," occurs when gastric contents travel past the upper esophageal sphincter (UES) into the larynx and pharynx. Unlike GERD, LPR primarily affects the respiratory epithelium, which is highly sensitive to pepsin and acid. **Why Option A is Correct:** The **24-hour double-probe pH monitoring** is the **Gold Standard** for diagnosing LPR. It utilizes two sensors: one placed above the Lower Esophageal Sphincter (LES) and a second "proximal" probe placed in the hypopharynx (above the UES). This allows clinicians to confirm that acidic contents are actually reaching the laryngeal tissues, rather than just remaining in the esophagus. **Why Other Options are Incorrect:** * **Option B (Esophageal biopsy):** This is used to diagnose Barrett’s esophagus or eosinophilic esophagitis. It does not provide information about the retrograde flow of acid into the larynx. * **Option C (Barium Swallow):** While it can detect structural abnormalities (like strictures or hiatal hernia), it has very low sensitivity for detecting transient reflux episodes. * **Option D (Motility studies):** Manometry is used to diagnose primary esophageal motility disorders (like Achalasia cardia) but cannot confirm the presence of acid reflux. **High-Yield Clinical Pearls for NEET-PG:** * **Most common symptom of LPR:** Globus pharyngeus (sensation of a lump in the throat). * **Most common sign on Laryngoscopy:** Interarytenoid erythema/pachydermia (thickening of the posterior commissure). * **Reflux Finding Score (RFS):** A clinical tool used during endoscopy to quantify LPR severity. * **Treatment:** LPR requires more aggressive and longer treatment than GERD (twice-daily PPIs for 3–6 months).

Question 76: In bilateral recurrent laryngeal nerve palsy, which of the following is seen?

A. Hoarseness, dyspnea, and stridor
B. Dyspnea and stridor with a normal voice (Correct Answer)
C. Inhalation of food and a feeble voice
D. Hoarseness and dyspnea

Explanation: In **Bilateral Recurrent Laryngeal Nerve (RLN) Palsy**, both vocal cords typically assume a **median or paramedian position**. This occurs because the cricothyroid muscle (supplied by the Superior Laryngeal Nerve) remains intact and acts as an adductor, pulling the cords toward the midline. ### Why Option B is Correct: * **Dyspnea and Stridor:** Because both cords are fixed near the midline, the glottic airway is severely narrowed. This leads to significant inspiratory stridor and respiratory distress (dyspnea), often requiring an emergency tracheostomy. * **Normal Voice:** Since the vocal cords are closely approximated (adducted), they can still vibrate against each other effectively during phonation. Consequently, the patient’s voice often remains surprisingly good or near-normal. ### Why Other Options are Incorrect: * **Option A & D:** Hoarseness is characteristic of **unilateral** RLN palsy (where one cord cannot meet the other) or late-stage bilateral palsy. In acute bilateral palsy, the airway is the primary concern, not the voice quality. * **Option C:** Inhalation of food (aspiration) and a feeble voice are features of **Bilateral Combined Paralysis** (involving both RLN and Superior Laryngeal Nerves). In such cases, the cords are in the "cadaveric" position (further apart), leading to a total loss of glottic protection and inability to phonate. ### High-Yield Clinical Pearls for NEET-PG: * **Most common cause:** Thyroid surgery (iatrogenic injury). * **Semon’s Law:** States that in progressive lesions of the RLN, the abductor fibers are injured before the adductor fibers. * **Position of cords:** In isolated RLN palsy, cords are **paramedian**. In combined (RLN + SLN) palsy, cords are **cadaveric** (mid-abduction). * **Management:** Acute cases often require **tracheostomy**. Definitive surgical options include **Kashima’s operation** (posterior cordectomy) or Woodman’s medialization.

Question 77: After laryngectomy, from where is dynamic esophageal voice produced?

A. Oral cavity
B. Pharynx and esophagus (Correct Answer)
C. Trachea
D. Pharynx

Explanation: **Explanation:** After a total laryngectomy, the natural sound source (the larynx) is removed, and the trachea is diverted to a permanent stoma. To regain speech, patients can learn **Esophageal Voice**, a technique where air is swallowed or "injected" into the upper esophagus and then expelled in a controlled manner. **Why Option B is correct:** The sound is produced at the **Pharyngoesophageal (PE) segment**, which acts as a "neoglottis." As air is expelled from the esophagus, it causes the mucosal folds of the **cricopharyngeal sphincter** and the lower **pharyngeal constrictors** to vibrate. Therefore, the voice is dynamically produced by the interaction between the **esophagus** (the air reservoir) and the **pharynx** (the vibratory source). **Why other options are incorrect:** * **A. Oral cavity:** The oral cavity acts as an articulator (forming words), but it cannot act as the primary sound generator. * **C. Trachea:** In a total laryngectomy, the trachea is physically disconnected from the pharynx/mouth. Air from the trachea exits through the stoma and cannot reach the mouth to produce esophageal voice. * **D. Pharynx:** While the pharyngeal muscles are involved in vibration, the esophagus is essential as the air reservoir. Option B is more comprehensive. **High-Yield Clinical Pearls for NEET-PG:** * **PE Segment:** The cricopharyngeus muscle is the most important component of the vibratory segment. * **Success Rate:** Esophageal speech is difficult to master; only about 25-30% of patients become fluent. * **Tracheoesophageal Puncture (TEP):** This is currently the "Gold Standard" for post-laryngectomy rehabilitation. It uses a one-way valve (e.g., Blom-Singer prosthesis) to divert tracheal air into the esophagus for better voice quality than simple esophageal speech. * **Electrolarynx:** An external device used by patients who cannot master TEP or esophageal speech.

Question 78: In acute epiglottitis, what is the common cause of death?

A. Acidosis
B. Respiratory obstruction (Correct Answer)
C. Atelectasis
D. Laryngospasm

Explanation: **Explanation:** **Acute Epiglottitis** (Supraglottitis) is a life-threatening medical emergency characterized by rapid inflammation and edema of the epiglottis and surrounding supraglottic structures. **Why Respiratory Obstruction is the Correct Answer:** The primary cause of death in acute epiglottitis is **acute respiratory obstruction**. The supraglottic tissues (epiglottis, aryepiglottic folds) are loosely attached and highly vascular. Rapid inflammatory edema can lead to a "ball-valve" effect, where the swollen epiglottis is sucked into the laryngeal inlet during inspiration, causing total airway occlusion. This can progress from mild stridor to complete obstruction within minutes to hours. **Analysis of Incorrect Options:** * **Acidosis:** While respiratory acidosis occurs secondary to CO2 retention during respiratory failure, it is a metabolic consequence rather than the primary mechanism of death. * **Atelectasis:** This is a chronic or subacute complication of bronchial obstruction or lung collapse; it does not cause the rapid, sudden death seen in epiglottitis. * **Laryngospasm:** This involves the involuntary contraction of the vocal cords (glottis). In epiglottitis, the obstruction is **supraglottic** (mechanical swelling) rather than a primary spasm of the intrinsic laryngeal muscles. **High-Yield Clinical Pearls for NEET-PG:** * **Causative Agent:** Historically *Haemophilus influenzae* type b (Hib), though incidence has decreased due to vaccination. * **Clinical Presentation:** The "4 Ds"—**D**rooling, **D**ysphagia, **D**ysphonia, and **D**istress (Stridor). Patients often assume the **"Tripod position"** to maintain the airway. * **X-ray Finding:** Lateral neck X-ray shows the **"Thumb sign"** (swollen epiglottis). * **Management Gold Standard:** Secure the airway first (intubation or tracheostomy). **Never** examine the throat with a tongue depressor in a non-controlled setting, as it can trigger fatal laryngospasm/obstruction.

Question 79: Maximum stridor is seen in which condition of vocal cord paralysis?

A. Unilateral incomplete paralysis
B. Bilateral incomplete paralysis (Correct Answer)
C. Unilateral complete paralysis
D. Bilateral complete paralysis

Explanation: ### Explanation The severity of stridor in vocal cord paralysis is determined by the **position of the vocal cords** and the resulting width of the glottic chink. **1. Why Bilateral Incomplete Paralysis is Correct:** In "incomplete" paralysis (specifically **Bilateral Abductor Paralysis**), the vocal cords are paralyzed in the **median or paramedian position**. Because the adductors (Cricoarytenoids) are often more resilient or affected differently than abductors (Semon’s Law), the cords remain tightly apposed in the midline. This results in a **critically narrowed airway**, leading to maximum inspiratory stridor and acute respiratory distress, even though the voice may remain relatively normal. **2. Analysis of Incorrect Options:** * **Unilateral Incomplete Paralysis:** The unaffected cord can still abduct sufficiently to maintain an adequate airway. Stridor is usually absent at rest. * **Unilateral Complete Paralysis:** The paralyzed cord assumes a **cadaveric position** (midway between midline and full abduction). The healthy cord compensates, preventing significant airway obstruction. The primary symptom here is hoarseness, not stridor. * **Bilateral Complete Paralysis:** Both cords lie in the **cadaveric position**. While the airway is reduced, the gap between the cords is significantly wider than in the paramedian position of incomplete paralysis. Patients experience moderate exertional dyspnea and a "breathy" voice, but the stridor is less intense than in the bilateral incomplete variety. ### Clinical Pearls for NEET-PG: * **Semon’s Law:** States that in progressive lesions of the recurrent laryngeal nerve, abductors (Posterior Cricoarytenoid) are paralyzed before the adductors. * **Wagner and Grossman Hypothesis:** Suggests that if the Superior Laryngeal Nerve is intact, the Cricothyroid muscle keeps the cord in a paramedian position. * **Management:** Bilateral abductor paralysis is a medical emergency often requiring immediate **Tracheostomy** to bypass the obstruction.

Question 80: What is the antibiotic of choice in acute epiglottitis pending culture sensitivity reports?

A. Erythromycin
B. Rolitetracycline
C. Doxycycline
D. Ampicillin (Correct Answer)

Explanation: **Explanation:** **Acute Epiglottitis** is a life-threatening emergency characterized by rapid inflammation of the epiglottis and supraglottic structures. Historically, the most common causative organism is ***Haemophilus influenzae* type b (Hib)**. **1. Why Ampicillin is the Correct Choice:** In the context of standard textbooks (like Dhingra) and traditional NEET-PG patterns, **Ampicillin** is considered the drug of choice for empirical management. It is highly effective against *H. influenzae*, which is the primary pathogen. While many modern guidelines suggest third-generation cephalosporins (like Ceftriaxone) due to rising beta-lactamase resistance, Ampicillin remains the classic "textbook" answer for this condition in the absence of resistance data. **2. Analysis of Incorrect Options:** * **Erythromycin (A):** This is a macrolide primarily used for *Legionella*, *Mycoplasma*, or Diphtheria. It does not provide adequate coverage for the aggressive Gram-negative nature of *H. influenzae*. * **Rolitetracycline (B) & Doxycycline (C):** Tetracyclines are generally bacteriostatic and are not indicated for acute, life-threatening airway infections like epiglottitis. They are also contraindicated in children (the primary demographic) due to effects on bone and teeth. **3. Clinical Pearls for NEET-PG:** * **Cardinal Signs:** The "3 Ds" – **D**rooling, **D**yspnea, and **D**ysphagia. * **X-ray Finding:** Lateral neck X-ray shows the **"Thumb sign"** (swollen epiglottis). * **Management Priority:** The first priority is **airway maintenance** (intubation or tracheostomy). Never examine the throat with a tongue depressor as it can trigger fatal laryngospasm. * **Modern Trend:** If Ampicillin/Amoxicillin resistance is suspected, **Ceftriaxone** is the preferred modern alternative.

Practice by Chapter

Acute Laryngitis

Practice Questions

Chronic Laryngitis

Practice Questions

Vocal Cord Nodules and Polyps

Practice Questions

Reinke's Edema

Practice Questions

Laryngeal Papillomatosis

Practice Questions

Vocal Cord Paralysis

Practice Questions

Laryngeal Trauma

Practice Questions

Laryngeal Stenosis

Practice Questions

Laryngeal Cancer

Practice Questions

Laryngomalacia

Practice Questions

Epiglottitis

Practice Questions

Voice Disorders

Practice Questions

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