ENT
9 questionsMost commonly used tuning fork in ear examination?
Hearing loss of 65dB, what is the grade of deafness?
Which of the following conditions is least likely to be associated with sensorineural hearing loss (SNHL)?
Which of the following statements about conductive deafness is true?
Which of the following can cause unilateral sensorineural hearing loss?
What is the most common fungal cause of otomycosis?
Bullous myringitis is caused by?
What are the potential causes of myringosclerosis?
What is the term for the condition where the tympanic membrane is retracted and touches the promontory?
NEET-PG 2013 - ENT NEET-PG Practice Questions and MCQs
Question 771: Most commonly used tuning fork in ear examination?
- A. 128 Hz
- B. 256 Hz
- C. 512 Hz (Correct Answer)
- D. 1024 Hz
Explanation: ***512 Hz*** - The **512 Hz tuning fork** is the most commonly recommended and used for auditory tests like **Rinne** and **Weber** because its vibratory decay is slow enough to allow adequate testing, and it falls within the **speech frequency range**. - Its frequency is optimal for assessing both **bone conduction** and **air conduction** without introducing confusing overtones or being too low to be felt as a vibration rather than heard as a tone. *128 Hz* - A **128 Hz tuning fork** produces a strong vibratory sensation and is primarily used for **neurological examinations** to test **vibration sense**, not typically for ear examinations. - Its low frequency can be easily perceived as a **tactile vibration** through bone, making it less ideal for purely auditory assessment. *256 Hz* - While it falls within the audible range, a **256 Hz tuning fork** is less commonly used than 512 Hz for standard hearing tests. - Its vibratory tone may have a faster decay and might not provide as clear a distinction for **bone conduction** as the 512 Hz fork. *1024 Hz* - A **1024 Hz tuning fork** is a higher frequency tone, which may decay too quickly for accurate **Rinne and Weber tests**, especially when assessing subtle differences in hearing. - While audible, its higher pitch can be less representative of the critical **speech frequencies** typically evaluated in basic hearing screenings.
Question 772: Hearing loss of 65dB, what is the grade of deafness?
- A. Mild
- B. Moderate
- C. Severe
- D. Moderately severe (Correct Answer)
Explanation: ***Moderately severe*** - A hearing loss of **65 dB** falls within the range defined as moderately severe. - The moderately severe range typically spans from **56 dB to 70 dB** in conventional audiometric classifications. *Mild* - **Mild hearing loss** is characterized by a threshold between **26 dB and 40 dB**. - Individuals with mild hearing loss may struggle with soft sounds or speech in noisy environments. *Moderate* - **Moderate hearing loss** is defined by a threshold between **41 dB and 55 dB**. - This level of loss causes difficulty understanding normal conversation without amplification. *Severe* - **Severe hearing loss** is characterized by a threshold between **71 dB and 90 dB**. - Individuals with severe hearing loss often require powerful hearing aids or other assistive listening devices.
Question 773: Which of the following conditions is least likely to be associated with sensorineural hearing loss (SNHL)?
- A. Bartter syndrome
- B. Distal renal tubular acidosis (Correct Answer)
- C. Alport syndrome
- D. Nail-patella syndrome
Explanation: ***Distal renal tubular acidosis*** - While dRTA is associated with various systemic abnormalities like **nephrolithiasis** and **osteomalacia**, **sensorineural hearing loss (SNHL)** is **not a typical feature** of this condition. - The primary defect in dRTA is impaired acid secretion in the distal tubules, leading to **metabolic acidosis**. *Bartter syndrome* - This is a rare genetic disorder affecting the thick ascending limb of the loop of Henle, leading to **salt wasting** and **hypokalemia**. - **SNHL** has been reported in certain variants of Bartter syndrome, particularly in those with mutations affecting the **NKCC2 transporter** or other associated genes. *Alport syndrome* - A well-known genetic disorder characterized by **glomerulonephritis**, **SNHL**, and ocular abnormalities. - The SNHL in Alport syndrome is typically **bilateral and progressive**, often beginning in childhood. *Nail-patella syndrome* - This is an autosomal dominant disorder primarily affecting the **nails**, **kneecaps**, elbows, and kidneys, with about 30-50% of affected individuals developing **renal disease**. - **SNHL** is a recognized, albeit less common, manifestation of Nail-patella syndrome, thought to be related to abnormalities in the **collagen IV** network in the cochlea.
Question 774: Which of the following statements about conductive deafness is true?
- A. Weber's test shows no lateralization in conductive deafness.
- B. There is no decay in threshold tone in conductive deafness.
- C. Rinne's test is negative in conductive deafness. (Correct Answer)
- D. Air conduction is always completely absent in conductive deafness during Rinne's test
Explanation: ***Rinne's test is negative in conductive deafness.*** - A **negative Rinne's test** indicates that **bone conduction is heard longer or equally as long as air conduction** in the affected ear. - This occurs because the sound transmission through the middle ear is impaired due to the conductive hearing loss. *Weber's test shows no lateralization in conductive deafness.* - In unilateral conductive deafness, the **Weber's test will lateralize to the affected ear**, not show no lateralization. - This is because the sound is perceived as louder in the ear with the conductive loss due to the masking effect of ambient noise being reduced. *There is no decay in threshold tone in conductive deafness.* - **Threshold tone decay** is typically associated with **retrocochlear lesions** (sensorineural hearing loss), not conductive deafness. - Conductive hearing loss is a mechanical problem that does not affect the persistence of auditory nerve firing. *Air conduction is always completely absent in conductive deafness during Rinne's test.* - While air conduction is poorer than bone conduction (making Rinne's negative), it is **not always completely absent**. - In a profound conductive loss, air conduction might be near absent, but in milder cases, it is simply significantly reduced compared to bone conduction.
Question 775: Which of the following can cause unilateral sensorineural hearing loss?
- A. Coronavirus
- B. Pertussis
- C. Rotavirus
- D. Acoustic neuroma (Correct Answer)
Explanation: ***Acoustic neuroma*** - An **acoustic neuroma** (vestibular schwannoma) is a benign tumor that grows on the **vestibulocochlear nerve** (cranial nerve VIII), which can compress the nerve and cause progressive unilateral sensorineural hearing loss. - Other associated symptoms often include **tinnitus** and **balance disturbances** (vertigo or unsteadiness). *Coronavirus* - While some reports suggest a rare association between **COVID-19** and sudden sensorineural hearing loss due to viral inflammation or vascular compromise, it is not a common or definitive cause of progressive unilateral hearing loss. - Hearing loss directly due to coronavirus infection is typically acute and bilateral, rather than chronic and unilateral. *Pertussis* - **Pertussis** (whooping cough) is a bacterial respiratory infection that does not typically cause sensorineural hearing loss. - Complications are primarily pulmonary, neurological (e.g., seizures due to hypoxia), or nutritional, not otological. *Rotavirus* - **Rotavirus** causes severe gastroenteritis, particularly in infants and young children. - There is no established link between rotavirus infection and sensorineural hearing loss.
Question 776: What is the most common fungal cause of otomycosis?
- A. Histoplasma
- B. Rhinosporidium
- C. Aspergillus (Correct Answer)
- D. Actinomyces
Explanation: ***Aspergillus*** - **Aspergillus niger** and **Aspergillus flavus** are the most frequently isolated fungal species in cases of **otomycosis**. - These fungi thrive in warm, moist environments like the **external auditory canal** and produce spores that can cause infection. *Histoplasma* - **Histoplasma capsulatum** is associated with **histoplasmosis**, a systemic fungal infection that primarily affects the lungs. - It is not a common cause of otomycosis, as it typically causes **pulmonary and disseminated disease**, not external ear canal infections. *Rhinosporidium* - **Rhinosporidium seeberi** causes **rhinosporidiosis**, a chronic granulomatous disease that primarily affects the **mucous membranes of the nose and nasopharynx**. - While it can affect other mucous membranes, it is not a typical cause of **otomycosis**. *Actinomyces* - **Actinomyces** is a genus of **gram-positive bacteria**, not fungi, known for causing **actinomycosis**. - Actinomycosis is characterized by **abscess formation and fistulas** and does not typically present as otomycosis.
Question 777: Bullous myringitis is caused by?
- A. Haemophilus influenzae
- B. Candida
- C. Mycoplasma pneumoniae (Correct Answer)
- D. Streptococcus pneumoniae
Explanation: ***Mycoplasma pneumoniae*** - **Bullous myringitis** is characterized by the formation of **blisters** (bullae) on the **tympanic membrane**, which is a classic presentation associated with *Mycoplasma pneumoniae* infection. - While other bacteria can cause otitis media, *Mycoplasma pneumoniae* has a strong association with the development of **hemorrhagic bullae** on the eardrum. *Streptococcus pneumoniae* - This bacterium is the **most common cause** of **acute otitis media (AOM)**, but it typically presents with inflammation and bulging of the tympanic membrane **without** the characteristic bullae. - While it can cause severe ear infections, its typical presentation does not involve the **blister formation** seen in bullous myringitis. *Haemophilus influenzae* - This is another **common bacterial cause** of **acute otitis media**, especially in children, often leading to bulging and redness of the eardrum. - Similar to *Streptococcus pneumoniae*, it is not typically associated with the development of **bullae** on the tympanic membrane. *Candida* - **Candida** species are **fungi** and are a cause of **otitis externa** (ear canal infection) or, less commonly, **chronic otitis media**, particularly in immunocompromised individuals. - Fungal infections of the ear, including Candida, do **not** typically cause the characteristic **bullous myringitis** presentation.
Question 778: What are the potential causes of myringosclerosis?
- A. Genetic predisposition
- B. Chronic inflammation from recurrent infections (Correct Answer)
- C. Otosclerosis
- D. None of the options
Explanation: ***Chronic inflammation from recurrent infections*** - **Myringosclerosis** is often a consequence of **chronic inflammation** and repair processes in the tympanic membrane (eardrum), commonly triggered by **recurrent otitis media** (middle ear infections). - The inflammatory exudates and subsequent healing lead to the deposition of **calcium and phosphate crystals** within the fibrous layer of the tympanic membrane, causing it to become stiff and opaque. *Genetic predisposition* - While genetics can play a role in some ear conditions, **myringosclerosis** is primarily an **acquired condition** rather than one solely determined by genetic factors. - No specific strong genetic link has been identified as a primary cause compared to environmental triggers. *Otosclerosis* - **Otosclerosis** is a condition affecting the **ossicles** (typically the stapes) in the middle ear, leading to conductive hearing loss due to abnormal bone growth, not directly affecting the tympanic membrane. - Myringosclerosis involves the eardrum itself, characterized by **calcification of the tympanic membrane**, which is distinct from the pathology of otosclerosis. *None of the options* - This option is incorrect because **chronic inflammation from recurrent infections** is a well-established cause of myringosclerosis. - The presence of a correct answer negates this choice.
Question 779: What is the term for the condition where the tympanic membrane is retracted and touches the promontory?
- A. Mild tympanic membrane retraction
- B. Severe tympanic membrane retraction
- C. Atelectasis of the tympanic membrane (Correct Answer)
- D. Adhesive otitis media (with middle ear adhesions)
Explanation: ***Atelectasis of the tympanic membrane*** - **Atelectasis of the tympanic membrane** (TM) specifically refers to severe **retraction** where the TM collapses onto the **promontory** or other middle ear structures. - This condition indicates a significant **negative middle ear pressure**, often leading to **conductive hearing loss** and potential long-term complications if not addressed. *Mild tympanic membrane retraction* - **Mild retraction** involves the TM being drawn inward, but it does not typically make contact with the **promontory**. - This is often observed as a prominent **short process of the malleus** or a **sharper cone of light**. *Severe tympanic membrane retraction* - While **severe retraction** describes the degree of inward pulling, **atelectasis** is the more precise term when the TM actually touches the **promontory** or other middle ear structures. - The term **severe retraction** alone might not imply contact with the bony structures of the middle ear. *Adhesive otitis media (with middle ear adhesions)* - **Adhesive otitis media** involves the formation of **fibrous adhesions** within the middle ear space, often as a result of chronic inflammation, which can **fixate** the ossicles or TM. - While severe retraction can be a precursor, **adhesive otitis media** specifically refers to the presence of these **adhesions**, which are not explicitly stated in the question.
Physiology
1 questionsWhich of the following is responsible for localization of sound ?
NEET-PG 2013 - Physiology NEET-PG Practice Questions and MCQs
Question 771: Which of the following is responsible for localization of sound ?
- A. Cochlear nerve
- B. Cochlea
- C. Superior olivary nucleus (Correct Answer)
- D. Cochlear nuclei
Explanation: ***Superior olivary nucleus*** - The **superior olivary nucleus** is the first site in the auditory pathway where binaural (two-ear) input is integrated, which is crucial for **sound localization**. - It processes **interaural time differences (ITDs)** and **interaural level differences (ILDs)** to determine the horizontal position of a sound source. *Cochlear nerve* - The **cochlear nerve** transmits auditory information from the cochlea to the brainstem but does not perform the initial processing for sound localization. - It carries impulses for both ears independently, which are then integrated at higher centers. *Cochlea* - The **cochlea** is responsible for converting sound vibrations into electrical signals (transduction), encoding properties like pitch and loudness, but not directly for sound localization. - It acts as a mechanical analyzer, separating sound into its frequency components. *Cochlear nuclei* - The **cochlear nuclei** receive input solely from the ipsilateral cochlear nerve and primarily process monaural (one-ear) auditory information. - While they are a crucial relay in the auditory pathway, they do not integrate binaural cues for sound localization.