UPSC-CMS 2012 Practice Questions

Q: A fracture of the middle cranial fossa may result in an injury of the

Sixth cranial nerve. ***Sixth cranial nerve*** - The **abducens nerve (CN VI)** passes through the **Dorello's canal (or petroclival ligament)**, located in the vicinity of the middle cranial fossa. - Fractures in this region can lead to **stretching or compression** of the abducens nerve, resulting in **lateral rectus palsy** and *diplopia*. *Tenth cranial nerve* - The **vagus nerve (CN X)** exits the skull via the **jugular foramen**, located in the **posterior cranial fossa**. - Injury to this nerve is less likely with a fracture specifically confined to the middle cranial fossa. *Eighth cranial nerve* - The **vestibulocochlear nerve (CN VIII)** courses through the **internal auditory meatus** in the **petrous part of the temporal bone**, which is part of the posterior cranial fossa. - While acoustic trauma or petrous bone fractures can affect it, it's not a primary concern with general middle cranial fossa fractures. *Eleventh cranial nerve* - The **spinal accessory nerve (CN XI)** exits the skull through the **jugular foramen**, similar to the vagus nerve, placing it in the **posterior cranial fossa**. - Damage to this nerve would primarily cause weakness in the **sternocleidomastoid** and **trapezius muscles**, and is not typically associated with isolated middle cranial fossa fractures.

Q: A meningomyelocele is most commonly situated in the

Lumbosacral spine. ***Lumbosacral spine*** - The **lumbosacral region** (L5-S1) is the most frequent anatomical site for meningomyelocele due to the timing of neural tube closure. - This area is the last portion of the **neural tube** to close, making it more susceptible to defects if closure is incomplete [1]. *Thoracic spine* - While meningomyeloceles can occur in the thoracic region, it is far less common than in the lumbosacral area [1]. - Defects in the thoracic spine are usually associated with a higher level of neurological impairment [1]. *Dorsolumbar spine* - This term encompasses the lower thoracic and upper lumbar regions; while possible, it is not the most common singular site. - The lumbosacral region has a higher prevalence of meningomyelocele formation. *Cervical spine* - Meningoceles and meningomyeloceles in the cervical spine are much rarer. - These defects often present with different neurological findings compared to lumbosacral lesions, such as upper limb weakness.

Q: A pulmonary artery (Swan-Ganz) catheter measures all of the following except

Left ventricular end diastolic volume (LVEDV). ***Left ventricular end diastolic volume (LVEDV)*** - While a Swan-Ganz catheter can measure **pulmonary artery wedge pressure (PAWP)**, which is a surrogate for **left ventricular end-diastolic pressure (LVEDP)**, it cannot directly measure **left ventricular end-diastolic volume (LVEDV)**. - LVEDV requires imaging techniques like **echocardiography** or **cardiac MRI** for direct measurement. *Pulmonary artery wedge pressure (PAWP)* - The Swan-Ganz catheter can measure **PAWP**, which reflects **left atrial pressure** and, in the absence of mitral valve disease, - Is an estimate of **left ventricular end-diastolic pressure (LVEDP)**, therefore assessing left ventricular preload. *Mixed venous oxygen saturation (SvO2)* - The catheter has a fiberoptic sensor that can continuously measure **SvO2** from the pulmonary artery. - **SvO2** provides an assessment of the balance between oxygen supply and demand. *Cardiac output (CO)* - **Cardiac output** is commonly measured using the **thermodilution method** via the Swan-Ganz catheter. - A bolus of saline is injected into the right atrium, and temperature changes are detected in the pulmonary artery to calculate flow.

Q: The treatment of choice for a mastoid fracture with immediate complete facial nerve paralysis is

Nerve decompression. ***Nerve decompression*** - For a mastoid (temporal bone) fracture causing **facial nerve paralysis**, surgical **nerve decompression** is the treatment of choice when surgery is indicated. - Most cases of facial nerve paralysis from temporal bone fractures result from **nerve compression or edema** within the fallopian canal, not complete transection. - **Decompression** relieves pressure on the nerve, allowing recovery of function, and is performed via **mastoidectomy** to access the facial nerve in its intratemporal course. - Indications for surgical decompression include **immediate complete paralysis** with evidence of nerve degeneration on electrodiagnostic testing, or failed conservative management. *Mastoidectomy with nerve grafting* - **Nerve grafting** is reserved for cases where the facial nerve is **completely transected or severed**, which is rare in temporal bone fractures. - Most temporal bone trauma causes nerve injury from compression or hematoma, not complete anatomical discontinuity requiring grafting. - Grafting would only be considered after direct visualization confirms irreparable nerve transection. *Steroid therapy* - High-dose **corticosteroids** are actually the **first-line treatment** for facial nerve paralysis following temporal bone fractures, especially in cases of **delayed or incomplete paralysis**. - Steroids reduce **inflammation and edema** around the injured nerve and are often effective for **delayed-onset paralysis**. - However, they are typically used as conservative management rather than the definitive "treatment of choice" when immediate complete paralysis occurs. *Sling operation* - A **sling operation** (facial reanimation surgery) is used for **long-standing, irreversible facial paralysis** when nerve recovery is no longer possible. - It provides **static facial support** but does not restore nerve function. - This is not appropriate for acute management of traumatic facial nerve injury.

Q: Which one of the following conditions produces sensorineural deafness ?

Mixed otosclerosis. ***Mixed otosclerosis*** - **Otosclerosis** is a bone remodeling disease primarily affecting the **ossicles** and **otic capsule**. - **Mixed otosclerosis** involves both **stapes fixation (conductive component)** and **cochlear involvement (sensorineural component)**. - Among the given options, this is the **only condition that produces sensorineural hearing loss**, although it presents as a mixed hearing loss with both conductive and sensorineural components. - The **cochlear otosclerosis** component causes the sensorineural deafness through involvement of the **otic capsule** and **cochlear structures**. *Atelectatic middle ear* - This condition involves the collapse of the **tympanic membrane** onto the ossicles due to **negative middle ear pressure**. - It causes **pure conductive hearing loss** by impairing sound transmission through the middle ear, with no sensorineural component. *Eustachian tube blockage* - Blockage of the **Eustachian tube** leads to **negative pressure** in the middle ear space. - This results in **pure conductive hearing loss** due to impaired movement of the tympanic membrane and ossicles, with no sensorineural component. *Tympanic membrane rupture* - A rupture in the **tympanic membrane** creates a direct opening between the external ear canal and the middle ear. - This condition causes **pure conductive hearing loss** by disrupting the normal sound conduction mechanism, with no sensorineural component.

Q: Which is the most common laryngeal abnormality that produces laryngeal stridor in a newborn?

Laryngomalacia. ***Laryngomalacia*** - **Laryngomalacia** is the most common cause of **congenital laryngeal stridor**, accounting for 60-70% of cases. - It results from the **floppiness of supraglottic structures** (epiglottis and arytenoids) that collapse inward during inspiration, causing stridor. *Congenital vocal cord paralysis* - While it can cause stridor, **congenital vocal cord paralysis** is much less common than laryngomalacia. - It typically results from neurological issues, and the stridor quality may differ. *Congenital web* - A **congenital web** is a rare cause of stridor, usually presenting with a **high-pitched persistent stridor** and often a weak cry. - The severity depends on the extent of the web across the glottis. *Congenital subglottic stenosis* - **Congenital subglottic stenosis** is the third most common cause of congenital stridor (after laryngomalacia and vocal cord paralysis). - It is characterized by narrowing of the airway below the vocal cords and often presents with biphasic stridor and recurrent croup-like symptoms.

Q: Consider the following statements regarding HCG : 1. HCG is a glycoprotein with two subunits α and β. 2. HCG levels reach the maximum between the 60th and 70th day in a normal pregnancy. 3. HCG is secreted by the syncytiotrophoblast. Which of the statements given above is/are correct ?

1, 2 and 3. ***Correct: 1, 2 and 3*** - **Human Chorionic Gonadotropin (HCG)** is a **glycoprotein hormone** composed of **alpha (α) and beta (β) subunits**, making statement 1 correct - HCG is primarily secreted by the **syncytiotrophoblast** cells of the placenta, confirming statement 3 - In a normal pregnancy, HCG levels typically **peak between 60-70 days (8-10 weeks)** after the last menstrual period, supporting statement 2 - All three statements are factually accurate regarding HCG structure, secretion, and physiological levels *Incorrect: 2 and 3 only* - This option incorrectly excludes statement 1 about HCG being a glycoprotein with α and β subunits - The structural composition of HCG as a heterodimeric glycoprotein is a fundamental characteristic *Incorrect: 1 and 2 only* - This option incorrectly excludes statement 3 about syncytiotrophoblast being the source of HCG - The syncytiotrophoblast is the outer layer of the trophoblast responsible for HCG secretion *Incorrect: 1 and 3 only* - This option incorrectly excludes statement 2 about HCG peak timing during pregnancy - Understanding that HCG peaks at 8-10 weeks (60-70 days) is crucial for monitoring early pregnancy

Q: Which one of the following statements is not correct regarding the haemodynamic changes occurring during a pregnancy?

The systemic vascular resistance is increased. ***The systemic vascular resistance is increased*** - During normal pregnancy, **systemic vascular resistance (SVR)** actually **decreases** due to vasodilation induced by factors like **prostaglandins** and **nitric oxide**. - A decrease in systemic vascular resistance helps accommodate the increased blood volume and cardiac output, ensuring adequate perfusion to the uteroplacental unit and other organs. *The cardiac output is increased* - **Cardiac output (CO)** progressively **increases** during pregnancy, peaking in the second and third trimesters. - This increase is primarily due to a rise in both **heart rate** and **stroke volume**. *The serum colloid pressure is decreased* - **Serum colloid osmotic pressure** (oncotic pressure) **decreases** in pregnancy due to a disproportionate increase in plasma volume relative to the increase in albumin production. - This leads to **dilutional hypoalbuminemia**, contributing to physiological edema. *The stroke volume is increased* - **Stroke volume (SV)** significantly **increases** during pregnancy, driven by increased end-diastolic volume and enhanced myocardial contractility. - This rise in stroke volume is a major contributor to the overall increase in cardiac output.

Q: A multiparous patient has been diagnosed to have foetal demise on a sonographic examination at 16 weeks of pregnancy. The ideal method for termination is

High vaginal insertion of dinoprostone gel. ***High vaginal insertion of dinoprostone gel*** - **Dinoprostone gel** (PGE2) is a **prostaglandin** that softens the cervix and stimulates uterine contractions, making it an ideal agent for medical induction in cases of fetal demise, particularly in the second trimester. - Its **vaginal insertion** allows for controlled, localized delivery and absorption, promoting efficient uterine evacuation while minimizing systemic side effects. *Extra-amniotic ethacridine* - **Ethacridine lactate** is typically used for **mid-trimester abortion** by direct instillation into the extra-amniotic space. - While effective, it carries a higher risk of infection and uterine rupture compared to prostaglandin administration for fetal demise at 16 weeks. *Dilation and evacuation (D&E)* - **D&E** is a surgical procedure commonly used for **second-trimester abortions**, involving cervical dilation and surgical removal of uterine contents. - While an option, medical induction with prostaglandins is generally preferred for **fetal demise** at 16 weeks due to lower risks of uterine injury and adhesions, as well as providing a more natural expulsion process. *Hysterectomy with tubectomy* - **Hysterectomy with tubectomy** (removal of the uterus and fallopian tubes) is a major surgical procedure that is **not indicated** for termination of pregnancy due to fetal demise. - It is reserved for severe medical conditions or desires for permanent sterilization, given its irreversible nature and significant surgical risks.

Q: Which of the following local anaesthetics causes irreversible cardiac arrest if it is given intravenously ?

Bupivacaine. ***Bupivacaine*** - Bupivacaine is known for its **cardiotoxicity**, which can lead to severe and often irreversible **cardiac arrest** if inadvertently administered intravenously. - This is due to its high potency, slow dissociation from cardiac sodium channels, and increased lipid solubility, leading to prolonged cardiac depression. *Lignocaine* - While lignocaine (lidocaine) can cause cardiac toxicity in overdose, it is generally considered less cardiotoxic than bupivacaine, and cardiac arrest is more readily reversible. - It is commonly used intravenously as an antiarrhythmic, indicating a safer cardiac profile at therapeutic doses. *Cocaine* - Cocaine is a vasoconstrictor and stimulant; its primary cardiovascular effects are **tachycardia**, hypertension, and arrhythmias due to inhibition of norepinephrine reuptake, rather than direct myocardial depression leading to irreversible cardiac arrest from intravenous injection in the same manner as bupivacaine. - Cocaine toxicity can cause myocardial ischemia and infarction, but not the same profound, irreversible cardiac depression seen with bupivacaine. *Prilocaine* - Prilocaine is associated with **methemoglobinemia** as a dose-dependent side effect, especially in large doses, due to its metabolite o-toluidine. - While it can cause cardiovascular depression at very high doses, it does not have the same potent and often irreversible direct negative inotropic effects on the heart as bupivacaine.

Question 1

A fracture of the middle cranial fossa may result in an injury of the

Accepted Answer

Sixth cranial nerve

Answer

Tenth cranial nerve

Answer

Eighth cranial nerve

Answer

Eleventh cranial nerve

Question 2

A meningomyelocele is most commonly situated in the

Accepted Answer

Lumbosacral spine

Answer

Thoracic spine

Answer

Dorsolumbar spine

Answer

Cervical spine

Question 3

A pulmonary artery (Swan-Ganz) catheter measures all of the following except

Accepted Answer

Left ventricular end diastolic volume (LVEDV)

Answer

Pulmonary artery wedge pressure (PAWP)

Answer

Mixed venous oxygen saturation (SvO2)

Answer

Cardiac output (CO)

Question 4

The treatment of choice for a mastoid fracture with immediate complete facial nerve paralysis is

Accepted Answer

Nerve decompression

Answer

Sling operation

Answer

Steroid therapy

Answer

Mastoidectomy with nerve grafting

Question 5

Which one of the following conditions produces sensorineural deafness ?

Accepted Answer

Mixed otosclerosis

Answer

Atelectatic middle ear

Answer

Eustachian tube blockage

Answer

Tympanic membrane rupture

Question 6

Which is the most common laryngeal abnormality that produces laryngeal stridor in a newborn?

Accepted Answer

Laryngomalacia

Answer

Congenital vocal cord paralysis

Answer

Congenital web

Answer

Congenital subglottic stenosis

Question 7

Consider the following statements regarding HCG :

1. HCG is a glycoprotein with two subunits α and β.

2. HCG levels reach the maximum between the 60th and 70th day in a normal pregnancy.

3. HCG is secreted by the syncytiotrophoblast.
Which of the statements given above is/are correct ?

Accepted Answer

1, 2 and 3

Answer

2 and 3 only

Answer

1 and 2 only

Answer

1 and 3 only

Question 8

Which one of the following statements is not correct regarding the haemodynamic changes occurring during a pregnancy?

Accepted Answer

The systemic vascular resistance is increased

Answer

The cardiac output is increased

Answer

The serum colloid pressure is decreased

Answer

The stroke volume is increased

Question 9

A multiparous patient has been diagnosed to have foetal demise on a sonographic examination at 16 weeks of pregnancy. The ideal method for termination is

Accepted Answer

High vaginal insertion of dinoprostone gel

Answer

Extra-amniotic ethacridine

Answer

Dilation and evacuation (D&E)

Answer

Hysterectomy with tubectomy

Question 10

Which of the following local anaesthetics causes irreversible cardiac arrest if it is given intravenously ?

Accepted Answer

Bupivacaine

Answer

Lignocaine

Answer

Cocaine

Answer

Prilocaine

UPSC-CMS 2012

Anatomy

Anesthesiology

ENT

Obstetrics and Gynecology

Pharmacology