Internal Medicine
1 questionsWhich of the following is NOT typically seen in 3rd nerve palsy?
NEET-PG 2012 - Internal Medicine NEET-PG Practice Questions and MCQs
Question 731: Which of the following is NOT typically seen in 3rd nerve palsy?
- A. Mydriasis
- B. Ptosis
- C. Loss of abduction (Correct Answer)
- D. Loss of light reflex
Explanation: ***Loss of abduction*** - The **oculomotor nerve (CN III)** controls adduction, elevation, and depression of the eye, but **not abduction**. [2] - **Abduction** is primarily controlled by the **abducens nerve (CN VI)**, so its loss would indicate a CN VI palsy. *Mydriasis* - The **oculomotor nerve (CN III)** innervates the **parasympathetic fibers** to the pupillary constrictor muscles. [3] - Palsy of these fibers leads to unopposed action of the sympathetic dilator muscles, causing **mydriasis (pupil dilation)**. [4] *Ptosis* - The **oculomotor nerve (CN III)** innervates the **levator palpebrae superioris muscle**, which lifts the eyelid. - Dysfunction of this nerve leads to **ptosis (drooping of the eyelid)**. [1] *Loss of light reflex* - The **efferent pathway** for the **pupillary light reflex** travels via the **oculomotor nerve (CN III)** to constrict the pupil. [3] - A 3rd nerve palsy, particularly affecting the parasympathetic fibers, **impairs pupillary constriction**, resulting in a loss of the direct and consensual light reflex in the affected eye. [4]
Ophthalmology
5 questionsWhich muscle is the earliest to be involved in thyroid ophthalmopathy?
What is the treatment of choice for amblyopia?
Most common orbital tumor has its origin from?
What is the most common cause of intermittent proptosis in adults?
Satellite nodules are typically associated with which of the following conditions?
NEET-PG 2012 - Ophthalmology NEET-PG Practice Questions and MCQs
Question 731: Which muscle is the earliest to be involved in thyroid ophthalmopathy?
- A. Medial Rectus (MR)
- B. Inferior Rectus (IR) (Correct Answer)
- C. Superior Rectus (SR)
- D. Lateral Rectus (LR)
Explanation: ***Inferior Rectus (IR)*** - The **inferior rectus muscle** is most commonly and earliest affected in **thyroid ophthalmopathy** due to its anatomical location and muscle fiber type, making it highly susceptible to inflammation and edema. - Involvement of the inferior rectus leads to restricted **upward gaze** and **diplopia**, which are characteristic early symptoms of thyroid eye disease. *Medial Rectus (MR)* - While the **medial rectus** is often involved in thyroid ophthalmopathy, it is typically affected *after* the inferior rectus. - Dysfunction of the medial rectus manifests as difficulty with **adduction** (moving the eye inwards). *Superior Rectus (SR)* - The **superior rectus** is less frequently and usually later involved compared to the inferior and medial rectus muscles. - Its involvement typically causes restricted **downward gaze**. *Lateral Rectus (LR)* - The **lateral rectus** muscle is the *least common* ocular muscle to be affected in thyroid ophthalmopathy. - When affected, it primarily causes difficulty with **abduction** (moving the eye outwards).
Question 732: What is the treatment of choice for amblyopia?
- A. Corrective spectacles
- B. Surgical intervention
- C. Occlusion therapy (Correct Answer)
- D. Convergent exercises for vision therapy
Explanation: ***Occlusion therapy*** - **Occlusion therapy** involves patching the stronger eye to force the weaker, amblyopic eye to work harder, thereby strengthening its neural connections. - This treatment is most effective when initiated during the **critical period of visual development** in childhood. *Corrective spectacles* - While essential for addressing **refractive errors** that may contribute to amblyopia, spectacles alone are often insufficient to resolve the amblyopia. - Spectacles primarily optimize the image quality on the retina, but don't directly address the **cortical suppression** of the amblyopic eye. *Surgical intervention* - **Surgical intervention** is typically reserved for correcting structural issues like **strabismus** (misalignment of the eyes) that contribute to amblyopia. - Surgery for strabismus aims to align the eyes, which can then be followed by occlusion therapy or other treatments to address the functional amblyopia. *Convergent exercises for vision therapy* - **Vision therapy exercises**, including convergent exercises, may be used as an adjunct to occlusion therapy or in cases of **convergence insufficiency**. - However, they are not the primary or solitary treatment of choice for amblyopia, which requires direct stimulation of the amblyopic eye.
Question 733: Most common orbital tumor has its origin from?
- A. Blood vessels (Correct Answer)
- B. Nerves
- C. Muscle
- D. Lymph node
Explanation: ***Blood vessels*** - The most common orbital tumor in childhood is a **capillary hemangioma**, which originates from blood vessels. - In adults, the most common primary orbital tumor is an orbital varix, also a **vascular lesion**. *Nerves* - Tumors of neural origin, such as **optic nerve gliomas** or **meningiomas**, are less common than vascular tumors. - While significant, they do not represent the *most* common overall origin for orbital tumors. *Muscle* - Tumors originating from muscle, such as **rhabdomyosarcoma** in children (a malignant tumor), are relatively rare. - **Pseudotumor** (idiopathic orbital inflammation), though common, is an inflammatory condition, not a true neoplasm of muscle origin. *Lymph node* - Tumors of lymphoid origin, such as **lymphomas**, are malignant and can occur in the orbit. - However, they are not the most common primary orbital tumor compared to those of vascular origin.
Question 734: What is the most common cause of intermittent proptosis in adults?
- A. Orbital varix (Correct Answer)
- B. Thyroid ophthalmopathy
- C. Neuroblastoma
- D. Retinoblastoma
Explanation: ***Orbital varix*** - An **orbital varix** is essentially a varicose vein within the orbit, which can cause intermittent proptosis. - Proptosis in an orbital varix is often exacerbated by activities that increase venous pressure, such as **Valsalva maneuvers**, crying, or bending over. *Thyroid ophthalmopathy* - This condition is characterized by **persistent proptosis**, lid retraction, and ophthalmoplegia, rather than intermittent symptoms. - While it can cause proptosis, it typically presents as **constant and progressive** rather than intermittent proptosis that varies with head position or straining. *Neuroblastoma* - This is a **malignant tumor** that primarily affects infants and young children, not typically adults. - Orbital metastasis from neuroblastoma would cause **progressive, constant proptosis** rather than intermittent proptosis. *Retinoblastoma* - **Retinoblastoma** is a malignant tumor of the retina that primarily affects young children, typically under the age of 5. - While it can cause proptosis in advanced stages, it presents as **constant and progressive proptosis** due to tumor growth, not intermittent proptosis.
Question 735: Satellite nodules are typically associated with which of the following conditions?
- A. Tuberculosis
- B. Sarcoidosis
- C. Viral ulcer
- D. Fungal corneal ulcer (Correct Answer)
Explanation: ***Fungal corneal ulcer*** - **Satellite lesions** (small, isolated infiltrates surrounding a larger central ulcer) are a characteristic feature of **fungal keratitis**, indicating the spread of fungal hyphae. - Unlike bacterial ulcers, fungal ulcers often have a feathery, indistinct margin and can be slow-growing. *Tuberculosis* - Ocular tuberculosis can present with granulomatous inflammation, often involving the uvea or retina, but **satellite nodules** around a corneal ulcer are not typical. - Corneal involvement in tuberculosis is rare and usually manifests as interstitial keratitis or phlyctenular keratitis. *Sarcoidosis* - Ocular sarcoidosis commonly causes **uveitis**, conjunctival nodules, or retinal vasculitis. - While it can cause corneal deposits or band keratopathy, it does not typically present with satellite lesions around a primary corneal ulcer. *Viral ulcer* - Viral corneal ulcers, particularly those caused by **herpes simplex virus**, often present as **dendritic ulcers** or geographic ulcers. - Although epithelial lesions can spread, the distinct **satellite infiltrates** in the stroma seen in fungal infections are not characteristic of viral keratitis.
Pathology
1 questionsIn which condition is retinal astrocytoma commonly seen?
NEET-PG 2012 - Pathology NEET-PG Practice Questions and MCQs
Question 731: In which condition is retinal astrocytoma commonly seen?
- A. Tuberous sclerosis (Correct Answer)
- B. Sturge weber syndrome
- C. Von Hippel-Lindau syndrome
- D. Neurofibromatosis
Explanation: ***Tuberous sclerosis*** - **Retinal astrocytoma**, also known as **retinal astrocytic hamartoma**, is a common ocular manifestation of **tuberous sclerosis complex (TSC)** [1]. - These lesions can appear as **mulberry-like nodules** or flat, whitish patches on the retina. - Found in approximately **40-50% of patients** with tuberous sclerosis. *Sturge weber syndrome* - Characterized by a **port-wine stain (facial nevus flammeus)**, **leptomeningeal angioma**, and **glaucoma**. - Ocular manifestations include **choroidal hemangiomas** and increased episcleral venous pressure. - Does not typically involve **retinal astrocytomas**. *Von Hippel-Lindau syndrome* - Associated with **retinal capillary hemangioblastomas** (vascular tumors) and various tumors in other organs like the kidneys, pancreas, and brain. - This condition involves **vascular tumors** in the retina, not astrocytic tumors. - Important differential as it also presents with retinal lesions. *Neurofibromatosis* - A neurocutaneous syndrome characterized by **café-au-lait spots**, **neurofibromas**, and **Lisch nodules** (iris hamartomas). - Ocular manifestations include **optic nerve gliomas** and iris hamartomas, but **not retinal astrocytomas**. - NF-1 is the most common neurocutaneous syndrome but has different retinal pathology. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Central Nervous System, pp. 1318-1319.
Pharmacology
3 questionsWhich of the following is an intermediate-acting insulin?
Long-term steroid ingestion leads to all of the following except:
Which antilipidemic drug reduces cholesterol levels by inhibiting cholesterol absorption?
NEET-PG 2012 - Pharmacology NEET-PG Practice Questions and MCQs
Question 731: Which of the following is an intermediate-acting insulin?
- A. Insulin lispro
- B. NPH insulin (Correct Answer)
- C. Insulin glargine
- D. Regular insulin
Explanation: ***NPH insulin*** - **NPH (Neutral Protamine Hagedorn) insulin** is characterized by its intermediate duration of action, typically peaking in 4-12 hours and lasting up to 24 hours [1]. - This intermediate profile is achieved by combining insulin with **protamine**, which slows its absorption from the subcutaneous injection site [1]. *Insulin lispro* - **Insulin lispro** is a **rapid-acting insulin** analog, designed to act very quickly after injection, typically within 15-30 minutes [1, 2]. - Its quick onset and short duration make it suitable for dosing **immediately before meals** to control post-prandial glucose levels [1]. *Regular insulin* - **Regular insulin** is a **short-acting insulin**, with an onset of action around 30-60 minutes and a peak effect typically within 2-4 hours. - It is often administered **30 minutes before meals** and can also be used intravenously in acute situations like diabetic ketoacidosis. *Insulin glargine* - **Insulin glargine** is a **long-acting insulin** analog, providing a prolonged and relatively peakless effect over 24 hours [1, 2]. - Its primary role is to provide **basal insulin coverage**, mimicking the body's continuous background insulin production [1, 2].
Question 732: Long-term steroid ingestion leads to all of the following except:
- A. Avascular necrosis of head of femur
- B. Growth retardation
- C. Hypoglycemia (Correct Answer)
- D. Cataract
Explanation: ***Hypoglycemia*** - Chronic steroid use primarily leads to **hyperglycemia** due to increased **gluconeogenesis** and **insulin resistance**, not hypoglycemia. - Steroids raise blood glucose levels, potentially inducing or worsening **diabetes mellitus**. *Avascular necrosis of head of femur* - Long-term steroid use is a well-established risk factor for **avascular necrosis**, particularly affecting the **femoral head**. - This occurs due to impaired blood supply to the bone, leading to its death. *Cataract* - **Posterior subcapsular cataracts** are a known ocular complication of prolonged systemic corticosteroid therapy. - The mechanism involves direct effects of steroids on lens metabolism and protein aggregation. *Growth retardation* - In children, chronic corticosteroid therapy can suppress growth, leading to **growth retardation**. - This is due to interference with **growth hormone secretion** and direct effects on bone formation.
Question 733: Which antilipidemic drug reduces cholesterol levels by inhibiting cholesterol absorption?
- A. Ezetimibe (Correct Answer)
- B. Orlistat
- C. Cholestyramine
- D. Statins
Explanation: ***Ezetimibe*** - **Ezetimibe** selectively inhibits the **Niemann-Pick C1-Like 1 (NPC1L1) protein**, which is responsible for plant sterol and cholesterol absorption in the small intestine. - This action leads to a reduction in **LDL-C** levels by decreasing the amount of cholesterol available to the liver. *Orlistat* - **Orlistat** is a **lipase inhibitor** that prevents the absorption of dietary fats by inhibiting gastric and pancreatic lipases. - While it aids in weight loss and can indirectly improve lipid profiles, its primary mechanism is *not* direct inhibition of cholesterol absorption. *Cholestyramine* - **Cholestyramine** is a **bile acid sequestrant** that binds to bile acids in the intestine, preventing their reabsorption. - This increases the excretion of bile acids, prompting the liver to synthesize more bile acids from cholesterol, thereby lowering cholesterol levels, but it does *not* directly inhibit cholesterol absorption. *Statins* - **Statins** (HMG-CoA reductase inhibitors) are considered first-line agents for lowering cholesterol by inhibiting the **rate-limiting step in cholesterol synthesis** in the liver. - Their primary action is to reduce endogenous cholesterol production, not to block cholesterol absorption from the gut.