Anatomy MCQ 0039

Zygomycosis, a destructive fungal infection of the sinuses, is likely to reach the brain by which of the following routes?

a. Cavernous sinus

b. External carotid artery

c. Internal carotid artery

d. Superior sagittal sinus

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The Correct option is A

Explanation with High Yield Facts:

The cavernous sinuses are located on either side of the body of the sphenoid bone, and become a potential route of infection because they receive blood both from the face (via the ophthalmic veins and sphenoparietal sinus) and some of the cerebral veins. The spread of infection, especially by Mucor sp., into the cavernous sinus, can produce either CNS infection or cavernous sinus thrombosis, both of which are potentially fatal.

The route from the face to the brain is not arterial (choices B and C).

The superior sagittal sinus (choice D) is located in the falx cerebri, and drains venous blood from the brain to other dural sinuses, from which it eventually drains into the jugular vein.

Zygomycosis does not reach the brain by way of the superior sagittal sinus.

The superior vena cava drains blood from the upper part of the body into the heart.

Anatomy MCQ 0034

The nerve supplying submandibular gland is

a. V

b. VII

c. IX

d. XII

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The Correct option is B

Explanation with High Yield Facts:

Parasympathetic innervation to the submandibular glands is provided by the superior salivatory nucleus via the chorda tympani, a branch of the facial nerve that synapses in the submandibular ganglion after which it follows the Lingual nerve leaving this nerve as it approaches the gland. Increased parasympathetic activity promotes the secretion of saliva.

The sympathetic nervous system regulates submandibular secretions through vasoconstriction of the arteries that supply it. Increased sympathetic activity reduces glandular blood flow, thereby decreasing salivary secretions and producing enzyme rich serous saliva.

Anatomy MCQ 0027

Which cranial nerve exits the skull base at the pars nervosa of the jugular foramen ?

1. Eight cranial nerve palsy
2. Ninth cranial nerve palsy
3. Tenth cranial nerve palsy
4. Eleventh cranial nerve palsy

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The Correct option is B

Explanation with High Yield Facts:

The glossopharyngeal (ie, CN IX), vagus (ie, CN X), and accessory (ie, CN XI) nerves emerge cranial to caudal, in that order, from the ventral medulla, lateral to the medullary olive. From there, they course toward the jugular foramen and exit the skull base at the jugular foramen. The glossopharyngeal nerve is located in the pars nervosa of the jugular foramen, and the vagus and accessory nerves are located within the more posterior pars vascularis. The hypoglossal nerve (CN XII) is formed by the fusion of multiple rootlets that emerge from the ventrolateral sulcus between the medullary olive and pyramid. The nerve exits the cranial vault via the hypoglossal canal, and then lies medial to CN IX, CN X, and CN XI. Schwannomas in the jugular foramen that arise from the glossopharyngeal, vagus, or accessory nerves, can present with variable cerebellar and acoustic symptoms, depending on the extent of the intracranial growth of the mass. They also can cause glossopharyngeal dysfunction (eg, hoarseness, difficultyswallowing) and/or spinal accessory symptoms (eg, trapezius atrophy). Schwannomas of the jugular foramen are rare. Patients often present with symptoms consistent with eighth cranial nerve injury or cerebellar or brain stem compression. Symptoms relating to injury of the ninth or 10th to 12th cranial nerves are less common. Although the clinical presentation of a schwannoma of the jugular foramen may suggest the presence of a vestibular schwannoma, appropriate imaging techniques and interpretation should permit correct differentiation of tumor origin and type and suggest the appropriate surgical approach. Schwannoma of the jugular foramen appears as a sharply demarcated, contrast-enhancing tumor, which is typically centered or based in an enlarged jugular foramen with sharply rounded bone borders having a sclerotic rim. The clinical presentation of schwannomas of the jugular foramen varies significantly according to the tumor's growth pattern. Deafness, vertigo, and ataxia were present if the mass is intracranial. Most patients present with symptoms of decreased hearing; Hoarseness and weakness of the trapezius and sternocleidomastoid muscles occur in some patients in whom the tumor is within the bone or extracranial. In patients with a large proportion of the tumor below the skull base, the symptoms tended to reflect glossopharyngeal injury.

Anatomy MCQ 0025

A patient has a tumour based in an enlarged jugular foramen , what is the most likely presentation?

1. Eight cranial nerve palsy
2. Ninth cranial nerve palsy
3. Tenth cranial nerve palsy
4. Eleventh cranial nerve palsy

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The Correct option is A

Explanation with High Yield Facts:

The glossopharyngeal (i.e., CN IX), vagus (i.e., CN X), and accessory (i.e., CN XI) nerves emerge cranial to caudal, in that order, from the ventral medulla, lateral to the medullary olive. From there, they course toward the jugular foramen and exit the skull base at the jugular foramen. The glossopharyngeal nerve is located in the pars nervosa of the jugular foramen, and the vagus and accessory nerves are located within the more posterior pars vascularis. The hypoglossal nerve (CN XII) is formed by the fusion of multiple rootlets that emerge from the ventrolateral sulcus between the medullary olive and pyramid. The nerve exits the cranial vault via the hypoglossal canal, and then lies medial to CN IX, CN X, and CN XI. Schwannomas in the jugular foramen that arise from the glossopharyngeal, vagus, or accessory nerves, can present with variable cerebellar and acoustic symptoms, depending on the extent of the intracranial growth of the mass. They also can cause glossopharyngeal dysfunction (e.g., hoarseness, difficulty swallowing) and/or spinal accessory symptoms (e.g., trapezius atrophy). Schwannomas of the jugular foramen are rare. Patients often present with symptoms consistent with eighth cranial nerve injury or cerebellar or brain stem compression. Symptoms relating to injury of the ninth or 10th to 12th cranial nerves are less common. Although the clinical presentation of a schwannoma of the jugular foramen may suggest the presence of a vestibular schwannoma, appropriate imaging techniques and interpretation should permit correct differentiation of tumour origin and type and suggest the appropriate surgical approach. Schwannoma of the jugular foramen appears as a sharply demarcated, contrast-enhancing tumour, which is typically centred or based in an enlarged jugular foramen with sharply rounded bone borders having a sclerotic rim. The clinical presentation of schwannomas of the jugular foramen varies significantly according to the tumour’s growth pattern. Deafness, vertigo, and ataxia were present if the mass is intracranial. Most patients present with symptoms of decreased hearing; Hoarseness and weakness of the trapezius and sternocleidomastoid muscles occur in some patients in whom the tumour is within the bone or extra cranial. In patients with a large proportion of the tumour below the skull base, the symptoms tended to reflect glossopharyngeal injury.

Anatomy MCQ 0024

An infarct involving the seventh nerve and nucleus is likely to be secondary to occlusion in the territory of the:

1. The Posterior Cerebral Artery
2. The Basilar Artery
3. The superior cerebellar artery
4. The anterior inferior cerebellar artery

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The Correct option is D

Explanation with High Yield Facts:

The AICA territory includes the middle cerebellar peduncle, fifth nerve sensory nucleus and tract, seventh nerve and nucleus, eighth nerve, vestibular nuclei and the descending sympathetic tracts. AICA-related lateral pontine infarction produces a syndrome similar to Wallenberg's; but instead of hoarseness, palatal weakness and loss of taste, there is ipsilateral facial paralysis and deafness.

Anatomy MCQ 0021

An infarct causing bilateral infarction of the occipital lobes is likely to be secondary to occlusion in the territory of the:

1. The Posterior Cerebral Artery
2. The Basilar Artery
3. The superior cerebellar artery
4. The anterior inferior cerebellar artery

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The Correct option is A

Explanation with High Yield Facts:

Atherothrombosis of the PCA is relatively uncommon, but when it occurs is generally in the proximal segment of the vessel. Sometimes thrombus may spread by contiguous ascent from the basilar apex. PCA infarction rarely involves the entire arterial territory; and the variability of the resulting clinical deficits of primary sensory, visual and behavioural function depend upon the degree of damage to the thalamus, occipital and inferomedial temporal lobes respectively. Blockage of vessels derived from the proximal PCA can cause infarction in sensory and motor nuclei of the thalamus and nearby subthalamic structures.

Anatomy MCQ 0015

Vidian Nerve is formed by

a. Deep Petrosal & Greater Superficial Petrosal nerve

b. Greater Superficial Petrosal Nerve and Lesser Superficial Petrosal Nerve.

c. Deep Petrosal Nerve and Lesser Superficial Petrosal Nerve

d. None of the above

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The Correct option is A

Explanation with High Yield Facts :

Greater Petrosal Nerve is joined by the deep petrosal nerve from the internal carotid sympathetic plexus to become the Vidian nerve or nerve of the pterygoid canal which traverses the pterygoid canal to terminate in the pterygopalatine ganglion.

Anatomy MCQ 0005

Seen in agenesis of corpus callosum is:

1. Astereognosis
2. Hemiparesis
3. Hemi sensory loss
4. No neurological deficit

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The Correct option is A

Explanation with High Yield Facts :

Agenesis of the Corpus Callosum (ACC) is a rare birth defect (congenital disorder) in which there is a complete or partial absence of the corpus callosum. Agenesis of the corpus callosum occurs when the corpus callosum, the band of tissue connecting the two hemispheres of the brain, does not develop typically in utero. In addition to agenesis of the corpus callosum, other callosal disorders include hypogenesis (partial formation), dysgenesis (malformation) of the corpus callosum, and hypoplasia (underdevelopment) of the corpus callosum.

Signs and symptoms:

• Signs and symptoms of Agenesis of the Corpus Callosum and other callosal disorders vary greatly among individuals.
• However, some characteristics common in individuals with callosal disorders include vision impairments, low muscle tone (hypotonia), poor motor coordination, delays in motor milestones such as sitting and walking, low perception of pain, delayed toilet training, chewing and swallowing difficulties, early speech and language delays, and social difficulties.
• Recent research suggests that specific social difficulties may be a result of impaired face processing.
• Unusual social behavior in childhood is often mistaken for or misdiagnosed as Asperger's syndrome or other autism spectrum disorders.
• Other characteristics sometimes associated with callosal disorders include seizures, spasticity, early feeding difficulties and/or gastric reflux, hearing impairments, abnormal head and facial features, and mental retardation.

Tags: Corpus callosum, hemiparesis, neurology, anatomy