Neurosurgery HARD MCQs need your help

[Dr.Hadi.11]

I need your help in these Neurosurgery Qs please help me

 

1. Cranial N damage will be intially produced by one of the following lesion:

a. oculomotor N is most commonly involve in subfrontal meningioma.

b. Facial N is mostly involved in acoustic neurinoma

c. Homonymous hemianopia mostly result from pituitary tumor

d. 3rd, 4th, 6th CN plasies result from Carotid cavernous fistula.

e. optic N damage by lateral sphenoid wing meningioma

 

2. which of the following is TRUE about pituitary adenoma ?

a. pituitary macroadenoma defined by compression of 3rd ventricle

b. they always secrete hormones

c. ACTH tumor cause acromegaly ( answer in old exam but I'm 100% sure it's WRONG )

d. cardiomyopathy could be one of the presentation ( another old answer ?!! )

e. prolactin secreting pituitary adenoma present in women with visual loss.

 

 

4. 35 year old female with head injury 4 hours previously her GCS is 7 , which one will NOT improve her outcome ?

a. avoid/ prevent hypoxia

b. induced hypothermia

c. avoid hypercapnea

d. Ca channel antagonist

e. prevent hypotension

 

5. regarding normal brain, which is NOT true ?

a. 4% of body weight ( DR said is 2% )

b. 20% of blood O2 supply

c. 15% of Cardiac output

d. autoregulation curve shifted to right in untreated chronic hypertension

e. hypoxemia is a powerful stimulus for cerebral vasodilation. ( old answer )

 

6. male patinet with coma, no eye no verbal response in decorticate position , what is TRUE about ttt :

a. diuretics is contraindicated ( WRONG )

b. ventilation is final step ( WRONG )

c. burrhole is needed for evacuation of hematoma

d. monitering ICP is not necessary

 

7. all of following cause enlargement of cerebral ventricles due to obstruction of CSF flow except one is least likely to :

a. epidural hematoma ??

b. IVH ( yes )

c. ependymoma ( yes )

d. subarachnoid hemorrhage ??

e. aqueduct stenosis ( yes )

 

Q8. with regard epidural hematoma which one is true

a. at least most of patinet managed without operation ( WRONG )

b. lucid interval occurs almost in three fourths of patients ???

c. most common occur from injury to branch of internal carotid ( WRONG )

d. is seen often with temporal linear fracture ??

e. seen only after sever head injury ( I think wrong )

 

Q9. Cerebral perfusion pressure :

a. is calculated by dividing the MAP by ICP ( wrong )

b. protocal do not necessarily requires ICP measurement

c. improve by lowering the BP

d. mangement requires precise ICP monitering

e. measurement have not been shown to have clinical utility & are of investigational use only

[10wattbulb]

Hi Dr.Hadi.11,

 

I am certainly not a neurosurgery expert, but I did some internet research (out of interest) and found what I believe to be the right answers for Qs 1, 2 and 5.

 

 

Question 1. E seems to be the correct answer.

 

(a) Wrong. Meningioma, ... , refers to a set of tumors that arise contiguously to the meninges. Meningiomas may occur intracranially or within the spinal canal. They are thought to arise from arachnoidal cap cells, which reside in the arachnoid layer covering the surface of the brain. Meningiomas commonly are found at the surface of the brain, either over the convexity or at the skull base. In rare cases, meningiomas occur in an intraventricular or intraosseous location.

 

Source: Googled subfrontal meningioma and found:

http://emedicine.medscape.com/article/1156552-overview#showall

 

( Wrong. An acoustic neuroma is a slow-growing tumor of the nerve that connects the ear to the brain. This nerve is called the vestibular cochlear nerve. It is behind the ear right under the brain.

 

Source: Googled acoustic neurinoma and found: http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001782/

 

© Wrong. Any type of intracranial lesion in the appropriate location can cause a homonymous hemianopia; however, vascular causes (cerebral infarction and intracranial hemorrhage) are the most frequent in adults, ranging from 42 to 89 percent, followed by brain tumors, trauma, surgical interventions, and other central nervous system diseases [1,8-13]. In children, neoplasms are the most common cause of homonymous hemianopia (39 percent), followed by cerebrovascular disease (25 percent) and trauma (19 percent) [14].

 

Source: Googled homonymous hemianopia and found:

http://www.uptodate.com/contents/homonymous-hemianopia

 

(d) Doesn’t seem right. Carotid-cavernous fistulas (CCFs) are abnormal communications between the carotid arterial system and the venous cavernous sinus. Most often, CCFs are broadly classified as either direct or indirect, on the basis of anatomic features depicted on angiograms. (See the images below.)

 

Source: Googled Carotid cavernous fistula and found:

http://emedicine.medscape.com/article/338870-overview

 

(e) Seems right. Sphenoid wing meningiomas are diagnosed by the combination of suggestive symptoms from the history and physical and neuroimaging by magnetic resonance imaging (MRI) or computer averaged tomography (CT). Tumors growing in the inner wing (clinoidal) most often cause direct damage to the optic nerve leading especially to a decrease in visual acuity, progressive loss of color vision, defects in the field of vision (especially cecocentral), and an afferent pupillary defect.

 

Source: Googled Sphenoid wing meningioma and found:

http://en.wikipedia.org/wiki/Sphenoid_wing_meningioma

 

 

Question 2. D seems to be the right answer (E as a second guess).

 

A is wrong. A macroadenoma is larger than 1 cm in size.

 

B is wrong. Pituitary adenomas are generally thought of as either hormone-producing or hormone-inactive tumors.

 

C is wrong. ACTH-secreting pituitary adenoma: excessive ACTH hormone produced by the pituitary gland causes Cushing's disease.

 

D – ambiguous, but cardiomyopathies may be caused by endocrine problems (hence, pituitary adenomas) according to: http://en.wikipedia.org/wiki/Cardiomyopathy.

 

E seems wrong. Prolactin-secreting pituitary adenoma (prolactinoma): over-production of prolactin by the pituitary tumor causes loss of menstrual periods and breast milk production in women.

 

Prolactinomas generally have very different presentations in women and in men. In women, relatively small elevations in prolactin cause irregular menstrual periods or complete loss of menses (amenorrhea), ability to ovulate (remain fertile) and may cause milky discharge from the breasts (galactorrhea). In addition, women may have a reduction in their sex drive. The normal prolactin level is < 20 ng/ml. In most women the tumors are detected when they are small (microadenomas) and the prolactin level is only moderately elevated (30 - 300 ng/ml). In contrast, in men prolactinomas are usually not detected until they are large (macroadenomas), most have prolactin levels over 500 ng/ml. Most men diagnosed with a prolactinoma have some degree of loss of sex hormone production. They may also have visual loss (from compression of the optic nerves or optic chiasm) and/or headache. A minority of patients with large tumors may have bleeding into the tumor (pituitary apoplexy) causing relatively sudden onset of headache, visual loss, double vision, and/or pituitary failure.

 

Source: Googled pituitary adenoma and found:

http://neurosurgery.ucla.edu/body.cfm?id=1123&ref=80&action=detail

http://www.clevelandclinicmeded.com/medicalpubs/diseasemanagement/endocrinology/pituitary-disorders/#cesec4

http://www.pituitary.org/disorders/prolactinomas.aspx

 

 

Question 5. A seems to be the correct answer.

 

A should be 2%.

 

B is true.

 

C seems right. Source: http://en.wikipedia.org/wiki/Cerebral_blood_flow. Cerebral blood flow, or CBF, is the blood supply to the brain in a given time.[1] In an adult, CBF is typically 750 millitres per minute or 15% of the cardiac output.

 

D seems right. Source: http://www.springerimages.com/Images/MedicineAndPublicHealth/2-ACA0201-07-008. Chronic untreated hypertension results in a rightward shift in the autoregulatory curve...

 

E seems right. See: Mechanisms of hypoxic cerebral vasodilatation; Source: http://www.ncbi.nlm.nih.gov/pubmed/7716183.

[10wattbulb]

For Question 9, my guess is B.

 

A is totally wrong. CPP = MAP - ICP

 

B seems correct (note that B is somewhat the opposite of D).

 

C is wrong. Cerebral Perfusion Pressure may be maintained by raising the Mean Arterial Pressure or by lowering the Intracranial Pressure. In practice, ICP is usually controlled to within normal limits (<20mmHg) and MAP is raised therapeutically.

 

D seems wrong. It is unknown whether ICP control is necessary providing CPP is maintained above the critical threshold.

 

E seems wrong. There is no class I evidence for the optimum level of CPP, but 70-80mmHg is probably the critical threshold. Mortality increases approximately 20% for each 10mmHg loss of CPP. In those studies where CPP is maintained above 70mmHg, the reduction in mortality is as much as 35% for those with severe head injury.

 

Source: http://www.trauma.org/archive/neuro/cpp.html.

 

 

Question 8. D or E is the correct answer.

 

A is wrong. Emergency surgery is almost always necessary to reduce pressure within the brain.

 

B is wrong. Fewer than 20% of patients demonstrate the classic presentation of a lucid interval between the initial trauma and subsequent neurological deterioration.

 

C is wrong.

 

D is a possible answer. Approximately 70-80% of epidural hematomas (EDHs) are located in the temporoparietal region where skull fractures cross the path of the middle meningeal artery or its dural branches.

An epidural hematoma may often occur with trauma to the temporal bone located on the side of the head above the ear. Aside from the fact that the temporal bone is thinner than the other skull bones (frontal, parietal, occipital), it is also the location of the middle meningeal artery that runs just beneath the bone. Fracture of the temporal bone is associated with tearing of this artery and may lead to an epidural hematoma. (http://www.emedicinehealth.com/head_injury/article_em.htm).

Linear fractures, the most common, involve a break in the bone but no displacement, and generally no intervention is required. These fractures are usually the result of low-energy transfer due to blunt trauma over a wide surface area of the skull. The fracture involves the entire thickness of the skull. Generally, these fractures are of little clinical significance unless they involve a vascular channel, a venous sinus groove, or a suture. Thus, complications include epidural hematoma, venous sinus thrombosis, and suture diastasis. See the following images. (http://emedicine.medscape.com/article/343764-overview).

 

E is a possible answer (the one thing I don’t like about E is the word ALWAYS). Epidural hematoma (EDH) results from traumatic head injury, usually with an associated skull fracture and arterial laceration. BUT another source states that: The most common cause of intracranial epidural hematoma is traumatic, although spontaneous hemorrhage is known to occur (Wikipedia article however).

 

Main Source: Epidural Hematoma in Emergency Medicine (medscape article – several sections to this article to read). http://emedicine.medscape.com/article/824029-overview.