Locked-in Syndrome - USMLE Forums
USMLE Forums Logo
USMLE Forums         Your Reliable USMLE Online Community     Members     Posts
Home
USMLE Articles
USMLE News
USMLE Polls
USMLE Books
USMLE Apps
Go Back   USMLE Forums > USMLE Step 1 Forum

USMLE Step 1 Forum USMLE Step 1 Discussion Forum: Let's talk about anything related to USMLE Step 1 exam


Reply
 
Thread Tools Search this Thread Display Modes
  #1  
Old 06-20-2010
good_boy_1234's Avatar
USMLE Forums Master
 
Steps History: 1 + CS
Posts: 546
Threads: 91
Thanked 320 Times in 145 Posts
Reputation: 366
Neuro Locked-in Syndrome

A 37-year-old pregnant woman is brought to the Emergency Department after being found unconscious. Her airway and circulation are stabilized. On examination, she is found to be completely paralyzed without response to voice or pain. When her eyelids are propped opened, she can respond to questions by moving her eyes upward for "yes" and downward for "no." She is unable to move her eyes laterally. A CT angiography study of her head and neck reveals a large occlusive thrombus. Which of the following locations of the thrombus would best account for this woman's presentation?
A. Basilar artery
B. Internal carotid artery
C. Middle cerebral artery
D. Posterior cerebral artery
E. Superior cerebellar artery
Reply With Quote Quick reply to this message
The above post was thanked by:
docoftheworld (05-27-2011)



  #2  
Old 06-20-2010
KaleKaleo's Avatar
USMLE Forums Scout
 
Steps History: Step 1 Only
Posts: 28
Threads: 2
Thanked 16 Times in 8 Posts
Reputation: 26
Default I choose B

I'd say the Internal carotid artery. because the extraocular muscles are still functioning which means that the brain stem is still OK but all her other muscles are paralyzed by a complete block of arterial supply to the entire cortex so the culprit should be the internal carotid.

Am I right!
Reply With Quote Quick reply to this message
  #3  
Old 06-20-2010
USMLE Forums Addict
 
Steps History: Not yet
Posts: 161
Threads: 60
Thanked 23 Times in 19 Posts
Reputation: 33
Send a message via Skype™ to Androide89
Default

no its basilar artery, abducent nerve axons leave brainstem from medial pons which is supplied by basilar artery

also corticospinal tracts are in the medial pons (locked-in syndrome)
Reply With Quote Quick reply to this message
 
  #4  
Old 06-20-2010
YoramFishke's Avatar
USMLE Forums Veteran
 
Steps History: 1+CK+CS
Posts: 248
Threads: 11
Thanked 308 Times in 127 Posts
Reputation: 338
I agree I agree with you

Quote:
Originally Posted by Androide89 View Post
no its basilar artery, abducent nerve axons leave brainstem from medial pons which is supplied by basilar artery

also corticospinal tracts are in the medial pons (locked-in syndrome)
I agree with you

Here's what emedicine said about it:

Basilar Artery Thrombosis Examination Findings:
The signs described can be present in different combinations. The recognized syndromes more commonly associated with basilar artery occlusion are:
  • Locked-in syndrome: It is caused by infarction of the basis pontis secondary to occlusive disease of the proximal and middle segments of the basilar artery, which leads to quadriplegia. Because the tegmentum of the pons is spared, the patient has a spared level of consciousness, preserved vertical eye movements, and blinking. Coma associated with oculomotor abnormalities and quadriplegia also indicates proximal basilar and midbasilar occlusive disease with pontine ischemia.
  • Top-of-the-basilar syndrome: This is the manifestation of upper brainstem and diencephalic ischemia caused by occlusion of the rostral basilar artery, usually by an embolus. Patients present with changes in the level of consciousness. They may experience visual symptoms such as hallucinations and/or blindness. Third nerve palsy and pupillary abnormalities are also frequent. Motor abnormalities include abnormal movements or posturing.
Reply With Quote Quick reply to this message
The above post was thanked by:
doctorF (06-21-2010), khushboo (06-20-2010)
  #5  
Old 06-20-2010
USMLE Forums Guru
 
Steps History: ---
Posts: 487
Threads: 69
Thanked 296 Times in 133 Posts
Reputation: 316
Default

A. Basilar artery ....
Reply With Quote Quick reply to this message
  #6  
Old 06-20-2010
USMLE Forums Scout
 
Steps History: Step 1 Only
Posts: 70
Threads: 0
Thanked 6 Times in 6 Posts
Reputation: 16
Default

i too will go with A. cos of the inability to move the eyes laterally. i.e effect on the abducens nerve whose nucleus is in the pons of the brainstem...
Reply With Quote Quick reply to this message
  #7  
Old 06-20-2010
good_boy_1234's Avatar
USMLE Forums Master
 
Steps History: 1 + CS
Posts: 546
Threads: 91
Thanked 320 Times in 145 Posts
Reputation: 366
Correct Answer The correct answer

The correct answer is A. This patient presents with a phenomenon known as "locked-in" syndrome. Unlike a persistent vegetative state, which is characterized by a loss of awareness and cognitive function, patients with locked-in syndrome are completely awake and cognitively intact with no abnormality of consciousness. However, they are unable to move the extremities and most of the face, and are often limited to communication by vertical eye movements or blinks. The disease results most commonly from large lesions in the brain stem, particularly at the base of the Pons, such as those produced by a thrombotic stroke to the basilar artery.
Occlusion of an internal carotid artery (choice B) is unlikely to present in the manner described because collateral circulation from the other internal carotid artery should compensate for the unilaterally reduced perfusion.
Middle cerebral artery strokes (choice C) usually present with lateralizing symptoms, such as a gaze deviation or hemiparesis. Since the parietal cortex is primarily perfused by this artery, symptoms involving parietal lobe dysfunction such as agnosias, apraxias, hemi-neglect, and language and calculation problems are more likely to occur.
The posterior cerebral artery (choice D) supplies the occipital lobe as well as the medial portions of the parietal and temporal cortex. Symptoms will usually be lateralizing, and visual changes are almost certainly present.
Occlusion of the superior cerebellar artery (choice E) would more likely present with ataxia and dysarthria than with the severe symptoms described in this patient.
A lesion of the ventral pons can result in "locked-in" syndrome, in which the patient develops quadriplegia and inability to speak but is aware, is awake, and can communicate by vertical eye movements or blinks. Branches of the basilar artery supply the ventral pons
Reply With Quote Quick reply to this message
The above post was thanked by:
doctorF (06-21-2010), dr.muhamad (11-20-2011), Evergreen (10-22-2011), nyflys (03-14-2011), usmle100 (06-21-2010)



Reply

Tags
Neuroanatomy-, Step-1-Questions

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the USMLE Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:
Medical School
Choose "---" if you don't want to tell. AMG for US & Canadian medical schools. IMG for all other medical schools.
USMLE Steps History
What steps finished! Example: 1+CK+CS+3 = Passed Step 1, Step 2 CK, Step 2 CS, and Step 3.

Choose "---" if you don't want to tell.

Favorite USMLE Books
What USMLE books you really think are useful. Leave blank if you don't want to tell.
Location
Where you live. Leave blank if you don't want to tell.

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes


Similar Threads
Thread Thread Starter Forum Replies Last Post
Turner Syndrome Sabio USMLE Step 1 Buzzwords 10 12-28-2016 06:43 AM
Man In Barrel Syndrome versus Locked In Syndrome Androide89 USMLE Step 1 Forum 7 12-04-2010 10:47 PM
VATER syndrome, What is the R for? Hohepa USMLE Step 2 CK Forum 1 05-07-2010 09:40 AM
Mononucleosis Syndrome? Hohepa USMLE Step 2 CK Forum 4 04-11-2010 12:27 PM
Differentiating Staphylococcal Scalded Skin Syndrome from Toxic Epidermal Necrolysis and Steven Johnson Syndrome lee-usmle USMLE Step 2 CK Bits & Pieces 0 03-21-2010 06:12 PM

RSS Feed
Find Us on Facebook
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.

USMLE® & other trade marks belong to their respective owners, read full disclaimer
USMLE Forums created under Creative Commons 3.0 License. (2009-2014)