Medial Medullary Syndrome (MMS)

This forum made possible through the generous support of SDN members, donors, and sponsors. Thank you.

MudPhud20XX

Full Member
10+ Year Member
Joined
Nov 26, 2013
Messages
1,349
Reaction score
193
MMS is mainly due to occlusion of anterior spinal artery.

According to Kaplan nuero, you get contralateral spastic paresis, loss of tactile, vibration, conscious proprioception.

These symptoms also should be bilateral right? Somehow, Kaplan does not seem to emphasize that these are bilateral and I don't think I understand why "contralateral" since most likely the occlusion of the ant. spinal artery will affect both side of the medial portion of the medulla just like it does in ASA syndrome. Can anyone explain this please?

Below is what I got from Firecracker comparing MMS with anterior spinal artery syndrome:

Anterior spinal artery (ASA) syndrome (infarction of anterior two-thirds of spinal cord): bilateral loss of pain and temperature (spinothalamic tract), bilateral weakness (lateral corticospinal tract) with preservation of fine touch, proprioception, and vibration (dorsal column)

  • Anterior spinal artery syndrome results in the occlusion of the artery at the level of the spine; this is in contrast to medial medullary syndrome which results from the occlusion of the anterior spinal artery at the level of the medulla (thus, producing different symptoms).

Members don't see this ad.
 
images

I think just like in the spinal cord, the ASA in the midline dives in and gives off branches to the left and right and thats what knocks out one side.
It seems like one of those things where if you're unlucky enough to have that specific block you get this neuroanatomically "interesting" pattern that deserves a name; Strokes involving the medial medulla at all are very rare (compared to posterolateral medullary stroke causing wallenburg), and your right in that some of them have been bilateral.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3807554/
http://stroke.ahajournals.org/content/14/3/413.full.pdf
http://stroke.ahajournals.org/content/26/9/1548.long
 
Last edited:
  • Like
Reactions: 1 user
images

I think just like in the spinal cord, the ASA in the midline dives in and gives off branches to the left and right and thats what knocks out one side.
It seems like one of those things where if you're unlucky enough to have that specific block you get this neuroanatomically "interesting" pattern that deserves a name; Strokes involving the medial medulla at all are very rare (compared to posterolateral medullary stroke causing wallenburg), and your right in that some of them have been bilateral.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3807554/
http://stroke.ahajournals.org/content/14/3/413.full.pdf
http://stroke.ahajournals.org/content/26/9/1548.long

I believe it is semantics really--you are correct, but when they say "block the anterior spinal artery" they really mean a branch of that artery that innervates one side of the other. Obviously, it will be very clear to you clinically whether a patient has unilateral or bilateral symptoms.Not to mention an MRI will be ordered anyway which will reveal it. But in terms of the concept, you understand it.
 
  • Like
Reactions: 1 user
Top