View source for Medial medullary syndrome

{{Redirect|Dejerine syndrome|other syndromes named after Dejerine|Joseph Jules Dejerine#Associated eponyms}}
{{Infobox medical condition (new)
| name            = Medial medullary syndrome
| image           = Gray700.png
| caption         = [[Medulla oblongata]], shown by a transverse section passing through the middle of the olive. (Medial medullary syndrome can affect structures in lower left: especially #5, #6, #8.)
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| synonyms        =  Inferior alternating syndrome
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| diagnosis       = Ipsilateral signs and symptoms - flaccid (lmn) paralysis and atrophy of one half of tongue (hypoglossal nerve)
Contralateral signs and symptoms- spastic (umn) paralysis of trunk and limbs (contralateral corticospinal tract)
Impaired tactile, proprioceptive, and vibration sense of trunk and limbs (contralateral medial lemniscus)
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'''Medial medullary syndrome''', also known as '''inferior alternating syndrome''', '''hypoglossal alternating hemiplegia''', '''lower alternating hemiplegia''',<ref>{{cite web |url=http://www.anatomyatlases.org/MicroscopicAnatomy/Section17/Plate17330.shtml |title=Atlas of Microscopic Anatomy: Section 17 - Central Nervous System. Plate 17.330 Medulla Oblongata |access-date=2007-06-07 }}</ref> or '''Dejerine syndrome''',<ref name="pmid12684991">{{cite journal |vauthors=Yokota J, Amakusa Y, Tomita Y, Takahashi S |title=[The medial medullary infarction (Dejerine syndrome) following chiropractic neck manipulation] |language=ja |journal=No to Shinkei |volume=55 |issue=2 |pages=121–5 |date=February 2003 |pmid=12684991 }}</ref> is a type of [[alternating hemiplegia]] characterized by a set of clinical features resulting from occlusion of the [[anterior spinal artery]]. This results in the infarction of medial part of the [[medulla oblongata]].
==Presentation==
The condition usually consists of:
{| class="wikitable"
|-
! Description
! Source of damage
! Number on diagram
|-
| a deviation of the tongue to the side of the infarct on attempted protrusion, caused by [[ipsilateral]] muscle weakness.
| [[hypoglossal nerve]] fibers
| #8
|-
| limb weakness (or [[hemiplegia]], depending on severity), on the [[contralateral]] side of the infarct
| [[medullary pyramid]] and hence to the corticospinal fibers of the [[pyramidal tract]]
| #5
|-
| a loss of discriminative touch, conscious [[proprioception]], and vibration sense on the [[contralateral]] side of the infarct (body below head)
| [[medial leminiscus]]
| #6
|}
[[Image:Human brainstem blood supply description.JPG|thumb|Human brainstem blood supply description. ASA is#13.]]
Sensation to the face is preserved, due to the sparing of the trigeminal nucleus.
The syndrome is said to be "alternating" because the lesion causes symptoms both contralaterally and ipsilaterally. Sensation of pain and temperature is preserved, because the [[spinothalamic tract]] is located more laterally in the brainstem and is also not supplied by the anterior spinal artery (instead supplied by the posterior inferior cerebellar arteries and the vertebral arteries).
==Pathophysiology==
The anterior spinal artery arises bilaterally as two small branches near the termination of the vertebral arteries which descend anterior to the medulla and unite at the level of the foramen magnum. The infarction (which arises in the paramedian branches of the anterior spinal artery and/or the vertebral arteries) leads to death of the ipsilateral [[medullary pyramid]], the [[medial lemniscus]], and the [[hypoglossal nerve]] fibers that pass through the medulla. The [[spinothalamic tract]] is spared because it is located more laterally in the brainstem and is not supplied by the anterior spinal artery, but rather by the [[vertebral artery|vertebral]] and [[posterior inferior cerebellar artery|posterior inferior cerebellar]] arteries. The [[trigeminal nucleus]] is also spared, since most of it is higher up in the [[pons]], and the spinal part of it found in the medulla is lateral to the infarct.{{cn|date=August 2021}}
==Diagnosis==
Ipsilateral signs and symptoms - flaccid paralysis (lmn) paralysis and atrophy of one half of tongue (hypoglossal nerve){{cn|date=August 2021}}
Contralateral signs and symptoms-spastic (umn) paralysis of trunk and limbs (contralateral corticospinal tract)
Impaired tactile, proprioceptive and vibration sense of trunk and limbs (contralateral medial lemniscus){{cn|date=August 2021}}
==Management==
{{Empty section|date=November 2017}}
==See also==
* [[Alternating hemiplegia of childhood]]
* [[Lateral medullary syndrome]]
* [[Lateral pontine syndrome]]
* [[Medial pontine syndrome]]
==References==
{{reflist}}
== External links ==
{{Medical resources
|   DiseasesDB     =
|   ICD10          = {{ICD10|G|46|3|g|40}}
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|   MedlinePlus    =
|   eMedicineSubj  = emerg
|   eMedicineTopic = 834
|   MeshID         =
}}
{{Cerebrovascular diseases}}
{{Lesions of spinal cord and brain}}
{{DEFAULTSORT:Medial medullary syndrome}}
[[Category:Brain disorders]]
[[Category:Syndromes affecting the nervous system]]