Localization of contralateral tongue deviation and hearing loss in stroke?

[danielmd06]

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Good morning,

I would appreciate a bit of clarification on a case I saw Friday.

I'm on a Neurorehab rotation and was examining a younger lady (mid-forties) who had suffered a large R MCA distribution cryptogenic stroke about two weeks prior. She was a smoker and had a histroy of drug use. No OCP's. Follow-up CTH (the only imaging I could reference) demonstrated that her caudate, lentiform nuclei, temporal lobe, frontal lobe, and parietal lobe were all involved.

On exam, she had L hemiparesis, a L superior quadrantanopia and interestingly...a L tongue deviation and subjective L hearing loss on finger rub and whisper test. She did complain of acute-onset L-sided hearing loss at the time of the stroke (was talking on the phone at onset).

I was at a loss regarding the tongue and hearing problems.

So I searched online. PubMed has article abstracts but I don't have a subscription to read the specific journals and I thought I would try here next for answers. I've got two specific questions:

(1) Is the twelfth cranial nerve akin to the seventh in that you can have UMN and LMN differences in laterality? For instance, if a lesion of the hypoglossal nucleus in a medial medullary syndrome produces an ipsilateral tongue deviation, could a unilateral cortical or subcortical stroke somehow cause a contralateral tongue deviation due to UMN involvement? Is there actually supranuclear innervation for the glossal musculature?

(2) Why would this lady have contralateral hearing loss? Brodmann's area 44/Heschl's gyrus (on the R mind you..) looks partially affected on the scan, but would this really produce diminished hearing in the contralateral ear? I thought bilateral innervation would prevent this, and that if anything the neurological impairment should be ipsilateral.

(3) In the absence of imaging confirmation, should I simply assume that the individual had multiple strokes to produce this complex of multifocal findings? This is the answer I'm leaning towards...but wanted a more senior/educated opinion first.

Thanks in advance.


-Dan

 

[bonran]

With cortical strokes, one often sees a "tongue deviation" (to the untrained eye) due to the underlying facial droop. Did you check for the alignment of the median raphe of the tongue with the upper incisors?? (it can be misleading if the person has a cross bite). Did you notice any atrophy in the tongue muscles ipsilateral to te side of the lesion?

As for the hearing loss, your exam is incomplete. Did you look inside the ear for causes of conduction deafness- most common being impacted ear wax? Where is the Weber's & Rinne's test? Was it a conduction or sensineural type of hearing loss? Were there associated symptoms ie tinnitus or nystagmus?

It is not possible to get a unilateral hearing loss with cerebral strokes unless the patient is a neuroanatomical freak. Herchel's gyrus has bilateral afferents (from both ears). One can have unilateral sensineural hearing loss from damage to neurons upto the cochlear nuclei in the medulla. Above it the neurons cross over & supply both hearing areas equally.

I guess we need to learn the importance of a complete physical exam as done by the "dinosaurs" of neurology before interpreting images.

 

[danielmd06]

With cortical strokes, one often sees a "tongue deviation" (to the untrained eye) due to the underlying facial droop. Did you check for the alignment of the median raphe of the tongue with the upper incisors?? (it can be misleading if the person has a cross bite). Did you notice any atrophy in the tongue muscles ipsilateral to te side of the lesion?

As for the hearing loss, your exam is incomplete. Did you look inside the ear for causes of conduction deafness- most common being impacted ear wax? Where is the Weber's & Rinne's test? Was it a conduction or sensineural type of hearing loss? Were there associated symptoms ie tinnitus or nystagmus?

Thanks for the reply.

(1) The tongue clearly protruded to the left, it was not an illusory phenomenon secondary to the facial droop. The raphe was left of the central incisors. There were no fasciculations or asymmetry of the tongue muscluature to my eye.

(2) The ear canal was clear, without debris or cerumen appreciated on otoscopic exam. There was no associated tinnitus, whooshing or hissing sounds, and no nystagmus.

I admittedly did not perform a Weber or Rinne test, nor did I check for orbital or temporal bruits.

 

[AlternateSome1]

My guess would be that she has neglect to hearing on the left rather than true hearing loss. Does she show other signs of neglect?

The tongue isn't a big surprise. The 12th can have asymmetric supranuclear innervation.

 

[bonran]

If there was no tongue atrophy, it is unlikely that this was a XII nerve ischemia. Medial medullary strokes with XII n. involvement usually lead to a hypotonia of the ipsilateral glossal muscles within minutes of the stroke. I have seen these develop within minutes in front of my eyes in the ER. Also, it is unusual for these patients to have an isolated XII (never seen it in the 4-5 cases I have seen), they require intubation due to involvement of the dorasl motor nu. of X n. & motor afferents to the pharyngeal Mm. in the pyramids with loss of tone of the pharynx & inability to maintain their airway. The stroke itself is due to pathology in the paramedian perforators of the lower basilar artery, vertebral artey or in the anterior spinal artery.

There is also contralateral hemiparesis & contralateral loss of joint position & vibration sense due to involvement of the motor tracts & the medial lemniscus.

Besides, isolated hearing loss of sudden onset occurs in AICA strokes. which is a mid-basilar branch artery. So if this patient had a clot extending from one of his verts to the AICA, it would have given him the stroke you describe. However, any patient with that kind of clot burden is first, extremely rare & secondly, usually ends in a neuroangio suite or six feet under.

I still think what you saw was a "tongue deviation" due to a facial droop. However, as I was not there myself, discussing this on a board will lead to no where.

 

[danielmd06]

My guess would be that she has neglect to hearing on the left rather than true hearing loss. Does she show other signs of neglect?

The tongue isn't a big surprise. The 12th can have asymmetric supranuclear innervation.

Yes. She had subjective numbness in the contralateral face, arm, and leg, specifically with extinction in the arm and leg.

Thank you for the info on the tongue!

 

[danielmd06]

I still think what you saw was a "tongue deviation" due to a facial droop. However, as I was not there myself, discussing this on a board will lead to no where.

Gee, thanks.

While I appreciate the offer of help, I fear you may have misunderstood the thread.

My purpose in posting was to inquire about neuroanatomy beyond my personal education level and internet searches that would explain the exam findings...not to discuss the quality of my exam. For instance, the post two entries prior to this one is well taken!

Yes, I am aware of the medial medullary syndrome. She clearly doesn't have one. Yes, an isolated AICA stoke (in addition to her aforementioned R MCA findings) would indeed give the hearing loss...you may have read in my post that I was concerned about multiple strokes beyond what was represented in the CT scan. Again, my post was asking if a single MCA distribution stroke could account for this complaint.

Thank you for trying to help.

 

[BlackFrancis33]

I think attributing hearing loss to neglect is more likely than true hearing loss. Remember all sensory modalities can be involved in a neglect syndrome. We all memorize stroke syndromes, this is important. But the nervous system is incredibly complex and often disappoints you with your ability to localize. I have seen peripheral looking CNVII's for example after subcortical infarcts so the supranuclear innervation is not always as the textbooks suggest. The important thing is going through this exercise with each patient and explaining the deficits as best you can, obviously you are doing this on a regular basis. But sometimes you have to be willing to accept the fact that you can't explain it all based upon what is known about the anatomy. It sure is fun though, isn't it?

 

[danielmd06]

It sure is fun though, isn't it?

It absolutely is...and I love it. Thanks for the reply and the answer.