Double Vision due to Damage to Cranial Nerve IV

Discussion in 'Eye-Care' started by amul.gupta, Jan 12, 2005.

  1. amul.gupta

    amul.gupta Guest

    My 8 year old son injured his right eye-lid while sledding on Christams
    day 2004. His sled went into brushes and most likely a tree branch hit
    his eye-lid causing the injury. He got 3 stitches on his right eye-lid.
    The wound seems to have healed well and his stitches were removed 5
    days after the injury.

    A detailed exam of his eye by two opthalmologists did not reveal any
    damage to the retina or the optic nerve. That's the good part.
    However, he now has double vision which is consistently seen in the
    down vertical position and also in the right tilt position.

    An MRI of the brain and the orbits did not reveal anything remarkable.
    A pediatric opthalmologist feels the double vision is most likely
    caused by IV nerve palsy. He feels very optimistic that this problem
    will self-correct, albeit in several months.
    I would appreciate any insights any one has to offer regarding this.
     
    amul.gupta, Jan 12, 2005
    #1
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  2. I'm not a doctor, and don't treat patients, but have some experience with
    eye movements.

    The description of double vision on down gaze is consistent with a
    trochlear palsey (that's nerve IV). The deviation is also worse when the
    head is tilted toward the side of the problem--check. This head tilt
    test is part of the diagnostic criteria. For a trochlear palsey, when
    the head is tilted down on the side of the lesion (the right side in this
    case), if you look at the eyes, the right eye would appear to be looking
    up compared to the left eye (a right hypertropia).

    The most diagnosed cause for this is head trauma, which is sometimes
    mild--also consistent. The MRI ruled out some other possible causes.
    The "bible" of clinical eye movements says that "If the results of
    inaging of the head and orbit are normal, and test results for diabetes
    and myasthenia are negative, then the outcome is usually favorable".
    With the onset involving the mild trauma, diabetes and myasthenia don't
    seem real likely.

    The MRI was probably appropriate to rule out some nasty stuff, and the
    description seems very appropriate for trochlear palsey given the normal
    MRI. Sounds like you've seen some good ophthalmologists.

    Scott
     
    Scott Seidman, Jan 12, 2005
    #2
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  3. amul.gupta

    Dr. Leukoma Guest

    I am not a strabismologist, but have seen numerous cases of acquired CN
    IV palsy, with most of those being idiopathic or due to trauma. I wish
    I could be as optimistic, but I cannot remember a single case of
    remission. Maybe improvement, but not total recovery.

    DrG
     
    Dr. Leukoma, Jan 12, 2005
    #3
  4. amul.gupta

    Dr. Leukoma Guest

    I hasten to add that the patient usually adopts a compensatory head
    posture to alleviate the double vision.

    DrG
     
    Dr. Leukoma, Jan 12, 2005
    #4
  5. Emedicine cites a Mayo study stating that ideopathic cases have a greater
    than 50% chance of sponteneous recovery, and that trauma cases were less
    likely to recover, but half these cases show some degree of improvement.

    http://www.emedicine.com/oph/topic697.htm

    Leigh and Zee doesn't say anything much beyond "favorable".

    There's also some surgical procedures available if this doesn't resolve,
    and these procedures seem to have good results. I would think that it
    makes sense to wait to see if it goes away on its own before going that
    route, but the docs probably can offer much better advice on this than I
    can.

    Scott
     
    Scott Seidman, Jan 12, 2005
    #5
  6. amul.gupta

    amul.gupta Guest

    Dear Dr. Leukoma,

    Thanks for your reply, I appreciate it a lot. At the time of my son's
    injury, I didn't notice any bruise or cuts on his forehead and skull.
    He was wearing a woolen hat and a parka though, so it possible that he
    did have an impact on his forehead along with the injury to the eyelid.
    I say all this to talk about the cause of the IV th nerve palsy which
    is suspected to be the cause of double vision.

    Given that there are no obvious signs of head trauma (also supported by
    unremarkable MRI of the brain and the orbits), could the IV th nerve
    have been damaged by the penetrating injury to the surface of the
    eye-lid?

    I recall the pediatric opthalmologist measured the degree of
    misalignment, and I believe it was 6 Diaopters. As I mentioned
    earlier, he thinks this will self-correct in 6 months. However, as a
    parent it has been extremely difficult to just let the faith keep me
    patient.

    Amul
     
    amul.gupta, Jan 13, 2005
    #6
  7. amul.gupta

    Dr. Leukoma Guest

    Amul,

    The degree of misalignment is relatively small. From what I know of
    the anatomy of the nerve, it inserts into the body of the muscle too
    far back into the orbit to have been damaged from whatever pierced the
    eyelid. What there any direct damage to the globe?

    Anyway, time will tell. The MRI was negative, and your son hasn't any
    brain injury -- looking on the bright side, of course.

    DrG
     
    Dr. Leukoma, Jan 13, 2005
    #7
  8. amul.gupta

    amul.gupta Guest


    Dear Dr. Leukoma,

    Thanks again your response. Yesterday, I took my son to the same
    opthalmologist who treated him on the day of the injury. His
    assessment of the double vision is that it is most likely due to a
    mechanical obstruction of the various eye muscles. One scenario being
    the 2 muscles behind the eye-lid are not moving freely. The assumption
    here is that whatever pierces the skin of the eye-lid might have caused
    some damage to the muscle. That said, the doctor felt this was less
    likely because my son is able to move the globe down, albeit not all
    the way.

    Another scenario he raised was a hair-line fracture in the bone under
    the eye which might have caused some restriction of the muscle. When I
    brought the liklihood of IV th nerve palsy, he opined that double
    vision due to nerve damage would be in ALL positions, unlike my son's
    case where he complains of it in downgaze and right tilt. He
    recommends waiting for six weeks (at least this recommendation is the
    same as that of the pediatric opthalmologist who thinks there is IV th
    nerve palsy). However, I am torn as to what diagnosis I should trust
    more.

    Now the answer to your question. We were told in ER that there was
    some laceration of the white of the eye. On follow-up visit, the
    pediatric doctor said the laceration was healing okay. There was a big
    red spot to right of the pupil but it is pretty much gone away. I see
    faint reddishness in his eye now. In conclusion, I don't believe there
    was damage to the globe. Thanks again.

    Regards,

    Amul
     
    amul.gupta, Jan 14, 2005
    #8
  9. amul.gupta

    g.gatti Guest

    Now, given your premises, what hampers you in starting the
    self-treatment with rest methods?

    You cannot do any harm, if not to the business of the doctors.
    Enquire better in the true science of the eye!
     
    g.gatti, Jan 14, 2005
    #9
  10. amul.gupta

    Dr. Leukoma Guest

    Of course, there is the possibility that some trauma may have occurred
    directly to the muscle or its insertion, except that the insertion of
    the superior obliques is slightly posterior to the equator, hence its
    primary action as a depressor in temporal gaze.

    In cases of orbital floor fracture, the inferior rectus/oblique may
    become entrapped, causing restriction of elevation.

    I also disagree that a fourth nerve palsy would cause diplopia in all
    positions, as that has never been my experience. This is why patients
    abopt a compensatory head tilt to eliminate double vision.

    I will say a little prayer for your son. The accident could have had a
    much worse outcome.

    DrG
     
    Dr. Leukoma, Jan 15, 2005
    #10
  11. amul.gupta

    RM Guest

    Because I too believe that the trochlear nerve inserts too far back in the
    orbit to be affected by a something piercing the eyelid, I wonder whether
    the diplopia may not be caused by muscle swelling associated with the
    trauma. Perhaps the globe is being prevented from making a complete range
    of movements by simple mechanical forces? If this is true, then time and
    healing could be on your side. In anycase, it seems like a case of "wait
    and see".
     
    RM, Jan 15, 2005
    #11
  12. amul.gupta

    g.gatti Guest

    healing could be on your side. In anycase, it seems like a case of
    "wait

    All cases are of "wait and see".
    The problem is the circumstances into which you force your patients to
    "wait and see".

    Usually, you force them to stay into strain, effort, suffering.
    Why you do this?
     
    g.gatti, Jan 15, 2005
    #12
  13. amul.gupta

    amul.gupta Guest

    Dr. Leukoma,

    Thanks again for your insights. Today marked 3 weeks since my son's
    accident. While we are still in the wait and see mode, I do think
    about how lucky we are in some ways as this accident could have been
    much worse. While no one has been able to tell us for sure whether our
    son will ever get back to normal vision, we are definitely sure and
    thankful to God that this could have been much worse. I now realize
    this may be the only way to keep ourselves optimistic amidst the
    sometimes uneasy uncertainty of medical field.

    One more question for you Sir. Assuming that the double vision does not
    completely go away on its own and surgery is not recommended, can the
    remaining double vision be corrected with Prism lenses (I think I read
    about that somewhere)? My son has 20/40 vision and needed glasses
    anyway as of his checkup two months ago, but his optometrist told us to
    wait. Anyways, if the answer to my question is yes, are there any
    downsides to that? Finally, what about vision therapy? There seems to
    be plenty of info. on that on internet. Please advise. Thanks,

    Amul
     
    amul.gupta, Jan 16, 2005
    #13
  14. amul.gupta

    Dr. Leukoma Guest

    Dear Amul,

    In answer to your question, I have used prism to help patients with
    fourth nerve palsy. My most recent case actually underwent surgery.
    While it did not completely resolve the double vision, it did change
    the position of the double vision from down gaze to up gaze. This
    meant that he could read without double vision. Because the magnitude
    of the deviation is not constant and changes depending on eye position,
    there is no single prescription that will eliminate double vision in
    all fields of gaze. In this case, the patient had a residual amount of
    deviation in the straight-ahead and down gaze which was of a fairly
    constant value, and so I prescribed it. He will still experience
    double vision when looking up beyond the midline.

    However, nature endows the visual system with great resilience. Your
    son will probably eventually come to suppress one of the images, tilt
    the head, and so forth. Unfortunately, I know very little about the
    utility of vision therapy in treating this type of problem. In school,
    it was taught that paralytic strabismus is fairly difficult to manage
    with therapy. One would think that therapy could be useful, since it
    has great utility in other areas of rehabilitation. It should be
    possible for a limited amount of damaged nerve to be regenerated, or at
    least on would hope.

    DrG
     
    Dr. Leukoma, Jan 16, 2005
    #14
  15. amul.gupta

    retinula Guest

    WTF are you talking about?
     
    retinula, Jan 17, 2005
    #15
  16. The primary action of the superior oblique is intorsion. Depression in
    temporal gaze is a secondary action. The latter might be more noticable
    clinically becuase torsion is not a foveating movement, but its still a
    secondary action. Abduction is a tertiary action.

    Scott
     
    Scott Seidman, Jan 17, 2005
    #16
  17. amul.gupta

    amul.gupta Guest

    Dr. Leukoma,

    Many thanks for educating me on issues related to double vision.
    Yesterday, I consulted a neurologist family friend of mine, who
    continues to believe that the root cause of my son's double vision is
    most likely 4th nerve damage. But he also was very optimistic of this
    nerve healing over time (perhaps a few months).

    I will keep you posted on how things are progressing, as we wait for
    our next appointment with the doctor(s) in late Feb.

    Finally, this may be of little help now, but as I was explaining to my
    neurologist friend yesterday the events in the ER on the day of injury,
    I mentioned that the attending opthalmologist injected anasthesia just
    below my son's eyebrow prior to stitching his cut skin. After
    listening to this, my neurologist friend raised the possibility of the
    injection itself potentially causing some trauma to the nerve, though
    he did say this is uncommon (maybe 1 in 10). If so, nothing can be
    done about that. I guess those things do happen (my friend also
    acknowledged that he may have done that too inadvertently in his 35
    plus years of practice).

    Be that as it may, we will wait and keep on praying and see what
    happens.

    Thanks again,

    Amul
    PS; Thanks to all who have contributed to this discussion, I have
    learned a lot.
     
    amul.gupta, Jan 17, 2005
    #17
  18. amul.gupta

    Dr. Leukoma Guest

    Thanks, for the revisit to ocular anatomy 101!

    Furthermore, the secondary action is depression on adduction and not on
    abduction.

    DrG
     
    Dr. Leukoma, Jan 18, 2005
    #18
  19. An ophthalmologist injecting anesthetic in this area stands almost NO chance
    of doing anything. You have to be at least a 1/2 inch into the orbit to even
    get at the tendon, which would not usually be damaged by an injection, The
    nerve itself it very deep in the orbit, and you would need a very loong
    neele to get anywhere near it.

    The issue is, it is a IV nerve palsy (due to head injury), or a mechanical
    restriction of the tendon due to local scarring/injury, a disrupted tendon,
    or a muscle palsy due to a sudden stretch. Certainly a penetrating injury
    to the tendon area can cause an inflammatory reaction that can cause
    restriction to eye movement. This can be usually sorted out of forced
    duction and active force generation testing in the office on a cooperative
    patient. (Age may be a limiting factor here.) If there is a restriction to
    passive movement, a local steroid injection may be of help, mainly in the
    relatively early stage. Once it is well healed, this would be of not real
    help.

    For example, I have seen a case of a finger injury to an eye, pushing it
    upwards rather hard. The inferior rectus seemed torn near its insertion, as
    the possible cause of the muscle weakness. However, suturing it back where
    it should be did not help - the muscle remained paretic (weak) as if the
    nerve was injured, which did not happen directly. However, just a vigorous
    stretch, as in this case, can cause a permanent muscle weakness.
     
    David Robins, MD, Jan 18, 2005
    #19
  20. You're right-- nasal gaze. I might not have it all down, but I'm glad my
    brainstem seems to get it right.

    Scott
     
    Scott Seidman, Jan 18, 2005
    #20
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