Horizontal Gaze Disorder Flashcards
What is the other name for Conjugate disorder?
Internuclear Ophthalmoplegia
What is damaged in internuclear ophthalmoplegia?
It is in the name
Medial Longitudinal Fasiculus- That runs from one abducens nucleus to other eye’s CN 3 nucleus.
In internuclear ophthalmoplegia, what function is spared and why?
Convergence is spared.
Because Convergence doesn’t require this pathway, agar yeh pathway damage ho bhee jaayay tou usko ghanta faraq nahyin parray ga.
In internuclear Ophthalmoplegia——-> What happens to the affected eye?
Affected eye cannot move toward the nose
In internuclear Ophthalmoplegia————-> What happens to the unaffected eye?
Unaffected eye develops nystagmus.
Left internuclear ophthalmoplegia means Left MLF is damaged,
Which eye is the affected eye?
Left ino will be visible when the person looks at?
Left eye is the affected eye.
Left ino will be visible when the person looks at right. Because while looking at right, right doesn’t need MLF to work, but affected eye needs MLF to move medially towards nose. So left eye/affected eye will be frozen.
Problem looking right= Left MLF lesion
Agar right INO hai, tou kahaan daekhein gey tou defect visible hoga?
(left or right?)
Left daekhein gey tou defect will be visible.
INO jiss side ka hota hai, iss sey opposite daekhein tou defect visible hota hai.
What happens to an abducting eye when the eyes are directed in a direction where the INO will become visible?
The INO will become visible in the direction opposite to the actual side of the INO defect,
So adducting eye will be frozen and abducting eye will have nystagmus/saccades
What can internuclear Ophthalmoplegia be confused with?
Abducens Nerve Palsy.
What is the characteristic horizontal gaze in Abducens Nerve Palsy?
EYES LOOK TOWARDS EACH OTHER.
Converged eyes!!!!!!!
When do eyes converge in an abducens Nerve Palsy?
They converge when the eye looks in the direction same as that of the defect.
For example———> Left Abducens nerve palsy will cause the eyes to converge when the eyes look towards left.
Difference between diagnosing Abducens Nerve Palsy and Internuclear Ophthalmoplegia?
Internuclear Ophthalmoplegia will manifest itself in the gaze opposite to the side of the defect. E.g. Left INO will be diagnosed when gaze is towards right.
Abducens Nerve Palsy will manifest itself as convergence when the gaze looks ipsilateral to the side of the defect.
Eg. Left Abducens nerve Palsy will cause converged eyes when gaze is towards left.
What part of brainstem if lesioned will cause PPRF lesion?
Medial Pons Lesion
What other lesion in brainstem can manifests exactly as that of PPRF lesion?
Abducens Nucleus lesion.
Both are found in Medial Pons.
Damage to Abducens Nucleus/PPRF causes what kind of gaze palsy?
Can’t look laterally on the side of the defect.
