santaclara
Forum Elite
Topics: 67
Posts: 299
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hey can u explain me swinging flashing light test?
and also how we check the cranial neve ii and iii with different tests?
pls explain me.
thanx.
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| vrach
Forum Junior
Topics: 3
Posts: 79
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Just testing myself. By "swinging flashing light", I'm assuming you meant the pupillary light reflex. I hope this explination helps.
Pupillary Light Reflex Pathway:
Light->retina->Optic nerve->Ipsilateral optic tract->Ipsilateral pretectal nucleus (situated just anterior to the superior colliculus of midbrain)->Accessory occulomotor nuclei (Edinger Westfall nuclei) bilaterally->occulomotor nerves bilaterally->constrictor pupillae muscels.
Optic Nerve Lesion (eg: Rt. eye):
-If light shined on Rt. eye: No pupillary constriction in Rt. and Lt. eye
-If light shined on Lt. eye: Pupillary constriction in both eyes (Lt. eye-direct light reflex; Rt. eye-consensual light reflex)
Opthalmic Nerve Lesion (eg: Rt. eye):
-If light shined on Rt. eye: No pupillary reflex in Rt. eye, but pupillary reflex present in Lt. eye-If light shined on Lt. eye: also No pupillary reflex in Rt. eye, but present in Lt. eye.
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| vrach
Forum Junior
Topics: 3
Posts: 79
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Please correct me if anyone finds anything wrong with my repply. Just started prep seriously.
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| mash
Forum Fanatic
Topics: 147
Posts: 1,326
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swinging light test is fr afferent pupillary defect (optic n lesions)
when light is presented to normal eye both pupils constrict(direct and consensual r normal)
when light is presented to affected eye, it will paradoxically dilate ....
this is ka marcus gunn pupil
pathway is light--->retina---->i/l optic nerve--->i/l optic tract---> i/l pretectal nucleus--->b/l edinger westphal nu.(3rd n.)--->b/l oculomotor nerves--->b/l pupillary constriction
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I hear and I forget. I see and I remember. I do and I understand.
--Confucius
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