click below
click below
Normal Size Small Size show me how
VEP interpretation 1
Visual evoked potential interpretation 1
Question | Answer |
---|---|
Binocular absence of VEPs | Technical problems; ocular abnormalities; lack of fixation or acuity; severe bilateral optic nerve defects |
Monocular absence of VEPs | Optic neuropathy, ocular diosrders |
Prolonged VEP latency | optic nerve lesion |
Increased VEP latency | Optic nerve lesion |
Increased interocular VEP latency difference | Optic nerve lesion |
Monocular decreased VEP amplitude | Ocular lesion |
Binocular decreased VEP amplitude | Ocular lesions or chiasmal lesion, any bilateral prechiasmal or chiasmal lesion; low amplitude with normal latencies may be normal |
Abnormal bilateral temporal VEPs | lesion at or near the optic chiasm |
Abnormal corresponding field VEPS | Lesion of the posterior visual pathways, the optic radiations or visual cortex |
Abnormal monocular hemifield VEP | Incomplete optic nerve lesion |
Pattern reversal VEP abnormalities with neurologic lesions in the ocular region | Absence of VEP, low amplitude VEP |
Pattern reversal VEP abnormalities with neurologic lesions in the optic nerve region | Absence of VEP, increased full field VEP latency, increased interside VEP latency difference |
Pattern reversal VEP abnormalities with neurologic lesions in the optic chiasm region | Abnormal bilateral full field VEP, bilateral temporal half-field VEP |
Pattern reversal VEP abnormalities with neurologic lesions in the optic tract | Abnormal bilateral corresponding half-field VEP; full field VEP may be normal |
Pattern reversal VEP abnormalities with neurologic lesions in the occipital cortex | Abnormal bilateral corresponding half field VEP; full field VEP may be normal |