"Intensive care and emergency point of care ultrasonography literature typically uses the following cutoffs, as measured inner-edge to inner-edge, for the upper limit of normal of the ONSD 6:"
"Further degrees of ICP elevation result in a linear increase in ONSD up to 7.5 mm, at which the diameter appears to plateau. Confirmation that the measured diameter represents a fluid shift due to elevated ICP can be confirmed with a "30 degree test;" measurements are taken in primary gaze and 30 degrees from primary gaze."
"A decrease in ONSD by >15% width on 30 degree eccentric gaze is moderately specific for increased intracranial pressure as the aetiology of the elevated ONSD, while a negative test (no change in nerve sheath diameter on eccentric gaze) would suggest alternative aetiologies, e.g. infiltrative disease."
"A decrease in ONSD by >15% width on 30 degree eccentric gaze is moderately specific for increased intracranial pressure as the aetiology of the elevated ONSD, while a negative test (no change in nerve sheath diameter on eccentric gaze) would suggest alternative aetiologies, e.g. infiltrative disease."
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"Values"