Teleb et al reported the Vision, Aphasia, Neglect (VAN) assessment for identifying large vessel occlusion in a patient with acute stroke. This can help to triage the patient for effective therapy. The authors are from Banner Health and Brown University.
Patient selection: acute stroke
Parameters:
(1) exclusion based on arm weakness
(2) visual disturbance (V)
(3) aphasia (A)
(4) neglect (N)
VAN is negative if there is any weakness (mild, moderate, severe) in either arm with both arms raised up.
Exception: possible basilar artery thrombosis(comatose; confused with dizziness, focal findings or no reason for altered mental status). If a basilar infarct is possible then CT angiography should be considered.
|
Parameter
|
Finding
|
Points
|
|
visual disturbance
|
field cut
|
1
|
|
|
double vision
|
1
|
|
|
new onset of blindness
|
1
|
|
|
none of the above
|
0
|
|
aphasia
|
expressive
|
1
|
|
|
receptive
|
1
|
|
|
mixed
|
1
|
|
|
none of the above
|
0
|
|
neglect
|
forced gaze or unable to track to one side
|
1
|
|
|
unable to feel both sides at the same time
|
1
|
|
|
unable to identify own arm
|
1
|
|
|
ignoring one side
|
1
|
|
|
none of the above
|
0
|
where:
• Expressive aphasia is inability to speak or paraphrasic errors but not slurred words.
• Receptive aphasia is inability to understand or follow commands (close eyes, open fists).
Criteria for VAN positive:
(1) not excluded (above)
(2) sum of points for VAN parameters >= 1
A patient with a positive VAN assessment is likely to have a large vessel occlusion.
Performance for detecting large vessel occlusion:
• Sensitivity 100%, specificity 90%.
• Negative predictive value 100%.
