VAN Stroke Scale

What is the VAN screening tool?

The Vision, Aphasia, Neglect (VAN) screening tool is a clinical assessment method used primarily in the evaluation of acute ischemic stroke patients, specifically to identify large vessel occlusion (LVO) strokes. A large vessel occlusion stroke is caused by a blockage in one of the major arteries of the brain, and it requires rapid identification and treatment, often including endovascular therapy.

Here are the VAN scale's components:

• Vision: This component assesses visual field defects. Patients are evaluated for any loss of vision or visual field cuts, which can indicate an issue with certain brain regions like the occipital lobe or specific large vessels like the posterior cerebral artery.
• Aphasia: This part of the assessment focuses on language. Aphasia refers to the impairment of language ability. The evaluation might include tasks like naming objects, repeating phrases, or following commands. Speech and language comprehension issues can point to dysfunction in brain areas such as the temporal or frontal lobes, often supplied by the middle cerebral artery.
• Neglect: This component assesses signs of neglect, a condition where the patient ignores or is unaware of one side of their body or the space around them. Neglect can be a sign of a stroke in the brain's right hemisphere, which may affect awareness and attention to the left side of the body and environment.

The VAN screening tool is specifically designed to quickly identify strokes that might benefit from advanced treatments like thrombectomy (a procedure to remove a blood clot from a blood vessel). It's valuable because it focuses on identifying symptoms associated with blockages in large vessels, which are crucial to recognize early for effective treatment.

In clinical settings, emergency medical services (EMS) personnel, nurses, and physicians often use the VAN tool to rapidly assess stroke symptoms and expedite decision-making regarding stroke care, particularly in deciding whether to transfer a patient to a comprehensive stroke center capable of performing rapid endovascular treatment.

Compared to other screening tools, such as the Cincinnati Prehospital Stroke Scale, the Rapid Arterial Occlusion Evaluation (RACE), and the Los Angeles Motor Scale (LAMS), the VAN Stroke Scale has shown a higher positive predictive value for detecting emergent large vessel occlusion (ELVO) strokes, particularly in patients with suspected ischemic strokes.

While the National Institutes of Health Stroke Scale (NIHSS) has a high negative predictive value (100%) for ruling out an emergent large vessel occlusion stroke (Teleb et al., 2016), it is not considered prehospital friendly due to its complexity (Curry, n.d.). By contrast, VAN’s simplicity makes it suitable for rapid prehospital use, especially by EMS personnel. Additionally, VAN’s streamlined approach helps identify patients who may benefit from advanced stroke interventions, such as thrombectomy, ensuring timely treatment.

How to use our VAN Stroke Scale template

Our VAN Stroke Scale template offers a structured approach for assessing patients with suspected strokes. The template includes fields for recording patient information, observations, and results for each component of the VAN assessment. Follow these steps to administer the test:

Step 1: Access the template

You can use our template by clicking the "Use template" button in the Carepatron app or downloading a non-customizable version by selecting "Download." Print the template and keep it handy for easy use during patient evaluations.

Step 2: Visual assessment

Perform the visual field test by asking the patient to cover one eye and focus on the nose. Wiggle your fingers in their visual field's quadrants and ask them to indicate when they see the movement. Record the results in the template.

• Normal vision: No visual field deficits in either eye.
• Abnormal vision: Partial or complete visual field deficits, such as hemianopia or quadrantanopia, may indicate LVO stroke.

Step 3: Aphasia assessment

Evaluate the patient's language abilities by asking them to name objects, repeat phrases, and follow commands. Document their performance.

• No aphasia: The patient can understand and express language normally.
• Aphasia present: Difficulty with language comprehension or production indicates a potential stroke in the left hemisphere.

Step 4: Neglect assessment

Assess for neglect by asking the patient to attend to both sides of their body or space. Use tasks like line bisection or figure copying.

• No neglect: The patient responds equally to both sides.
• Neglect present: Ignoring one side, particularly on bilateral stimulation, is abnormal and points to right hemisphere involvement.

Step 5: Interpreting the overall VAN results

After all the assessments are done, start interpreting the results

• All components normal: A normal VAN result reduces the likelihood of an LVO stroke but doesn't rule it out.
• Any abnormal component: If vision, aphasia, or neglect are abnormal, further evaluation, including neuroimaging, is needed.
• Multiple abnormalities: The presence of two or more abnormalities strongly suggests LVO stroke, requiring immediate intervention.

Use this insight in planning your next steps, which we will discuss next.

Next steps

After conducting the VAN Stroke Ccale, the general steps include:

• Assessment interpretation: Evaluate VAN results to identify potential LVO stroke.
• Medical response activation: If LVO stroke is suspected, activate a stroke code for immediate response.
• Comprehensive neurological evaluation: Conduct a full neurological examination, potentially including other stroke scales such as the Cincinnati Stroke Scales or the NIHSS Stroke Scale.
• Advanced imaging: Perform urgent brain imaging, like CT or MRI, to confirm diagnosis.
• Stroke team consultation: Consult with a multidisciplinary stroke team for treatment planning.
• Treatment decision: Decide on treatment, considering thrombolytic therapy or mechanical thrombectomy as options.
• Specialized care transfer: Transfer to a stroke center if necessary for advanced care.
• Monitoring and supportive care: Provide continuous monitoring and manage vital functions.
• Rehabilitation and education: Plan for rehabilitation and educate the patient and family about stroke recovery, using resources like the Stroke Nursing Care Plan and the Stroke Impact Scale.
• Secondary stroke prevention: Initiate measures to reduce the risk of another stroke.
• Follow-up planning: Arrange for ongoing care and follow-up appointments.
• These steps ensure comprehensive care and management for stroke patients, from initial assessment to rehabilitation and prevention of future strokes.

Benefits of the VAN Stroke Scale

The VAN screening tool is a valuable asset in stroke assessment. Let's take a peek at its strong suits:

• Rapid LVO stroke identification: Quickly identifies large vessel occlusion strokes.
• Simple and easy to use: Accessible to various healthcare providers.
• Facilitates early intervention: Helps expedite treatments like thrombectomy.
• Improves triage and resource allocation: Streamlines patient management.
• Flexible: Usable in prehospital and emergency settings.
• Complementary: Can be paired with other stroke assessment tools for a comprehensive evaluation.

Limitations of the VAN Stroke Scale

While the VAN scale certainly has some strengths, it also comes with some drawbacks that you should account for:

• Scope limitation: Focuses on LVO strokes and might miss other types.
• Accuracy issues: Potential for false positives or negatives.
• Training variability: Results may depend on provider experience.
• Symptom onset misjudgment: Mistiming symptom onset may affect test results.
• Limited use in certain demographics: Effectiveness can vary among different populations.

These limitations underscore the need for its use in conjunction with other diagnostic tools and clinical judgment for effective stroke management.

When to use this assessment

The VAN (Vision, Aphasia, Neglect) assessment is specifically used in the following situations:

• Suspected stroke cases: To quickly assess patients with potential stroke symptoms.
• Pre-hospital screening: EMS personnel and other emergency department staff can use it for on-site assessment.
• Initial hospital evaluation: Employed in emergency departments for rapid diagnosis.
• Triage for imaging/treatment: Helps prioritize patients for advanced imaging or treatment like thrombectomy.
• Monitoring in hospital settings: Used in stroke units for patients at risk of stroke or showing worsening symptoms.

References

Curry, J. C. (n.d.). The prehospital VAN stroke assessment prehospital evaluation for large vessel occlusions. https://www.heart.org/-/media/files/affiliates/swa/qi-files/van-assessment-for-lvo-detection--james-curry.pdf

Teleb, M. S., Ver Hage, A., Carter, J., Jayaraman, M. V., & McTaggart, R. A. (2016). Stroke vision, aphasia, neglect (VAN) assessment—a novel emergent large vessel occlusion screening tool: pilot study and comparison with current clinical severity indices. Journal of NeuroInterventional Surgery, 9(2), 122–126. https://doi.org/10.1136/neurintsurg-2015-012131