1. Differential Diagnosis of Dizziness and Vestibular Screening
How to screen the vestibular patient

2. Differential Diagnosis of Dizziness
What is dizziness?
Very subjective symptom, often described as:
Light headedness
Loss of balance
Dysequilibrium
Vertigo

3. Differential Diagnosis
Common Complaints
Considerations
Weakness, Fatigue, Light-Headedness
Tripping, Clumsy, Gait Abnormalities
Spinning/Vertigo***
Low BP, O2 Sat
Potential cardiac issues
Decreased coordination, strength or ROM
Potential neurologic or neuromuscular involvement
Vestibular Dysfunction

4. What is Vertigo?
“A sensation of motion in which the individual or the individual's surroundings seem to whirl dizzily”
-Webster
Dysequilibrium often occurs when a conflict between balance senses are unresolved or if the vestibular system is not functioning correctly.

5. Neuro Screens: Oculomotor Exam
Smooth Pursuits
Saccades
Vergence Testing
VOR Cancellation Test

7. Oculomotor Exam: Smooth Pursuits
“Draw a large, imaginary rectangle” in front of your patient with your pen.
Instruct your patient to “follow the pen with your eyes only, don’t move your head”
Observe for smooth pursuits of the eyes. Watch for abnormal, saccadic movements or end-range nystagmus.
This can be repeatable if you perform this test several times.
Saccades may be more observable with increased target speed.

8. Smooth Pursuits Video
Are the subject’s eyes moving smoothly or are there saccades?

9. Oculomotor Screen: Saccades
Hold a target inches next to your head.
Instruct your patient to look at the target, then look at your nose.
Try this in different directions including lateral and horizontal.
Observe for saccadic eye movements. Note the direction where you observe saccades.
Saccades are abnormal.

10. Saccade video
Does this subject move her eyes directly from target to target?

11. Oculomotor Screen: Vergence
Have your subject stare at your pen as you move it from 12” away to the subjects nose. Look t see if the subject can go cross-eyed.
Watch both eyes converge onto the pen.
Normally, the subject can converge up to 6cm away. Anything further away is abnormal.

12. Convergence Video
Does this subject have the ability to converge within 6cm?

13. Oculomotor Screen: VOR Cancellation Test
Have your patient clasp their hands in front of them. Instruct them to rotate their entire body side to side and ask the subject to look at their thumbs the entire time.
Watch the subject’s eyes as they look at their thumbs.
Eyes should be able to “cancel” the VOR and look at their thumbs the entire time.
Inability to cancel their VOR is abnormal.

14. VOR Cancellation Video
Is this subject able to “cancel” his VOR?

15. VOR Screening Head Thrust Test Dynamic Visual Acuity Test
Infrared/Frenzel Tests
Gaze Holding Nystagmus
Head Shake Test
These tests are sensitive to vestibular function and can be performed in most facilities. Infrared tests can be more expensive and I recommend taking the complete vestibular rehab course before considering purchasing one.

16. Be Advised….
These screens are NOT diagnostic tests. They are screens to assist with our evaluation of the patient and formulation of treatment plans.
Not any single screen is definitive. Performing several screens will help to determine the potential problem and its severity.
Tests are repeatable.

17. VOR Screen: Head Thrust Test
Hold your patient’s head firmly on both sides.
Instruct your patient to look at your nose while you turn their head from side to side. Advise the patient you will be moving their head slowly and also fairly quickly.
Tilt your patient’s head down degrees.
Slowly more your patient’s head side to side, then follow with a quick thrust in one direction.
Tilting your patient’s head down will put the horizontal canal in a more horizontal position relative to the ground.

18. VOR Screen: Head Thrust Test
Look for a “refixation” saccade or a delay to the side you are testing. The presence of a saccade is abnormal.
A positive head thrust test may be consistent with a vestibular hypofunction/weakness.

19. Head Thrust Test Video
Is the patient able to look at the tester’s nose with a head thrust?
A refixation saccade can be quite subtle, but it is repeatable and more observable with a quicker thrust.

20. Head Thrust Video #2 What observations can be made with this test?
This is more complicated being that this patient has end range nystagmus when looking to her left side. This is more likely a false positive as the nystagmus may look similar to a saccade in this test.

21. VOR Screen: Dynamic Visual Acuity Test
This test requires good lighting, a Lighthouse eye chart and 10 feet of distance from the patient to the eye chart.
Ask the patient to read each letter from left to right. Stop the patient when they make their second error.
While standing behind your patient, hold their head firmly on both sides and quickly turn their head side to side at a speed of 45 degrees each for up to 10 seconds.
I use the metronome app. 2hz is roughly two cycles per second which means 4 turns per second. I set it for 240 beats per minute.

22. VOR Screen: Dynamic Visual Acuity Test
Ask your patient to read the letters again while turning their head. Stop the patient when they make their second error.
The difference between the rows (in LogMar) should be < Anything greater than that is abnormal.
An abnormal test may be consistent with a vestibular hypofunction/weakness.
This is a good way to quantify the severity of the problem.

23. This eye chart uses LogMar on the sides which aids you with measuring DVA.

24. VOR Screen: IR/Frenzel Tests
IR and Frenzel goggles allow us to view the subject’s eye movements while eliminating the subject’s visual reference.

25. VOR Screen: IR/Frenzel Tests
Gaze Holding Nystagmus
Head Shake Test
Special Tests

26. IR Tests: Gaze Holding Nystagmus Video
Allows you to observe nystagmus in patients when it is not as apparent in room light.

27. IR Tests: Head Shake Test
Head shake test can increase observable nystagmus and help clarify direction.
Positive test may be consistent with a vestibular hypofunction/weakness

28. Head Shake Test
What is the direction of the nystagmus after the head shake test?
What does this mean?

29. Head Shake Nystagmus Video
What is the direction of the nystagmus after the head shake test?
What does this mean?

30. Special Test: Fukuda Test
Tests for vestibular involvement.
Have patient march in place with knees high, arms forward for up to 50 steps.
Observe the patient for safety, but also for rotation.
An observed rotation may be consistent with a vestibular dysfunction.
(Fukuda, 1959)

31. Group Exercise
Pick a partner and perform parts of the oculomotor exam.
Refer to the Group Exercise page.

32. Common Clinical Diagnoses
Vestibular Hypofunction/Dysfunction
Concussion
Benign Paroxysmal Positional Vertigo (BPPV)
Most General Diagnosis is Dizziness and Giddiness ICD10 R42
Dizziness and giddiness is non specific and is often the code given my primary MD’s and neurologists who have not performed diagnostic tests for these patients. This may include other diagnoses including central vestibular dysfunction,d meniere’s and

33. Vestibular Hypofunction
Diagnostic tests for this is Video Nystagmography (VNG) or Electronystagmography (ENG) which may quantify a patient’s overall weakness.
Patients present with severe onset of dizziness that lasts for days. May report oscillopsia once severity resolves.
Typical findings with vestibular screen may include:
Pos Head Thrust
Pos Head Shake Nystagmus
Spontaneous nystagmus with IR tests
Abnormal DVA (>3.0 Logmar)

34. Concussion Considered a mild TBI
Dizziness is common complaint with concussion (Zhou, 2015)
Up to 60 percent of these patients present with BPPV
This is an entirely different discussion, but we will touch on it as it is a hot topic in vestibular therapy.

35. Questions?