Vestibular Assessment

Transcription

1 Oculomotor Examination A. Tests performed in room light Vestibular Assessment 1. Spontaneous nystagmus 2. Gaze holding nystagmus 3. Skew deviation 4. Vergence 5. Decreased vestibular ocular reflex i. Head thrust test ii. Dynamic visual acuity 6. Visual tracking i. Smooth pursuit ii. Saccadic eye movement iii. VOR cancellation 7. Gait and balance i. Feet together ii. Heel/toe iii. Single limb stance iv. Modified CTSIB v. Timed 10m walk vi. Dynamic Gait Index B. Tests performed using Frenzel lenses or IR goggles 1. Spontaneous nystagmus 2. Gaze holding nystagmus 3. Decreased vestibular ocular reflex vii. Head shaking nystagmus 4. Manoeuvre induced vertigo and eye movement i. Hallpike Dix ii. Head roll test iii. Pressure test F:\Intranet\BIRU website\physiotherapy section\vestibular Testing Handout v.doc 1

2 Oculomotor Examination Prior to testing check eye movement ROM cervical ROM Eye movement ROM 2. Ask the patient to follow your finger (keeping it inches away from the patient s face) to test for full vertical and horizontal eye movements. ROM Conjugate eye movement Vertical movements decrease slightly in older people A small amount of end point nystagmus may be seen at the point of full ocular range in all directions, minimal in young people and increasing with age A. Tests performed in room light 1. Spontaneous Nystagmus 2. Ask patient to look straight ahead at a point several feet away. Nystagmus and note direction. 2. Gaze Holding Nystagmus 2. Ask patient to follow your finger (keeping it inches away from the patient s face) while you move your finger 30 degrees to the left, right, up and down. 3. Pause in each position to observe nystagmus, note direction. 3. Skew Deviation 2. Cover one eye. 3. Switch the cover from one eye to the other eye. a vertical corrective movement of the eye as it is uncovered Effect of direction of gaze on the skew deviation Any spontaneous tilt of the head and the effect of tilt on the skew deviation F:\Intranet\BIRU website\physiotherapy section\vestibular Testing Handout v.doc 2

3 4. Vergence 1. Hold the patient s forefinger in your hand about 2 feet away from the patient s face. 2. Ask the patient to focus on the finger while you move it toward the patient s nose. Convergence of the eyes Conjugate eye movement Pupillary constriction 5. Decreased vestibular ocular reflex (VOR) i. Head thrust test 1. Inform the patient that you will be moving their head very quickly, but only through a small range. 2. Grasp patient s head firmly with both hands on the sides of the head 3. Tilt the head forward 30 degrees so that the horizontal semicircular canal is level in the horizontal plane. 4. Instruct the patient to look at your nose. 5. Move the patient s head side to side slowly, making sure the patient is relaxed. 6. Then, suddenly move the patient s head in one direction and stop. The head movement should be small amplitude with the position held at the end. Patient s ability to maintain visual fixation Corrective saccades to re-fixate to your nose, noting the direction of head movement that caused re-fixation saccades. 7. Repeat the test with visual fixation on a distant target if corrective saccades are found with near target fixation. If the patient has pain or significant restriction of cervical movement, the test should be performed with extreme caution or deferred. ii. Dynamic visual acuity 1. Patient sits the appropriate distance from the acuity chart, wearing their glasses if they need distance correction. 2. Patient reads to the lowest line that they can until they cannot correctly identify all the letters on a given line. 3. Note the line where this occurs and the number of letters the patient incorrectly identifies. 4. Standing behind the patient, grasp patient s head firmly with both hands on the sides of the head. 5. Tilt the head forward 30 degrees so that the horizontal semicircular canal is level in the horizontal plane. F:\Intranet\BIRU website\physiotherapy section\vestibular Testing Handout v.doc 3

4 6. While moving the patient s head side to side at a frequency of 2Hz (2 complete side to side cycles per second) through a ROM of 1-2 inches in each direction, (so as to not restrict the visual field which may occur in patients who wear glasses) ask them to read to the lowest line that they can until they cannot correctly identify all the letters on a given line. 7. Note the line and where this occurs and or the number of incorrect letters. A difference of less than or equal to 2 lines is normal. A difference of greater than or equal to 3 lines is abnormal. (likely vestibular deficit) If the patient has restriction of the cervical movement which limits your ability to perform the head movement the test cannot be properly performed and should be ceased. 6. Visual tracking i. Smooth pursuit eye movements 1. Hold the patient s head with one hand. 2. ask the patient to follow your slowly moving finger (< 20 degrees per second) horizontally, 30 degrees from the centre to the left and to the right 3. Repeat this vertically, moving 30 degrees above and below the horizontal. You may have to hold the eyelids up in order to see the downward eye movement clearly. Smooth conjugate eye movement. Abnormal is jerky (or saccadic) eye movement. Note the direction of pursuit when saccades occurred. Eye movements may be saccadic if you are moving your finger too fast. Slow the speed of your finger to see it the person can follow smoothly. Smooth pursuit eye movements become more and more saccadic with age. Vertical eye movement is often interrupted by a saccade in younger individuals. ii. Saccadic eye movements 1. Hold the patient s head with one hand. 2. Hold your finger about 15 degrees to one side of your nose. 3. Ask the patient to look at your finger and then at your nose several times. Perform this left, right, up and down. The number of eye movements it takes for the patient s eyes to reach the target, normal is less than 2. F:\Intranet\BIRU website\physiotherapy section\vestibular Testing Handout v.doc 4

5 Abnormal is several small movements or a big movement and overshoot. You may have to ask the patient to only make one eye movement. If you can clearly see the eye the saccade is slow. iii. VOR cancellation 1. Grasp patient s head firmly with both hands on the sides of the head. 2. Tilt the head forward 30 degrees so that the horizontal semicircular canal is level in the horizontal plane. 3. Instruct the patient to look at your nose. 4. Move the patient s head from side to side approximately 30 degrees while you move in the same direction so that your face remains directly in front of the patient s face. Patient s ability to maintain visual fixation and/or if the patient makes saccadic eye movements. 7. Gait and balance i. Feet together 1. Position the patient 3 feet from a wall, facing toward it. 2. Patient stands, without shoes if possible, with their ankles touching each other and arms crossed over the chest with hands touching the opposite shoulders. 3. Time how long the patient can maintain this position with eyes opened, looking straight ahead to a maximum of 30 seconds. 4. Repeat the test having the patient close their eyes. Test is stopped if the patient moves their feet on the floor, changes the position of their arms or opens their eyes. In addition to timing the test, it is useful to rate the amount of sway. ii. Heel/toe 1. Position the patient 3 feet from a wall, facing toward it. 2. Patient stands with one foot directly in front of the other in a straight line, and arms crossed over the chest with hands touching the opposite shoulders. 3. Time how long the patient can maintain this position with eyes opened, looking straight ahead, to a maximum of 30 seconds. 4. Repeat the test having the patient close their eyes. Test is stopped if the patient moves their feet on the floor, changes the position of their arms or opens their eyes (for the eyes closed test). F:\Intranet\BIRU website\physiotherapy section\vestibular Testing Handout v.doc 5

6 iii. Single limb stance 1. Position the patient 3 feet from a wall, facing toward it. 2. Patient stands on one leg with their arms crossed over the chest with hands touching the opposite shoulders. 3. Time how long the patient can maintain this position with eyes opened, looking straight ahead, to a maximum of 30 seconds. 4. Repeat the test having patient close their eyes once they are in position. Legs should not touch each other Test is stopped if the patients legs touch each other, the feet move on the floor, the foot touches down or the arms are moved from their starting position or the eyes are opened (for the eyes closed test). iv. Modified CTSIB Patient stands (without shoes if possible) erect without moving, looking straight ahead as long as possible or until the trial is complete. Each test is performed 3 times. Condition 1: (normal vision, fixed support) 1. Patient stands on the floor with arms crossed over their chest and hands on opposite shoulders and feet together. 2. Time for a maximum of 30 seconds. Condition 2: (absent vision, fixed support) 1. Patient stands on the floor with arms crossed over their chest and hands on opposite shoulders with feet together and eyes closed. 2. Time for a maximum of 30 seconds. Condition 4: (normal vision, sway referenced support) 1. Patient stands on a 3 inch high density foam cushion with arms crossed over their chest and hands on opposite shoulders and feet together. 2. Time for a maximum of 30 seconds. Condition 5: (absent vision, sway referenced support) 1. Patient stands on a 3 inch high density foam cushion with arms crossed over their chest and hands on opposite shoulders with feet together and eyes closed. 2. Time for a maximum of 30 seconds. Sway should also be documented as minimal/ mild/ moderate/ or loss of balance. Test is stopped if the patient s arms are moved from starting position, feet are moved or eyes are opened (for eyes closed tests). Results from different pieces of foam cannot be compared. F:\Intranet\BIRU website\physiotherapy section\vestibular Testing Handout v.doc 6

7 v. Timed 10m Walk Patient stands two metres from the start of a 10m walking tack Ask the patient to walk as fast as they can safely past the line Time the patient between the start and finish lines using the same anatomical reference over the line. Time to walk 10m number of steps taken vi. Dynamic Gait Index Refer to assessment sheet. Patient may use an assistive device. Scores of 19 or less are related to falls in older adults. B. Tests performed using Frenzel lenses or IR goggles 1. Spontaneous Nystagmus 2. Ask patient to look straight ahead. Nystagmus and note direction. As for tests performed in room light 2. Gaze Holding Nystagmus 2. Ask patient to move their eyes to look 30 degrees to the left, right, up and down. 3. Pause in each position to observe nystagmus, note direction. If patient looks beyond 20 to 30 degrees, end point nystagmus may be observed rather than gaze holding nystagmus. 3. Decreased vestibular ocular reflex (VOR) i. Head shaking nystagmus test 1. Inform the patient you will be moving their head from side to side. 2. Grasp patient s head firmly with one hand on either side of the head 3. Tilt the head forward 30 degrees so that the horizontal semicircular canal is level in the horizontal plane. 4. Have the patient close their eyes. 5. Move the head side to side 20 times, asking the patient to help with the movement. 6. Ask patient to open their eyes quickly. F:\Intranet\BIRU website\physiotherapy section\vestibular Testing Handout v.doc 7

8 Nystagmus, noting direction 1 or 2 beats of nystagmus is not significant If horizontal head shaking induces persistent nystagmus the procedure should be repeated vertically, but only moving the patient s head 10 times. 4. Manoeuvre induced vertigo and eye movement i. Hallpike Dix 1. Patient long sits on the examination table and head is rotated The head and trunk are quickly taken straight back en bloc so that the head is over the edge of the examination table by Hold for 30 seconds, observing for nystagmus and question for vertigo. 4. Patient is then brought up slowly to a sitting position with the head maintained in 45 0 rotation. 5. Again, observe for nystagmus and question for vertigo. 6. Test is repeated with head rotated 45 0 in opposite direction. Nystagmus, noting direction, latency, and duration. Critical element is position of the head in space (not relative to the body). ii. Head roll test 1. Patient lies supine with the head flexed The head is turned quickly to one side. 3. Hold for 30 seconds, observing for nystagmus and question for vertigo. 4. Roll the head slowly back to the supine position, hold for 30 seconds. 5. Roll the head quickly to the other side. 6. Observe for nystagmus and question for vertigo. Observe nystagmus, noting direction, latency and duration. Ask the patient which side is worse. iii. Pressure test 1. Occlude the external auditory canal by applying pressure to the tragus. Nystagmus or a drift of the eyes, noting direction. F:\Intranet\BIRU website\physiotherapy section\vestibular Testing Handout v.doc 8