Vestibular Concussion Rehabilitation Sheri Fedor PT, DPT, NCS
Objectives Understand the central and peripheral vestibular system structure and function Discuss vestibular, ocular, and balance screening for health professionals VOMS administration and clinical utility Describe the components of a vestibular assessment Explain the treatment of common vestibular impairments after concussion
Vestibular System 3 components: Peripheral sensory apparatus Membranous and bony labyrinths and hair cells Central processor Cerebellum, cerebral cortex, brainstem Mechanism for motor output Vestibulo-ocular reflex
Central Vestibular System Comprised of: Vestibule (sensory organ) 8th cranial nerve (vestibularcochlear) Brainstem vestibular nuclei Cerebellar pathways Vestibular cortex Thalamus
Central Vestibular System
Peripheral Vestibular System 3 Semicircular canals Sense rotational movement and velocity Otoliths: utricle & saccule Linear acceleration Vestibular ganglia Vestibular nerve
Peripheral Vestibular System Semicircular Canals: Each contains an enlarged area known as the ampulla Ampulla Contains innervated hair cells embedded in sensory epithelium called crista ampullaris Cilia of the hair cells (stereocillia) extend into gelatinous cap called the cupula
Peripheral Vestibular System Semicircular Canals Located at 90 angles to each other for each plane of movement Function- Receptors in canals detect rotation and velocity. Semicircular canals send impulses to the cerebrum through the vestibular nerve
Vestibulo-ocular Relex (VOR) Reflex eye movement that stabilizes images on retina during head movement 3 Neuron Arc: Vestibular Ganglia: Afferent fibers: semicircular ducts Vestibular Nuclei: Neurons send axons to nuclei of extraocular muscles through medial longitudinal fasciculus Oculomotor Nuclei: Motor Neurons: Send axons to the extraocular muscles
VOR
VOR (VOR) Reflex eye movement that stabilizes images on retina during head movement When the head moves to the right the eyes move to the left Fastest active reflex Shortest latency
VOR Properties of VOR Gain Stimulus: response relationship Slow component eye velocity/head velocity Eye velocity 30 o /s =.5 Head velocity 60 o /s Normal Gain = 1
VSR Vestibular Spinal Reflex (VSR) Maintains postural stability Comprised of several reflexes
VOR/VSR Function Vestibulo-Ocular Reflex (VOR) Stabilize image on retina while head moves Vestibulo-Spinal Reflex (VSR) Coordinate head and neck movement with body and trunk Postural Control VOR and VSR should be assessed separately because they have separate neuronal circuitry Patients who report dizziness do not always report decreased balance and vice versa (Cullen 2012; Allum 2012; Lau 2011)
Screening For Vestibular/Ocular Motor Impairment after Concussion
Vestibular Ocular Motor Screen (VOMS) Developed to screen vestibular and ocular motor impairment after concussion Population Age 9-40 When used with patients outside of this range interpretation may vary Equipment: Tape measure (cm), Metronome, Target 14 point font print Baseline Symptoms: Headache, dizziness, nausea, and fogginess symptoms 0-10 (severe) scale ***Abnormal findings or symptoms ³ 2/10 on any test should cause a referral to a specialized health care professional (Mucha et al., 2014)
VOMS The VOMS consists of brief assessments in the following five domains: 1. Smooth Pursuits 2. Horizontal and Vertical Saccades 3. Near Point Convergence 4. Horizontal Vestibular Ocular Reflex 5. Vertical Vestibular Ocular Reflex 6. Visual Motion Sensitivity Following each assessment: Patient rates changes in: Headache, dizziness, nausea, and fogginess symptoms 0-10 (severe) scale 5 min total (Mucha et al., 2014)
VOMS- Screening Form (Mucha et al., 2014)
VOMS- Smooth Pursuit Test the ability to follow a slowly moving target. The patient and the examiner are seated. The examiner holds a fingertip at a distance of 3 ft. from the patient. The patient is instructed to maintain focus on the target as the examiner moves the target smoothly in the horizontal direction 1.5 ft. to the right and 1.5 ft. to the left of midline. One repetition is complete when the target moves back and forth to the starting position, and 2 repetitions are performed. The target should be moved at a rate requiring approximately 2 seconds to go fully from left to right and 2 seconds to go fully from right to left. Repeat with the examiner moving the target smoothly and slowly in the vertical direction 1.5 ft. above and 1.5 ft. below midline for 2 complete repetitions up and down. Record: Headache, Dizziness, Nausea & Fogginess ratings after the test (Mucha et al., 2014)
VOMS- Saccades Test the ability of the eyes to move quickly between targets. The patient and the examiner are seated. Horizontal: Examiner holds two single points (fingertips) horizontally at a distance of 3 ft. from the patient, and 1.5 ft. to the right and 1.5 ft. to the left of midline so that the patient must gaze 30 degrees to left and 30 degrees to the right. Instruct the patient to move their eyes as quickly as possible from point to point. One repetition is complete when the eyes move back and forth to the starting position, 10 repetitions. Record: Headache, Dizziness, Nausea & Fogginess ratings after the test. Vertical: Repeat the test with 2 points held vertically at a distance of 3 ft. from the patient, and 1.5 feet above and 1.5 feet below midline so that the patient must gaze 30 degrees upward and 30 degrees downward. Record: Headache, Dizziness, Nausea & Fogginess ratings after the test (Mucha et al., 2014)
VOMS- Convergence Measure the ability to view a near target without double vision. The patient is seated and wearing corrective lenses (if needed). Examiner sits in front of the patient and observes their eye movement during this test. Patient focuses on a small target (approximately 14 point font size) at arm s length and slowly brings it toward the tip of their nose. The patient is instructed to stop moving the target when they see two distinct images or when the examiner observes an outward deviation of one eye. The distance in cm. between target and the tip of nose is measured and recorded. Repeated 3 times & record measures each time Record: Headache, Dizziness, Nausea & Fogginess ratings after the test Abnormal: Near Point of convergence 6 cm from the tip of the nose (Mucha et al., 2014)
Convergence Insuffiency Binocular vision disorder in which the eyes have a tendency to drift outward with close work Symptoms: Eye strain Frontal Headaches Diplopia Losing place with reading Words moving on page Difficulty concentrating
Convergence Insuffiency Approximately 42% of athletes had convergence insuffiency within one month of concussion Athletes with convergence insuffiency had higher symptom scores and worse outcomes on neurocognitive testing (Pearce et al 2015)
VOMS- Gaze Stability Assess the ability to stabilize vision as the head moves horizontally. The patient and the examiner are seated. The examiner holds a target of approximately 14 point font size in front of the patient in midline at a distance of 3 ft. The patient is asked to rotate their head horizontally while maintaining focus on the target. The head is moved at an amplitude of 20 degrees to each side and a metronome is used to ensure the speed of rotation is maintained at 180 beats/minute (one beat in each direction). One repetition is complete when the head moves back and forth to the starting position, and 10 repetitions are performed. Record: Headache, Dizziness, Nausea & Fogginess ratings after the test Perform series for vertical and horizontal gaze stability (Mucha et al., 2014)
VOMS- Visual Motion Sensitivity Test visual motion sensitivity and the ability to inhibit vestibular-induced eye movements using vision. The patient stands with feet shoulder width apart, facing a busy area of the clinic. The examiner stands next to and slightly behind the patient, so that the patient is guarded but the movement can be performed freely. The patient holds arm outstretched and focuses on their thumb. Maintaining focus on their thumb, the patient rotates, together as a unit, their head, eyes and trunk at an amplitude of 80 degrees to the right and 80 degrees to the left. A metronome is used to ensure the speed of rotation is maintained at 50 beats/min (one beat in each direction). One repetition is complete when the trunk rotates back and forth to the starting position, and 5 repetitions are performed. Record: Headache, Dizziness, Nausea & Fogginess ratings after the test (Mucha et al., 2014)
Interpreting the VOMS Any VOMS item symptom score ³ 2 and NPC distance ³ 5cm represent clinically useful cut-offs (Mucha et al., 2014) 3 VOMS items (VOR, VMS, NPC distance) resulted in 89% accuracy for identifying patients with concussion (Mucha et al., 2014) Initial research provides preliminary support for the utility of the VOMS as a brief vestibular/ocular motor screen following SRC (Mucha et al., 2014) Similar Findings: Measuring NPC and optokinetic stimulation (moving striped visual stimulus) adds to sensitivity and specificity of discriminating concussed athletes from controls in the subacute stage. Optokinetic stimulation was the most sensitive measure for discrimination (McDevitt et al., 2016)
Interpreting the VOMS 0 0 0 0 0 0 0 0 2 2 1 1 2 2 1 1 4 2 1 3 0 0 0 4 0 2 0 4 0 3 4 0 6 cm 10 cm 14 cm Is this screen abnormal? Would you make a referral? Where?
Interpreting the VOMS Healthy subjects: Internal consistency of the VOMS was high (Cronbach a =.97) 11% false-positive rate Female athletes and those with a personal history of motion sickness were more likely to have 1 VOMS symptom score above cutoff levels Sport Related Concussion: Females more likely to have higher VOMS VOR score Females had higher PCSS scores (Kontos et al., 2016; Sufrinko et al., 2016)
Balance Screening and Assessment
Sensory Organization Testing Computerized Dynamic Posturography Vision Somatosensation Vestibular Gold standard for measuring motor and sensorineural contribution to balance
Sensory Organization Testing Computerized Dynamic Posturography Objectively measure postural sway and center of pressure (COP) under 6 testing conditions as the feet shoulder width apart Equilibrium Score: quantifies the center of gravity (COG) sway or postural stability under each of the three trials of each of six sensory conditions (higher scores indicative of better balance)
Sensory Organization Testing Clinical test of Sensory Interaction and Balance (CTSIB) Arms at side, Feet together Condition: 1.Stand on firm surface, eyes open 2.Stand on firm surface, eyes closed 3. Stand on firm surface, visual conflict dome (not included in mctsib) 4.Stand on foam surface, eyes open 5.Stand on foam surface, eyes closed 6.Stand on foam surface, visual conflict dome (not included in mctsib (Shumway-Cook & Horak, 1986)
Sensory Organization Testing BESS Test: 3 Postures Standing feet together Single-limb Stance Tandem Stance Firm/Airex Foam Surface Eyes Closed 20 seconds Scored by number of errors committed Currently no cut off scores (Riemann & Guskiewicz, 2000)
Vestibular Therapy Examination Symptoms of dizziness Decreased balance Nausea Light headed Sensation of motion Vertigo Difficulty in busy environments
Vestibular Therapy Examination Examination Components: Ocular Examination Smooth Pursuit Assessing quality: saccadic Saccades Assessing quality: hypometric, slow Abnormal: hypermetric- potentially more serious neurological finding Convergence/recovery ***Refer out to neuro optometry or neuro ophthalmology if moderate convergence insuffiency
Vestibular Therapy Examination Accommodation Age related norms Normal: R/L eye within 2 cm of each other Ocular Alignment Cover/uncover testing Cross Cover testing Refer to neuro optometry or neuro ophthalmology if there is a tropia or vertical misalignment
Vestibular Therapy Examination Vestibular Examination Gaze stability Visual motion sensitivity BPPV Balance Examination CTSIB BESS Dynamic balance
Vestibular Therapy Examination Benign Paroxysmal Positional Vertigo Benign Paroxysmal No permanent vestibular dysfunction Sudden, short lived (typically < 60 seconds) symptoms Positional Vertigo Dependent on head position Sensation of rotation Calcium carbonate crystals (otoconia) break and move into the semi-circular canals
BPPV Mechanism Post traumatic High velocity: Pedestrian vs car, motorcyclist, slip and fall on ice Low incidence rate post concussion Symptoms: Vertigo triggered by head positons: Laying down/sitting up Rolling over Looking up Bending over
Vestibular Therapy Exaination Testing for BPPV Bilateral Dix Hallpike Posterior/anterior canals Patient on exam table in long sitting head is rotated 45 toward PC test side Patient lowered quickly into supine with head extended 30 Patient reports: vertigo, dizziness, or falling Treatment Canalith Repositioning Maneuver
Treatment (Collins et al., 2014)
Vestibular Treatment Vestibular Physical Therapy Evaluation and Treatment of post-concussion dizziness and motion sensitivity Gaze stability Balance Oculomotor treatment of mild ocular dysfunction Assessment and treatment of BPPV
Vestibular Treatment- Balance Training Static Balance: Foam Rocker board Bosu Decrease BOS Feet together Tandem Single Leg Stance Dynamic head movements Visual imput Dynamic Balance: Walking with head turns Tandem ambulation Sport Specific Training Standing in narrow base of support throwing/catching Cheerleader standing in liberty position on elevated foam pad
Vestibular Treatment- Gaze Stability As tolerated, progress via increasing: Speed Duration Complexity of Background Surface Dynamic motion VORx2
Vestibular Treatment- VMS Training Habituation to the stimulus Start in quiet environment with one stimulus Use 2 dimensional videos- optokinetic videos Use of backgrounds Training in busy environments
Literature Vestibular rehabilitation may reduce dizziness and improve gait and balance after concussion and is not age dependent (Alsalaheen, 2010) In a RCT of sport related concussion, Treatment group: cervical and vestibular PT 73% (11/15) of participants were medically cleared within 8 weeks of treatment 7% (1/14) of control group were cleared within same time frame (Schneider, 2013)
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