Subjective Visual Vertical Test

Last Updated

November 12, 2013

Purpose

The purpose of the subjective visual vertical test is to assess a person’s perception of verticality; vestibular tone imbalance may affect this perception.

Acronym SVV Test

Area of Assessment

Vestibular

Assessment Type

Performance Measure

Cost

Free

Diagnosis/Conditions

Vestibular Disorders

Vestibular Disorders

Hemispheric dome method: Patients sit with their chin resting on a fixed pad and looking into a hemispheric dome. The dome is 60 cm in diameter and completely fills one’s visual field. The dome is characteristically covered with a random pattern of colored dots, providing no cues to gravitational orientation. Thirty centimeters in front of the subject is a linear target whose center is fixed on the shaft of a computer-controlled servomotor. During the test, the target is rotated in the subject’s frontal plane according to examiner specifications. Following random rotation of the target from vertical, the patient is instructed to align the target with his or her perceived vertical using a joystick device. Differences between the patient’s adjusted orientation and true spatial vertical are calculated by the examiner using the system computer taking the average of 10 readjustments. SVV is determined binocularly (Zwergal et al., 2009).
Bucket method: Patients sit upright and look into a translucent plastic bucket; the visual field is covered completely by the rim of the bucket. On the bottom, inside the bucket, there is a dark, straight, diametric line. On the bottom outside there is a perpendicular line originating from the center point of a quadrant divided into degrees with the zero line adjusted to the dark line inside. For measurement the bucket is randomly rotated right or left by the examiner (to exclude haptic clues) to various end positions and then slowly rotated back to the zero degree position. Patients signal when they estimate the inside bottom line to be truly vertical by saying “stop.” Degrees are read off on the outside scale by the examiner. Measurements can be made with both eyes open (binocular) and with one eye covered (monocular left/right) (Zwergal et al, 2009).
Light bar: Patients are seated upright with the head restrained or unrestrained 1.5 meters in front of a wall. Patients are instructed to gaze at a dim, wall mounted light bar (30 x 1 cm) in a completely darkened exam room. Prior to testing, the examiner positions the bar at an oblique angle. During testing, the light bar is rotated by the examiner about its center axis according to the patient’s verbal instruction until the bar reaches the patient’s perception of verticality (“as it would coincide with a plumb line”) (Bohmer & Rickenmann, 1995).

Number of Items

Bucket SVV device
Hemispheric dome SVV device
Light bar SVV device

20 minutes

Average time for hemispheric dome testing = 15 minutes.
Average time for light bar testing = not reported
Average time for bucket testing = 5 minutes (Zwergal et al, 2009).

Required Training

Training Course

Child

6 - 12

years

Adolescent

13 - 17

years

Adult

18 - 64

years

Instrument Reviewers

Jennifer L. Stoskus, PT, MSPT, DPT and Matthew R. Scherer PT, PhD, NCS of the Vestibular EDGE task force of the Neurology section of the APTA.

ICF Domain

Body Function

Measurement Domain

Sensory

Professional Association Recommendation

Recommendations for use of the instrument from the Neurology Section of the American Physical Therapy Association’s Multiple Sclerosis Taskforce (MSEDGE), Parkinson’s Taskforce (PD EDGE), Spinal Cord Injury Taskforce (PD EDGE), Stroke Taskforce (StrokEDGE), Traumatic Brain Injury Taskforce (TBI EDGE), and Vestibular Taskforce (Vestibular EDGE) are listed below. These recommendations were developed by a panel of research and clinical experts using a modified Delphi process.

For detailed information about how recommendations were made, please visit: http://www.neuropt.org/go/healthcare-professionals/neurology-section-outcome-measures-recommendations

Abbreviations:
HR	Highly Recommend
R	Recommend
*LS / UR*	Reasonable to use, but limited study in target group / Unable to Recommend
NR	Not Recommended

Recommendations for use based on acuity level of the patient:

Acute

(CVA < 2 months post)

(SCI < 1 month post)

(Vestibular < 6 weeks post)

Subacute

(CVA 2 to 6 months)

(SCI 3 to 6 months)

Chronic

(> 6 months)

(Vestibular > 6 weeks post)

Vestibular EDGE

Recommendations based on vestibular diagnosis

	Peripheral	Central	Benign Paroxysmal Positional Vertigo (BPPV)	Other
Vestibular EDGE	LS	LS	LS	NR

Recommendations for entry-level physical therapy education and use in research:

	Students should learn to administer this tool? (Y/N)	Students should be exposed to tool? (Y/N)	Appropriate for use in intervention research studies? (Y/N)	Is additional research warranted for this tool (Y/N)
Vestibular EDGE	No	No	No	Yes

Considerations

Subjective Visual Vertical as measured with the “bucket test” lacks the robust evidence base necessary for a stronger test psychometric rating; however, with increased research the strong feasibility of the bucket test (relative to the dome or the light bar), could provide a low-cost, easily administered metric for use in laboratory as well as clinical settings.
Monocular measurements tend to reveal a greater degree of SVV deviation than binocular measurements (Dieterich and Brandt, 1992)
SVV is a reliable tool to aid topographical diagnosis: Brainstem lesions caudal to the upper pons commonly result in ipsiversive tilts (i.e., toward the side of the lesion); upper brainstem lesions commonly result in contraversive tilts (i.e. away from the lesion side) (Dieterich and Brandt, 1993)
SVV correlates strongly with Ocular Tilt Response (Dieterich and Brandt, 1993)
SVV deficits in persons with UVH diminish significantly during sub-acute (~11 days) and chronic (~47 days) evaluation time frames suggesting that this evaluation technique may be more useful for assessment during the acute phase (Kim et al 2008).
Diagnostic utility above the level of the brainstem is limited. The effects of lesions in cortical vestibular processing regions (2v, 3a, posterior insula), specific thalamic nuclei, upper vestibular pathways, and cerebellar structures (flocculus, nodulus, uvula, and fastigial nucleus) on eye verticality is still poorly understood (Dieterich and Brandt, 1993)
Bucket test is useful for describing spatial deficits in patients however not useful for screening people for possible vestibular impairments due to low ROC curve characteristics (Cohen et al 2012).

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Cut-Off Scores

Brainstem Lesion/ Central Pathology:

(Dieterich and Brandt, 1993; n = 111, mean age = 49 with unilateral vascular brainstem lesion, control n = 110; 20 per decade 20-60 yr, 10 for decade 10-20)

> 2.5 degrees considered pathological (hemispheric dome)

Unilateral Vestibular Loss S/P Labyrinthectomy:

(Friedmann, 1971; labyrinthectomy due to Meniere’s Disease n = 6, mean age = 48.8 years; labyrinthectomy due to cochleo-saccular degeneration = 5, mean age = 27.4)

± 2 degrees pathological (light bar)

Unilateral Vestibular Weakness and BPPV:

(Cohen and Sangi-Haghpeykar, 2012; n = 100: Unilateral Vestibular Weakness n = 25, mean age = 58.3; BPPV n = 25, mean age = 60.1; control n = 50, mean age = 49.5)

1.3 degrees on normal side for those < 50 with a sensitivity = 0.77, specificity = 0.72

Normative Data

Peripheral Vestibular Dysfunction:

Study	Sample Characteristics n =	Mean Age (years)	Mean Subjective Visual Vertical on involved side (degrees)	Measurement Acuity/ Method
Friedmann, 1971	Labyrinthectomy due to Menieres Disease n = 6	48.8	Range = 8.8 - 18	Within 1 week after surgery Light bar
	Labyrinthectomy due to cochleo-saccular dysfunction n = 5	27.4	Range = 0.2 - 7.1◦	Within 1 week after surgery
Bohmer and Rickenmann, 1995	Acute vestibular neuronectomy n = 10	Not reported	1.3 ± 5.8◦ Range = 4.8 - 21.4	2 weeks after surgery Light bar
	Chronic vestibular neurectomy n = 8		1.2 ± 2◦ Range = 2.0 - 6.4	6 months - 20 years Light bar
	Vestibular neuritis n = 20		6.8 ± 7.1◦ Range = -0.2 - 33.0	Within 2 weeks after onset of symptoms Light bar
	BPPV n = 19		0.2 ± 0.8◦ Range = -1.2 - 2.4	9 days - 8 years after diagnosis (no treatment given) Light bar
Kim et al 2008	Unilateral Hypofunction n = 51	59.3	6.8 ± 4.3◦ (Binocular)	0 - 7 days, average = 3 days Light Bar
			Not reported	8 - 15 days, average = 11 days Light Bar
			Improved to < ± 2 in 20% of patients	27 - 57 days average = 47 days Light Bar
Zwergal et al, 2009	Total n = 30 Vestibular neuritis n = 15 Unilateral brain infarctions n = 12 Unilateral Neurectomy n = 3	51.3 ± 17.1	Dome method = 8.9 ± 5.4 Bucket method: 8.3 ± 5.0	Not reported Dome Bucket
Faralli et al, 2011	Posterior canal BPPV n = 30	Mean age = 52	R BPPV = 0.88 ± 0.50 L BPPV = -0.62 ± 0.47	Immediately before repositioning
			50% of patients demonstrated reversal of SVV	Immediately after repositioning
			R = 0.25 ± 0.78 L = 0.04 ± 0.66	1 week after repositioning
Cohen and Sangi-Haghpeykar 2012	Unilateral vestibular weakness n = 25	58.3	Normal side: 1.9 ± 1.5 Abnormal side:2.3 ± 1.8 Normal + abnormal side: 2.1 ± 1.7	Mean length of diagnosis: 127 weeks
	BPPV n = 25	60.1	2.1 ± 1.5	Mean length of diagnosis: 34.8 weeks

Cervicogenic Headache:

Study

Sample Characteristics

n =

Mean Age (years)

Subjective Visual Vertical on involved side (degrees)

Measurement

Acuity/

Method

Dieterich et al, 1993:

cervicogenic headache

n = 14

42.8

11/12 WNL

(< 2.5^◦)

1/12

Patient with 6^th CN palsy demonstrated

-2.7 ^◦ before, -4.7^◦ after a C2-blockade

4.3 years

Dome

Central Vestibular:

Study	Population tested/ n =	Mean Age (years)	Mean Subjective Visual Vertical (degrees)	Measured
Dieterich and Brandt, 1992	Wallenberg syndrome (lateral medullary lesions) and Mesodiancephalic lesions (Intersticial Nucleus of Cajal and rostral medial longitudinal fasciculus) n = 36	54	NOTE: Normative values estimated from figure. Grade I: ~3±1^◦ ^{(N = 7)} ^ Grade II: ~7±3^◦ ^{(N = 10)} ^ Grade III: ~13±6^◦ ^{(N = 16)} ^ Grade IV: ~25±8^◦ ^{(N = 3)} ^** Range = 2.7-53.3^◦(different monocular values, each eye)	Day 1- week 9 (mean = 11-19 days) Dome
Dieterich and Brandt, 1993	Unilateral vascular brainstem lesion (acute) n = 111	49	Mean tilt angle = 8.1 ± 5^◦ Range = 2-26^◦	Not reported (acute) Dome
Zwergal et al, 2009	Total n= 30 Vestibular neuritis n = 15 Unilateral brain infarctions n = 12 Unilateral Neurectomy n = 3	51.3 ± 17.1	Mean tilt angle = 8.9 ± 5.4^◦ Mean tilt angle: 8.3 ± 5.0^◦	Not reported Dome Bucket

Control Groups:

Study	n =	Mean Age (years)	Mean Subjective Visual Vertical (degrees)
Dieterich and Brandt, 1993	n = 110: 20 per decade 20-60+, 10 for decade 10-20	Range 11-60	10-20 yr: 0.1 ± 0.9^◦ 21-30 yr: 0.2 ± 0.7^◦ 31-40 yr: 1.2± 0.9^◦ 41-50 yr: 0.35 ± 1.1^◦ 51-60 yr: 0.1 ± 1.2^◦ > 60 yr: -0.05 ± 1.2^◦ ^Dome
Bohmer and Rickenmann, 1995	Control group n = 25	Range 13-57	Mean: -0.1 ± 0.6^◦ Range = -1.8- 1.0^◦ Light bar
Zwergal et al, 2009	Healthy controls n = 30	41.6 ± 16.4	Mean (Dome method): 1.1 ± 0.9^◦ Mean (Bucket Method): 0.9± 0.7^◦
Farella et al 2011	Control group n = 20	Not reported	Mean = 0.1 ± 0.73^◦
Cohen and Sangi-Haghpeykar, 2012	Controls n = 50	49.5	Mean (total group) = 1.2 ±0.75^◦ Range = 0–3.2^◦ Mean (control <50 yrs) = 1.1 ± 0.7^◦ Range = 0–3.0^◦ Mean (control >50 yrs) = 1.2 ± 0.8^◦Range = 0–3.2^◦

Test/Retest Reliability

Vestibular Neuritis, Unilateral Brain Infarction, Unilateral Neurectomy, Healthy Control:

(Zwergal et al, 2009):

Excellent test-retest reliability: Pearson’s r = 0.92

Internal Consistency

Vestibular Neuritis, Unilateral Brain Infarction, Unilateral Neurectomy, Healthy Control:

(Zwergal et al, 2009):

Inter-test reliability of dome compare to bucket

Excellent agreement for Binocular assessment: Pearson’s r = 0.90
Excellent agreement for Monocular assessment: Pearson’s r = 0.89

Criterion Validity (Predictive/Concurrent)

Unilateral Vascular Brainstem Lesion:

(Dieterich and Brandt, 1993):

Excellent sensitivity: 94% sensitive to patients with unilateral vascular brainstem lesion with abnormal SVV to the pathologic side.
Good correlation between SVV of ipsilateral and contralateral eyes- Spearman coefficient alpha = 0.59, n = 70, p < 0.001

Construct Validity

Convergent Validity

Vestibular Hypofunction:

(Kim et al 2008)

Investigators identified abnormal SVV in patient with acute VH: 94% (48/51); and sub-acutely at 6 weeks: 25% (10/40) (chronic VH)
% Agreement between abnormal Occular Torsion (OT) on SVV and vestibular function tests in acute (n = 51) / chronic (n = 40) vestibulopathy:
- (+) Head Impulse Test: 100%/ 45%
- (+) Head Shaking Nystagmus Test:
  - Acute: 100%, SVV abnormality = 21 + 8.9° (range 15-67°)
  - Chronic: 80%, SVV abnormality = 6.7 + 2.5° (range 3.7 - 10.5°)
- Caloric Asymmetry/ Canal Paresis (> 25%)
  - Acute: 100%, 73 + 20% (range 38-100%)
  - Chronic: 78%, 51 + 34.5% (range 0-100%)
- Abnormal Cervical VEMP to lesioned side
  - Acute: 49% (25/51)
  - Chronic: 15% (6/40)

Face Validity

Friedmann, 1971:

Spontaneous improvement in SVV in patients noted in 1-6 weeks

Dieterich and Brandt, 1992:

Dramatic and spontaneous improvement of SVV in first 4 weeks with significant improvement (p < 0.001) in weeks to months

Brandt et al, 1994:

Repeated tests tended to show spontaneous recovery in patient (acute and sub-acute with unilateral supratentorial infarctions)

Bohmer and Rickenmann, 1995:

SVV normalized in patients with vestibular neuritis within 1-24 months.

Faralli et al, 2011:

SVV typically inaccurate on the ipsilesional side with acute BPPV, found to reverse in some patients immediately following a maneuver with full resolution of SVV in most patients 1 week after resolution of symptoms.

Bibliography

Böhmer, A. and Rickenmann, J. (1995). "The subjective visual vertical as a clinical parameter of vestibular function in peripheral vestibular diseases." Journal of vestibular research: equilibrium & orientation.

Brandt, T., Dieterich, M., et al. (1994). "Vestibular cortex lesions affect the perception of verticality." Ann Neurol 35(4): 403-412. Find it on PubMed

Cohen, H. S. and Sangi-Haghpeykar, H. (2012). "Subjective visual vertical in vestibular disorders measured with the bucket test." Acta Otolaryngol 132(8): 850-854. Find it on PubMed

Dieterich, M. and Brandt, T. (1992). "Wallenberg's syndrome: lateropulsion, cyclorotation, and subjective visual vertical in thirty-six patients." Ann Neurol 31(4): 399-408. Find it on PubMed

Dieterich, M. and Brandt, T. (1993). "Ocular torsion and tilt of subjective visual vertical are sensitive brainstem signs." Ann Neurol 33(3): 292-299. Find it on PubMed

Faralli, M., Manzari, L., et al. (2011). "Subjective visual vertical before and after treatment of a BPPV episode." Auris Nasus Larynx 38(3): 307-311.

Friedmann, G. (1971). "The influence of unilateral labyrinthectomy on orientation in space." Acta Otolaryngol 71(4): 289-298. Find it on PubMed

Gomez Garcia, A. and Jauregui-Renaud, K. (2003). "Subjective assessment of visual verticality in follow-up of patients with acute vestibular disease." Ear Nose Throat J 82(6): 442-444, 446. Find it on PubMed

Kim, H. A., Hong, J. H., et al. (2008). "Otolith dysfunction in vestibular neuritis: recovery pattern and a predictor of symptom recovery." Neurology 70(6): 449-453. Find it on PubMed

Zwergal, A., Rettinger, N., et al. (2009). "A bucket of static vestibular function." Neurology 72(19): 1689-1692. Find it on PubMed

Last Updated

Purpose

Area of Assessment

Assessment Type

Cost

Diagnosis/Conditions

Number of Items

Required Training

Instrument Reviewers

ICF Domain

Measurement Domain

Professional Association Recommendation

Considerations

Summary of Human Ankle Mechanical Impedance During Walking

Design and Testing of a Bionic Dancing Prosthesis

Cut-Off Scores

Normative Data

Test/Retest Reliability

Internal Consistency

Criterion Validity (Predictive/Concurrent)

Construct Validity

Face Validity

Bibliography

Four Square Step Test

Berg Balance Scale, BBS

Dynamic Gait Index