Table 1 Evidence table of the included studies

Dispenza et al., 2011 [33]

33 WAD (36.5y, 21–53)

23 CON (30.4y, 19–49)

WAD (without loss of consciousness)

1–12 months after accident

video-oculography:

velocity 18°/s;

fully- automated analysis

SPNT

neutral: WAD 0.86, CON 0.87

torsion to the right : WAD 0.87

torsion to the left: WAD 0.86

SPNT-diff: WAD 0

type of WAD not described, selection of controls not described,

no SP in relatively rotated position tested in controls

Grip et al., 2009 [39]

6 WAD (28y)

20 CON (32y)

WAD

>3 months after accident

electro-oculography

gaze stability;

sequential eye and head movement (SEHM)

gaze stability: WAD: head angle reduced (no exact data)

SHEM: WAD: mean angular head velocity reduced (no exact data)

small population (n = 7)

no individual data, results presented in boxplots

Heikkila et al., 1998 [20]

27 WAD (38.8y, 18–66)

25 CON (34y, 25–40y)

acute WAD II, III (without loss of consciousness)

electro-oculography:

velocity 20°/s and 30°/s;

fully- automated analysis

SP

30° right rotation of the eyes: WAD 2× abnormal;

30° left rotation of the eyes: WAD 5× abnormal;

20° right rotation of the eyes: WAD 2× abnormal;

20° left rotation of the eyes: WAD 0× abnormal

only SP in neutral position tested, no torsion of the neck

only quantity of abnormal scores provided, no individual data

Janssen et al., 2015 [40]

11 WAD, 44 non-WAD (44.2y, 25–67)

20 CON (28.4, 20–51)

WAD

> 6 months after accident

video- oculography:

frequency 0.4Hz;

0°, 15°, 30° and 45° chair position;

predictable and unpredictable stimuli;

semi- automated analysis

SPNT

SPNTdiff predictably: WAD 0.08, non-WAD 0.05, CON 0.02

SPNT unpredictably: WAD 0.01, non-WAD 0.01, CON 0

no specification of grade of WAD

Kelders et al., 2005 [23]

8 WAD (32y, 25–42)

8 CON (35y, 30–45)

WAD I, II, III

5–36 months after accident

video- oculography

cervico-ocular reflex

COR higher in WAD than in CON^a

little data provided, only graphs

Kongsted et al., 2007 [36]

34 WAD (39.4y, 20–51)

60 CON (40y, 18–63))

WAD I, II, III

> 6 months after accident

electro-oculography:

max velocity 37°/s; frequency 0.2Hz; fully- automated analysis

SPNT

neutral: WAD 0.9, CON 0.96 (median)

torsion to the right: WAD 0.89, CON 0.94

torsion to the left: WAD 0.93, CON 0.95

SPNTdiff: WAD 0, CON 0

patient population heterogeneous regarding symptoms, disability and duration of symptoms

Montfoort et al., 2006 [21]

13 WAD (40y, 26–60)

18 CON (36y, 23–64)

WAD I, II

video-oculography

cervico-ocular reflex;

vestibulo-ocular reflex;

optokinetic reflex

COR: P = 2.9 × 10^−6a

VOR: P = 0.27

OKR: P = 0.25

only comparison between groups, no individual data

Montfoort et al., 2008 [22]

COR: 10 WAD (42y, 22–52), 10 CON (31y, 18–54)

VOR: 10 WAD (39y, 19–56), COR 30y, 24–39)

WAD I, II

video-oculography

cervico-ocular reflex;

vestibulo-ocular reflex;

optokinetic reflex

COR adaptation:

WAD ∆G = 0.13 ± 0.24,

CON ∆G = −0.19 ± 0.06^a

VOR adaptation:

WAD ∆G = 0.037 ± 0.062,

CON

∆G = −0.2 ± 0.072^a

no comparison between characteristics of patients and controls, little data provided

Prushansky et al., 2004 [35]

26 WAD (40.3y, 25–55)

23 CON (34.2y, 18–54)

WAD II, III

6–84 months after accident

electro-oculography:

velocity 0.75 m/s; no information about type of analysis

SPNT

neutral: WAD 0.79^a, CON 0.86

torsion to the right: WAD 0.74, CON 0.82

torsion to the left: WAD 0.75, 0.80

SPNTdiff:

WAD 0.026, CON 0.035

remarkable variation in duration of neck pain;

no information about velocity in degrees per second

Tjell et al., 1998 [34]

50 WAD D (39y, 18–60)

25 WAD ND (34y, 21–63)

≥ WAD II

> 6 months after accident

electro-oculography:

velocity 20°/s; frequency 0.2Hz; manual analysis

SPNT

SPNTdiff: WAD D 0.14^a; WAD ND 0.10^a; CON 0.02

vague exclusion criteria for controls: tension in neck

Treleaven et al., 2005 [37]

100 WAD:

50 WAD D (35y, 19–46)

50 WAD ND (35y, 18–46)

50 CON (30y, 19–45)

WAD II

> 3 months after accident

electro-oculography:

velocity 20°/s; frequency 0.2Hz;

semi- automated analysis

SPNT

neutral: WAD ND 0.82, CON 0.88^a

torsion to the right: WAD ND 0.78, CON 0.88^a

torsion to the left: WAD ND 0.74, CON 0.87^a

SPNTdiff: WAD D 0.11^a; WAD ND 0.07, CON 0.01^a

Treleaven et al., 2006 [16]

50 WAD D (35.5y, 19–46)

50 WAD ND (35y, 18–46)

40 CON (29.6y, 19–45)

WAD II

> 3 months after accident

electro-oculography:

velocity 20°/s; frequency 0.2Hz;

semi- automated analysis

SPNT

WAD D: 45 abnormal SPNT scores

WAD ND: 39 abnormal SPNT scores

only quantity of abnormal scores provided, no individual data

Treleaven et al., 2008 [41]

20 WAD (46.5, 40–60)

20 CON (49.5y, 43–59)

WAD with dizziness,

> 3 months after accident

electro-oculography:

velocity 20°/s; frequency 0.2Hz;

semi- automated analysis

SPNT

SPNTdiff: WAD ~0.12^a; CON ~ <0.02^a

no specification of grade of WAD;

only graphic presentation of data, no exact values

Treleaven et al., 2011 [19]

20 WAD (37y)

20 CON (33y)

WAD

symptoms >3 months, < 5 year

electro-oculography

gaze stability;

sequential eye and head movement (SEHM)

gaze stability: WAD 27.7^a/30.5^a, CON 44.5/43.5 (degrees of head ROM right and left)

WAD 16.9/20.2, CON 33.0/37.4^a (head rotation velocity in degrees/s)

SHEM: WAD 23.6/30, CON 36.9^a, WAD 30, CON 36.9/36.9^a (head rotation velocity in degrees/sec)

remarkable variation in duration of neck pain