Visual Disorders and Mal De Debarquement Syndrome: a Potential Comorbidity questionnaire-based Study

Figures & data

Table 1. Sample description

	MT MdDS	NMT/SO MdDS		MdDS (combined)	General population
Respondent type, n (%)	146 (74.5%)	50 (25.5%)		196 (50.1%)	197 (49.1%)
Age (years), mean (SD)	51.4 (11.9)	47.1 (14.9)	t 71.7 = 1.853, p = 0.068 ^†	50.3 (12.8)	50.5 (13.0)	t 391 = -0.210, p = 0.834 ^†
Gender, n (%)
Female	136 (93.2%)	41 (82.0%)	p = 0.028 ^‡	177 (90.3%)	171 (86.8%)	p = 0.342 ^‡
Male	10 (6.8%)	9 (18.0%)		19 (9.7%)	26 (13.2%)
Age at onset (years), mean (SD)	44.1 (12.3)	38.3 (14.6)	t 194 = 2.775, p = 0.006 ^†	42.6 (13.2)	–

† Independent Samples t-test (two-sided significance).

‡ Fisher's exact test (two-sided significance).

Detailed data of the general population group and MdDS patients; MT and NMT/SO, including group number, gender and age. Data for onset age for MdDS patients only.

Bold p values are statistically significant.

MdDS: Mal de debarquement syndrome; MT: Motion-triggered; NMT/SO: Non-motion triggered/spontaneous-other; SD: Standard deviation.

Table 2. Associated symptoms

	MT (n = 146) (within group %)	NMT/SO (n = 50) (within group %)	Fisher's exact test (two-sided significance)	Total MdDS respondents, n = 196 (%)
Unsteadiness	117 (80.1%)	44 (88.0%)	0.285	161 (82.1%)
Brain fog	119 (81.5%)	37 (74.0%)	0.309	156 (79.6%)
Light sensitivity	104 (71.2%)	30 (60.0%)	0.160	134 (68.4%)
Anxiety	92 (63.0%)	34 (68.0%)	0.609	126 (64.3%)
Dizziness	56 (38.4%)	25 (50.0%)	0.183	81 (41.3%)
Depression	56 (38.4%)	24 (48.0%)	0.247	80 (40.8%)
Migraine	57 (39.0%)	21 (42.0%)	0.740	78 (39.8%)
Nausea	39 (26.7%)	21 (42.0%)	0.051	60 (30.6%)
‘Shaking’ peripheral vision	31 (21.2%)	17 (34.0%)	0.086	48 (24.5%)
Double vision	15 (10.3%)	17 (34.0%)	<0.001	32 (16.3%)

Comparison of the rate of associated symptoms expressed as a percentage of the MT and NMT/SO groups, and total percentage of all MdDS respondents.

Bold p values are statistically significant.

MdDS: Mal de debarquement syndrome; MT: Motion-triggered; NMT/SO: Non-motion triggered/spontaneous-other; SD: Standard deviation.

Table 3. Pre-existing visual disorders

	MdDS relative to general population OR (95% CI)	p-value	NMT/SO relative to MT OR (95% CI)	p-value
Visual Induced Dizziness	22.3 (2.9,167.7)	0.003	2.1 (0.8,5.6)	0.123
Binocular visual dysfunction	5.8 (1.3,26.5)	0.023	2.6 (0.8,8.9)	0.130
Myopia	0.8 (0.6,1.2)	0.385	1.1 (0.6,2.2)	0.719
Hyperopia	0.8 (0.5,1.3)	0.351	1.1 (0.5,2.4)	0.828
Glaucoma	Too few		Too few
Cataracts	0.9 (0.4,2.1)	0.847	2.2 (0.7,7.3)	0.195
Presbyopia	1.7 (0.9,3.2)	0.136	0.7 (0.2,2.0)	0.500
Astigmatism	0.6 (0.2,1.7)	0.317	1.5 (0.3,8.3)	0.657
None	1.1 (0.7,1.6)	0.805	1.1 (0.6,2.1)	0.770

Comparison of the frequency of previously diagnosed visual disorders in the general population group compared with the MdDS patients, and between MT and NMT/SO MdDS subtypes using logistic regression.

Bold p values are statistically significant.

CI: Confidence interval; MdDS: Mal de debarquement syndrome; MT: Motion-triggered; NMT/SO: Non-motion triggered/spontaneous-other; OR: Odds ratio; SD: Standard deviation.

Table 4. Visual Vertigo Analogue Scale, Situational Vertigo Questionnaire scores and Binocular Visual Dysfunction Questionnaire scores

				MdDS
	General population	MdDS	p-value	MT	NMT/SO	p-value
VVAS score (SD) (out of 10)	0.7 (1.3)	4.5 (2.7)	t282.762 = 18.041, p < 0.001	4.3 (2.6)	4.9 (2.8)	t 194 = -1.318, p = 0.189
SVQ score (SD) (out of 4)	0.4 (0.6)	1.6 (1.0)	t308.623 = 15.109, p < 0.001	1.6 (1.0)	1.8 (1.1)	t 194 = -1.631, p = 0.105
BVDQ score (SD) (out of 75)	11.8 (10.3)	32.0 (14.9)	t 345.420 = 15.627, p < 0.001	30.7 (14.7)	35.6 (15.1)	t 194 = -2.026, p = 0.044

This table reports a summary of statistical and comparisons for the VVAS, SVQ scores and BVDQ scores of the general population group and MdDS patients, and between the MT and NMT/SO MdDS groups, using independent samples t-tests.

Bold p values are statistically significant.

BVDQ: Binocular Visual Dysfunction Questionnaire; MdDS: Mal de debarquement syndrome; MT: Motion-triggered; NMT/SO: Non-motion triggered/spontaneous-other; SD: Standard deviation; SVQ: Situational vertigo questionnaire; VVAS: Visual vertigo analogue scale.

Table 5. Relevant Binocular Visual Dysfunction Questionnaire symptom domain questions

		Occasionally		Frequently		Always		p-value	Occasionally		Frequently		Always		p-value
		Control	MdDS	Control	MdDS	Control	MdDS		MT	NMT/SO	MT	NMT/SO	MT	NMT/SO
Headache	Do you have headaches and / or facial pain?	81.6%	38.5%	18.4%	42.3%	0.0%	19.2%	p < 0.001	41.6%	30.2%	40.7%	46.5%	17.7%	23.3%	p = 0.391
	Do you have pain in your eyes with eye movement?	88.4%	62.0%	11.6%	22.8%	0.0%	15.2%	p = 0.002	67.9%	50.0%	18.9%	30.8%	13.2%	19.2%	p = 0.277
Head tilt	Do you experience neck or shoulder discomfort?	57.8%	22.7%	25.9%	36.4%	16.3%	40.9%	p < 0.001	27.7%	8.7%	36.2%	37.0%	36.2%	54.3%	p = 0.013
	Do you ever find yourself with your head tilted to one side?	41.7%	45.2%	28.6%	28.2%	8.3%	26.6%	p < 0.001	48.3%	37.8%	28.7%	27.0%	23.0%	35.1%	p = 0.362
Vestibular	Do you have dizziness and / or light headedness?	86.4%	25.9%	10.9%	38.5%	2.7%	35.6%	p < 0.001	27.3%	21.7%	42.2%	28.3%	30.5%	50.0%	p = 0.065
	Do you experience dizziness, light headedness, or nausea while performing closeup activities (computer work, reading, writing, etc.)?	81.3%	37.9%	6.3%	26.2%	12.5%	35.9%	p < 0.001	42.5%	25.6%	28.3%	20.5%	29.2%	53.8%	p = 0.029
	Do you experience dizziness, light headedness, or nausea while performing far-distance activities (driving, television, movies, etc.)?	79.2%	56.5%	12.5%	26.9%	8.3%	16.7%	p = 0.147	61.8%	43.8%	28.9%	21.9%	9.2%	34.4%	p = 0.009
	Do you experience dizziness, light headedness, or nausea when bending down and standing back up, or when getting up quickly from a seated position?	76.3%	31.5%	20.3%	32.7%	3.4%	35.8%	p < 0.001	32.5%	28.6%	35.0%	26.2%	32.5%	45.2%	p = 0.343
	Do you feel unsteady with walking, or drift to one side while walking?	74.0%	24.0%	20.0%	29.6%	6.0%	46.4%	p < 0.001	26.3%	17.4%	27.8%	34.8%	45.9%	47.8%	p = 0.423
	Does riding in a car make you feel dizzy or uncomfortable?	83.0%	53.4%	11.3%	20.7%	5.7%	25.%	p = 0.002	59.0%	42.1%	17.9%	26.3%	23.1%	31.6%	p = 0.527
Binocular vision	Do you experience poor depth perception or have difficulty estimating distances accurately?	71.0%	32.5%	16.1%	33.3%	12.9%	34.2%	p < 0.001	33.7%	28.6%	30.2%	42.9%	36.0%	28.6%	p = 0.484
	Do you experience double / overlapping / shadowed vision at far distances?	76.7%	45.0%	6.7%	30.0%	16.7%	25.0%	p = 0.009	39.0%	57.9%	39.0%	10.5%	22.0%	31.6%	p = 0.074
	Do you experience double / overlapping / shadowed vision at near distances?	72.7%	43.5%	18.2%	31.9%	9.1%	24.6%	p = 0.021	45.8%	38.1%	31.3%	33.3%	22.9%	28.6%	p = 0.844
	Do you experience glare or have sensitivity to bright lights?	63.1%	22.5%	23.1%	25.4%	13.8%	52.1%	p < 0.001	22.5%	22.5%	24.8%	27.5%	52.7%	50.0%	p = 0.970
	Do you close or cover one eye with near or far tasks?	62.2%	37.7%	27.0%	37.7%	10.8%	24.6%	p = 0.057	34.9%	44.4%	39.5%	33.3%	25.6%	22.2%	p = 0.824
Standard vision	Do you tire easily with close-up tasks (computer work, reading, writing)?	65.6%	32.1%	26.7%	27.0%	7.8%	40.9%	p < 0.001	33.6%	27.5%	27.7%	25.0%	38.7%	47.5%	p = 0.624
	Do you experience blurred vision with far-distance activities (driving, television, movies, chalkboard at school, etc.)?	64.4%	51.4%	20.5%	26.6%	15.1%	22.0%	p = 0.225	55.6%	39.3%	22.2%	39.3%	22.2%	21.4%	p = 0.192
	Do you experience blurred vision with close-up activities (computer work, reading, writing, etc.)?	54.1%	43.0%	33.8%	29.8%	12.2%	27.3%	p = 0.039	48.9%	27.3%	25.0%	42.4%	26.1%	30.3%	p = 0.076
	Do you blink to “clear up” distant objects after working at a desk or working with closeup activities (computer work, reading, writing, etc.)?	69.0%	39.2%	22.4%	33.3%	8.6%	27.5%	p < 0.001	40.9%	34.4%	30.7%	40.6%	28.4%	25.0%	p = 0.655

This table shows the scores on the BVDQ section between the general population and the MdDS group, between the MT and NMT/SO MdDS groups, using the Fisher's exact test.

Bold p values are statistically significant.

BVDQ: Binocular Visual Dysfunction Questionnaire; MdDS: Mal de debarquement syndrome; MT: Motion-triggered; NMT/SO: Non-motion triggered/spontaneous-other.

Table 6. Patient history

				MdDS
	General population	MdDS	p-value	MT	NMT/SO	p-value
Eye operations	25 (12.7%)	33 (16.8%)	0.259	29 (19.9%)	4 (8.0%)	0.078
Mild traumatic brain injury/concussion	18 (9.1%)	23 (11.7%)	0.415	11 (7.5%)	12 (24.0%)	0.004

This table represents prior injuries and eye operations reported on the BVDQ in the general population compared with the MdDS groups, and between the MT and NMT/SO MdDS groups, using Fisher's exact test.

Bold p values are statistically significant.

BVDQ: Binocular Visual Dysfunction Questionnaire; MdDS: Mal de debarquement syndrome; MT: Motion-triggered; NMT/SO: Non-motion triggered/spontaneous-other.