Study of Oculomotor Dysfunction Leading to Children Vertigo
Condition: Vertigo; Headache; Anomaly of Vergence System; Accommodation Disorders; Orthoptic Rehabilitation
MeSH terms: Vertigo; Headache; Dizziness
Study type: Interventional

Summary: 
      The eye movements of vergence allow binocular vision whatever the viewing distance or the
      body movements are and the perception of depth. Vergence dysfunction can lead to erroneous
      visual sensation of movements. In our daily life using screens (computer, game boys..) is
      increasing and this approach heavily the ocular vergence and can lead to symptoms if
      oculomotor and accommodative systems are dysfunctioning (Ped. Neurology 2000). Not knowing
      this pathology lead to inappropriate and expensive prescription CT scan or NMR. To evaluate
      the vergence performances just evaluation in static condition is currently available in
      ophthalmology departments. The CNRS laboratory (IRIS, FRE 3154) adapted a technic of eye
      movement recording to study ocular vergence in dynamic condition.
    

Detailed description: 
      The goals of the study are:

        1. to compare the coordination of binocular eye movements, postural stability on a
           force-plate during visual tasks (looking at a target or reading) and dynamic visual
           acuity between two groups of children and teenagers: one group with oculomotor vergence
           disorders and vertigo and one group with normal eye movements. Children will undergo
           complete vestibular testing (by Dr WIENER-VACHER) to eliminate a vestibular origin for
           vertigo. Normal children will be volunteers.

        2. in order to evaluate objectively the effect of rehabilitation, a second oculomotor
           evaluation (identical to the initial one) will be done in children with vertigo after an
           orthoptic rehabilitation focused on ocular vergence. We hypothesize that functional
           oculomotor disorders can be rehabilitated because of the plasticity of the oculomotor
           system (proved by several studies for many years) provided that the spatial temporal
           parameters of the training are precisely tailored to patient malfunction.

        3. Establish normative data of the binocular eye movements and posturography, and validate
           a protocol for complete static and dynamic oculomotor evaluation for clinical use. To a
           longer term modification of the rehabilitation protocols of eye movements will be
           designed to fit each patient problems in function of the abnormalities revealed by the
           static and dynamic evaluation.

      Study calendar :

      All the children referred for vertigo with vergence abnormalities and normal vestibular
      functional evaluation will be proposed for participate to the study.

      The patients included in the study will perform an oculomotor complete evaluation (static and
      dynamic and accommodation), posturography test and a visual dynamic acuity test. These tests
      will last for 60 minutes, including breaks to avoid fatigue of the children. Then, the
      children will follow orthoptic rehabilitation :12 sessions (2 sessions per week). These
      sessions will be done by an orthoptist installed close to home, in contact with the research
      team.

      At the end of a series of 12 sessions of orthoptic, the child will be examined and will again
      perform a static and dynamic oculomotor evaluation and control of postural balance.

      In order to highlight the prolonged effects of rehabilitation a third oculomotor evaluation
      and control of postural balance will be made six months after inclusion.

      Healthy children (control group) will be recruited at Robert Debré hospital. A poster
      campaign in the corridors of the hospital, as well as general information (mailing) for the
      Hospital staff will be made.

      A questionnaire prior to a half-hour will confirm the normal vestibular children. After
      completing the questionnaire, a test Postural oculomotor (one hour) and a test orthoptics
      (half hour) will be made.

      Conduct of Research: We will study with a multidisciplinary approach children with vergence
      abnormalities and vertigo and/or headache. Healthy children will also be examined for
      baseline data.

      Methodology :

      Statistical analysis will be conducted at the Unite de Recherche Clinique Paris Nord, Robert
      Debré Hospital.

      The qualitative data will be described in terms of frequency and percentages, quantitative
      data as mean (SD) if the distribution follows a normal distribution, as median (quartiles)
      otherwise. The influence of sex adjusted for age will be tested by parametric methods after
      normalization of distributions.

      The establishment of standards will be conducted according to the method described by EM
      Wright et P. ROYSTON (Simplified estimation of age-specific reference intervals for skewed
      data, Statistics in Medicine 1997, vol 16, 2785-2803). The method is to produce smoothed
      percentile curves by time (age) using parametric methods.

      Analysis of sick children will be purely descriptive. She will describe the differences for
      different standard deviation scores of variables described in the previous paragraph between
      the time of diagnosis and after 12 weeks of rehabilitation and orthoptic vergence.
    

Intervention name(s): orthoptic rehabilitation; Orthoptic diagnostic
Intervention type(s): Procedure; Other
Intervention description(s): Orthoptic rehabilitation: 12 sessions (2 sessions per week) At the end of a series of 12 sessions of orthoptic, the child will be examined and will again perform an static and dynamic oculomotor evaluation and control of postural balance.; postural, oculomotor and orthoptics tests
Allocation: Non-Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Diagnostic
Keywords: Vergence-accommodation evaluation; Vergence and postural control; Dynamic visual acuity