Emmanuel Bui Quoc

Vertical and horizontal smooth pursuit eye movements in children: A neuro-developmental study

An evaluation of eye movements is very useful in neurological disorders but is complicated by issues such as maturation and lack of normative data in children. In order to address these issues we studied smooth pursuit eye movements of 65 normal children aged 7-11 years old. The gain of horizontal smooth pursuit (HSP) was higher than the gain of the vertical smooth pursuit (SP) and this difference had a statistical tendency to disappear with aging from 7 to 11 years. These data suggest that, in the cerebral regions involved in the control of SP, i.e. posterior parietal and superior temporal lobe regions, the networks for VSP mature latter than those for HSP.

Familial congenital oculomotor apraxia: Clinical and electro-oculographic features

The electro-oculographic (EOG) features of both horizontal and vertical eye movements in congenital oculomotor apraxia (COMA) were not previously reported. A girl referred to the ophthalmologic department for abnormal eye movements was diagnosed as COMA. The same abnormal ocular movements were observed in her younger sister and her father who was unaware of his difficulties to initiate voluntary saccades. When performed, EOG recordings of all horizontal and vertical saccadic eye movements were severely altered whatever the age of the patient. Pursuit was normal for these patients. It confirms that the control of saccadic eye movements is still altered in adults in both directions horizontal and vertical that were never reported. EOG is necessary to rule out inherited form of this saccade initiation failure.

Accuracy and results of photopic flash electroretinogram performed with skin electrodes in infants.

Purpose As it is not always possible to use corneal electrodes for recording electroretinograms (ERG) in children, it is necessary to check the feasibility of performing ERG with skin electrodes and to try to establish normative data. Methods Fifty-one healthy children (aged 7-11 years) were recruited. Cone ERG and 30-Hz flicker ERG were recorded with one active skin electrode positioned over the lower eyelid and a reference electrode at the outer canthus of the eye. Responses were recorded to full-field stimuli. Correlations between results of both eyes were studied. Results were compared to normative data obtained with corneal electrodes. Results Cone ERG response was obtained in 100/102 eyes. Flicker ERG was obtained in 88/102 eyes. No correlation between eyes was found for the a-wave latency, the a-wave amplitude, and the latency of the flicker. Mean b-wave implicit time of the cone ERG was 38.71±1.6 ms; the median of its amplitude was 10.0 µV. The median of the amplitude of the flicker ERG was 12.55 µV. Conclusions Amplitudes are significantly reduced, with a scaling factor of 8.75 for the b-wave amplitude of the cone ERG compared to corneal electrodes (9.6 for the a-wave amplitude and 8.87 for the flicker amplitude). Our study contributes to the establishment of normative data for skin electrode ERG. It emphasizes the feasibility and accuracy of this method. It is very useful to assess the normality of the ERG in many clinical situations, such as nystagmus and suspicion of delayed visual maturation.