Visual Evoked Potentials & Visual Motor Perception in Hearing Loss Esra Ozcebe 1 PhD, Erol Belgin 1 PhD, Meral Topçu 2 MD, Ferhunde Öktem 3 PhD, Bora Eldem 4 MD, Şeniz Özusta 3 MS 1. Hacettepe University Faculty of Medicine, Department of Otorhinolaryngology, Section of Audiology and Speech Pathology, Ankara-Turkey 2. Hacettepe University Faculty of Medicine, Department of Pediatrics Section of Pediatric Neurology Ankara-Turkey 3. Hacettepe University Faculty of Medicine, Department of Child Psychiatry Ankara-Turkey 4. Hacettepe University Faculty of Medicine, Department of Ophthalmology Ankara-Turkey
The aim of the study was to investigate visual evoked potentials & visual motor perception in children with severely-profoundly hearing loss
Participants In study group was consisted of 23 prelingual children with severely-profoundly hearing loss and control group was consisted of age and sex matched 23 children with normal hearing. Mean age of children for study group is 9 years 4 months Mean age of children for control group is 9 years 5 months METHODS 114 7.6 123 100 7 16 Conrtol Group 113 7.4 125 97 7 16 Study Group Mean (Std) Max Min Girl Boy Age (month) Gender
VEP ( ST 10 Sensör Medelec ER 94/a VEP ) test applied while patient is in sit down position and the test room was darkened during the test.
Children were made to sit 80 centimeters far from the monitor with a total view angle of 16 degree, 50 minutes of the view angle of the squares to be evoked and 80% percent of contrast ratio in black and white squares was adjusted.
According to the 10- 20 international application system, reference electrode was placed on the frontal region and the recorder electrode was placed on the occipital region. The neutral electrode was placed randomly some where on the head.
Items are scored on their presence or absence. The total score is the number of items judged to be a defined error.
RESULTS - VEP Results of the study revealed that VEP findings were found to be pathological in the 26% of the children severely-profoundly hearing loss. (Fisher’s Exact Chi Square Test). p Value Control Group Study Group VEP 0.021 23 17 Normal 0 6 Pathologic
Total number of error in Bender-Gestalt Test for study and control group Total numbers of error were analysed with Levene’s t test for independent groups. RESULTS- BENDER-GESTALT 1.022 0.9565 23 Control Group 0.001 2.976 4.6957 23 Study Group p Value S td Mean
V isual evoked potentials and Bender- Gestalt findings were found abnormal in study group.
Results of the study support the perceptual defiency theory
DISCUSSION VEP Studies There are contradictory results reported in the literature. Adults Deaf poor readers Abnormal VEP Samar et al, 2002 Adults Support the compensation theory Neville, Schmidt, & Kutas, 1983 Adolescents No significant latency differences were found Chlubnová et al. 2005
Neurobiological evidence that developmental dyslexia exists within the deaf population and is associated with the same underlying magnocellular system deficit.
Samar, Parasnis & Berent (2002)
DISCUSSION Visual-motor perception studies Our results are consistent with the previously published data Delay in visual motor integration skills Tiber, 1985 Deficiencies perceptual motor areas (visual memory,spatial organization, Gesell copy forms) Mohindra, 1976 Delay in visual motor integration skills Horn et al. 2007 Figure-ground perception, position in space, design copying tests / impaired Erden, Otman & Tunay, 2004 Visual processing deficit Rettenbach et al 1999 Visual motor insufficiency Wiegersma and Van der Velde,1983
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