Gilles de la Tourette syndrome and the afferent visual system

Abstract

Step-like visual field defects, identified by kinetic perimetry, have been reported in all children with Gilles de la Tourette syndrome (TS) and in many of their parents. In order to confirm this finding, the authors evaluated the afferent visual systems of 18 children with TS (ages 8–14) and an affected parent.

Thirty-four were able to perform quantitative automated threshold perimetry. Of 68 fields, 17 fields (25%) had a significantly elevated corrected pattern standard deviation and ten (15%) had an abnormal hemifield test. To evaluate the possibility of transient visual field abnormalities, fields were repeated on nine individuals. Five out of eight fields that were initially abnormal reverted to normal and ten of ten fields remained normal during the repeat examination. Visual field defects do not appear to occur in patients with TS at a rate substantially different from that observed in normal patients. These data demonstrate that visual field defects are not likely to be useful as markers for Gilles de la Tourette syndrome.

Key Words:

• afferent visual system
• dopamine
• perimetry
• tic disorder
• Gilles de la Tourette syndrome
• visual field