Disorders of oculomotor scanning and graphic orientation in developmental Gerstmann syndrome

Abstract

A patient with developmental Gerstmann syndrome who experiences great difficulty in performing tasks requiring visuoconstructive and reading abilities is described. Neuropsychological assessment revealed normal range verbal abilities but severe deficits in directional orientation, finger differentiation, calculational ability, copying, and reading ability. Achievement in reading was measured at the sixth-grade level despite the fact that this patient is a third-year college student. Using infrared photoelectric sensors, we monitored the horizontal saccades of this patient while reading from a standardized reading test. Fixation durations were not abnormal. However, instances of reverse-staircase movement were exhibited. While reading from an inverted test, she showed a normal eye-movement pattern (although in the reverse direction since the task now called for right-to-left saccades). The processing of spatial information in this patient is severely disturbed and this may account for the apparently abnormal oculomotor scanning, an “irrepressible tendency” to move her eyes in a right-to-left direction.