Saccadic eye movements in young-onset Parkinson’s disease
Reviewed by Claire Howard

The objective of this study was to understand control of saccadic eye movements in patients with young onset Parkinson’s disease (YOPD) where onset of disease symptoms appears early in life (<40 years of age). Functional magnetic resonance imaging (fMRI) was performed in patients with YOPD and control subjects while they performed saccadic tasks, which consisted of a reflexive task and another task that required inhibitory control of eye movements (Go-NoGo task). Analysis of blood-oxygen-level-dependent (BOLD) fMRI was performed using Statistical Parametric Mapping (SPM) software and compared in patients and controls. In patients with YOPD, greater activation was seen significantly in the middle frontal gyrus, medial frontal gyrus, angular gyrus, cingulate gyrus, precuneus and cerebellum, when compared with the control group, during the saccadic tasks. Gap and overlap protocols revealed differential activation patterns. The abnormal activation during reflexive saccades was observed in the overlap condition, while during Go-NoGo saccades in the gap condition. The results suggest that impaired circuitry in patients with YOPD results in recruitment of more cortical areas. Authors suggest this increased frontal and parietal cortical activity possibly reflects compensatory mechanisms for impaired cognitive and saccadic circuitry.

Saccadic eye movements in young-onset Parkinson’s disease – a BOLD fMRI study.
Srivastava A, Sharma R, Goyal V, et al.
NEURO-OPHTHALMOLOGY
2020;44(1):89-99.