Knowledge of neural pathways helps in diagnosis of gaze disorders

October 12, 2005

Some eye movements are mediated through the temporal lobe for target position; the saccades and pursuits are initiated in the posterior parietal lobe.

"The most common supranuclear disorders seen in practices are internuclear ophthalmoplegia (INO), skew deviation, dissociated vertical deviation (DVD), dorsal midbrain syndrome, and horizontal and vertical gaze palsies. Disorders of eye movement modulation include nystagmus, ocular myotonia, convergence and divergence problems, saccadic and pursuit disorder, and vestibulo-ocular reflex abnormalities," he said.

Key brainstem nuclei

He emphasized the importance for ophthalmologists to remember the key brainstem nuclei involved in the control of eye movement.

Eye movements

He reminded the audience that the cortex controls many ocular movements. Processes start in the visual primary cortex; however, some eye movements are mediated through the temporal lobe for target position; the saccades and pursuits are initiated in the posterior parietal lobe; and eye movements are planned in the frontal eye fields. Many of these go through the basal ganglia into the brainstem. Fine control of eye movements is through the cerebellum.