Diagnosis and Management of Central Motor Deficits Following Trauma

Abstract

Following facial or head trauma, a few unfortunate individuals lose the ability to fuse. With time or treatment, some regain this ability; others have permanent loss of fusion. The fusional mechanism comprises both sensory and motor components with motor fusion being synonymous with the vergence system. If the vergence mechanism is damaged, motor fusion is affected. Although it may be possible to superimpose images, they are not maintained together over a range. If sensory fusion is disrupted centrally, superimposition of images is unlikely. Central fusion loss is rare, and almost always follows a head injury. A careful history about the injury may contribute to the differential diagnosis. Convergence paralysis is the most common vergence disorder following head injury.

• diplopia
• head trauma
• fusion
• fusional amplitudes
• motor fusion
• sensory fusion
• central loss of fusion
• vergence system
• convergence
• divergence