DAMAGE TO CEREBELLOCORTICAL PATHWAYS AFTER CLOSED-HEAD INJURY - A BEHAVIORAL AND MAGNETIC-RESONANCE-IMAGING STUDY

The objective was to investigate the anatomical substrate of ataxia se en after severe head injury. Five patients were recruited from present and former inpatients at Rivermead Rehabilitation Centre. Ah patients had had a closed head injury and all had cerebellar type ataxia. Four normal controls were also studied. Brain MRI, clinical examination, c omputer based recording, and analysis of visuomotor tracking were carr ied out. Focal damage was found in the superior cerebellar peduncle in all five ataxic patients. The patients' tracking movements showed pro found tremor, and unusual reliance on visual feedback. Ataxia seen aft er severe head injury can arise from damage to the superior cerebellar peduncle, which may interfere with the cerebellocortical circuits inv olved in coordinated movement.