Primary brainstem injury: benign course and improved survival.

Primary brainstem injury following head injury is a rare event. The victims often have features of supratentorial injury, and a primary isolated injury to the brainstem occurring due to shearing stresses or to injury from the tentorial edge is extremely rare. In the presence of supratentorial injury, these patients may have altered sensorium. Isolated brainstem injury may manifest itself as internuclear ophthalmoplegia, anisocoria, rigidity and cerebellar tremor. Such injuries are now being diagnosed more often due to improved imaging techniques. We treated nine such cases who had sustained primary brainstem injury in road traffic accidents, all but one of whom were subsequently independent. Primary brainstem injuries need not be associated with poor prognosis and mortality and may run a benign course with good quality of survival.