Localization of post-traumatic trochlear nerve palsy associated with hemorrhage at the subarachnoid space by magnetic resonance imaging.

PURPOSE: To report evaluation of traumatic trochlear nerve palsy using head magnetic resonance imaging.

DESIGN

Observational case reports.

METHODS

We examined two cases involving trochlear nerve palsy after closed head injury.

RESULTS

Using a fluid attenuated inversion recovery pulse sequence, MRI showed a high-intensity lesion consistent with subarachnoid hemorrhage at the trochlear nerve area in the ambient cisterns.

CONCLUSION

An impact force directed toward the tentorium can be a mechanism of injury in some post-traumatic trochlear nerve palsies. Fluid attenuated inversion recovery pulse sequence is a sensitive method for detection of abnormalities in cases associated with head injury.