Correspondence

Traumatic Cranial Nerve Palsy

N Engl J Med 2006; 354:1096March 9, 2006

Article

To the Editor:

Baker and Cannon (Nov. 3 issue)1 describe a patient with left-sided ptosis and mydriasis after cranial trauma. The computed tomographic scan in Panel C of the image shows a bone fragment posteromedial to the dorsum sellae, suggesting a fracture of the anterior part of the petrous bone, rather than a lesion of the sella turcica, which is located more medially and cranially and would not be visible on the slice presented. A fracture of the anterior petrous bone may affect the third cranial (oculomotor) nerve as well as the eighth (acoustic) nerve. This matches perfectly with the clinical symptoms presented — that is, mydriasis (parasympathetic portion of the third nerve) and ptosis (motor portion of the third nerve), together with tinnitus and vertigo (eighth nerve). The combination of these symptoms is improbable in a patient with a fracture of the sella turcica. A careful clinical examination including pupil reactions and ocular movements would have been extremely helpful to localize the traumatic lesion.

Johannes R.M. Cruysberg, M.D., Ph.D.
Thomas Theelen, M.D., Ph.D.
Radboud University Nijmegen Medical Center, 6525 EX Nijmegen, the Netherlands

1 References

1. 1

   Baker C, Cannon J. Traumatic cranial nerve palsy. N Engl J Med 2005;353:1955-1955
   Full Text | Web of Science | Medline

Author/Editor Response

Drs. Cruysberg and Theelen have raised some interesting points. Their disagreement with our description of the fracture may be related to a difference in terminology. In fact, the sella turcica is a fossa within the sphenoid bone, which is fractured in the image in the report. Perhaps it would have been better to describe the lesion as a complex fracture of the lateral aspect of the sphenoid bone. Our neuroradiologists do not agree that the image shows a fracture of the anterior petrous bone.

Finally, with regard to performing a careful clinical examination, we would point out that the patient was intubated and paralyzed on arrival at the trauma center. The appropriate examinations were performed when the patient stabilized and was extubated.

Christopher C. Baker, M.D.
Jeremy Cannon, M.D.
Beth Israel Deaconess Medical Center, Boston, MA 02215