To the Editor:—
I read with interest the case report by Dietrich and Smith1describing a rare and potentially catastrophic complication of cervical epidural steroid injection. In their discussion, the authors comment on the technical aspects of cervical epidural steroid injection and also describe measures to minimize such complications. They suggest using the prone position, advancing the needle under continuous fluoroscopic guidance, and avoiding performing the injection at the level of a large protruding disc.
As for the prone position as a way to minimize the likelihood of such complication, there is no evidence presented supporting that notion. In fact, many practitioners continue to use the sitting position for cervical epidural steroid injection but with the forehead supported on a fixed object. Their suggestion of advancing the needle under continuous fluoroscopic guidance is impractical and involves significant radiation beam exposure to both the patient and the clinician performing the procedure. On the other hand, the epidural anatomy may explain the complication that the authors describe. In his article, Hogan2found that above the C7–T1 level, the posterior epidural space is almost nonexistent. That makes the use of the loss-of-resistance technique or the hanging drop technique more hazardous and difficult if performed above this level. Hogan warned against advancing the needle in areas of the spine where the anteroposterior depth of the posterior epidural space is diminished, predicting dural puncture. Furthermore, it is common practice to perform cervical epidural steroid injection at C7–T1 or below when the interlaminar approach is used. Hogan advocates the use of an epidural catheter when attempting a cervical epidural steroid injection for treatment of pathology in the upper cervical spine. In this case, the dural puncture was not recognized, and possible intraneural injection in the spinal cord or the nerve root resulted in granuloma formation. That could explain the “lightening bolt” feeling that the patient experienced in the different aspects of her right arm. It has been also advocated to avoid entry at a spinal level where a large protruding disc is present. The authors addressed that issue adequately. Therefore, the choice of entry at C6–C7 could not be ruled out as the etiology of this unfortunate accident. If the entry had been at a lower level, this complication might have been avoided.
In conclusion, the meticulous study of the anatomy of the spine and its surrounding tissues is an essential first step before embarking into such a hazardous invasive procedure. The clinical concepts that were presented by Hogan2in his article are extremely valuable. Through this clinical report and others, we continue to learn and identify the hazardous potential of the many procedures we perform in the field of pain medicine.
Case Western Reserve University and Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Cleveland, Ohio. firstname.lastname@example.org