We would like to express our gratitude for your valuable comments on our report, and we agree with some of your opinions. The authors extensively discussed the mechanism of intradural extramedullary (IDEM) hematoma in our case. As you correctly pointed out, it is theoretically possible for a hematoma caused by cervical interlaminar epidural steroid injection (CESI) to develop in the posterior epidural space.

Some studies have reported that the paramedian approach of CESI may inadvertently enter the intradural space, which is highly undesirable [1,2]. It has also been recently recognized that the paramedian approach allows for direct access and solution transfer over the ventral epidural space and the dorsal root ganglion [3-5]. In fact, one study showed that the paramedian approach resulted in a significantly higher proportion of ventral epidural spread compared to the midline approach [6].

However, this alone does not fully explain the occurrence of IDEM hematoma, particularly at the anterior aspect of the spinal cord in our case. The neurosurgeon who performed the operation observed a well-developed network of venous structures, resembling capillaries, surrounding the hematoma. Furthermore, it is known that even minimal injuries can lead to the development of intradural hematoma through a sequential series of pachymeningeal pathologies, especially in the elderly. Trauma-induced loss of integrity in the pachymeninges and the expression of anticoagulants have been suggested as possible mechanisms [7,8].

In this case report, we believe that several factors mentioned above may have contributed to the occurrence of IDEM hematoma anterior to the spinal cord. However, further studies or case series are necessary to confirm the exact mechanism.

No potential conflict of interest relevant to this article was reported.