This is a case of left lumbar fifth (L5) and sacral first (S1) radiculopathy that resembled peripheral neuropathy after spinal anesthesia for an emergent cesarean delivery. Even though there were no particular concerns in the anesthetic procedures, the radiculopathy was caused by localized adhesive arachnoiditis away from the puncture site. Characteristic of neurological findings and the delivery course helps us infer the pathophysiology of postpartum nerve injuries. For example, prolonged delivery in the lithotomy position might induce compressive nerve injuries, including peroneal nerve . The fetal head position in the pelvis might injure the unilateral nerve root. The well-known neurological complications associated with neuraxial anesthesia are transient neurological symptoms, cauda equina syndrome, and neuropathy associated with hematoma or abscess formation . A puncture needle might directly injure spinal cord or nerve root near the puncture site. Literature indicates that even well-trained anesthesiologists could misidentify the vertebrae ; however, in this case, there was little chance to puncture L5/S1 interspace because the vertebral spaces were counted up after clearly identifying the posterior superior iliac spine. Therefore, the diagnosis was challenging because neurological findings in the present case did not fit any of the conditions above.
Initially, the neurologist presumed that the neurological findings were derived from peripheral nerve injury. However, he decided to conduct diagnostic imaging since the patient’s neurological symptoms were difficult to correlate with the anesthetic procedure or the delivery course. Surprisingly, MRI revealed an unexpected lesion of adhesive arachnoiditis. However, it remained unclear why the patient developed such a rare complication after uneventful spinal anesthesia. Adhesive arachnoiditis is an infrequent but severe complication of neuraxial blockade that potentially induces syringomyelia in severe cases . Arachnoiditis is presumed to be triggered by conditions such as intrathecal infection and bleeding, local anesthetics, or contamination with chemicals such as chlorhexidine used for disinfection before neuraxial anesthesia . Therefore, one of the potential explanations for this case is that the hyperbaric bupivacaine or the tiny amount of hemorrhage upon puncture could have accumulated around the left L5/S neuronal root and caused inflammation as she spent most of the time in the left lateral position after cesarean delivery. However, it is still questionable to conclude that positional bias was the problem.
Symptoms that show a clear tendency to improve spontaneously do not always undergo a detailed workup. In this case, the decision to perform an MRI was made on the third postoperative day, not on the onset of the neurological symptoms. The fact that the scheduled discharge date was approaching, and the patient’s strong desire to know the problem, prompted us to perform the MRI. If the patient had accepted to be followed up without imaging, the patient might not have gone through a diagnostic MRI. Therefore, the pathology might have occurred more than expected.
A detailed workup may provide several advantages. For example, we can consider how this patient should be managed in the next delivery. Because the patient in the present case is still young, and since a cesarean delivery was chosen for her first child, cesarean delivery might be selected for a future delivery unless she opts for a trial of labor after a cesarean. However, if the problem was due to some anatomical factor of the patient, it is likely to recur in the subsequent anesthetic management. Epidural anesthesia alone or in combination with spinal anesthesia could minimize the amount of local anesthesia administered to the subarachnoid space, even though epidural anesthesia itself could induce adhesive arachnoiditis . The use of isobaric bupivacaine might reduce the risk of neurological complications if positional bias was the actual cause in this case, as she reported that she had spent most of the time in the left lateral position after cesarean delivery. In case the patient prefers general anesthesia, a careful and multidisciplinary discussion, including the patient, would be required to decide whether general anesthesia is indicated. In case of any issues, the obstetrician and anesthesiologist should discuss future anesthetic procedures thoroughly, provide sufficient explanations with the patient, and obtain consent before the next cesarean delivery. At least, the patient should be informed of the advantages of delivering in a general hospital where postoperative neurological consultations, including MRI scans, are readily available.
In conclusion, spinal anesthesia from the L2/3 intervertebral space for an emergency cesarean delivery caused unilateral L5 and S1 radiculopathy with residual neurological symptoms for 2 months. It was challenging to unveil the pathophysiology directly from the delivery course and anesthetic procedure. The MRI scan revealed the development of adhesive arachnoiditis with an unknown etiology. Although a rare condition resolves spontaneously, and does not always undergo a detailed workup, the data obtained by imaging such a case may cumulatively provide helpful information to understand the cause of such a rare complication and provide information that may aid in the future anesthetic management of the individual patient.