Complications are rare but can be serious.

It is generally accepted that ic-ESI is safer than transforaminal epidurals. There are numerous reports of arterial invasion or irritation with the latter despite an inherently greater risk of cord puncture with the former. The likelihood of cord interruption rises when ic-ESIs are performed above C6-C7 as there is a relatively slim epidural layer compared to lower cervical epidural zones. Though most cases of devastating outcomes, such as hemiplegia and death, have been reported during cervical transforaminal epidural injections and rarely with ic-ESI, it is important to understand the symptoms and potential pitfalls of performing any cervical epidural injection.

Cervical epidural malpractice claims are uncommon, but exceed those of steroid blocks at all the levels combined, demonstrating the need for improved awareness of potential complications in ic-ESI ¹⁾.

Various complications associated with CESIs have been reported. Complications are directly associated with the technical procedures of CESIs. Particulate steroids may have a prolonged duration of action but non-particulate steroids are safer for CESIs. Blunt-beveled needles are less likely than sharp-beveled needles to penetrate blood vessels to cause bleeding complications during CTFESI procedures. Small doses of local anesthetics appear to be safe and assist in identifying intravascular injections previously overlooked by conventional techniques ²⁾.

Dural puncture from an interlaminar cervical epidural injection reportedly range from 0.25% to 2.65%. An epidural blood patch is a possible treatment option when conservative treatment fails. Relief could be secondary to 'sealing' of the dural tear from the clotted blood and reestablishment of physiological intracranial pressure. Another theory is an increase in the subarachnoid pressure from the injected blood. The increased pressure may restore normal intracranial pressure.

Subdural injection of local anesthetic and steroid represents a rare but potentially life threatening complication.

Lebrun et al. describe 2 cases of cervical post-dural puncture headache (PDPH) treated with lumbar epidural blood patch. In 1 case, there was complete resolution of the symptoms and in the other case, there was great improvement of symptoms and a high thoracic blood patch was performed to resolve the remaining headache ³⁾

A 54-year-old man with cervical radicular pain who was treated with cervical epidural steroid injection. Injection was administered twice under fluoroscopic guidance with the loss-of-resistance technique using air to confirm the epidural space. After the second procedure, the patient complained of severe persistent headache and was diagnosed with pneumocephalus on brain computed tomography. The patient returned home without any neurological complication, after a few days of conservative treatment. Though, a fluoroscopic guidance cervical epidural injection is also known to diminish the risk of complications. Physicians should always keep in mind that it does not guarantee safety, particularly in the cervical region, related to its anatomical considerations ⁴⁾.

A case wherein intramuscular ketorolac and oral fluoxetine contributed to a spinal epidural hematoma (SEH) and tetraplegia following a cervical interlaminar (ESI). A 66 year-old woman with chronic renal insufficiency and neck pain radiating into her right upper extremity presented for evaluation and was deemed an appropriate CESI candidate. Cervical magnetic resonance imaging (MRI) revealed multi-level neuroforaminal stenosis and degenerative intervertebral discs. Utilizing a loss of resistance to saline technique, an 18-gauge Tuohy-type needle entered the epidural space at C6-7. After negative aspiration, 4 mL of saline with 80 mg of methyl-prednisolone was injected. Immediately thereafter, the patient reported significant spasmodic-type localized neck pain with no neurologic status changes. A decision was made to administer 30 mg intramuscular ketorolac as treatment for the spasmodic-type pain. En route home, she developed a sudden onset of acute tetraplegia. She was brought to the emergency department for evaluation including platelet and coagulation studies which were normal. MRI demonstrated an epidural hematoma extending from C5 to T7. She underwent a bilateral C5-T6 laminectomy with epidural hematoma evacuation and was discharged to an acute inpatient rehabilitation hospital. Chronic renal insufficiency, spinal stenosis, female gender, and increasing age have been identified as risk factors for SEH following epidural anesthesia. In the present case, it is postulated that after the spinal vascular system was penetrated, hemostasis was compromised by the combined antiplatelet effects of ketorolac, fluoxetine, fish oil, and vitamin E. Although generally well tolerated, the role of ketorolac, a potent anti-platelet medication used for pain relief in the peri-neuraxial intervention period, should be seriously scrutinized when other analgesic options are readily available. Although the increased risk of bleeding for the alternative medications are minimal, they are nevertheless well documented. Additionally, their additive impairment on hemostasis has not been well characterized. Withholding NSAIDs, fluoxetine, fish oil, and vitamin E in the peri-procedural period is relatively low risk and should be considered for all patients with multiple risk factors for SEH ⁵⁾.

A patient presented with left sided cervical pain radiating into the left upper extremity with motor deficit. MRI showed absent lordosis with a broad left paramedian disc-osteophyte complex impinging the spinal cord at C5-6. During C5-6 transforaminal epidural steroid injection contrast in AP fluoroscopic view demonstrated a subdural contrast pattern. The needle was withdrawn slightly and repositioned. Normal lateral epidural and nerve root contrast pattern was subsequently obtained and injection followed with immediate improvement in radicular symptoms. There were no postoperative complications on subsequent clinic follow-up. The subdural space is a potential space between the arachnoid and dura mater. As the subdural space is larger in the cervical region, there may be an elevated potential for inadvertent subdural injection. Needle placement in the cervical subdural space during transforaminal injection is uncommon. Failure to identify aberrant needle entry within the cervical subdural space may result in life threatening complications. We recommend initial injection of a limited volume of contrast agent to detect inadvertent subdural space placement ⁶⁾.