Radiculopathy After Blood Patch
Use of prophylactic epidural blood patches is controversial. Common side effects of epidural blood patch include pain at the site of injection and back and lower extremity discomfort. Less common complications include compression of nerve roots and radiculopathy with resultant with lower extremity sensory disturbances and weakness. An epidural blood patch is an effective treatment for headaches occurring after a lumbar puncture. The common clinical impression is that total relief from the headache is immediate. There are some studies suggesting that pain relief may increase over the next several days. An epidural blood patch is an effective treatment for headaches occurring after a lumbar puncture. The common clinical impression is that total relief from the headache is immediate. There are some studies suggesting that pain relief may increase over the next several days.
Dear Editor,
Postdural puncture headache (PDPH) is a well-known complication of the epidural block and usually treated by bed rest, intravenous hydration, caffeine and analgesics, and epidural blood patch. The epidural blood patch has been considered as the “gold standard” in the treatment of PDPH and regarded to safe procedure, but various complications, including delayed radicular pain [1] and severe low back pain and lower extremity pain [2] have been reported. We experienced a patient who complained of radiating pain immediately after an epidural blood patch in the lumbar region for PDPH.
A 44-year-old woman with 2-year history of chronic low back pain visited our pain clinic due to an exacerbation of low back pain radiating down to the lateral aspect of the right leg from 2 days before. On physical examination, she had a 60-degree limitation on the straight leg raising test of the right leg because of pain. There was no other motor or sensory deficit, and deep tendon reflexes were also normal. Under the impression of a herniated lumbar disc at the right L4-L5 level, we planned to perform a lumbar epidural block with blind technique after getting an informed consent at the L4-L5 level. Laboratory findings, including bleeding tendency revealed no abnormalities. She was in the prone position with a pillow under her pelvis to reduce lumbar lordosis. A 20-gauge Tuohy needle was inserted into the epidural space at the level of L4-L5 by using the “loss of resistance” technique with normal saline. After confirming the epidural space without CSF leakage or blood aspiration, 6cc of 0.5% mepivacaine was administered. She was discharged without any complications.
The next day, she visited our pain clinic again and complained of a severe headache. The headache had started about 5 hours after the block. It was relieved in the supine position and aggravated in the sitting or standing positions. Because she was so nervous and complained of a very severe headache, we were suspicious of a PDPH. Therefore, we decided to perform an epidural blood patch. Ten milliliters of autologous blood was administered into the epidural space under fluoroscopic guidance at the level of the L4-L5. There were no specific events or discomforts during the epidural blood patch. After 5 minutes, she complained of new onset right buttock pain radiating to the right thigh and calf. However, her headache was improved. There were no neurologic abnormalities such as sensory and motor function deficits. She then underwent a selective transforaminal epidural block at the right L4-L5 level with using 0.5% mepivacaine 6 mL and the pain was relieved. She was discharged without any discomforts. On the day following the epidural blood patch, she came back to our pain clinic again because her right buttock pain was re-aggravated with the same characteristics as that of the day before. We suspected epidural hematoma or other structural abnormality. We managed to get her the lumbar magnetic resonance imaging (MRI) 3 days after the epidural blood patch. The lumbar MRI showed slight disc protrusions at the L3-L4, L4-L5, and L5-S1 levels, a tiny hematoma at L5-S1 on a sagittal image (Figure 0001), and blood clot-like materials around the spinal cord at L5-S1 on an axial image (Figure 0002). Her pain was much improved without symptoms or signs of other complications 7 days later.
Sagittal T2 MRI.
Sagittal T2 MRI.
Axial T1 (A) and T2 (B) MRI at L5-S1.
Axial T1 (A) and T2 (B) MRI at L5-S1.
Epidural blocks always have many potential risks [3,4]. Dura puncture is one of the most frequent complications even if many attentions are given during the procedure. Particularly in the prone position, the CSF will not dribble due to gravity so it is difficult to notice the dura puncture by CSF leakage. We could not recognize the dura puncture in this case because of doing a blind epidural block in the prone position. When dura puncture occurs, the risk of PDPH is approximately 50% [4].
The epidural blood patch is effective in the treatment of PDPH because it induces prolonged elevation of subarachnoid and epidural pressures. Radicular pain is one of the possible complications following an epidural blood patch. A mechanism for radicular pain is the inflammatory response in the epidural space by heme in blood clots as well as the mechanical compression of nerve roots by injected blood clots [1]. An alternative method for performing an epidural blood patch has been performed using saline and dextran 40, especially for the patient who has HIV or a septic condition [5,6]. In our case, the patient already had radicular pain due to the central protrusion of intervertebral disc before the epidural blood patch. Therefore, when the patient has signs or symptoms suspicious of epidural space narrowing, it is appropriate to consider using normal saline or colloid instead of blood for the treatment of PDPH.
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