Epidural hematoma after caudal epidural pulsed radiofrequency stimulation: A case report

RATIONALE

Epidural hematoma is a possible complication after neuraxial procedures. Recently, caudal epidural pulsed radiofrequency (PRF) stimulation was reported as an effective method for controlling several types of chronic pain. Herein, we report on a patient who developed a lumbar epidural hematoma after receiving caudal epidural PRF stimulation.

PATIENT CONCERNS

A 75-year-old woman, who was taking oral warfarin (2 mg/d), received caudal epidural PRF stimulation for symmetrical neuropathic pain in both legs due to chronic idiopathic axonal polyneuropathy. She did not discontinue warfarin use before undergoing the procedure. Three days and 12 hours after the procedure, motor weakness suddenly manifested in the right leg (manual muscle testing [MMT] = 2-3).

DIAGNOSES

Lumbar magnetic resonance imaging (MRI) performed 7 days after the PRF procedure showed a spinal epidural hematoma at the L1 to L5 levels, compressing the thecal sac. The international normalized ratio was 6.1 at the time of the MRI.

INTERVENTIONS

Decompressive laminectomy from L1 to L5 with evacuation of the hematoma was performed.

OUTCOMES

Three months postoperatively, the motor weakness in the patient's right leg improved to MMT = 4 to 5.

LESSONS

This case suggests that clinicians should carefully check if patients are taking an anticoagulant medication and ensure that it is discontinued for an appropriate length of time before a caudal epidural PRF procedure is performed.

Polymorphisms of GSTT1, GSTM1, and EPHX genotypes in patients with cryptogenic polyneuropathy: a case-control study

The aim of this study was to analyze whether polymorphisms for the null alleles of Glutathione S-Transferase Mu-1 (GSTM1), Glutathione S-Transferase Theta-1 (GSTT1), and a low-activity genetic variation of epoxide hydrolase exon three (EPHX*3) affect the risk of developing polyneuropathy. The enzymes of these genes are important in the metabolism of toxic compounds. Seventy-nine patients with cryptogenic polyneuropathy (equivalent to chronic idiopathic axonal neuropathy) and 398 controls were tested for the genetic polymorphism. Medical records were reviewed to collect data regarding clinical findings at diagnosis, and exposure data was collected via questionnaires. The odds ratios (ORs) for the null forms of GSTM1 and GSTT1 and the normal activity YY form of EPHX*3 were close to one except GSTT1, which reached 1.86. The highest risk of polyneuropathy was found in smokers with GSTT1 null, who had a 3.7 times increased risk. Interactions between genes were analyzed and confirmed the increased OR for GSTT1, which was strongest if the patients had the low-activity HH form of EPHX*3 (OR 2.37). Our hypothesis is that the GSTT1 null polymorphism may be related to an impaired metabolism of toxic substances that could lead to nerve damage in the peripheral nervous system.