A 30-year-old woman (G1P1) known to have vitamin B12 deficiency on 5,000mcg of sublingual methyl-cobalamin weekly presented for normal vaginal delivery (NVD). EA was performed under sterile techniques at the L4-L5 level. The epidural space was identified by loss of resistance to fluid, the catheter placed without difficulty and taped at 9cm, and the analgesia mixture (Ropivacaine 0.2%, Fentanyl 0.2mcg/ml) administered at a rate of 10ml/hr. Hemodynamic stability was maintained throughout the procedure and delivery. As the anesthesia was more effective over the right LE, the patient was repositioned in left lateral decubitus. Six hours after EA initiation, the patient had an uneventful NVD following 20 minutes of lithotomy position.
Neurology team was consulted ten hours after the epidural catheter removal because of persistent numbness and weakness below knees bilaterally, and urination difficulty requiring Valsalva maneuvers. Further questioning was negative for a history of coagulopathy, previous neurologic deficit, antiplatelet or anticoagulant intake.
Neurologic examination revealed decreased strength in the LEs distally more than proximally and left more than right (Table 1). Deep tendon reflexes were present symmetrically with bilateral flexor plantar responses. Sensory exam revealed decreased light touch/pinprick/cold sensation in the posterolateral legs and the feet, more severe on the left. It also showed decreased vibration and absent proprioception in the distal LEs.
An injected lumbosacral spine Magnetic Resonance Imaging (MRI) was unremarkable. Vitamin B12 level was 109 pg/mL so daily intramuscular injections were initiated (Vitamin B12 1,000mcg, B1 100mg, B6 100mg).
Neurological deficits improved gradually. Upon discharge (day-2 post-EA), the patient had mild residual weakness in the left foot (Table 1), and minimal decreased light touch and pinprick in the right sole and left posterolateral leg. The discharge diagnosis was probable neurotoxicity related to EA.
Table 1
Motor Power in the lower extremities day-1 and day-2 post- EA
Motor Power | Day 1 | Day 2 |
Left | Right | Left | Right |
Hip Flexion | 4+ | 5- | 5 | 5 |
Knee Flexion | 3 | 3+ | 5 | 5 |
Knee Extension | 5 | 5 | 5 | 5 |
Knee Abduction | 5 | 5 | 5 | 5 |
Knee Adduction | 5 | 5 | 5 | 5 |
Inversion | 1 | 3 | 4+ | 5 |
Eversion | 1 | 3 | 3 | 5 |
Dorsiflexion | 1 | 3 | 3 | 5 |
plantarflexion | 1 | 3 | 4+ | 5 |
The patient received intensive out-patient physiotherapy. Due to persistent symptoms, Nerve Conduction studies/Electromyography (NCS/EMG) was performed on day-23 post-EA and revealed normal NCS with decreased recruitment in the left L5-S1 myotomes suggesting nerve injury to the corresponding roots. Supplementation with Vitamin B12 was continued.