Regional Anesthesia and Pain Targeted thoracic epidural blood patch placed under electrical stimulation guidance (Tsui test)

Abstract

Purpose: This case report describes the use of electrical epidural stimulation (Tsui test) to confirm accurate placement of a thoracic epidural catheter when administering an epidural blood patch for headache management in a patient suffering from spontaneous intracranial hypotension. Clinical features:A 41-yr-old female presented to the Chronic Pain Clinic with a history of postural headache symptoms worsening in severity over several years. Two previous blood patches performed at T11-12 and T10-11 respectively provided short-term relief only. The presumed diagnosis of a spontaneous dural tear was confirmed by a nuclear flow test to be at T2-T4. The epidural site was accessed at T6 with a Tuohy needle. To accurately place the epidural blood patch at the level of the dural tear, the Arrow catheter with electrode adapter was advanced under nerve stimulation guidance to T4. Ten millilitres of autologous blood injected through the catheter was confirmed on magnetic resonance imaging, one hour postprocedure, to lie between T3 and T9. Sustained headache relief was achieved. Conclusion:The use of electrical stimulation guidance may be useful when precise epidural blood patch placement is required. Objectif

Low-dose intrathecal local anesthetic does not increase the threshold current for the epidural stimulation test: a prospective observational trial of neuraxial analgesia in labouring women

“…[8][9][10][11][12][13][14][15][16][17][18] The motor threshold current (MTC) achieved when using the EST can distinguish whether the catheter tip is positioned epidurally (medium MTC: 2-15 mA), subcutaneously (high MTC: [ 15 mA), or intrathecally (low MTC: \ 2 mA), although a low MTC might also conceivably be due to the catheter abutting a nerve root. It should be emphasized that these MTC ranges are somewhat arbitrary depending on the individual interpreting the EST results.…”

A safe and effective technique for application of a multi-level cervical epidural blood patch

“…We herein report the successful treatment of SIH with a neurostimulation-guided cervical epidural blood patch using the electrical epidural stimulation Tsui test. 2 A 48-yr-old woman presented to our neurosurgery department with a five-month history of a left occipital headache and episodes of aphasia. Magnetic resonance imaging (MRI) showed a 13-mm frontoparietal subdural hematoma with evidence of subacute-on-chronic hemorrhage and dural enhancement throughout ( Figure A).…”

Risks of dural puncture associated with thoracic epidurals

“…We appreciated the case report by Morley-Forster et al demonstrating the elegant utility of the Tsui test for the precise placement of a thoracic epidural blood patch. 1 However, we are troubled by the unwarranted (in our opinion) caution the authors used to initiate their epidural entry at T 6-7 rather than begin at the T2-4 level where the indium cerebrospinal fluid flow (CSF) flow study demonstrated the CSF leak. Their stated reason for avoiding the T2-4 interspace was based on "a recent study (that) showed that the cervical and upper thoracic ligamentum flavum above T4 frequently fails to fuse in the midline."…”

“…We appreciate the interest shown by Drs. Beriault and Korzeniewski in our recent case report 1 describing the use of the Tsui test to target placement of a thoracic epidural blood patch. These authors object to our expressed caution in entering the epidural space between T2 and T4, based on both their own extensive experience with high thoracic epidural placement, and their concern that the cited findings of failure of ligamentum flavum fusion in the midline reported by Lirk et al, 2 Although we agree that, in experienced hands, epidural catheter placement at the T2-4 level is generally safe, not all anesthesiologists share this level of experience and confidence with the anatomy.…”