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Updated: Aug 9, 2026
Subcutaneous Trigeminal Nerve Field Stimulation for Refractory Facial Pain
Published on: May 10, 2017
Targeted thoracic epidural blood patch placed under electrical stimulation guidance (Tsui test)
Patricia K Morley-Forster1, Ahmed Abotaiban, Sugantha Ganapathy
1Department of Anesthesia and Perioperative Medicine, University of Western Ontario Interdisciplinary Pain Program, London, Ontario, Canada. pat.morley-forster@sjhc.london.on.ca
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.
