Analgesia Nociception Index Monitor is an Objective Monitor for Predicting Successful Treatment after Epidural Blood Patch in a Spontaneous Intracranial Hypotension Patient - A Case Report

Headache induced by spontaneous intracranial hypotension (SIH) is a secondary headache syndrome. An epidural blood patch (EBP) serves as a treatment option when conservative measures fail. Analgesia nociceptive index (ANI) monitoring has been demonstrated to have advantages over standard clinical practice during general anesthesia and for detecting nociceptive stimulation during surgery. However, few studies have investigated ANI in postural headache patients. We presented a 38-year-old woman who experienced postural headache and was subsequently diagnosed with SIH. Despite her receiving conservative treatment, including hydration and analgesics, she continued to suffer from postural headaches. EBP was performed under ANI monitoring. Monitoring with the ANI revealed a rise in the mean ANI (ANIm) value from 44 to 93 during the EBP, which was correlated with headache relief. Two days post-EBP, the ANIm value reached 84. This case highlights the potential utility of ANI monitoring for objectively assessing SIH treatment outcomes and guiding therapeutic interventions.