Brain Regions and Functional Neuronal Network Characteristics of Dexmedetomidine Analgesia

Brain Regions and Functional Neuronal Network Characteristics of Dexmedetomidine Analgesia Under Intraoperative fMRI

Background: Dexmedetomidine (Dex) is a highly selective 2-adrenergic receptor agonist with significant analgesia affection. This study is planned to explore the brain regions and functional neuronal network involved in promoting analgesia of Dexmedetomidine. Methods: Select 28 patients with the proposed intraoperative MR-guided radiofrequency ablation of epilepsy. The subjects were randomized into the Dexmedetomidine group (Dex group) (n=14) and the Placebo group (PO group) (n=14). DEX group: continuous intravenously administered 1.5 µg kg-1 h-1 dexmedetomidine 15min before anesthesia induction, continuous infusion for 15min after anesthesia induction, and then Intraoperative functional magnetic resonance imaging scanning was started. PO group: the equivalent administered speed 0.9% sodium chloride was continuously pumped for 15min before anesthesia induction, then induce and intraoperative fMRI scanning started after continuous 30min infusion. The intraoperative fMIR scan results were compared and analyzed to find the unique analgesic brain regions of DEX, and the differences of the functional neuronal network of analgesia effect between the two groups.On January 8, 2024, the protocol was amended and approved by the Institutional Review Board (IRB) of China International Neuroscience Institution (Approval No. CINI-AD-20220706). In this approved amendment, to ensure a direct assessment of the most clinically meaningful patient-centered benefit, the primary outcome was redefined as postoperative pain measured by the Numerical Rating Scale (NRS) at 4, 24, and 48 hours. The pre-specified imaging measures BOLD were re-designated as secondary outcomes to explore the neural correlates of the analgesic effect. This protocol amendment was finalized prior to the enrollment of the first participant on January 15, 2024.

Study Overview

• Status: Completed
• Conditions: Epilepsy; Radiofrequency Ablation; Intracranial Surgery
• Intervention / Treatment: Drug: Dexmedetomidine Injectable Solution; Drug: Sodium Chloride 0.9% Inj

Detailed Description

On January 8, 2024, the protocol was amended and approved by the Institutional Review Board (IRB) of China International Neuroscience Institution (Approval No. CINI-AD-20220706). In this approved amendment, to ensure a direct assessment of the most clinically meaningful patient-centered benefit, the primary outcome was redefined as postoperative pain measured by the Numerical Rating Scale (NRS) at 4, 24, and 48 hours. The pre-specified imaging measures BOLD were re-designated as secondary outcomes to explore the neural correlates of the analgesic effect. This protocol amendment was finalized prior to the enrollment of the first participant on January 15, 2024.

Background: Dexmedetomidine (DEX) is a highly selective 2-adrenergic receptor agonist with significant analgesia affection. This study is planned to explore the brain regions and functional neuronal network involved in promoting analgesia of Dexmedetomidine. Methods: Select 12 patients with the proposed intraoperative MR-guided radiofrequency ablation of epilepsy. The subjects were randomized into the Dexmedetomidine group (DEX group) (n=14) and the Placebo group (PO group) (n=14). DEX group: continuous intravenously administered 1.5 µg kg-1 h-1 dexmedetomidine 15min before anesthesia induction, continuous infusion for 15min after anesthesia induction, and then Intraoperative functional magnetic resonance imaging scanning was started. OPI group: the equivalent administered speed 0.9% sodium chloride was continuously pumped for 15min before anesthesia induction, then induce and intraoperative fMRI scanning started after continuous 30min infusion. The intraoperative fMIR scan results were compared and analyzed to find the unique analgesic brain regions of DEX, and the differences of the functional neuronal network of analgesia effect between the two groups.

• Study Type: Interventional
• Enrollment (Actual): 28
• Phase: Phase 4

Contacts and Locations

Study Locations

• China
  • Beijing Municipality
    • Beijing, Beijing Municipality, China, 100053
      • Xuanwu Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 20 years to 50 years (Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

1. Clinical diagnosis of epilepsy and eligible for radiofrequency ablation
2. 20-50 years old;
3. American Society of Anesthesiologists rated (ASA) I-II
4. body mass index (BMI)18.5~27.9 kg·m2.

Exclusion Criteria:

1. pre-existing neuropsychiatric disorders;
2. emergency surgery;
3. coma;
4. depression;
5. cognitive impairment;
6. implanted with metal devices.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Health Services Research
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Quadruple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Dexmedetomidine group; 1.5 µg kg-1 h-1 dexmedetomidine	Drug: Dexmedetomidine Injectable Solution; continuous pump of 1.5ug / kg / h Dexmedetomidine 15min before anesthesia induction, continuous infusion for 30min after anesthesia induction, and then nuclear magnetic scanning was started.; Other Names: Dexmedetomidine
Placebo Comparator: Placebo group; 0.9% sodium chloride injection	Drug: Sodium Chloride 0.9% Inj; the equivalent Sodium Chloride 0.9% Inj was continuously pumped before anesthesia induction, induced by opioids for 15min, and intraoperative fMRI scanning was started after continuous infusion for 30min.; Other Names: only opioid and Sodium Chloride as placebo administration

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
NRS	NRS immediately after operation at rest.(The NRS was an 11-point scale with 0 indicating no pain and 10 equaled worst possible pain)	Hour 4, Hour 24, Hour48 post-operatively

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Measurement of analgesia relative brain regions assessed by BOLD under fMRI scanning	Measurement of analgesia relative brain regions inDexmedetomidine group (DEX group) and the Opioid group (OPI group) assessed by BOLD under fMRI scanning, and compare the two group different at the same time	during operation
Measurement of analgesia relative brain regions assessed by T1-MPRAGE under fMRI scanning	Measurement of analgesia relative brain regions inDexmedetomidine group (DEX group) and the Opioid group (OPI group) assessed by T1-MPRAGE under fMRI scanning, and compare the two group different at the same time	during operation
Measurement of analgesia relative brain regions assessed by T2-SPACE under fMRI scanning	Measurement of analgesia relative brain regions inDexmedetomidine group (DEX group) and the Opioid group (OPI group) assessed by T2-SPACE under fMRI scanning, and compare the two group different at the same time	during operation
systolic blood pressure (SBP)	hemodynamic change of the two groups included systolic blood pressure (SBP)	during operation
diastolic blood pressure (DBP)	hemodynamic change of the two groups included diastolic blood pressure (DBP)	during operation
mean arterial pressure (MAP)	hemodynamic change of the two groups included mean arterial pressure (MAP)	during operation
heart rate (HR)	hemodynamic change of the two groups included heart rate (HR)	during operation

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
PONV	modified postoperative nausea vomiting (PONV) score	Day 7 postoperatively

Collaborators and Investigators

• Sponsor: China International Neuroscience Institution
• Investigators: Study Chair: Xinya Wang, Dr, China International Neuroscience Institute

Study record dates

Study Major Dates

• Study Start (Actual): January 15, 2024
• Primary Completion (Actual): December 15, 2024
• Study Completion (Actual): December 20, 2024

Study Registration Dates

• First Submitted: August 8, 2022
• First Submitted That Met QC Criteria: August 11, 2022
• First Posted (Actual): August 15, 2022

Study Record Updates

• Last Update Posted (Actual): September 10, 2026
• Last Update Submitted That Met QC Criteria: September 8, 2026
• Last Verified: April 1, 2025

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Epilepsy; Heterocyclic Compounds, 1-Ring; Heterocyclic Compounds; Azoles; Imidazoles; Inorganic Chemicals; Chlorine Compounds; Sodium Compounds; Chlorides; Hydrochloric Acid; Dexmedetomidine; Sodium Chloride
• Other Study ID Numbers: CINI-AD-20220706

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No