Protocol summary

Study aim
To compare the efficacy of conventional radiofrequency (CRF) and pulsed radiofrequency combined with conventional radiofrequency (PRF+CRF) in reducing pain intensity, improving quality of life, and reducing treatment-related adverse events in patients with drug-resistant classical trigeminal neuralgia.
Design
Randomized, single-blind, parallel-group clinical trial with 1:1 allocation. Block randomization with block size 4 will be used. Total sample size is 28.
Settings and conduct
This randomized clinical trial will be conducted at the Pain Clinic of Imam Khomeini Hospital Complex, Tehran University of Medical Sciences. Eligible participants will be enrolled after providing written informed consent and randomly allocated to the CRF or PCRF group. The study is single-blind, with participants and outcome assessors blinded to treatment allocation. Participants will be followed for 3 months.
Participants/Inclusion and exclusion criteria
Inclusion criteria: Age 18–80 years, classical trigeminal neuralgia (ICHD-3), ≥50% pain reduction after diagnostic block, ASA I–II, written informed consent, and failure of standard two- or three-drug therapy. Exclusion criteria: Secondary trigeminal neuralgia, coagulopathy or non-discontinuable anticoagulant therapy, active infection, allergy to lidocaine or dexamethasone, previous trigeminal RF or surgery, unstable cardiopulmonary disease, pregnancy, or breastfeeding.
Intervention groups
Group 1: Conventional radiofrequency (CRF). Group 2: Pulsed radiofrequency combined with conventional radiofrequency (PCRF). Participants will be randomly allocated in a 1:1 ratio.
Main outcome variables
Pain intensity measured by the Numeric Rating Scale (NRS); quality of life assessed using the SF-36 questionnaire; treatment-related adverse events.

General information

Reason for update
Acronym
PCRF-TN
IRCT registration information
IRCT registration number: IRCT20260623069925N1
Registration date: 2026-06-26, 1405/04/05
Registration timing: prospective

Last update: 2026-06-26, 1405/04/05
Update count: 0
Registration date
2026-06-26, 1405/04/05
Registrant information
Name
asma amiri
Name of organization / entity
Country
Iran (Islamic Republic of)
Phone
+98 21 8826 8180
Email address
dr.amiri@jmu.ac.ir
Recruitment status
recruiting
Funding source
Expected recruitment start date
2026-07-23, 1405/05/01
Expected recruitment end date
2026-10-23, 1405/08/01
Actual recruitment start date
empty
Actual recruitment end date
empty
Trial completion date
empty
Scientific title
Comparison of the Effectiveness of Conventional Radiofrequency Versus Combined Pulsed-Conventional Radiofrequency in the Treatment of Drug-Resistant Trigeminal Neuralgia: A Randomized Clinical Trial
Public title
Comparison of Two Radiofrequency Techniques for the Treatment of Drug-Resistant Trigeminal Neuralgia
Purpose
Treatment
Inclusion/Exclusion criteria
Inclusion criteria:
Age 18 to 80 years Diagnosis of classical trigeminal neuralgia according to ICHD-3 criteria Positive response to diagnostic block with at least 50% reduction in pain intensity based on the NRS ASA physical status I or II Ability to understand the study and sign the informed consent form Failure to respond adequately to standard two-drug or three-drug therapy
Exclusion criteria:
Refusal to participate in the study or failure to provide informed consent Secondary trigeminal neuralgia due to multiple sclerosis or tumor lesions Coagulation disorders or use of anticoagulant drugs that cannot be discontinued Active local or systemic infection Known allergy to lidocaine or dexamethasone History of open trigeminal surgery or previous radiofrequency procedures Unstable cardiopulmonary disease Pregnancy or breastfeeding
Age
From 18 years old to 80 years old
Gender
Both
Phase
N/A
Groups that have been masked
  • Participant
  • Outcome assessor
Sample size
Target sample size: 28
Randomization (investigator's opinion)
Randomized
Randomization description
Eligible participants who provide written informed consent will be randomly allocated in a 1:1 ratio to the Conventional Radiofrequency group or the Pulsed Radiofrequency plus Conventional Radiofrequency group using block randomization. The random allocation sequence will be generated using statistical software, and allocation concealment will be ensured by sequentially numbered, opaque, sealed envelopes.
Blinding (investigator's opinion)
Single blinded
Blinding description
This study is a single-blind randomized clinical trial. Participants will be blinded to the allocated intervention (Conventional Radiofrequency or Pulsed Radiofrequency combined with Conventional Radiofrequency). Outcome assessors responsible for data collection and clinical outcome assessment will also be blinded to treatment allocation. The physician performing the procedure (investigator) will not be blinded because of the nature of the intervention. Clinical care providers and data analysts will also not be blinded.
Placebo
Not used
Assignment
Parallel
Other design features

Secondary Ids

empty

Ethics committees

1

Ethics committee
Name of ethics committee
Research Ethics Committee of Neuroscience Institute, Tehran University of Medical Sciences
Street address
No. 8, Unit 4, Golparvar Alley, Mousavi St., Shahrara Neighborhood, Tehran, Iran
City
Tehran
Province
Tehran
Postal code
1445753955
Approval date
2026-06-24, 1405/04/03
Ethics committee reference number
IR.TUMS.NI.REC.1405.035

Health conditions studied

1

Description of health condition studied
Trigeminal Neuralgia
ICD-10 code
G50.0
ICD-10 code description
Trigeminal neuralgia

Primary outcomes

1

Description
Pain intensity measured by the Numerical Rating Scale (NRS)
Timepoint
Pain intensity will be measured at baseline, before the intervention, and then 1 month and 3 months after the intervention.
Method of measurement
Pain intensity will be measured using the Numerical Rating Scale (NRS), scored from 0 to 10.

Secondary outcomes

1

Description
Quality of life measured by the 36-Item Short Form Health Survey (SF-36)
Timepoint
Before the intervention, 1 month after the intervention, and 3 months after the intervention
Method of measurement
Quality of life will be measured using the 36-Item Short Form Health Survey (SF-36).

2

Description
Incidence of intervention-related adverse events
Timepoint
Before the intervention, 1 month after the intervention, and 3 months after the intervention
Method of measurement
Adverse events will be assessed by clinical examination, patient interview, and documentation of all intervention-related adverse events, including facial numbness, dysesthesia, masticatory muscle weakness, decreased corneal reflex, and other potential complications.

Intervention groups

1

Description
Control group: Participants will undergo conventional radiofrequency (CRF) treatment of the trigeminal nerve. After fluoroscopic needle placement and confirmation by sensory and motor stimulation, conventional radiofrequency will be applied at 70°C for 60 seconds in three consecutive cycles using a four-channel NeuroTherm radiofrequency generator (NeuroTherm, USA).
Category
Treatment - Devices

2

Description
Intervention group:Participants will undergo pulsed radiofrequency (PRF) at a maximum temperature of 42°C for 240 seconds (20-ms pulse width, 2 Hz), followed immediately by conventional radiofrequency (CRF) at 70°C for 60 seconds in two consecutive cycles using a four-channel NeuroTherm radiofrequency generator (NeuroTherm, USA).
Category
Treatment - Devices

Recruitment centers

1

Recruitment center
Name of recruitment center
Pain Clinic, Imam Khomeini Hospital, Tehran University of Medical Sciences
Full name of responsible person
Asma Amiri
Street address
Pain Clinic, Imam Khomeini Hospital Complex, End of Keshavarz Blvd, Tehran
City
Tehran
Province
Tehran
Postal code
1419733141
Phone
+98 21 6119 0000
Email
Imamhospital@tums.ac.ir

Sponsors / Funding sources

1

Sponsor
Name of organization / entity
Tehran University of Medical Sciences
Full name of responsible person
Dr. Ramin Kordi
Street address
No. 21, Dameshgh St., Vali-e Asr Ave., Tehran, Iran
City
Tehran
Province
Tehran
Postal code
1416753955
Phone
+98 21 8889 6690
Email
Gsia@tums.ac.ir
Grant name
Grant code / Reference number
Is the source of funding the same sponsor organization/entity?
Yes
Title of funding source
Tehran University of Medical Sciences
Proportion provided by this source
100
Public or private sector
Public
Domestic or foreign origin
Domestic
Category of foreign source of funding
empty
Country of origin
Type of organization providing the funding
Academic

Person responsible for general inquiries

Contact
Name of organization / entity
Tehran University of Medical Sciences
Full name of responsible person
Asma Amiri
Position
Fellow of Pain Medicine
Latest degree
Specialist
Other areas of specialty/work
Anesthesiology
Street address
No. 8, Golparvar Alley, Mousavi St., Shahrara Neighborhood, Tehran, Iran
City
Tehran
Province
Tehran
Postal code
1445753955
Phone
+98 21 8826 8180
Email
asma.amirid@gmail.com

Person responsible for scientific inquiries

Contact
Name of organization / entity
Tehran University of Medical Sciences
Full name of responsible person
Reza Atef Yekta
Position
Associate Professor
Latest degree
Subspecialist
Other areas of specialty/work
Pain Medicine
Street address
Pain Medicine Department, Dr. Shariati Hospital, North Kargar St., Tehran
City
Tehran
Province
Tehran
Postal code
1411713135
Phone
+98 21 8490 1000
Email
atefyekta@tums.ac.ir

Person responsible for updating data

Contact
Name of organization / entity
Tehran University of Medical Sciences
Full name of responsible person
Asma Amiri
Position
Fellow of Pain Medicine
Latest degree
Specialist
Other areas of specialty/work
Anesthesiology
Street address
No. 8, Golparvar Alley, Mousavi St., Shahrara Neighborhood, Tehran, Iran
City
Tehran
Province
Tehran
Postal code
1445753955
Phone
+98 21 8826 8180
Email
asma.amirid@gmail.com

Sharing plan

Deidentified Individual Participant Data Set (IPD)
Undecided - It is not yet known if there will be a plan to make this available
Study Protocol
Undecided - It is not yet known if there will be a plan to make this available
Statistical Analysis Plan
Undecided - It is not yet known if there will be a plan to make this available
Informed Consent Form
Undecided - It is not yet known if there will be a plan to make this available
Clinical Study Report
Undecided - It is not yet known if there will be a plan to make this available
Analytic Code
Undecided - It is not yet known if there will be a plan to make this available
Data Dictionary
Undecided - It is not yet known if there will be a plan to make this available
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