Digital Nerve InjuryNCT07904286
Sensory Neurography and S2PD After Digital Nerve Injury
An observational study of Digital Nerve Injury and Sensory Neurography, run by Cecilia Mellstrand Navarro at 2 sites in Sweden.
Trial summary
The goal of this clinical comparative cross sectional study, is to investigate neurophysiological findings and S2PD (static two point discrimination test) measurements after digital nerve injury. Read more about this study
- Who is it for?
- Ages 20 to 60 years
- Conditions the study is for
- Digital Nerve Injury, Sensory Neurography, S2PD
- What is being tested?
- Sensory neurography and Static two point discrimination test, S2PD
- How many people
- 60 participants
- Where
- 2 sitesSweden
- Study dates
- 28 Sep 2026to 31 Dec 2026
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 20 to 60 years
- All sexes
- No healthy volunteers
- Adult
Study population: Patients treated surgically for a digital nerve injury at the Sodersjukhuset Hand Surgery Clinic from 2013 to 2023.
Who may be able to join
- Injury: One year or more prior to inclusion
- Injured finger: digit II, III or radial dig IV
- Level of injury: base or middle phalanx
- Age at injury>20
- Age at inclusion<60
Who cannot join
- Neurologic disease
- Dementia
- Cognitive disability
- Severe psychiatric disorder (not be able to participate)
- Ongoing drug abuse
- Not understanding swedish language
- History of carpal tunnel syndrome
- Negative experience of electric stimulation
Trial locations and contacts
2 sites in 1 country. Contact the study team or a site near you to ask about taking part.
Sweden2 sites, 2 recruiting
- Not yet recruiting
Karolinska Institutet Södersjukhuset, Department of clinical research and education
Stockholm, 11883
- Recruiting
South General Hospital
Stockholm, 11883
Carin Carlsson, MD, 004681236000, carin.carlsson@regionstockholm.se
About this study
Official title: Investigation of the Correlation of Sensory Neurography Findings and S2PD Measurements After Digital Nerve Injury
The goal of this clinical comparative cross sectional study, is to investigate neurophysiological findings and S2PD (static two point discrimination test) measurements after digital nerve injury.
The main aim is to find out if there are measurable neurophysiological differences in fingers following digital nerve injury that correlate with discriminative sensory function (S2PD) as experienced by the patient. Secondary aim is to investigate how well neurophysiological measurements predict specific S2PD values in the affected fingers.
Read more
Participants with a sutured digital nerve injury will be examined with neurophysiology and S2PD testing. Both injured finger and corresponding uninjured finger on the other hand will be examined, i.e participants will be their own control.
Prior to the study the investigators will perform a test-re-test study on ten participants to ensure that the method is reliable (separate registration)
Read the detailed description
The aim of this project is to use neurophysiological assessment to gain a better understanding of what is actually measured by S2PD (static two-point discrimination). A neurophysiological examination can objectively measure any remaining function in an injured digital nerve. Using this method, axons responsible for pressure, vibration, and touch that are still able to conduct an action potential, are assessed.
The response can be measured both as the amplitude of the summed action potentials from the nerve's axons and as the area, which corresponds to the area under the curve formed by the recorded action potentials. The area is a somewhat more precise measurement method, as it includes all axons, both those with low and high conduction velocities. Amplitude measurements may give falsely low values if nerves with poorer degrees of myelination are included in the measurement. Amplitude is measured in µV and area in µV/ms.
The method currently used to assess discriminative sensation, S2PD, is influenced by many external factors, such as the clinician's level of experience, the patient's desire to give the correct answer, language barriers, and similar issues. Furthermore, this examination method does not clarify what is actually being measured beyond the patient's subjective discriminative sensation.
If neurophysiological assessment is used as a complement to S2PD and can provide an objective measurement tool with high reliability and reproducibility, it could become an important addition to the clinical arsenal for follow-up after nerve injury. Such knowledge would make it easier to clinically evaluate, understand, and monitor the healing process of the injured nerve. It would also facilitate the assessment and systematic follow-up of treatment outcomes.
The investigators also believe that patients would benefit from being able to follow nerve healing in a more objective manner, which could help motivate continued training and rehabilitation (such as tactile stimulation, mirror therapy, desensitization, etc.).
Participants will be identified through the national quality register for hand surgery (HAKIR), and will be invited to attend an examination at the Hand Surgery Outpatient Clinic at Sodersjukhuset by phone (postal invitation if no response). If the response rate is low, patients will be contacted by phone one additional time.
The visit, which is estimated to last approximately 60 minutes, will include assessment using static two-point discrimination (S2PD) and neurophysiological examination of the injured finger as well as the corresponding finger on the contralateral, uninjured hand. Sensory assessment with S2PD will be performed on the fingertip pulp, radially or ulnarly, using a discriminator. Sensory thresholds, measured in millimetres, will be recorded in the study protocol.
Finger temperature will be measured using an infrared thermometer (Testo 826-T2), and, if necessary, the fingers will be warmed (using a water bath or heating pad) to a target temperature of a minimum of 32 °C. The hands will then be gently abraded using a preparation gel (NuPrep). Conductive gel (Ten20) will be applied to the electrodes.
A recording electrode will be placed volarly over the wrist, a ground electrode in the palm, and a stimulating electrode on the finger (digits II, III, or IV). Electrical stimulation will be delivered in an orthodromic direction, from the finger toward the wrist. The stimulus intensity will be gradually increased as long as the recorded amplitude continues to rise, up to a maximum of 20% above the intensity at which no further increase in amplitude is observed. This approach ensures inclusion of all excitable axons in the recording, regardless of individual firing thresholds.
- Conditions
- Digital Nerve Injury, Sensory Neurography, S2PD
- Being tested
- Sensory neurography, Static two point discrimination test, S2PD
- Keywords
- S2PD, Sensory nerve action potential, Neurophysiology, Static two-point discrimination test, Digital nerve injury, Sensory neurography
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Sensory neurographyDiagnostic test
Participants will be examined with sensory neurography (orthodromic stimulation).
Static two point discrimination test, S2PDDiagnostic test
Participants will be examined with S2PD.
| Study group | Role | What they receive |
|---|---|---|
| Sensory and neurophysiology outcome in injured digit | The finger with an injured digital nerve will be examined with S2PD and sensory neurography Receives: Diagnostic Test: Sensory neurography; Diagnostic Test: Static two point discrimination test, S2PD | |
| Sensory and neurophysiology outcome in normal digit | The contralateral uninjured finger will be examined with S2PD and sensory neurography Receives: Diagnostic Test: Sensory neurography; Diagnostic Test: Static two point discrimination test, S2PD |
What is being measured
The primary outcome is the main question the study is designed to answer.
Is there a correlation between the amplitude of the sensory nerve action potential and S2PD?
A potential correlation between the sensory nerve action potential amplitude (microvoltage) measured with sensory neurography and S2PD (in millimeters) measured with a discriminator, will be analysed with test for correlation and presented as a value between -1 and 1
Measured: Participant assessments will be conducted during a single session lasting approximately 60 minutes
Is there a correlation between sensory nerve action potential area and S2PD?
A potential correlation between the sensory nerve action potential area (milliseconds*microvoltage) measured with sensory neurography and S2PD (in millimeters) measured with a discriminator, will be analysed with test for correlation and presented as a value between -1 and 1
Measured: Participant assessments will be conducted during a single session lasting approximately 60 minutes
Secondary outcomes (7)
Does a certain value of S2PD correspond to a specific (percentage) value of the amplitude or area of the action potential?
We will evaluate the correlation between S2PD (in 1 mm steps) and the percentages of sensory neurography amplitude and area of the injured nerve.
Measured: Participant assessments will be conducted during a single session lasting approximately 60 minutes
How does age affect the potential correlation between sensory neurography measures (amplitude and area) and S2PD?
A regression analysis will be used to evaluate what impact age (years) has on primary outcomes.
Measured: Participant assessments will be conducted during a single session lasting approximately 60 minutes
How does participants' sex affect the potential correlation between sensory neurography measures (amplitude and area) and S2PD?
A regression analysis will be used to evaluate what impact participants' sex (male or female) has on primary outcomes.
Measured: Participant assessments will be conducted during a single session lasting approximately 60 minutes
How does smoking affect the potential correlation between sensory neurography measures (amplitude and area) and S2PD?
A regression analysis will be used to evaluate what impact smoking (yes or no) has on primary outcomes.
Measured: Participant assessments will be conducted during a single session lasting approximately 60 minutes
How does the type of injured nerve affect the potential correlation between sensory neurography measures (amplitude and area) and S2PD?
A regression analysis will be used to evaluate what impact type of injured nerve (digital nerves to second, third or radial side of the fourth finger) has on primary outcomes.
Measured: Participant assessments will be conducted during a single session lasting approximately 60 minutes
How does time from injury affect the potential correlation between sensory neurography measures (amplitude and area) and S2PD?
A regression analysis will be used to evaluate what impact time from injury (in years) has on primary outcomes.
Measured: Participant assessments will be conducted during a single session lasting approximately 60 minutes
How does the level of injury affect the potential correlation between sensory neurography measures (amplitude and area) and S2PD?
A regression analysis will be used to evaluate what impact level of injury (proximal or middle phalanx) has on primary outcomes.
Measured: Participant assessments will be conducted during a single session lasting approximately 60 minutes
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted29 Oct 2026
- Study start28 Sep 2026
- Primary completion31 Dec 2026 (estimated)
- Study completion31 Dec 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (4)Papers the sponsor has linked to this study.
- Other trials for Digital Nerve InjuryStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Case-control
- Time perspective
- Cross-sectional
- Enrolment
- 60 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Cecilia Mellstrand Navarro
- Sponsor type
- University, hospital or other
- Collaborators
- Stockholm South General Hospital, AFA Insurance
- Responsible party
- Sponsor-investigator, Cecilia Mellstrand Navarro, Karolinska Institutet
- Investigators
- Cecilia Mellstrand-Navarro, Ass. prof, Principal investigator, Karolinska Institutet Södersjukhuset, Department of clinical research and education
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07904286
- Sponsor's protocol ID
- 2023-05732-01
- Other IDs
- 2023
- Status last verified
- Oct 2026
- First submitted
- 9 Oct 2026
- Last updated
- 29 Oct 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: Data will be available in pseudonymized form
Publications
https://doi.org/10.1016/S1531-0914(03)00069-X
Zanette G, Lauriola MF, Tamburin S. An electrodiagnostic technique for assessing palmar proper digital nerves of the hand: Normative data and clinical application. Muscle Nerve. 2015 Dec;52(6):972-80. doi: 10.1002/mus.24668. Epub 2015 Sep 15.
PubMed 25845854Lundborg G, Rosen B. The two-point discrimination test--time for a re-appraisal? J Hand Surg Br. 2004 Oct;29(5):418-22. doi: 10.1016/j.jhsb.2004.02.008.
PubMed 15336741Wolny T, Linek P. Reliability of two-point discrimination test in carpal tunnel syndrome patients. Physiother Theory Pract. 2019 Apr;35(4):348-354. doi: 10.1080/09593985.2018.1443358. Epub 2018 Feb 26.
PubMed 29482409
Study at a glance
From the registry record, last updated by the sponsor on 29 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Investigation of the Correlation of Sensory Neurography Findings and S2PD Measurements After Digital Nerve Injury
- ClinicalTrials.gov ID
- NCT07904286
- Acronym / sponsor ID
- 2023-05732-01
- Conditions
- Digital Nerve Injury, Sensory Neurography, S2PD
- Keywords
- S2PD, Sensory nerve action potential, Neurophysiology, Static two-point discrimination test, Digital nerve injury, Sensory neurography
- Study type
- Observational
- Recruitment status
- Recruiting
- Enrolment
- 60 participants (estimated)
- Lead sponsor
- Cecilia Mellstrand NavarroUniversity, hospital or other
- Collaborators
- Stockholm South General Hospital, AFA Insurance
- Study start
- 28 Sep 2026 (actual)
- Primary completion
- 31 Dec 2026 (estimated)
- Study completion
- 31 Dec 2026 (estimated)
- First posted
- 29 Oct 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The goal of this clinical comparative cross sectional study, is to investigate neurophysiological findings and S2PD (static two point discrimination test) measurements after digital nerve injury.
The main aim is to find out if there are measurable neurophysiological differences in fingers following digital nerve injury that correlate with discriminative sensory function (S2PD) as experienced by the patient. Secondary aim is to investigate how well neurophysiological measurements predict specific S2PD values in the affected fingers.
Participants with a sutured digital nerve injury will be examined with neurophysiology and S2PD testing. Both injured finger and corresponding uninjured finger on the other hand will be examined, i.e participants will be their own control.
Prior to the study the investigators will perform a test-re-test study on ten participants to ensure that the method is reliable (separate registration)
Detailed description
The aim of this project is to use neurophysiological assessment to gain a better understanding of what is actually measured by S2PD (static two-point discrimination). A neurophysiological examination can objectively measure any remaining function in an injured digital nerve. Using this method, axons responsible for pressure, vibration, and touch that are still able to conduct an action potential, are assessed.
The response can be measured both as the amplitude of the summed action potentials from the nerve's axons and as the area, which corresponds to the area under the curve formed by the recorded action potentials. The area is a somewhat more precise measurement method, as it includes all axons, both those with low and high conduction velocities. Amplitude measurements may give falsely low values if nerves with poorer degrees of myelination are included in the measurement. Amplitude is measured in µV and area in µV/ms.
The method currently used to assess discriminative sensation, S2PD, is influenced by many external factors, such as the clinician's level of experience, the patient's desire to give the correct answer, language barriers, and similar issues. Furthermore, this examination method does not clarify what is actually being measured beyond the patient's subjective discriminative sensation.
If neurophysiological assessment is used as a complement to S2PD and can provide an objective measurement tool with high reliability and reproducibility, it could become an important addition to the clinical arsenal for follow-up after nerve injury. Such knowledge would make it easier to clinically evaluate, understand, and monitor the healing process of the injured nerve. It would also facilitate the assessment and systematic follow-up of treatment outcomes.
The investigators also believe that patients would benefit from being able to follow nerve healing in a more objective manner, which could help motivate continued training and rehabilitation (such as tactile stimulation, mirror therapy, desensitization, etc.).
Participants will be identified through the national quality register for hand surgery (HAKIR), and will be invited to attend an examination at the Hand Surgery Outpatient Clinic at Sodersjukhuset by phone (postal invitation if no response). If the response rate is low, patients will be contacted by phone one additional time.
The visit, which is estimated to last approximately 60 minutes, will include assessment using static two-point discrimination (S2PD) and neurophysiological examination of the injured finger as well as the corresponding finger on the contralateral, uninjured hand. Sensory assessment with S2PD will be performed on the fingertip pulp, radially or ulnarly, using a discriminator. Sensory thresholds, measured in millimetres, will be recorded in the study protocol.
Finger temperature will be measured using an infrared thermometer (Testo 826-T2), and, if necessary, the fingers will be warmed (using a water bath or heating pad) to a target temperature of a minimum of 32 °C. The hands will then be gently abraded using a preparation gel (NuPrep). Conductive gel (Ten20) will be applied to the electrodes.
A recording electrode will be placed volarly over the wrist, a ground electrode in the palm, and a stimulating electrode on the finger (digits II, III, or IV). Electrical stimulation will be delivered in an orthodromic direction, from the finger toward the wrist. The stimulus intensity will be gradually increased as long as the recorded amplitude continues to rise, up to a maximum of 20% above the intensity at which no further increase in amplitude is observed. This approach ensures inclusion of all excitable axons in the recording, regardless of individual firing thresholds.
Study design
- Observational model
- Case-control
- Time perspective
- Cross-sectional
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Sensory and neurophysiology outcome in injured digit | – | Diagnostic Test: Sensory neurography, Diagnostic Test: Static two point discrimination test, S2PDThe finger with an injured digital nerve will be examined with S2PD and sensory neurography |
| Sensory and neurophysiology outcome in normal digit | – | Diagnostic Test: Sensory neurography, Diagnostic Test: Static two point discrimination test, S2PDThe contralateral uninjured finger will be examined with S2PD and sensory neurography |
Who may qualify
- Ages
- 20 to 60 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult
- Study population
- Patients treated surgically for a digital nerve injury at the Sodersjukhuset Hand Surgery Clinic from 2013 to 2023.
Key inclusion criteria (5 listed)
- Injury: One year or more prior to inclusion
- Injured finger: digit II, III or radial dig IV
- Level of injury: base or middle phalanx
- Age at injury>20
- Age at inclusion<60
Key exclusion criteria (8 listed)
- Neurologic disease
- Dementia
- Cognitive disability
- Severe psychiatric disorder (not be able to participate)
- Ongoing drug abuse
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Sensory neurographyParticipants will be examined with sensory neurography (orthodromic stimulation). | Diagnostic test | Sensory and neurophysiology outcome in injured digit, Sensory and neurophysiology outcome in normal digit |
| Static two point discrimination test, S2PDParticipants will be examined with S2PD. | Diagnostic test | Sensory and neurophysiology outcome in injured digit, Sensory and neurophysiology outcome in normal digit |
Primary outcome
Is there a correlation between the amplitude of the sensory nerve action potential and S2PD?
Time frame: Participant assessments will be conducted during a single session lasting approximately 60 minutes
A potential correlation between the sensory nerve action potential amplitude (microvoltage) measured with sensory neurography and S2PD (in millimeters) measured with a discriminator, will be analysed with test for correlation and presented as a value between -1 and 1
Is there a correlation between sensory nerve action potential area and S2PD?
Time frame: Participant assessments will be conducted during a single session lasting approximately 60 minutes
A potential correlation between the sensory nerve action potential area (milliseconds*microvoltage) measured with sensory neurography and S2PD (in millimeters) measured with a discriminator, will be analysed with test for correlation and presented as a value between -1 and 1
7 secondary outcomes
Does a certain value of S2PD correspond to a specific (percentage) value of the amplitude or area of the action potential?
Time frame: Participant assessments will be conducted during a single session lasting approximately 60 minutes
How does age affect the potential correlation between sensory neurography measures (amplitude and area) and S2PD?
Time frame: Participant assessments will be conducted during a single session lasting approximately 60 minutes
How does participants' sex affect the potential correlation between sensory neurography measures (amplitude and area) and S2PD?
Time frame: Participant assessments will be conducted during a single session lasting approximately 60 minutes
How does smoking affect the potential correlation between sensory neurography measures (amplitude and area) and S2PD?
Time frame: Participant assessments will be conducted during a single session lasting approximately 60 minutes
How does the type of injured nerve affect the potential correlation between sensory neurography measures (amplitude and area) and S2PD?
Time frame: Participant assessments will be conducted during a single session lasting approximately 60 minutes
How does time from injury affect the potential correlation between sensory neurography measures (amplitude and area) and S2PD?
Time frame: Participant assessments will be conducted during a single session lasting approximately 60 minutes
How does the level of injury affect the potential correlation between sensory neurography measures (amplitude and area) and S2PD?
Time frame: Participant assessments will be conducted during a single session lasting approximately 60 minutes
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 29 Oct 2026.
- Backgroundhttps://doi.org/10.1016/S1531-0914(03)00069-X
- Background: PubMed 25845854Zanette G, Lauriola MF, Tamburin S. An electrodiagnostic technique for assessing palmar proper digital nerves of the hand: Normative data and clinical application. Muscle Nerve. 2015 Dec;52(6):972-80. doi: 10.1002/mus.24668. Epub 2015 Sep 15.
- Background: PubMed 15336741Lundborg G, Rosen B. The two-point discrimination test--time for a re-appraisal? J Hand Surg Br. 2004 Oct;29(5):418-22. doi: 10.1016/j.jhsb.2004.02.008.
- Background: PubMed 29482409Wolny T, Linek P. Reliability of two-point discrimination test in carpal tunnel syndrome patients. Physiother Theory Pract. 2019 Apr;35(4):348-354. doi: 10.1080/09593985.2018.1443358. Epub 2018 Feb 26.
- Individual participant dataSharing planned: No. Data will be available in pseudonymized form
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Cecilia Mellstrand-Navarro, Ass. prof principal investigator
Karolinska Institutet Södersjukhuset, Department of clinical research and education
2 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Digital Nerve Injury and Sensory Neurography, run by Cecilia Mellstrand Navarro at 2 sites in Sweden.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 5 inclusion and 8 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 29 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 2 sites in Sweden. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Carin Carlsson, MD (0046812361000, carin.carlsson@regionstockholm.se), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Is there a correlation between the amplitude of the sensory nerve action potential and S2PD? (time frame: Participant assessments will be conducted during a single session lasting approximately 60 minutes). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT07904286, which also lists 4 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 29 Oct 2026.