Symptom Recovery Time After the Phalen Test in Carpal Tunnel Syndrome

The Phalen test is widely used in the clinical assessment of carpal tunnel syndrome. In routine practice, the test is generally interpreted as positive or negative according to whether typical symptoms occur within a defined period. However, this approach does not describe how quickly symptoms appear or how long they continue after the wrist is returned to a neutral position. Symptom recovery time may reflect functional and clinical burden that is not fully explained by electrodiagnostic severity alone.Previous studies have examined the relationship between Phalen test findings and electrodiagnostic severity; however, the clinical meaning of symptom recovery time after the test remains unclear.

This dual-center, observational, cross-sectional study will include adults with clinical symptoms of carpal tunnel syndrome confirmed by nerve conduction studies. For participants with bilateral carpal tunnel syndrome, the hand with greater nighttime paresthesia will be evaluated. If symptoms are equal in both hands, the dominant hand will be selected.

Before the Phalen test, paresthesia intensity in the evaluated hand will be recorded using a 0-10 Numeric Rating Scale. Participants will then sit with the backs of both hands placed together and the wrists held in full flexion without external pressure. The test will continue for a maximum of 60 seconds. It will be stopped immediately when typical symptoms in the median nerve distribution newly appear or clearly increase. The time from the beginning of the test to symptom onset will be recorded in seconds.

After the test is stopped, the participant will return the wrists to a neutral position and a second timer will be started. Symptom recovery time will be defined as the time required for the provoked symptoms to return to their pre-test level. Recovery will be observed for up to 300 seconds. If typical symptoms do not occur within 60 seconds, the Phalen test will be classified as negative and recovery time will not be defined.

Clinical symptom severity and hand function will be evaluated using the Boston Carpal Tunnel Questionnaire. Nighttime symptoms will be assessed using the number of carpal tunnel syndrome-related awakenings during the previous seven nights, nighttime numbness or tingling intensity, and the duration of morning numbness. Nerve conduction findings and electrodiagnostic severity will be collected as part of the study assessment.

The primary analysis will examine the relationship between symptom recovery time and the Functional Status Scale of the Boston Carpal Tunnel Questionnaire. Electrodiagnostic severity, symptom onset latency during the Phalen test, and study center will be considered in the adjusted analysis. Secondary analyses will examine the relationships of recovery time with symptom severity, nighttime complaints, and electrodiagnostic findings.

To evaluate test-retest reliability, a subgroup of participants with a positive Phalen test will repeat the same procedure after 3-7 days using the same hand, evaluator, and standardized test method. This study is observational, and no treatment or therapeutic intervention will be assigned.

• Timed Phalen Test (Diagnostic test): Participants will sit with the backs of both hands placed together and the wrists held in full flexion without external pressure. The test will continue for up to 60 seconds and will be stopped when typical symptoms in the median nerve distribution newly appear or clearly increase. Symptom onset latency will be recorded in seconds. After the wrists are returned to a neutral position, the time required for symptoms to return to their pre-test level will be recorded for up to 300 seconds. This diagnostic test is performed for assessment purposes and does not involve treatment.

Primary outcomes

• Symptom Recovery Time After the Phalen Test [Baseline]: For participants with a positive Phalen test, symptom recovery time will be measured in seconds from the moment the wrists are returned to a neutral position until the provoked symptoms return to their pre-test level. The minimum value is 0 seconds. Recovery will be observed for up to 300 seconds. Participants whose symptoms do not return to baseline within this period will be recorded as having a recovery time exceeding 300 seconds; 300 seconds will be used in the primary analysis, with a sensitivity analysis excluding these observations. Higher values indicate slower symptom recovery. The relationship between recovery time and the Boston Carpal Tunnel Questionnaire Functional Status Scale will be evaluated, with adjustment for electrodiagnostic severity, symptom onset latency, and study center.

Secondary outcomes

• Boston Carpal Tunnel Questionnaire Functional Status Scale Score [Baseline]: Hand function will be assessed using the eight-item Functional Status Scale of the Boston Carpal Tunnel Questionnaire. Each item is scored from 1 to 5, and the final score is the mean of the completed items. The total score ranges from 1 to 5, with higher scores indicating greater difficulty in hand-related activities and worse functional status.
• Boston Carpal Tunnel Questionnaire Symptom Severity Scale Score [Baseline]: Symptom severity will be assessed using the 11-item Symptom Severity Scale of the Boston Carpal Tunnel Questionnaire. Each item is scored from 1 to 5, and the final score is the mean of the completed items. The total score ranges from 1 to 5, with higher scores indicating more severe carpal tunnel syndrome symptoms.
• Symptom Onset Latency During the Phalen Test [Baseline]: The time from the beginning of the Phalen test until typical symptoms in the median nerve distribution newly appear or clearly increase will be recorded in seconds. Values range from 0 to 60 seconds. Higher values indicate a longer time before symptom onset and do not necessarily represent a better or worse clinical outcome. Participants without typical symptoms within 60 seconds will be classified as having a negative Phalen test.
• Carpal Tunnel Syndrome-Related Nighttime Awakenings [Baseline]: Participants will report the total number of awakenings caused by carpal tunnel syndrome symptoms during the previous seven nights. The minimum value is 0 and there is no predefined maximum. Higher values indicate more frequent sleep disruption.
• Nighttime Numbness or Tingling Intensity [Baseline]: Nighttime numbness or tingling in the evaluated hand will be rated using an 11-point Numeric Rating Scale ranging from 0 to 10, where 0 indicates no numbness or tingling and 10 indicates the worst imaginable numbness or tingling. Higher scores indicate greater symptom intensity.
• Duration of Morning Numbness [Baseline]: The duration of numbness in the evaluated hand after waking in the morning will be reported in minutes. The minimum value is 0 minutes and there is no predefined maximum. Higher values indicate longer-lasting morning numbness.
• Test-Retest Reliability of the Timed Phalen Test [Baseline and 3-7 days after baseline]: A subgroup of participants with a positive Phalen test will repeat the standardized test after 3-7 days. The reliability of symptom recovery time will be evaluated using the intraclass correlation coefficient among participants with a positive test at both assessments. Agreement in Phalen test positivity will be evaluated using Cohen's kappa coefficient. Higher coefficient values indicate greater test-retest reliability or agreement.

Sex: All, ages: 18 Years to 75 Years

Inclusion Criteria:

* Age between 18 and 75 years
* Clinical symptoms consistent with carpal tunnel syndrome
* Carpal tunnel syndrome confirmed by nerve conduction studies
* Ability to complete the Boston Carpal Tunnel Questionnaire and study assessments
* Provision of written informed consent

Exclusion Criteria:

* Polyneuropathy
* Clinical or electrodiagnostic evidence of cervical radiculopathy or brachial plexopathy
* Previous carpal tunnel surgery in the evaluated hand
* Local injection into the evaluated hand within the previous 3 months
* Another neurological or musculoskeletal disorder that substantially affects hand or upper-extremity function
* Inflammatory arthritis or severe rheumatologic disease affecting the wrist
* Acute hand or wrist trauma
* Marked restriction of wrist range of motion preventing performance of the Phalen test
* Pregnancy, postpartum period, or breastfeeding
* Cognitive or communication problems preventing completion of the study assessments

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