Clinical and Brain Activity Assessment Before and After Physiotherapy in People With Chronic Non-specific Neck Pain

It is a single-item patient-reported outcome that aims to quantify a patient's perceived improvement or deterioration over time. The questionnaire is scored with 7 positive items to assess the patient's subjective improvement progressively. It also presents 7 negative items to assess whether the patient has worsened. The 0 is defined as no improvement or worsening.

11-point tool used to measure pain intensity from 0 (no pain) to 10 (worst pain imaginable)

The Neck Disability Index consists of 10 items assessing disability related to neck pain. Each item is scored from 0 to 5, giving a total score from 0 to 50. Higher scores indicate greater neck-related disability. The score may also be expressed as a percentage from 0% to 100%.

Spectral characteristics will be derived from 64-channel electroencephalography recorded while participants are seated comfortably with their eyes closed in a quiet environment and instructed to remain relaxed and minimize movement. Mean peak alpha frequency will be reported in hertz (Hz) at baseline and post-intervention.

The Pain Catastrophizing Scale consists of 13 items scored from 0 to 4. The total score ranges from 0 to 52, with higher scores indicating greater pain catastrophizing.

Anxiety and depressive symptoms will be assessed using the 14-item Hospital Anxiety and Depression Scale. The anxiety and depression subscale scores will be summed to obtain a total score ranging from 0 to 42, with higher scores indicating greater psychological distress.

Symptoms associated with central sensitization will be assessed using Part A of the 25-item Central Sensitization Inventory. The total score ranges from 0 to 100, with higher scores indicating greater symptom severity.

Fear of movement will be assessed using the 11-item Tampa Scale for Kinesiophobia. The total score ranges from 11 to 44, with higher scores indicating greater kinesiophobia.

Sleep quality will be assessed using a single 0-to-10 numerical rating scale, where 0 indicates the worst possible sleep quality and 10 indicates the best possible sleep quality.

Participants will indicate the location and extent of their pain using a digital body chart. Total pain extent will be calculated as the percentage of the body chart area marked as painful.

Pressure pain threshold will be assessed using a pressure algometer with a 1-cm² contact surface. Participants will be instructed to press a button when the sensation first changes from pressure to pain. Measurements will be performed at the most painful cervical location and at the contralateral hand. Three measurements will be obtained at each anatomical location, and the mean of the three measurements will be used for analysis. Values from the cervical location and the hand will be reported separately. Results will be reported in kilopascals.

Cold pain threshold will be assessed as part of a quantitative sensory testing protocol using the MSA Thermotest (Somedic) with a 9-cm² contact thermode. The baseline temperature will be set at 32°C, and the minimum safety limit will be 5°C. Temperature will decrease at a rate of 1°C/s. Participants will press a button when the cold sensation first becomes painful, immediately stopping the stimulus. Three valid consecutive measurements will be obtained, and their mean temperature will be used for analysis. Results will be reported in degrees Celsius.

Heat pain threshold will be assessed as part of a quantitative sensory testing protocol using the MSA Thermotest (Somedic) with a 9-cm² contact thermode. The baseline temperature will be set at 32°C, and the maximum safety limit will be 50°C. Temperature will increase at a rate of 1°C/s. Participants will press a button when the heat sensation first becomes painful, immediately stopping the stimulus. Three valid consecutive measurements will be obtained, and their mean temperature will be used for analysis. Results will be reported in degrees Celsius.

Mechanical temporal summation of pain will be assessed using calibrated pinprick stimulators (MRC Systems). Participants will rate the perceived pain intensity of a single 256-mN pinprick stimulus and the overall pain intensity elicited by a series of 10 pinprick stimuli of the same force applied at a rate of 1 stimulus per second. Pain intensity will be rated using a numerical rating scale ranging from 0, no pain, to 10, worst imaginable pain. The temporal summation ratio will be calculated by dividing the pain rating for the series of 10 stimuli by the pain rating for the single stimulus. When the pain rating for the single stimulus is 0, a value of 1 will be used as the denominator to avoid division by zero. Higher ratios indicate greater temporal summation of pain.

Conditioned pain modulation will be assessed using the cold pressor test as the conditioning stimulus and pressure pain threshold as the test stimulus. Participants will immerse the foot contralateral to the most painful cervical location in an insulated container filled with cold water, initially set at 10°C, for up to 2 minutes. The water temperature may be adjusted to achieve a pain intensity of approximately 5 out of 10. Immediately after removal of the conditioning stimulus, pressure pain threshold will be measured three times at the cervical location, with 15 seconds between measurements, and the mean of the three measurements will be used for analysis. The conditioned pain modulation response will be calculated as the absolute change in pressure pain threshold between the pre-conditioning and post-conditioning measurements and reported in kilopascals (kPa). Higher positive values indicate greater endogenous pain inhibition.