The PHQ-9 is a screening instrument with 9 items, developed to measure depression. For each item the patients are asked to assess how much they were bothered by the symptoms over the last two weeks. There are four answer options: not at all (0), several days (1), more than half of the days (2), and nearly every day (3). The sum score (range 0 to 27) indicates the degree of depression, with scores of ≥5, ≥10, and ≥15 representing mild, moderate, and severe levels of depression.

The EQ-5D-5L is a widely used generic measure of health status consisting of two parts. The first part (the descriptive system) assesses health in five dimensions (MOBILITY, SELFCARE, USUAL ACTIVITIES, PAIN / DISCOMFORT, ANXIETY / DEPRESSION), each of which has five levels of response (no problems, slight problems, moderate problems, severe problems, and unable to). The second part of the EQ-5D questionnaire provides a descriptive profile that can be used to generate a health state profile. Health state index scores generally range from less than 0 (where 0 is a health state equivalent to death; negative values are valued as worse than death) to 1 (perfect health), with higher scores indicating higher health utility, though health state preferences can differ between countries. This part of the questionnaire consists of a VAS on which the patient rates his / her perceived health from 0 (the worst imaginable health) to 100 (the best imaginable health).

Blood test known as 'inflammatory markers' can detect inflammation in the body, caused by many diseases including infections and auto-immune conditions. It helps to distinguish between inflammatory and noninflammatory causes of pain. The blood tests will be undertaken in this study to perform the measurements of serum inflammatory markers at baseline and follow-up visits. This measurement will include inflammatory markers such as: IL-1β, IL-6 and TNF-α.

It is an electrophysiological monitoring method to record electrical activity of the brain. It is typically non-invasive, with electrodes placed along the scalp. The procedure begins with the participant lying on the exam table or bed. The technician puts about 20 small sensors on the scalp. Theses sensors (electrodes) pick up electrical activity from neurons and send them back to a machine, they show up as series of lines records on paper or displayed on a computer screen. When recording begins, participants asked to remain still with their eyes open first, then with them closed

QST systems have been developed to assess and quantify sensory function in patients with neurologic symptoms or in those at risk of developing neurologic disease. QST measures the detection threshold of accurately calibrated sensory stimuli. investigates the submodalities of the somatosensory system, such as temperature, touch, vibration, and pain. It provides information on the state of peripheral sensory nerves, as well as pain perception and central sensitization.

The timed up and go (TUG) is an outcome measure to assess balance and mobility. The TUG is recommended as a routine screening test for falls in guidelines published by the American Geriatric Society and the British Geriatric Society, and the National Institute of Clinical Evidence (NICE) guidelines also support use the TUG for assessment of gait and balance in the prevention of falls in older people. Participants start the test in a seated position, stand up upon a command to walk for 3 m, turn around and walk back to the chair and sit down. The participants supposed to complete this as quickly as possible, while being as comfortable and as safe as possible. A stopwatch measures the time (in seconds) above 12 second is considered as the cut-off.