Evaluation of Neuropathic Pain in the Context of Clinical Symptoms, Quantitative Sensory Tests and Imaging With FMRI
Condition: Neuropathic Pain; Radiculopathy, Cervical
MeSH terms: Neuralgia; Radiculopathy
Study type: Observational

Summary: 
      This study is planned to evaluate patients with upper extremity neuropathic pain due to
      cervical radiculopathy with clinical symptoms, Quantitative Sensory Testing(QST) and
      Functional Magnetic Resonance Imaging(fMRI). Patients with similar charactheristics will be
      grouped and comparisons will be conducted in fMRI results, as well as QST.
    

Detailed description: 
      Neuropathic pain is a type of pain which usually accompanies injuries or conduction defects
      in the central or peripheral nervous system, as well as receptors. Unlike the other types of
      pain, neuropathic ones are more resistant to therapy and prone to be chronic.

      In recent years, there are many novel techiques to assess the neurological status and create
      standardized test protocols. One of these techiques is QST(Quantitative Sensory Testing). QST
      is a specific type of sensory examination, usually done through computerized stimuli of heat,
      cold or vibration, or specific test equipment. There are many types of QST protocols around
      the world, and their results can also be expressed as phenotypes through statistics. While
      there are 3 types of pain phenotypes with the 13 item QST protocol suggested by German
      Neuropathic Pain Research group(DFNS), all patient groups can be classified differently as
      well, according to the common findings they express. These different phenotypes are also
      shown to have different responses to the different pain treatments. Such differences are
      usually attributed to the different mechanisms and fibers underlying the pathogenesis.

      While patients show differences in QST results, evidence for the correlation between these
      variables and clinical symptoms of the patients are still scarce. Moreover, it is still yet
      to be known if these differences have a central origin as well as the peripheral mechanisms.

      Functional Magnetic Resonance Imaging(fMRI) is a method to evaluate cerebral functions. It is
      mainly based on the blood flow changes that occur locally in regions that are in function[5].
      As a result of the increased blood flow, the oxygen concentration also increases, creating a
      signal response called BOLD(Blood Oxygen Level Dependent) response. Since different types of
      pain are conducted through different fibers and pathways, it is also probable that they might
      show changes in cortical response as well.

      In this study, the aim is to find whether QST results are correlated to clinical symptoms and
      pain properties of the patients, and these changes are related to the changes in the central
      nervous system
    

Intervention name(s): Functional MRI
Intervention type(s): Diagnostic Test
Intervention description(s): In fMRI, patients will first be taking a resting state phase in case of activations. In the block design phase, they will be given tactile stimuli in affected extremity, and then healthy extremity in 3 blocks, followed by pauses.
Primary and secondary sensorial cortex, insular cortex, anterior cingulate cortex, preforntal cortex and amygdala activation will be chosen as regions of interest, and their activation will be recorded for analyses.
Observational model: Case-Control
Time perspective: Cross-Sectional
Sampling method: Non-Probability Sample
Study population: 
        Adult patients with upper extremity neuropathic pain due to radiculopathy Duration of >1
        month Unilateral extremity pain will be included in the study. Patients will then be
        stratified according to their total Scores in PainDetect, and neuropathic pain probable or
        not probable patients will be compared in analyses.