Validity and Inter-rater Reliability fo the Vagus Nerve Neurodynamic Test Among Healthy Subjects
Condition: Vagus Nerve Diseases; Diagnoses Disease
MeSH terms: Nervous System Diseases; Vagus Nerve Diseases
Study type: Observational

Summary: 
      Vagus nerve neurodynamic test (VN-NDT) will be validated detecting the changes in vagus nerve
      anatomical position due to the combination of movements of the test. Healthy subjects will be
      enrolled and screened for neurological problems. A checklist for autonomic dysfuntion
      symptoms will be administered and heart rate at rest will be measured. Inter-rater
      reliability will be assessed comparing positive and negative cases identified by two blinded
      assessors, one expert and one novice. It will also be monitored and compared the amount of
      motion induced by the expert and the novice assessors during the VN-NDT admimistration. If
      symptoms will be produced by the VN-NDT using a pain drawing tool it will be defined the
      qualitiy and the location of them. Accuracy of the VN-NDT will be tested in the autonomic
      dysfunction symptom detection.
    

Detailed description: 
      _A growing body of evidence has shown that the Vagus Nerve (VN) is not only the main
      anatomical structure responsible for the brain and guts communication but is also a target
      for many interventions in which drugs or classic treatments have failed. The VN cervical
      tract stimulation has reported positive results for high social burden problems like acute
      and chronic pain, psychiatric diseases, disturbs of consciousness and epilepsy. Also, it is
      well known that the selective tension of the Peripheral Nervous System, or neurodynamic test
      (NDT), is useful for diagnosis and treatment of neuropathic diseases and pain. Over the last
      30 years NDTs were validated for upper and lower limb nerves but nowadays a VN-NDT is lacking
      and could be a potential alternative in diagnosis and treatment for critical or neglected
      conditions. Methods_ An estimated sample of 30 healthy participants will complete a
      questionnaire on vagal symptoms and perceived health status. A neurological assessment of the
      cervical tract will be performed before the test. The VN-NDT will be administered through a
      standardized sequence of physiological neck movements. Symptoms and heart rate (HR) will be
      monitored. Validity of NDT will be tested with ultrasonography assessment (C6-VN distance)
      during the tests administered by an expert and a novice. Motion of both assessors and
      subjects will be tracked through an infra-red optoelectronic system. Inter-examiner
      accordance will be obtained and comparisons between assessors' positive and negative tests
      due to symptoms provocation and reduction (Cohen's Kappa) will be performed. A two-way
      analysis of variance (ANOVA) will be performed with factors experience and side tested (2 ×
      2). Receiver operating characteristic (ROC) curves will be adopted to define the accuracy,
      sensitivity, specificity, positive and negative likelihood ratios of the VN-NDT in autonomic
      dysfunction symptoms detection and on perceived health status.Results_ It is expected to
      determine the inter-examiner accordance and to not detect significant assessors effects on
      test results. It is also expected to detect a change of the C6-VN distance and HR during the
      test and to estimate the accuracy of the test for autonomic dysfunctions
      detection.Conclusions_ Normative physiological values parameter variations at the
      administration of the VN-NDT are fundamental to determine the hallmarks needed to screen
      clinical and preclinical conditions involving autonomic dysfunctions_
    

Intervention name(s): Vagus Nerve Neurodynamic test
Intervention type(s): Diagnostic Test
Intervention description(s): The VN-NDT has been developed starting from the VN morphology selecting the physiological movements that induce the greater mechanical tension on the nerve. The subjects will be assessed supine on an examination table with assessors standing at the cranial short side of the table. Upper cervical flexion and contralateral lateral flexion had been selected for loading the intracranial portion. The ipsilateral neck rotation had been selected for loading the cervical tract. Keeping the subject's head in the final movements combination gentle movements of the upper abdomen caudally and cranially had been selected for loading the thoracic tract and used as discrimination maneuver. The test will be declared positive (indicating abnormal responses) if symptoms will be felt in anatomical regions other than the neck on the same side of the test and discrimination maneuvers changed the subject's symptoms indicating a neurogenic source, otherwise it will be declared negative.
Other intervention name(s): Heart rate monitoring using a digital pulsossimeter
Observational model: Cohort
Time perspective: Cross-Sectional
Sampling method: Probability Sample
Study population: 
        Healthy subjects that want to participate in the study
      
Keywords: Validation Studies; Vagus Nerve Diseases; Diagnostic imaging; Motion analysis; Healthy Volunteers