The proposed study will set the foundation for future multi-center studies. To validate tMS as a non-contact and non-invasive pain treatment option for reducing pain in Veterans with PTP-NP and improving their overall functions.

This study will only be conducted at the VA hospital in San Diego.

Inclusion Criteria:

• Evidence of a personally signed and dated informed consent document indicating that the subject has been informed of all pertinent aspects of the study

• Subject is willing and able to comply with scheduled visits, treatment plan, daily pain, sleep and all study related assessments and procedures

• Subjects must be literate in the language used in the assessments and pain diary

• Veterans (men or women) of any race or ethnicity who are at least 18 years of age

• Female subjects of childbearing potential must agree to use a highly effective method of contraception throughout the study and for at least 7 days after the last session of the assigned treatment

  • A subject is of childbearing potential if, in the opinion of the investigator, he/she is biologically capable of having children and is sexually active

• Subject must have chronic peripheral neuropathic pain present for more than 4 months after a traumatic or surgical event per medical history, this may include, for example:

  • motor vehicle accident
  • fall
  • sports injury
  • knee or hip replacement
  • hernia repair
  • thoracotomy
  • mastectomy
  • focal/localized burns or crush injury

• In addition, to be eligible for inclusion in the study, all subjects must:

  • have an average daily Numerical Pain Rating Scale (NPRS) score >3 during B1; and
  • have a spontaneous pain intensity >30 on 0-100 Mechanical Visual Analogue Scale (M-VAS) to be eligible for randomization

• Must have their implicated peripheral nerve(s) identified

• Must meet criteria for neuropathic pain assessment to meet eligibility for the study [46]. Pain distribution across a nerve territory and history indicates relevant lesion or disease plus criteria listed in a and/or b

• (A): At least one negative or positive sensory sign or symptom confined to innervation territory of the lesioned nervous structure. Examples of negative or positive signs or symptoms include:

  • Burning, stabbing or tingling sensation/pain
  • Numbness/paresthesia
  • Cold, heat or pressure
  • Hyperalgesia or allodynia
  • Hypoesthesia
  • Increased or decreased sharp sensation (e.g., pinprick testing)
  • Decreased vibration/vibratory sensation

• (B): Prior diagnostic tests confirming lesion or disease explaining neuropathic pain (Nerve conduction studies, EMG, skin or nerve biopsy). Documentation of affected nerve(s) indicating that the subject's pain is of neuropathic origin and is a result of injury/trauma to the affected/implicated nerve(s).

Exclusion Criteria:

Subjects presenting with ANY of the following will NOT be included in the study:

• Subjects with neuropathic pain due to:

  • diabetic peripheral neuropathy
  • post herpetic neuralgia
  • Human Immunodeficiency Virus
  • chemo/anti-viral therapy
  • trigeminal neuralgia
  • carpal tunnel syndrome
  • subjects whose post-traumatic neuropathic pain is categorized as central (e.g., spinal cord injury) rather than peripheral

• Subjects with pain due to Complex Regional Pain Syndrome (CRPS, Type I or Type II)

• Phantom limb pain after amputation. However, subjects with stump pain and phantom sensation but no phantom pain will not be excluded

• Subjects with skin conditions in the affected dermatome that in the judgment of the investigator can interfere with evaluation of the neuropathic pain condition

• Subjects with other pain such as lumbar or cervical radiculopathy that may confound assessment or self-evaluation of the peripheral neuropathic pain

  • subjects with significant somatic pain at the site of their trauma that may confound assessment or self-evaluation of their neuropathic pain

• Any subject considered at risk of suicide or self-harm based on investigator judgment and/or the details of a risk assessment

• Use of prohibited medications in the absence of appropriate washout periods

• Participation in any other clinical trial within the 30 days prior to screening and/or during participation in this study

• Subjects with a history of a cardiac arrhythmia that has led to the placement of a cardiac pacer or defibrillator will be excluded from the study

• Pregnant females and females of childbearing potential not using highly effective contraception or not agreeing to continue highly effective contraception during the study

• Subjects with a current diagnosis of DSM-IV-TR Axis I disorder, including, for example:

  • schizophrenia
  • bipolar disorder
  • other psychotic disorders such as schizoaffective disorder and delusion disorder
  • somatoform disorders or factitious disorders
  • bipolar disorders, even if controlled or stable
  • alcohol or substance related disorders in the past 2 years
  • however, diagnoses of Generalized Anxiety Disorder (GAD) or major depression (MDD) that is clinically stable are allowed

• Subjects with pending Worker's Compensation, Worker's Compensation, civil litigation or disability claims pertinent to the subject based upon trauma

  • current involvement in out-of-court settlements for claims pertinent to subject's trauma
  • subjects with fully resolved litigation and compensation claims can participate

• Subjects who have previously received either transcranial or transcutaneous magnetic stimulation therapy in the past

Adverse event data was collected from first treatment to 4 weeks after the last treatment.

One limitation of this study is small sample size. In addition, the location of nerve damage (whether it is extremities or truncal region) could be a confounding factor for the effectiveness of the treatment.