Please select the eligibility criteria that correspond to the clinical trial below.
Title: The Efficacy of Spinal Cord Stimulation at Varying Stimulation Frequencies and Pulse-Widths
Brief Summary: The purpose of the study is to measure the efficacy of varying spinal cord stimulation frequencies and pulse-width settings on chronic pain management. The spinal cord stimulator settings that are most effective in chronic pain management hope to be revealed for the purposes of this study. In this double-blind study, both the patient and the staff will not be aware of the spinal cord stimulator settings for each patient each week. The representative that will set the settings each week will be blinded to the identity of each patient and will set the spinal cord stimulator from another room. While there are few papers that show the efficacy of spinal cord stimulation in treating chronic pain, there has yet to be a study performed that measures the role of stimulation frequency and pulse-widths. This study hopes to be the first.


Options:
A: Inclusion Criteria:

* Diagnosis of PHN with pain present for at least three months after the healing of a Herpes Zoster skin lesion.
* Subjects must have completed the Daily Pain Rating Scale in the electronic diary at least 4 times during screening and have an average daily pain rating score of greater than or equl to 4 during the 7 +/- 3 days prior to randomization (Visit 2).

Exclusion Criteria:

* History of neurolytic or neurosurgical therapy for PHN.
* Presence of any severe pain associated with conditions other than PHN that may confound the assessment or self-evaluation of the pain due to PHN.
B: Inclusion Criteria:

* Diagnosis of Type 1 or 2 diabetes mellitus.
* Diagnosis of painful DPN for at least 12 months but less than 5 years in duration.

Exclusion Criteria:

* Neurologic Disorders unrelated to diabetic neuropathy that may confuse or confound the assessment of neuropathic pain.
* Presence of any severe pain associated with conditions other than DPN that may confuse or confound the assessment of neuropathic pain.
C: Inclusion Criteria:

* The patient must have SCS implanted for at least 2 months before study start date
* The patient must be at least 18 years old
* The patient must currently be receiving pain relief from SCS usage
* The patient must be willing to participate in a 9-week study
* The patient must have at least 20% of battery life remaining in his/her spinal cord stimulator
* The patient must be able to tolerate Vicodin-Extra Strength as well as Tylenol, but can also take their own pain medication if it is not one of the two mentioned

Exclusion Criteria:

* The patient is pregnant or intends to become pregnant during the course of the study.
* The patient by report, and/or by physician assessment, exhibits any or all of the following, which might bias reporting of treatment outcome:

A strong untreated dependency on prescription medication such as benzodiazepines and narcotic analgesics.

A strong potential for secondary gain issues.

A significant, untreated psychiatric comorbidity.

* The patient possesses a coexisting clinically relevant or disabling chronic pain problem not treated by SCS
* The patient has been diagnosed with unstable angina
* The patient receives a Karnofsky's performance score of \<60
D: Inclusion Criteria:

* Moderate-to-severe PDP in the lower limbs

  * The pain intended to treat has been present for more than 12 months
  * Previous treatment has been unsuccessful (insufficient pain relief and/or unacceptable side-effects) with drugs from the following drug categories:
  * Amitriptylin or an other tricyclic antidepressant and/or
  * Pregabalin (Lyrica®) or Gabapentin (Neurontin®) and/or
  * Duloxetine (Cymbalta®) and/or
  * Tramadol or strong opioids Patients were treated with 3 drugs from the above mentioned drug categories and followed the treatment algorithm for painful diabetic polyneuropathy according to Jensen. Starting dosage was based on individual patient characteristics. Each drug was tried for at least 3 weeks and dose was raised once, if possible. By insufficient pain relief and/or unacceptable side-effects, the drug treatment was stopped. Patients reached a steady state in medication use and it is not allowed to increase dosage during the study.
* Mean pain intensity during daytime and/or night time should be 5 or higher measured on a numeric rating scale (NRS). Pain during daytime will be scored 3 times per day during for 4 days according to Jensen.
* Patient's age is between 18 and 75 years.

Exclusion Criteria:

* The patient has had neuromodulation therapy during the month before the intake
* Neuropathic pain is most prevalent in the upper limbs (NRS\>3)
* Neuropathy or chronic pain of other origin than diabetes mellitus (NRS\> 3)
* Addiction: drugs, alcohol (\> 5E / day) and/or medication

  * Drugs: cocaine, heroine, marihuana.
  * Alcohol: wine, beer, liquor (max 5E / day)
  * Medication: benzodiazepines.
* Insufficient cooperation from the patient (little motivation, understanding or communication)
* Blood clotting disorder, when using 2 or more different kinds of anti coagulation
* Immune deficiency (HIV-positive, corticosteroids with a dose equivalent to \> prednisolone 10 mg, immunodepressive, etc.)
* Peripheral vascular disease without palpable peripheral pulses at both feet (inclusion is possible if pulses are absent, but ankle brachial index is between 0.7 and 1.2 in both feet)
* Active foot ulceration
* Life expectancy \< 1 year
* Pacemaker
* Local infection or other skin disorders at site of incision
* Psychiatric problems potentially interfering with cooperation in the study
* Pregnancy
* Severe cardiac or pulmonary failure (\> NYHA classification II)
* Unstable blood glucose control (change in HbA1c\>1,0% in three months prior to inclusion)

Answer: C