Small fiber neuropathy Small fiber neuropathy
Conditions
Interventions
Repetitive transcranial magnetic stimulation (rTMS) 
Sponsors
Maastricht Universitair Medisch Centrum +
Eligibility
Age
18 Years to 99 Years
Inclusion criteria
Inclusion criteria: 18 years of age or older.Skin-biopsy proven idiopathic small fiber neuropathy.Pain intensity (maximum pain) rated =5 on the PI-NRS, that must have existed for at least 12 weeks before the study.Written informed consent.
Exclusion criteria
Exclusion criteria: Signs of large nerve fiber dysfunction (i.e., weakness, loss of vibration sense, hyporeflexia or areflexia, abnormal nerve conduction studies).Identifiable underlying cause of SFN (diabetes, SCN9A/SCN10A/SCN11A pathogenic mutations, hypothyroidism, vitamin B12 deficiency, monoclonal gammopathy, alcohol abuse (more than 5 IU/day), malignancies, or drugs that cause neuropathy).Implanted ferromagnetic devices or other magnetic-sensitive metal implants close to the magnetic coil.History of epilepsy.Using pain medication that has changed in the 30 days prior to randomization.Mentally challenged subjects unable to give independent informed consent.Pregnancy
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| As pain is the main future of SFN, the primary outcome measure will be based on pain intensity. This will be evaluated using the 11-point PI-NRS (0 = no pain to 10 = worst imaginable pain). The primary outcome parameter is defined as the difference in the mean weakly peak pain intensity. A responder is defined as = 1-point decline on the PI-NRS at week 6 compared to baseline. The primary outcome measure is based on the IMMPACT criteria.12The primary efficacy endpoint is the proportion of responders of rTMS compared to the proportion of responders of sham stimulation after the 6-week treatment period. | — |
Secondary
| Measure | Time frame |
|---|---|
| Secondary outcomesA secondary efficacy endpoint is a comparison between the percentage responders treated by rTMS and sham stimulation, when the responder is defined as = 2-point decline on the PI-NRS at week 6 compared to baseline.Also, the efficacy of the maintenance treatment is based on pain intensity. The maintenance period is considered to be successful, if the PI-NRS at week 12 is still = 1-point lower compared to baseline.Other secondary outcome measures include changes in:The daily pain intensity (defined as the mean pain experienced during the day: from waking up to 6 pm), the nocturnal pain intensity (6 pm until waking up), and the average of these two, using the PI-NRS. Pain symptoms, using the patients’ global impression of change (PGIC) on a 7-point Likert scale. Subsequent scores of the PGIC are 1) worse than ever; 2) much worse; 3) little worse; 4) no change; 5) little improved; 6) much improved; 7) very much improved. ‘Very much improved and ‘much improved’ are considered as a relevant improvement. Clinically relevant pain reduction on PGIC for pain will be defined as score 6 (‘much improved’) or 7 (‘very much improved’).SFN-related symptoms, measured by the Rasch-transformed 13 items SFN symptoms inventory questionnaire (RT-SFN-SIQ). Severity of various pain qualities, using the neuropathic pain scale (NPS).Activity and participation level, measured by the Rasch-built Overall disability Outcome Scale specifically designed for SFN (SFN-RODS).QoL, using EQ5D (EuroQol 5D). | — |
Countries
Netherlands
Contacts
Public ContactJ.G.J. Hoeijmakers
Maastricht Universitair Medisch Centrum +
Outcome results
None listed