chronic idiopathic axonal polyneuropathy nerve pain
Conditions
Interventions
Patients will test one of the following interventions every 2 weeks: phenytoin
20% cream, phenytoin 10% cream and placebo cream, with the instruction to apply
the cream 2 to 4 times a day to the pai
Sponsors
Universitair Medisch Centrum Utrecht
Eligibility
Age
18 Years to 99 Years
Inclusion criteria
Inclusion criteria: * CIAP is defined as presence of symmetrical distal sensory or sensorimotor symptoms such as numbness, pins and needles, tightness, coldness, unsteadiness, muscle cramps, and weakness with onset in the feet, compatible with polyneuropathy; presence of symmetrical distal sensory or sensorimotor signs with evidence of large nerve fiber involvement such as decreased sense of touch, vibration, and propriocepsis, usually in the presence of decreased pin prick/temperature sense, decreased/absent tendon reflexes, or slight muscle weakness on neurologic examination, compatible with polyneuropathy; an insidious onset and slow or no progression of the polyneuropathy over the course of at least 6 months; no identifiable cause for the polyneuropathy after thorough history-taking, clinical examination, and extensive laboratory testing; no suggestion of a hereditary polyneuropathy based on detailed kinship history (i.e., one or more affected family member), neurologic examination, or confirmation by genetic analysis; and nerve conduction studies excluding a demyelinating polyneuropathy and confirming large nerve fiber involvement if the findings on neurologic examination are equivocal considering the patient*s age. * Presence of chronic localized neuropathic pain due to CIAP * Neuropathic pain localized in two anatomically symmetrical areas of feet/lower legs * Duration of neuropathic pain * 3 months * Duration of *1 hour neuropathic pain per day * Neuropathic pain characteristics defined by a DN4 score *4 * Mean pain score of *4 and
Exclusion criteria
Exclusion criteria: * Painful (poly)neuropathy other than CIAP * Pregnancy or planned pregnancy in the study period * Use of oral phenytoin * Open wounds in the neuropathic pain area * Current use of topical analgesics * Presence of other pain syndromes such as the widespread pain syndrome or pain in joints * Presence of serious psychological/psychiatric morbidity * Addiction to intoxicants * Hypersensitivity to the study medication (active substance and excipients) * Insufficient mastery of the Dutch language * Cognitive impairment and insufficiently capable to understand the purpose of the study
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| The primary endpoint is the change in pain intensity from baseline NRS to the mean NRS in the second week. | — |
Secondary
| Measure | Time frame |
|---|---|
| All secondary endpoints are for phenytoin 20% versus 10% versus placebo cream in DOBRET positive, negative and all participants. The change between baseline and week 2 of each intervention is assessed for: 1) pain intensity measured on the NRS, 2) EQ5-5D-5L, subscales of the BPI, pain characteristics as assessed with the NPSI, worst pain characteristics 3) Correlations between the following items: duration of painful CIAP, baseline NRS level, PCS, pain treatment naïve versus pain treatment resistant participants, worst pain characteristic, pain reducing effect on NRS, DOBRET results and PGIC 4) 30% and 50% improvement (MEC30 and MEC50) or more on the NRS compared to placebo within one patient 5) Time of carry-over effects after a treatment period 6) Number of participants who are responders on the PGIC after a treatment period 7) Onset of analgesic effect after application 8) Duration of analgesic effect 9) Daily number of cream applications 10) Percentage of analgesic effect as rated by the patient 11) Local and/or systemic side effects 12) Detection of phenytoin in plasma 13) Predictive value of DOBRET 14) Use of escape pain medication | — |
Countries
Netherlands
Outcome results
None listed