Chronic Idiopathic Axonal Polyneuropathy (CIAP)
Conditions
Interventions
Phenytoin 10% & 20% cream, placebo cream
Sponsors
University Medical Center Utrecht, the Netherlands
Eligibility
Inclusion criteria
Inclusion criteria: • Age 40 years or older • Patients have been diagnosed with CIAP defined as:26 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 27 • Mean pain score of =4 and <10 on the NRS at study entry (baseline) • Difference of pain intensity between left and right foot and/or lower leg of not more than 1 point on the NRS • No changes in neuropathic pain medication for at least 1 month • Absence of any of the exclusion criteria outlined below
Exclusion criteria
Exclusion criteria: • Painful (poly)neuropathy other than CIAP • Presence of neuropathic pain due to any other condition than CIAP • Neuropathic pain (distribution, duration, characteristics, intensity) not fulfilling the inclusion criteria • Pregnancy or planned pregnancy in the study period (will only be asked) • 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 in DOBRET positive participants. | — |
Secondary
| Measure | Time frame |
|---|---|
| The main secondary parameters are various other parameters of changes in pain intensity and pain characteristics, quality of life, participant’s impression of change/analgesic effect, catastrophizing, side effects, use of escape pain medication, detection of plasma phenytoin levels, predictive value of the DOBRET, carry-over effects, onset and duration of analgesic effect and number daily cream applications. | — |
Contacts
Public ContactDavid Kopsky
Institute for Neuropathic Pain
Outcome results
None listed