Clinical trial NCT00959595: Improvement of Sensibility in the Foot in Diabetic Patients Induced by EMLA-application to the Lower Leg
Official title: Improvement of Sensibility in the Sole of the Foot in Diabetic Patients, Induced by EMLA-application to the Lower Leg - a Double Blind Study
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: PHASE3
Conditions: Diabetes Mellitus
Keywords: Diabetes mellitus
neuropathy
foot
sensibility
brain plasticity
Lead sponsor: Lund University Hospital
Sponsor class: OTHER
First posted: 2009-08-14
Enrollment: 32
Sex: ALL
Minimum age (years): 18
Maximum age (years): 75
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: TREATMENT

Brief summary: Sensory input from the foot as well as all other body parts results in activation of sensory cortex.

It is well known that the cortical body map is experienced-dependant and can rapidly change in response to changes in activity and sensory input from the periphery \[10-12\]. Increased activity and sensory input from the hand results in expansion of the cortical hand representation \[13-15\], while decreased sensory input, for instance by anaesthesia, amputation or nerve injury, results in shrinkage of the cortical hand representation \[16-21\]. Due to the constant ongoing "cortical competition" between body parts the adjacent cortical areas expand and take over the silent area, deprived of sensory input.

The investigators have recently described striking examples of such rapid cortical re-organisations induced by selective cutaneous anaesthesia of the forearm: application of EMLA cream to the volar aspect of the forearm results in improved sensory functions of the hand \[18\] linked to expansion of the hand representational area in sensory cortex . In analogy, EMLA application to the lower leg in healthy controls results in improved sensory functions in the sole of the foot linked to expansion of the foot representational area in sensory cortex.

To test the hypothesis that EMLA application to the lower leg of diabetic patients will result in improved sensory functions in the sole of the foot as well as expansion of the foot representation in sensory cortex. The investigators hypothesize that repeated applications of EMLA will result in a long lasting sensibility improvement.


Eligibility criteria: Inclusion Criteria:

* Adult patients (18-75 years) suffering from diabetes with subjective sensory impairment in the sole of the foot.

Exclusion Criteria:

* Patients with painful neuropathy or established ulcer formation in toes or sole of the foot, known hypersensitivity to local anaesthetics, major vascular reconstructions, communication problems due to severe language problems.
* Patients with pacemakers or magnetic implants or suffering from claustrophobia will not be subjected to fMRI-investigation.

Primary outcomes:
measure: Touch thresholds in the sole of the foot (Semmes-Weinstein monofilaments)
timeFrame: Screening, before application, 90 min after application, 24 hours after application
Secondary outcomes:
measure: MRI
timeFrame: MRI-examination, before application, 90 min after application, 24 hours after application
measure: fMRI
timeFrame: fMRI-examination, before application, 90 min after application, 24 hours after application
Other outcomes:
Locations:
city: Malmö
country: Sweden
facility: Department of Hand Surgery, Malmö University Hospital
Study officials:
affiliation: Dpt of Hand Surgery, Malmö University Hospital, Lund University, Sweden
name: Göran Lundborg, Professor
role: PRINCIPAL_INVESTIGATOR
References:
citation: Lundborg GN, Bjorkman AC, Rosen BN, Nilsson JA, Dahlin LB. Cutaneous anaesthesia of the lower leg can improve sensibility in the diabetic foot. A double-blind, randomized clinical trial. Diabet Med. 2010 Jul;27(7):823-9. doi: 10.1111/j.1464-5491.2010.03014.x.