Vasodilators in cold type Complex Regional Pain Syndrome.

In most cases, adequate pharmacotherapeutic treatment of patients with complex regional pain syndrome type 1 (CRPS1, formerly indicated as post-traumatic dystrophy) in an extremity, who left the acute phase of the disease, is not available. Some pain relief could be obtained, but recovery of the neuro-inflammatory signs of the disease is barely achieved. Chronic CRPS1 could even lead to amputation of the dystrophic hand. Usually this is a direct effect of unbearable continuous pain and disuse of the extremity. Evidence has been found that both disuse and damages of nerve endings could lead to obstructions in the blood distribution of the involved extremity. Improvement of the blood distribution through nitric oxide - cyclic guanosine monophosphate (NO-cGMP) induced vasodilation could attribute to the recovery of this invalidating disease. Therefore, patients will be treated either with isosorbide dinitrate (ISDN), Tadalafil or placebo. In combination with an intensive physiotherapeutic program, this approach could diminish the progression of the disease, stabilize or even cause complete recovery in the patient. In this project, monitoring the patient during the treatment will be achieved by means of objective parameters such as Doppler flow and computer assisted videothermography, whereas clinically important parameters such as pain intensity, mobility and quality of life are registered. Furthermore, blood samples and blister fluid from both the involved and uninvolved extremity will be subjected to measurements of biochemical mediators. These data will provide detailed information of vascular changes in relation to the experience of pain and immobility. Treatment by ISDN or Tadalafil could improve chronic phase CRPS1 and furthermore provide more insight in mechanisms underlying this disabling disease.

Nitric oxide depending and independing vasodilation in patients with disused, cold type CRPS, will regenerate blood tissue distribution and consequently improve mobility and quality of life factors.

N/A

Subjects are assigned to receive either 1 gram ISDN ointment 1% or placebo 4 times daily (groups 1 and 2) or 1 tablet of 10 mg tadalafil or palcebo daily (groups 3 and 4). The treatment period will be 10 weeks.