Dopaminergic Loss and Pain in Parkinson's Disease

Study Overview
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Brief Summary
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About 46% of patients suffering from Parkinson's disease present pain disorders. Parkinson disease is characterized by loss of dopaminergic neurons. The aim of this study is to assess the relationship between the loss of dopaminergic neurons and the existence of pain in Parkinson's disease. Using single photon emission computerized tomography (SPECT) imaging (123I FP-CIT, which binds dopamine transporter) and the determination of subjective pain threshold, the investigators will establish correlations between dopaminergic degeneration and pain perception.

Detailed Description
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Parkinson's disease is a frequent neurodegenerative disease leading to motor handicap, cognitive and pain disorders. These pain disorders could be correlated to dopaminergic loss. The clinical trial will be conducted in a single center (Neurology Department, Purpan Hospital, Toulouse, France). The study is classified as a physiopathology one. Twenty patients with Parkinson's disease, presenting pain disorders or not, will be selected. This clinical trial will last one year. All the exams, including image acquisition will be done the same day. These will take about 6 hours for each patient. Expected results: Binding of 123I FP-CIT to dopamine transporters should negatively correlate with pain intensity and also with thermal pain thresholds in patients suffering from Parkinson's disease.

Official Title
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Evaluation of Radioligand Uptake (FP-CIT) of Dopamine Transporters in Patients Suffering From Parkinson's Disease With or Without Pain

Conditions
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Parkinson's Disease, Pain

Intervention / Treatment
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* Drug: ioflupane 123I (DATSCAN®)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients with clinically established Parkinson's disease according to the UKPDSBB (UK Parkinson's Disease Society Brain Bank) (Gibb et Less, 1998; Hugues et al, 1992). Male or Female patients, aged from 30 to 70 years. Patients must benefit from the French Social security system. Patients must give a written informed consent. Female fertile patients must use an efficient method of contraception. If patients suffer from chronic pain, pain must be related to Parkinson's disease. Exclusion Criteria: Patients with a syndrome other than the idiopathic Parkinson's disease. Patients suffering from important trembling during the OFF periods or abnormal involuntary movements (dyskinesia) during the ON periods, not allowing the imagery exam to be performed. Patients suffering from another disease causing chronic pain. Patients suffering from cancer. Patients with cognitive dysfunction. Patients not able to complete the scales. Pregnant, breastfeeding or fertile female patients not using an efficient method of contraception. Patients not willing to participle in the trial.

Ages Eligible for Study
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Minimum Age: 30 Years
Maximum Age: 70 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: pain disorders<br>patients with Parkinson's disease presenting pain disorders | Drug: ioflupane 123I (DATSCAN®)<br>* One administration (2,5 ml) of ioflupane 123I 0,07-0,13 µg/ml; 74 MBq/ml; IV (in the vein)<br>* Other names: - FP-CIT;|
| Other: without pain disorders<br>patients with Parkinson's disease without pain disorders | Drug: ioflupane 123I (DATSCAN®)<br>* One administration (2,5 ml) of ioflupane 123I 0,07-0,13 µg/ml; 74 MBq/ml; IV (in the vein)<br>* Other names: - FP-CIT;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Single photon emission computerized tomography (SPECT) will be used to evaluate binding of 123I FP-CIT to dopamine transporters. This exam will allow calculation of the ratio of specific to non specific binding of 123I FP-CIT to dopamine transporters. |  | Image acquisition (SPECT) will be performed after three hours post-injection of 123I FP-CIT. | 
| Pain perception will be evaluated by the determination of subjective pain thresholds (thermal pain thresholds, thermotest). A thermode will be used to determine the heat and cold pain thresholds. |  | Image acquisition (SPECT) will be performed after three hours post-injection of 123I FP-CIT. | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Severity of Parkinson's disease will be evaluated with the Unified Parkinson's disease Rating Scale (UPDRS) and the Hoehn and Yahr scale |  | Evaluation will be done within three hours before image acquisition (SPECT). | 
| Short French version of McGill pain questionnaire (MPQ). |  | Evaluation will be done within three hours before image acquisition (SPECT). | 
| Pain intensity will be assessed using a 10 cm visual analogue scale (VAS) (0 = no pain; 10 = worst possible pain). |  | Evaluation will be done within three hours before image acquisition (SPECT). | 
| DN4 scale |  | Evaluation will be done within three hours before image acquisition (SPECT). | 
| Brief Inventory Pain |  | Evaluation will be done within three hours before image acquisition (SPECT). | 
| Hospital Anxiety and Depression (HAD) scale |  | Evaluation will be done within three hours before image acquisition (SPECT). | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Parkinson's disease, pain, dopamine transporters imaging