Brain Scans Studying Serotonin Changes in Parkinson's Disease

Trial details

Who runs it

University of Exeter

Trial code

NCT05516732

Record updated

7 October 2025

Original description

In this study, the investigators aim to provide a deeper understanding of Parkinson's disease and find a biomarker of Parkinson's disease. This is done using imaging scans called Positron Emission tomography (PET), Single Photon Emission Computed Tomography (SPECT), and Magnetic Resonance Imaging (MRI). The findings will provide a deeper understanding of the brain changes in Parkinson's disease. More importantly, this study will help with the discovery and development of new medications aiming to delay progression of Parkinson's disease symptomsRead full original descriptionShow less

Evaluation of Serotonergic Neurotransmission in Premotor and Motor Parkinson's Disease.

In this study, the investigators aim to provide a deeper understanding of Parkinson's disease and find a biomarker of Parkinson's disease. This is done using imaging scans called Positron Emission tomography (PET), Single Photon Emission Computed Tomography (SPECT), and Magnetic Resonance Imaging (MRI). The findings will provide a deeper understanding of the brain changes in Parkinson's disease. More importantly, this study will help with the discovery and development of new medications aiming to delay progression of Parkinson's disease symptoms

Inclusion: Subjects must understand the nature of the study and must provide signed and dated written HRA-approved informed consent in accordance with local regulations before any protocol-specific screening procedures are performed; Males and females, age 25-85 years, inclusive; Women of child-bearing potential must use protocol-defined contraceptive measures and must have a negative β-hCG test at screening. For sexually active subjects (except females of non-childbearing potential-e.g., at least 2 years postmenopausal or surgically sterile), condoms should be used in addition to other birth control methods for the duration of the study and for 3 months after the last administration of PET or SPECT ligands. These patients must be willing to remain on their current form of contraception for the duration of the study. All male subjects must agree to refrain from donating sperm for the duration of the study and for 3 months after the last administration of PET or SPECT ligands. Sexually active male subjects must agree to use condoms to protect their partners from becoming pregnant for the duration of the study and for 3 months after the last administration of PET or SPECT ligands (i.e. for 15 consecutive months following baseline PET and SPECT scans); agree to ensure that they and their partners are routinely using a medically approved contraceptive method. It is important that male subjects not impregnate others for the duration of the study and for 3 months after the last administration of PET or SPECT ligands; Able and willing to participate in all scheduled evaluations, abide by all study restrictions, and complete all required tests and procedures; Adequate visual and auditory acuity to complete the psychological testing; In the opinion of the investigator, the subject must be considered likely to comply with the study protocol and to have a high probability of completing the study.

Exclusion: Subjects taking serotonin acting drugs such as antidepressants (i.e. tricyclic or selective serotonin reuptake inhibitors etc.); Within 1 year prior to screen or between screen and baseline (Day -1), any of the following: myocardial infarction; hospitalization for congestive heart failure; hospitalization for, or symptoms of, unstable angina; or syncope not related to PD; Clinically important infection (e.g., chronic, persistent, or acute infection) within 30 days prior to screen or between screen and baseline (Day -1); Use of antipsychotic medication within 3 months prior to screen or between screen and baseline (Day -1); Use of any anticoagulant within 30 days prior to baseline and follow-up PET scans; Use of any oral corticosteroid within 30 days prior to baseline and follow-up PET scans; Use of metoclopramide within 30 days prior to baseline and follow-up (Day -1); Use of any thyroid medication within 30 days prior to baseline and follow-up (Day -1); Regular use (e.g., taken > 3 days/week) of narcotic pain medications within 30 days prior to baseline and follow-up (Day -1); Patients who had previous surgery for PD (including but not limited to deep brain stimulation [DBS] or cell transplantation); Patients who are treated with duodopa or apomorphine; Initiation or change in pharmacologic therapy for symptoms of PD within 30 days prior to screen or between screen and baseline and follow-up (Day -1); Subjects with current or a recent history of drug or alcohol abuse/dependence; Subjects who have other neurological disorders and known intracranial co-morbidities such as stroke, hemorrhage, space-occupying lesions; Presence of any clinically significant medical condition (including cardiovascular, respiratory, cerebrovascular, hematological, hepatic, renal, gastrointestinal, or other disease) that, based on the judgment of the investigator, is clinically unstable, is likely to deteriorate during the course of the study, could put the patient at risk because of participation in the study, could affect the subject's ability to complete the study, or could influence the study results; History of suicidal behaviour or active suicidal ideation; History or presence of renal disease or impaired renal function; History of cancer within the last 5 years, with the exception of nonmetastatic basal cell carcinoma of the skin; Presence of any of the following MRI contraindications: pacemaker; cardiac defibrillator; spinal cord or vagus nerve stimulator; aneurysm clip; artificial heart valve; recent coronary or carotid stent; ear implant; CSF shunt; other implanted medical device (e.g., Swan-Ganz catheter, insulin pump); or metal fragments or foreign objects in the eyes, skin, or body; Claustrophobia or history of back pain that makes prolonged laying on the PET or MRI scanner intolerable; History of severe skin allergy; Clinically significant blood clotting or bleeding disorder, including clinically significant abnormal findings in laboratory assessments of coagulation or hematology; Subjects lacking capacity according to investigator judgement; Pregnancy or breastfeeding or intent to become pregnant in the next 18 months; Negative modified Allen test in both hands, unless the brachial artery is used for arterial cannulation; GDS score greater than or equal to 10 (GDS score of 5 - 9 requires Investigator discretion to enter study); STAI Form Y-1 greater than or equal to 54 requires Investigator discretion to enter study.

ClinicalTrials.gov NCT05516732