Relevance of Fluorodopa PET Scan in Dopamine Responsive Dystonia and Juvenile Parkinsonism: A Systematic Review
Juan Moncayo1, Maite Vargas2, Juan Fernando Ortiz3, Pablo Granda1, Alex Aguirre2, Pamela Davila-siliezar4, Santiago Rivadeneira Yugsi5, Jennifer Argudo6, Willians Tambo7, Gabriela Garofalo8, Christian Capirig9, Melisa German-Montenegro1, Luis Rueda Carrillo10
1Pontificia Universidad Católica del Ecuador, 2Universidad San Francisco de Quito, 3Spectrum Health /Michigan State University, 4Texas Tech University, 5Hospital Universitario de Toledo, 6Universidad de Cuenca, 7Northwell Health, 8Universidad de Central del Ecuador, 9Davao Medical School Foundation, 10Augusta University
Objective:
We focused our attention on the FD PET scan mainly because, even though it is not a very common test to perform, it is more available than genetic testing in developing countries. In addition, this test allows us to have a quick, sensitive, specific marker for a disease that prompts treatment and may go undiagnosed for a significant amount of time if there is no test to confirm the correct diagnosis. Finally, it creates a reliable and measurable finding to compare as the diseases progress.
This systematic review aims to gather information about the differentiation of these two diseases in the setting of a young patient with parkinsonian symptoms and its use in the clinical setting.
Background:
Dopamine Responsive Dystonia (DRD) and Juvenile Parkinsonism (JP) are two diseases commonly presenting with parkinsonian symptoms in young patients. Current clinical guidelines offer a diagnostic approach based on molecular analysis.
Design/Methods:
We performed a systematic literature review in English using the preferred reporting items for systematic reviews and meta-analyses (PRISMA) and meta-analysis of observational studies in epidemiology (MOOSE) protocols. We only used human clinical trials about dopamine responsive dystonia and juvenile parkinsonism patients in which a fluorodopa (FD) positron emission tomography (PET) scan was performed to identify its use in these diseases.
Results:
We included six studies that fulfilled our criteria. We found a clear pattern of decreased uptake in the putamen and caudate nucleus in JP cases. At the same time, the results in DRD were comparable to normal subjects, with only a slightly decreased marker uptake in the previously mentioned regions by the FD PET scan.
Conclusions:
We found a distinctive pattern for each of these diseases. Identifying these findings with FD PET scans can shorten the delay in making a definitive diagnosis when genetic testing is unavailable, a common scenario in developing countries.