title: Role of ¹⁸F-FDG PET imaging in paediatric primary dystonia and dystonia arising from neurodegeneration with brain iron accumulation.
abstract: OBJECTIVE
  No current neuroimaging modality offers mechanistic or prognostic information to guide management in paediatric dystonia. We assessed F-fluorodeoxyglucose (¹⁸F-FDG) PET/computed tomography (CT) brain imaging in childhood primary dystonia (PDS) and neurodegeneration with brain iron accumulation (NBIA) to determine whether it would identify altered metabolism and hence constitute a potentially useful 'biomarker' indicating functional disturbances associated with dystonia and severity of the disease.
  
  
  METHODS
  A total of 27 children (15 PDS and 12 NBIA) underwent brain ¹⁸F-FDG PET/CT imaging under anaesthesia during acquisition. The images were assessed visually and the two groups were compared quantitatively with statistical parametric mapping. PET/CT images were spatially transformed to Montreal Neurological Institute standard space. Voxelwise ¹⁸F-FDG uptake was normalized to whole-brain uptake. Data of both groups were correlated separately with duration and severity of dystonia as assessed using the Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS).
  
  
  RESULTS
  Visual inspection did not identify any abnormalities in ¹⁸F-FDG uptake within the cerebral cortex, basal ganglia, or thalami in either group. Quantitative analysis identified higher uptake in the posterior cingulate and bilateral posterior putamina but decreased uptake in the occipital cortex and cerebellum in NBIA compared with PDS. The NBIA group had more severe dystonia scores compared with the PDS group. BFMDRS was negatively correlated with age but not with duration of dystonia.
  
  
  CONCLUSIONS
  Compared with PDS, NBIA is dominated by relative overactivity in the putamen and by cerebellar underactivity, patterns that may reflect the increased severity of dystonia in NBIA cases. Hence, there is a potential role for ¹⁸F-FDG PET/CT imaging in paediatric dystonia, particularly in the NBIA group.
authors: aClinical PET Centre, Division of Imaging Sciences and Biomedical Engineering, Kings College London, St Thomas' Hospital bComplex Motor Disorders Service, Evelina Children's Hospital, Guy's & St Thomas' NHS Foundation Trust cDepartment of Medicine, Centre for Mental Health, Division of Brain Sciences, Imperial College London, London, UK.
authors: Teresa A
authors: TA
authors: Szyszko
authors: Joel T
authors: JT
authors: Dunn
authors: Michael J
authors: MJ
authors: O'Doherty
authors: Laurence
authors: L
authors: Reed
authors: Jean-Pierre
authors: JP
authors: Lin
mesh_terms: D000293:Adolescent; D001921:Brain / Q000378:metabolism*; D002648:Child; D020821:Dystonic Disorders / Q000150:complications* / Q000000981:diagnostic imaging* / Q000378:metabolism; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D007501:Iron / Q000378:metabolism*; D008297:Male; D019636:Neurodegenerative Diseases / Q000150:complications*; D049268:Positron-Emission Tomography; D012189:Retrospective Studies; D055815:Young Adult
chemical_list: D019788:Fluorodeoxyglucose F18; D007501:Iron