title: 18F-FDG PET in neurodegenerative Langerhans cell histiocytosis : results and potential interest for an early diagnosis of the disease.
abstract: BACKGROUND
  The so called "neurodegenerative Langerhans cell histiocytosis" (ND-LCH) is a rare and severe complication of LCH presenting as a progressive cerebellar ataxia associated with pyramidal tract signs, and cognitive impairment. MRI is the gold standard to investigate CNS lesions of ND-LCH but little is known about functional changes observed in this disease.
  
  
  OBJECTIVE
  To search for CNS metabolic changes in NDLCH.
  
  
  METHODS
  Seven patients suffering from ND-LCH were investigated by 18F-FDG PET in this prospective study and compared with 21 healthy controls.
  
  
  RESULTS
  ND-LCH patients demonstrated recurrent abnormalities including bilateral hypometabolism in the cerebellum, the basal ganglia (caudate nuclei), frontal cortex and, bilateral, a relatively increased metabolism in the amygdalae (p < 0.001). Functional changes in these anatomical regions may be detected in the absence of any apparent lesion on MRI.
  
  
  CONCLUSIONS
  ND-LCH demonstrates a recurrent 18F-FDG PET metabolic signature. Our results suggest that 18F-FDG PET might be a useful tool for an early diagnosis of ND-LCH before neuroradiologic abnormalities appear.
authors.affiliation: Service Hospitalier Frédéric Joliot, DRM/DSV, CEA 4, place du Général Leclerc, 91406 Orsay, France. maria-joao.ribeiro@cea.fr
authors.forename: Maria-João
authors.initials: MJ
authors.lastname: Ribeiro
authors.forename: Ahmed
authors.initials: A
authors.lastname: Idbaih
authors.forename: Caroline
authors.initials: C
authors.lastname: Thomas
authors.forename: Philippe
authors.initials: P
authors.lastname: Remy
authors.forename: Nadine
authors.initials: N
authors.lastname: Martin-Duverneuil
authors.forename: Yves
authors.initials: Y
authors.lastname: Samson
authors.forename: Jean
authors.initials: J
authors.lastname: Donadieu
authors.forename: Khê
authors.initials: K
authors.lastname: Hoang-Xuan
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001921:Brain / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology; D001931:Brain Mapping / Q000379:methods; D002524:Cerebellar Ataxia / Q000000981:diagnostic imaging / Q000209:etiology / Q000503:physiopathology; D003072:Cognition Disorders / Q000000981:diagnostic imaging / Q000209:etiology / Q000503:physiopathology; D003937:Diagnosis, Differential; D042241:Early Diagnosis; D005260:Female; D019788:Fluorodeoxyglucose F18; D006646:Histiocytosis, Langerhans-Cell / Q000150:complications*; D006801:Humans; D008297:Male; D008875:Middle Aged; D016472:Motor Neuron Disease / Q000000981:diagnostic imaging / Q000209:etiology / Q000503:physiopathology; D019636:Neurodegenerative Diseases / Q000000981:diagnostic imaging* / Q000209:etiology / Q000503:physiopathology*; D049268:Positron-Emission Tomography / Q000379:methods* / Q000592:standards; D011237:Predictive Value of Tests; D011379:Prognosis
chemical_list: D019788:Fluorodeoxyglucose F18