title: Early evaluation of cerebral metabolic rate of glucose (CMRglu) with 18F-FDG PET/CT and clinical assessment in idiopathic normal pressure hydrocephalus (INPH) patients before and after ventricular shunt placement: preliminary experience.
abstract: OBJECTIVE
  We evaluated the relationships between the cerebral metabolic rate of glucose (CMRglu) measured by dynamic (18)F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) and the clinical and neuropsychological assessment before and after the surgical procedure in idiopathic normal pressure hydrocephalus (INPH) patients.
  
  
  METHODS
  Eleven selected INPH patients underwent clinical assessment (modified Rankin scale, Krauss scale, Larsson categorization system and Stein-Langfitt scale), cognitive evaluation (Mini-Mental State Examination, MMSE) and dynamic (18)F-FDG PET/CT scan 3 days before and 1 week after ventricular shunt placement.
  
  
  RESULTS
  After shunting, the global CMRglu significantly increased (2.95 ± 0.44 vs 4.38 ± 0.68, p = 10(-7)) in all INPH patients with a mean percentage value of 48.7%. After shunting, no significant change was found in the Evans ratio whereas a significant decrease in all clinical scale scores was observed. Only a slight reduction in the MMSE was found. After shunting, a significant correlation between the global CMRglu value and clinical assessment was found (R (2) = 0.75, p = 0.024); indeed all clinical scale scores varied (decreasing) and the CMRglu value also varied (increasing) in all INPH patients.
  
  
  CONCLUSIONS
  Our preliminary data show that changes in the CMRglu are promptly reversible after surgery and that there is a relationship between the early metabolic changes and clinical symptoms, independently from the simultaneous changes in the ventricular size. The remarkable and prompt improvement in the global CMRglu and in symptoms may also have important implications for the current concept of "neuronal plasticity" and for the cells' reactivity in order to recover their metabolic function.
authors: Institute of Nuclear Medicine, Università Cattolica del Sacro Cuore, Largo A. Gemelli, 8, 00168 Rome, Italy. ml.calcagni@rm.unicatt.it
authors: Maria Lucia
authors: ML
authors: Calcagni
authors: Mariadea
authors: M
authors: Lavalle
authors: Annunziato
authors: A
authors: Mangiola
authors: Luca
authors: L
authors: Indovina
authors: Lucia
authors: L
authors: Leccisotti
authors: Pasquale
authors: P
authors: De Bonis
authors: Camillo
authors: C
authors: Marra
authors: Armando
authors: A
authors: Pelliccioni
authors: Carmelo
authors: C
authors: Anile
authors: Alessandro
authors: A
authors: Giordano
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001931:Brain Mapping / Q000379:methods; D002557:Cerebrospinal Fluid Shunts; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000494:pharmacology*; D006801:Humans; D006850:Hydrocephalus, Normal Pressure / Q000175:diagnosis* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging / Q000379:methods*; D009474:Neurons / Q000473:pathology; D049268:Positron-Emission Tomography; D013997:Time Factors; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome
chemical_list: D019788:Fluorodeoxyglucose F18