18F-FDG PET Identifies Altered Brain Metabolism in Patients with Cri du Chat Syndrome

Esophageal Cancer with Early Onset in a Patient with Cri du Chat Syndrome

BACKGROUND

In Cri du Chat (CdC), cancer as comorbidity is extremely rare. In databases from Denmark, Spain, Australia, New Zealand, and Japan, no cancer was reported; in Italy and Germany, four cancers were identified out of 321 CdCs.

METHODS

In a 29-year-old CdC patient, clinical investigations following hematemesis led to the diagnosis of esophageal adenocarcinoma (EAC). A high pain threshold was also observed. Conventional and molecular cytogenetic defined the size of the deletion, and exome analysis on the trio completed the molecular work.

RESULTS

Cytogenetic analysis showed a de novo chromosomal alteration: 46,XY,ishdel(5)(p14.3)(D5S28-) and arr[GRCh37] 5p15.33p14.3(1498180_19955760)x1. A quantitative sensory test demonstrated a high heat threshold. A 18f-fluorodeoxyglucose PET/TC scan of the brain failed to detect reduction of metabolism in the somatosensory area or insular cortex. Exome analysis in the trio (patient and parents) failed to identify variants to be interpreted as a likely risk factor for EAC.

CONCLUSION

We conclude that the presence of well-known risk factors (maleness, obesity, gastroesophageal reflux, and Barrett's metaplasia) in a patient with very limited capability of expressing discomfort or referring clinical symptoms have been the main risk factors for developing EAC. At present, based on the available data, there is no evidence of any increased risk of developing cancer in CdC patients.

Brain positron emission tomography in idiopathic normal-pressure hydrocephalus: new 18 F-fluorodeoxyglucose pattern in a long-known syndrome

AIM

Patients with idiopathic normal-pressure hydrocephalus (iNPH) can show a global reduction in cerebral glucose metabolism at [ 18 F]Fluorodeoxyglucose (FDG) PET. The presence of caudate hypometabolism has been identified as a potential biomarker in iNPH, yet there is limited evidence of hypermetabolic findings in patients with iNPH so far.

METHODS

We retrieved retrospectively patients with iNPH and normal cognitive assessment, evaluated before surgery undergoing brain [ 18 F]FDG-PET. The 18 F-FDG-PET brain scans were compared to those of a control group of healthy subjects, matched for age and sex, by statistical parametric mapping (SPM) to identify areas of relative hypo- and hypermetabolism. Furthermore, the existence of a correlation between areas of hypo- and hypermetabolism in the patient group was tested.

RESULTS

Seven iNPH patients (mean age 74 ± 6 years) were found in the hospital database. SPM group analysis revealed clusters of significant hypometabolism ( P  = 0.001) in the iNPH group in the dorsal striatum, involving caudate and putamen bilaterally. Clusters of significant hypermetabolism ( P  = 0.001) were revealed in the bilateral superior and precentral frontal gyrus (BA 4, 6). A significant inverse correlation between striatal hypometabolism and bilateral superior and precentral frontal gyrus hypermetabolism was revealed ( P  < 0.001 corrected for multiple comparisons).

CONCLUSION

In this cohort, patients with iNPH showed subcortical hypometabolism, including bilateral dorsal striatum. To the best of our knowledge, this is the first report demonstrating a hypermetabolic pattern in the primary motor and premotor areas, and showing an inverse correlation between the striatum and motor cortex in patients with iNPH.

18F-FDG PET brain findings in disease-discordant monozygotic mosaic twins with Cri du Chat (5p-) syndrome

We describe the first report on the genotype-phenotype patterns and [18F] fluoro-deoxygluycose (¹⁸F-FDG) Positron Emission Tomography (PET) findings in two disease-discordant monozygotic twins with Cri du Chat syndrome (CdcS) presenting deletion of 5p, 46, XY, del(5)(p14)/46, XY. One twin showed a severe phenotype; significant ¹⁸F-FDG PET hypometabolism (p=0.001) was revealed in the left and right hemispheres, thalamus, cerebellum, and midbrain, whereas hypermetabolism was detected in the left premotor cortex. The other twin presented a mild phenotype; significant hypometabolism was detected only in the right side (parahippoccampal gyrus and cerebellum). Further studies should investigate the causes of phenotypic discordance in twins with CdcS.