Plasmatic profiles of cytokines/chemokines, glial fibrillary acidic protein (GFAP) and MRI brain damage in neonates with hypoxic ischemic encephalopathy (HIE)

BACKGROUND

Perinatal hypoxia triggers the release of cytokines and chemokines by neurons, astrocytes and microglia. In response to hypoxia-ischemia resting/ramified microglia proliferate and undergo activation, producing proinflammatory molecules. The brain damage extension seems to be related to both the severity of hypoxia and the balance between pro and anti-inflammatory response and can be explored with neuroimaging.

AIMS

The aim of this preliminary study was to explore possible relationships between plasma levels of inflammatory cytokines/chemokines and the severe brain damage detectable by Magnetic Resonance Imaging (MRI), performed during the hospitalization.

METHODS

In 10 full terms neonates with hypoxic ischemic encephalopathy (HIE) undergoing therapeutic hypothermia (TH), divided into cases and controls, according to MRI results, we measured and compared the plasma levels of CCL2/MCP-1, CXCL8, GFAP, IFN y, IL-10, IL-18, IL-6, CCL3, ENOLASE2, GM-CSF, IL-1b, IL-12p70, IL-33, TNFα, collected at four different time points during TH (24, 25-48, 49-72 h of life, and 7-10 days from birth). Five of enrolled babies had pathological brain MRI (cases) and 5 had a normal MRI examination (controls). Cytokines were measured by Magnetic Luminex Assay. MRI images were classified according to Barkovich's score.

RESULTS

Mean levels of all cytokines and molecules at time T1 were not significantly different in the two groups. Comparing samples paired by day of collection, the greatest differences between cases and controls were found at times T2 and T3, during TH. At T4, levels tended to get closer again (except for IL-6, IL10 and IL18). Infants with worse MRI showed higher plasmatic GFAP levels than those with normal MRI, while their IL-18 was lower. The mean levels of CCL3MIP1alpha, GMCSF, IL1BETA overlapped throughout the observation period in both groups.

CONCLUSION

In a small number of infants with worse brain MRI, we found higher levels of GFAP and of IL-10 at T4 and a trend toward low IL-18 levels than in infants with normal MRI, considered early biomarker of brain damage and a predictor of adverse outcome, respectively. The greatest, although not significant, difference between the levels of molecules was found in cases and controls at time points T2 and T3, during TH.

Congenital Malformations of the Eye: A Pictorial Review and Clinico-Radiological Correlations

Congenital malformations of the eye represent a wide and heterogeneous spectrum of abnormalities that may be part of a complex syndrome or be isolated. Ocular malformation severity depends on the timing of the causative event during eye formation, ranging from the complete absence of the eye if injury occurs during the first weeks of gestation, to subtle abnormalities if the cause occurs later on. Knowledge of ocular malformations is crucial to performing a tailored imaging protocol and correctly reporting imaging findings. Together with the ophthalmologic evaluation, imaging may help frame ocular malformations and identify underlying genetic conditions. The purpose of this pictorial review is to describe the imaging features of the main ocular malformations and the related ophthalmologic findings in order to provide a clinico-radiological overview of these abnormalities to the clinical radiologist. Sight is a crucial sense for children to explore the world and relate with their parents from birth. Vision impairment or even blindness secondary to ocular malformations deeply affects children's growth and quality of life.

A New Pattern of Brain and Cord Gadolinium Enhancement in Molybdenum Cofactor Deficiency: A Case Report

Molybdenum cofactor deficiency (MoCD) is a rare and severe autosomal recessive in-born error of metabolism caused by the mutation in MOCS1, MOCS2, MOCS3 or GEPH genes, with an incidence ranging between 1 in 100,000 and 200,000 live births. The clinical presentation with seizures, lethargy and neurologic deficits reflects the neurotoxicity mediated via sulphite accumulation, and it occurs within the first hours or days after birth, often leading to severe neurodegeneration and the patient's death within days or months. The Imaging of Choice is a brain-specific MRI technique, which is usually performed without contrast and shows typical radiological findings in the early phase, such as diffuse cerebral oedema and infarction affecting the cortex and the basal ganglia and the white matter, as well as in the late phase, such as multicystic encephalomalacia. Our case report represents a novelty in the field, since the patient underwent a contrast-enhanced MRI to exclude a concomitant infectious disease. In the frame of the clinical presentation and laboratory data, we describe the MoCD Imaging findings for MRI morphological and advanced sequences, presenting a new contrast-enhanced MRI pattern characterized by the diffuse and linear leptomeningeal enhancement of brain, cord and spinal roots. The early identification of molybdenum cofactor deficiency is crucial because it may lead to the best multidisciplinary therapy for the patient, which is focused on the prompt and optimal management of the complications.

Neurodevelopmental and genetic findings in neonates with intracranial arteriovenous shunts: A case series

Background

Despite the latest advances in prenatal diagnosis and postnatal embolization procedures, intracranial arteriovenous shunts (AVSs) are still associated with high mortality and morbidity rates. Our aim was to evaluate the presentation and clinical course, the neurodevelopmental outcome, and the genetic findings of neonates with AVSs.

Methods

In this retrospective observational study, medical records of neonates with cerebral AVSs admitted to our hospital from January 2020 to July 2022 were revised. In particular, we evaluated neuroimaging characteristics, endovascular treatment, neurophysiological features, neurodevelopmental outcomes, and genetic findings.

Results

We described the characteristics of 11 patients with AVSs. Ten infants (90.9%) required embolization during the first three months of life. In 5/9 infants, pathological electroencephalography findings were observed; of them, two patients presented seizures. Eight patients performed Median Nerve Somatosensory Evoked Potentials (MN-SEPs): of them, six had an impaired response. We found normal responses at Visual Evoked Potentials and Brainstem Auditory Evoked Potentials. Eight patients survived (72.7%) and were enrolled in our multidisciplinary follow-up program. Of them, 7/8 completed the Bayley-III Scales at 6 months of corrected age: none of them had cognitive and language delays; conversely, a patient had a moderate delay on the Motor scale. The remaining survivor patient developed cerebral palsy and could not undergo Bayley-III evaluation because of the severe psychomotor delay. From the genetic point of view, we found a novel pathogenic variant in the NOTCH3 gene and three additional genomic defects of uncertain pathogenicity.

Conclusion

We propose SEPs as an ancillary test to discern the most vulnerable infants at the bedside, particularly to identify possible future motor impairment in follow-up. The early identification of a cognitive or motor delay is critical to intervene with personalized rehabilitation treatment and minimize future impairment promptly. Furthermore, the correct interpretation of identified genetic variants could provide useful information, but further studies are needed to investigate the role of these variants in the pathogenesis of AVSs.

Clinical and Neurodevelopmental Characteristics of Enterovirus and Parechovirus Meningitis in Neonates

Background

Non-polio-enteroviruses (EV) and human parechoviruses (HPeV) are small RNA viruses, which in newborns cause infections with a wide range of severity. Today molecular biology tools allow us to diagnose viral meningitis in neonates, sparing patients from useless antibiotics. Data on neurodevelopmental outcome of children who contract enterovirus meningitis in early childhood are still limited in the literature.

Aims

To evaluate the neurodevelopmental outcome of newborns with documented enterovirus and parechovirus meningitis contracted within the first months of life.

Methods

Enterovirus and parechovirus were detected on cerebrospinal fluid (CSF) and plasma by RT-PCR. The virological typing was done according to WHO recommendations. During the hospitalization each neonate underwent many diagnostic and instrumental examinations, to evaluate any neurological lesions attributable to the infection. After the discharge children entered in an outpatient interdisciplinary assessment process, comprehensive of the administration of Bayley III scales up to 12 months old.

Results

We observed longitudinally 30 children, born at term (mean GA 39.7 ± 0.8 weeks, mean birthweight was 3,457 ± 405 grams), who contracted enterovirus and parechovirus meningitis within the first month of life (mean age at diagnosis was 15.8 ± 7.33 days). We were able to perform the genetic typing only on 15/30 (50.0%) cerebrospinal fluid (CSF) samples from 15 neonates. We found MRI anomalies in 9/26 observed neonates (34.6%): one of them presented brainstem abnormality that are specific of enteroviral central nervous system (CNS) involvement. During the follow up children displayed an overall normal neurodevelopment and no deficit in visual and hearing areas. The mean cognitive (105.19 ± 8.71), speech (100.23 ± 8.22) and motor (97.00 ± 8.98) composite scores, assessed by Bayley III, were normal in 29/30 (96.7%). Despite this, children with pathological brain magnetic resonance imaging (MRI) scored significantly lower (p = 0.01) than children with normal brain MRI on cognitive subscale at 12 months of life.

Conclusions

Early enterovirus infections can be associated to brain MRI abnormalities, more frequently the earlier the infection. Although within a normal range, our children with pathological brain MRI scored significantly lower than those with normal brain MRI on cognitive subscale at 12 months of life.

Neurological and Neuroimaging Features of CYB5R3-Related Recessive Hereditary Methemoglobinemia Type II

Recessive hereditary methemoglobinemia (RHM) due to NADH-cytochrome b5 reductase deficiency is a rare disease caused by pathogenic variants in CYB5R3. Unlike type I, in RHM type II (RHM2), the enzymatic defect affects erythrocytes and all body tissues, thus resulting in cyanosis and neurological impairment. Although the first description of RHM2 dates back to the mid-1950s, detailed clinical and neuroimaging information are available for only a few patients. Here, we describe a new patient with RHM2 that harbors an unreported homozygous 31 Kb deletion involving part of CYB5R3, and showing a peculiar neuroimaging pattern resembling a ponto-cerebellar hypoplasia-like condition. A careful review of the available literature was performed with the aim of better delineating neurological and neuroimaging as well as the genotypic spectra of this extremely rare disease.

Secondary cytomegalovirus infections: How much do we still not know? Comparison of children with symptomatic congenital cytomegalovirus born to mothers with primary and secondary infection

Congenital cytomegalovirus (cCMV) infection can follow primary and secondary maternal infection. Growing evidence indicate that secondary maternal infections contribute to a much greater proportion of symptomatic cCMV than was previously thought. We performed a monocentric retrospective study of babies with cCMV evaluated from August 2004 to February 2021; we compared data of symptomatic children born to mothers with primary or secondary infection, both at birth and during follow up. Among the 145 babies with available data about maternal infection, 53 were classified as having symptomatic cCMV and were included in the study: 40 babies were born to mothers with primary infection and 13 babies were born to mothers with secondary infection. Analyzing data at birth, we found no statistical differences in the rate of clinical findings in the two groups, except for unilateral sensorineural hearing loss (SNHL) which was significantly more frequent in patients born to mother with secondary infection than in those born to mother with primary infection (46.2 vs. 17.5%, P = 0.037). During follow up, we found a higher rate of many sequelae (tetraparesis, epilepsy, motor and speech delay, and unilateral SNHL) in the group of children born to mothers with secondary infection, with a statistical difference for tetraparesis and unilateral SNHL. Otherwise, only children born to mothers with primary infection presented bilateral SNHL both at birth and follow up. Our data suggest that the risk of symptomatic cCMV and long-term sequelae is similar in children born to mother with primary and secondary CMV infection; it is important to pay appropriate attention to seropositive mothers in order to prevent reinfection and to detect and possibly treat infected babies.

Neonatal Cerebral Venous Thrombosis following Maternal SARS-CoV-2 Infection in Pregnancy

A possible consequence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is the development of an exacerbated thrombophilic status, and cerebral venous thrombosis (CVT) is a rare but possible complication of SARS-CoV-2 infection reported both in adults and in children. The present case report describes the clinical course of a term neonate showing extended CVT of unclear origin, whose mother had developed SARS-CoV-2 infection during the third trimester of pregnancy. We speculate that the prothrombotic status induced by maternal SARS-CoV-2 infection may have played a pathophysiological role in the development of such severe neonatal complication. Further investigations are required to confirm such hypothesis.

Severe COVID-19 Complicated by Cerebral Venous Thrombosis in a Newborn Successfully Treated with Remdesivir, Glucocorticoids, and Hyperimmune Plasma

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is responsible for the coronavirus disease 2019 (COVID-19) pandemic, affecting all age groups with a wide spectrum of clinical presentation ranging from asymptomatic to severe interstitial pneumonia, hyperinflammation, and death. Children and infants generally show a mild course of the disease, although infants have been observed to have a higher risk of hospitalization and severe outcomes. Here, we report the case of a preterm infant with a severe form of SARS-CoV-2 infection complicated by cerebral venous thrombosis successfully treated with steroids, hyperimmune plasma, and remdesivir.

Early alterations of cortical thickness and gyrification in migraine without aura: a retrospective MRI study in pediatric patients

Background

Migraine is the most common neurological disease, with high social-economical burden. Although there is growing evidence of brain structural and functional abnormalities in patients with migraine, few studies have been conducted on children and no studies investigating cortical gyrification have been conducted on pediatric patients affected by migraine without aura.

Methods

Seventy-two pediatric patients affected by migraine without aura and eighty-two controls aged between 6 and 18 were retrospectively recruited with the following inclusion criteria: MRI exam showing no morphological or signal abnormalities, no systemic comorbidities, no abnormal neurological examination. Cortical thickness (CT) and local gyrification index (LGI) were obtained through a dedicated algorithm, consisting of a combination of voxel-based and surface-based morphometric techniques. The statistical analysis was performed separately on CT and LGI between: patients and controls; subgroups of controls and subgroups of patients.

Results

Patients showed a decreased LGI in the left superior parietal lobule and in the supramarginal gyrus, compared to controls. Female patients presented a decreased LGI in the right superior, middle and transverse temporal gyri, right postcentral gyrus and supramarginal gyrus compared to male patients. Compared to migraine patients younger than 12 years, the ≥ 12-year-old subjects showed a decreased CT in the superior and middle frontal gyri, pre- and post-central cortex, paracentral lobule, superior and transverse temporal gyri, supramarginal gyrus and posterior insula. Migraine patients experiencing nausea and/or vomiting during headache attacks presented an increased CT in the pars opercularis of the left inferior frontal gyrus.

Conclusions

Differences in CT and LGI in patients affected by migraine without aura may suggest the presence of congenital and acquired abnormalities in migraine and that migraine might represent a vast spectrum of different entities. In particular, ≥ 12-year-old pediatric patients showed a decreased CT in areas related to the executive function and nociceptive networks compared to younger patients, while female patients compared to males showed a decreased CT of the auditory cortex compared to males. Therefore, early and tailored therapies are paramount to obtain migraine control, prevent cerebral reduction of cortical thickness and preserve executive function and nociception networks to ensure a high quality of life.

Morphometric Analysis of Brain in Newborn with Congenital Diaphragmatic Hernia

Congenital diaphragmatic hernia (CDH) is a severe pediatric disorder with herniation of abdominal viscera into the thoracic cavity. Since neurodevelopmental impairment constitutes a common outcome, we performed morphometric magnetic resonance imaging (MRI) analysis on CDH infants to investigate cortical parameters such as cortical thickness (CT) and local gyrification index (LGI). By assessing CT and LGI distributions and their correlations with variables which might have an impact on oxygen delivery (total lung volume, TLV), we aimed to detect how altered perfusion affects cortical development in CDH. A group of CDH patients received both prenatal (i.e., fetal stage) and postnatal MRI. From postnatal high-resolution T2-weighted images, mean CT and LGI distributions of 16 CDH were computed and statistically compared to those of 13 controls. Moreover, TLV measures obtained from fetal MRI were further correlated to LGI. Compared to controls, CDH infants exhibited areas of hypogiria within bilateral fronto-temporo-parietal labels, while no differences were found for CT. LGI significantly correlated with TLV within bilateral temporal lobes and left frontal lobe, involving language- and auditory-related brain areas. Although the causes of neurodevelopmental impairment in CDH are still unclear, our results may suggest their link with altered cortical maturation and possible impaired oxygen perfusion.

DTI parameters in neonates with hypoxic-ischemic encephalopathy after total body hypothermia

BACKGROUND AND PURPOSE

MR imaging provides means for discriminating different patterns of Hypoxic-ischemic encephalopathy (HIE) and may distinguish most severe cases from less severe but is unable to predict long-term outcome. Diffusion tensor imaging (DTI) offers information for a more complete characterization of HIE. The purpose of this study is to compare the modifications of DTI parameters in newborns one week and six months following total-body cooling to healthy controls.

METHODS

Forty-seven cooled newborns were studied with MRI, 20 underwent follow-up at 6 months. 12 healthy newborns and nine children at 6 months were enrolled as control groups (HC). Inferior Longitudinal Fasciculus (ILF), Corpus Callosum Fasciculus (CCF), Corticospinal Tract (CST), Optical Tract (OT), Optic Radiation (OR) were generated in all subjects. DTI parameters were evaluated in basal ganglia (BG), thalamus (TH) and tracks. Statistical analysis was performed with MANOVA.

RESULTS

In newborns HIE versus HC, there were significantly lower fractional anisotropy (FA) on OR and CST and higher axial diffusivity (AD), apparent diffusion coefficient (ADC) and radial diffusivity (RD) values on CST, BG and TH in HIE-N. At 6 months there were no significant grouping effects. The analysis showed a significant increase of FA, decrease of ADC, AD, RD after 6 months for HIE and HC.

CONCLUSIONS

We observed modifications of parameter values in HIE newborns vs HC; however normalization of values at 6 months suggests that changes of parameters cannot be considered early biomarkers for evaluation of therapeutic hypothermia in newborns with moderate HIE and normal conventional MRI.

A new MRI severity score to predict long-term adverse neurologic outcomes in children with congenital Cytomegalovirus infection

BACKGROUND

Congenital cytomegalovirus (CMV) infection is one of the main causes of deafness in childhood. It frequently causes serious long-term neurological sequelae. In children who are asymptomatic at birth, tests to accurately predict these sequelae are still unavailable.

AIMS

We describe different brain MRI patterns of congenital CMV infection correlated with clinical data and propose a new MRI severity score to early predict long-term neurological sequelae.

MATERIALS AND METHODS

We explored clinical records and neuroimaging data of 224 neonates and children with congenital Cytomegalovirus infection, 180 of them did not meet inclusion criteria. Forty-four babies met inclusion criteria and were enrolled in the study. We retrospectively collected clinical data concerning hospitalization, 2 years outpatient follow-up and brain MRI findings of those 44 children, symptomatic and asymptomatic at birth. Clinical data were then correlated with children's brain MRI examinations. We defined neurological and sensorial impairment (hearing or visual) as "adverse neurological outcomes". Brain MRI score was constructed assigning different values to white matter and ventricular dilation.

RESULTS

In 44 children enrolled in the study we found that 28/35 (80%) with abnormal and 2/9 (22,2%) with normal MRI examination developed adverse neurological outcomes (OR = 3.6) (95% IC 1.0-12.0). Infants who were symptomatic at birth showed a probability of MRI brain lesions 3.2 times higher than those who were asymptomatic. Ten out of 17 (59%) children who were asymptomatic at birth showed MRI-WM alterations or ventriculomegaly.

CONCLUSIONS

Brain MRI abnormalities, such as WM alterations and ventriculomegaly, expressed as MRI score higher than 2 are associated with an increased probability of long-term adverse neurological outcome in congenitally CMV infected infants, symptomatic and asymptomatic at birth.

Accuracy and Clinical Correlates of Two Different Methods for Chromogranin A Assay in Neuroendocrine Tumors

Measurement of chromogranin A (CgA) plays a major role in the management of neuroendocrine tumors (NET); however, reliable assaying of CgA is made difficult by the rapid hydrolysis following its release into the bloodstream. This study was aimed at the assessment of two assays for CgA in NET patients. CgA was measured in 93 patients by means of an enzyme-linked immunosorbent assay (ELISA) and an immunoradiometric assay (IRMA). The specificity and sensitivity of CgA were evaluated in relation to tumor histology. The clinical accuracy of the two assays was evaluated by receiver-operating characteristic (ROC) curve analysis. Regression analysis demonstrated different immunoreactivity for CgA of the antibodies used in the two kits (r=0.61). The two assays had different accuracy also in classifying patients according to their clinical condition (91% vs 64% specificity and 79% vs 79% sensitivity for the ELISA and IRMA assay, respectively) and tumor histology (81% vs 85% sensitivity for the ELISA and IRMA assays, respectively, in carcinoids; 92% vs 67% sensitivity for the ELISA and IRMA assays, respectively, in pancreatic islet cell tumors). The different clinical accuracy of the two assays was confirmed by the ROC analysis (AUC=0.90 vs AUC=0.87 for the ELISA and IRMA assays, respectively). In conclusion, because of the poor standardization of the commercially available measurement tools the clinical accuracy of CgA measurement depends on the assay used. This makes it difficult to compare CgA values measured with different kits and affects the clinical accuracy of the different assays for CgA.

Epileptic seizures heralding a relapse in high grade gliomas

PURPOSE

Seizures are a common clinical symptom in high-grade gliomas (HGG). The aim of the study was to investigate the relationship between seizures and HGG relapse (HGG-R).

METHODS

We retrospectively evaluated 145 patients who were surgically treated for HGG-R. By analyzing clinical characteristics in these patients (all operated and treated by the same protocol), we identified 37 patients with seizures during follow-up. This cohort was divided into four subgroups according to a) presence or absence of seizures at the time of diagnosis and b) temporal relationship between seizure occurrence and HGG-R during follow-up: subgroup A (25pts) had seizures at follow-up but not at onset, subgroup B (12pts) had seizures both at follow-up and onset, subgroup C (30pts) had seizures before MRI-documented HGG-R, and subgroup D (7pts) had seizures after MRI-documented HGG-R.

RESULTS

Although the datum was not statistically significant, survival was longer in patients with seizures during follow-up than in those without seizures (59.3% vs 51.4% alive at 2 years). In 30 patients (subgroup C) seizures heralded HGG-R. In a correlation analysis for this last subgroup, the time interval between seizure and the HGG-R was significantly associated with the number of chemotherapy cycles (r=0.470; p=0.009) and follow-up duration (r=0.566; p=0.001). A linear regression model demonstrated a reciprocal association between the above factors and that it may be possible to estimate the timing of HGG-R by combining these data.

CONCLUSIONS

Seizures may herald HGG-R before MRI detection of relapse, thus suggesting that seizures should always be considered a red flag during follow-up.

Ictal EEG/fMRI study of vertiginous seizures

Vertigo and dizziness are extremely common complaints, related to either peripheral or central nervous system disorders. Among the latter, epilepsy has to be taken into consideration: indeed, vertigo may be part of the initial aura of a focal epileptic seizure in association with other signs/symptoms, or represent the only ictal manifestation, a rare phenomenon known as "vertiginous" or "vestibular" seizure. These ictal symptoms are usually related to a discharge arising from/involving temporal or parietal areas, which are supposed to be a crucial component of the so-called "vestibular cortex". In this paper, we describe three patients suffering from drug-resistant focal epilepsy, symptomatic of malformations of cortical development or perinatal hypoxic/ischemic lesions located in the posterior regions, who presented clusters of vertiginous seizures. The high recurrence rate of such events, recorded during video-EEG monitoring sessions, offered the opportunity to perform an ictal EEG/fMRI study to identify seizure-related hemodynamic changes. The ictal EEG/fMRI revealed the main activation clusters in the temporo-parieto-occipital regions, which are widely recognized to be involved in the processing of vestibular information. Interestingly, ictal deactivation was also detected in the ipsilateral cerebellar hemisphere, suggesting the ictal involvement of cortical-subcortical structures known to be part of the vestibular integration network.

Atypical presentation of Non-Hodgkin Lymphoma (NHL): a case report

Lymphomas infrequently cause peripheral nerve complications. These syndromes mostly occur by direct compression or infiltration of nerves (neurolymphomatosis), but may also be due to a remote effect as paraneoplastic syndromes, neurotoxic complications of chemotherapy, antibody-mediated or autoimmune mechanisms.We report the case of a 60-year-old woman who presented with a complex peripheral nervous system involvement as initial manifestation of Non-Hodgkin Lymphoma (NHL). This case sheds light on “protean” mechanism of peripheral nerve complications during the course of NHL and related diagnostic dilemma.

Exploring dopaminergic activity in ring chromosome 20 syndrome: a SPECT study

AIM

Several lines of evidence indicate that the dopaminergic system may play a role in the propagation of epileptic seizures and, indeed, DOPA metabolism impairment has recently been demonstrated in PET studies of ring chromosome 20 [r(20)] patients. We conducted a study looking for correlations between r(20) mosaicism, other clinical variables and both pre-synaptic dopamine transporter (DAT) expression and post-synaptic D2 receptor density.

METHODS

Five patients with r(20) and epilepsy were enrolled in the study. DAT expression and D2 density were measured by single photon emission tomography (SPECT) imaging with 185 MBq of [¹²³I]ioflupane and [¹²³I]IBZM, respectively, on different days. Linear correlations between r(20) mosaicism, clinical variables and binding of [¹²³I]ioflupane or [¹²³I]IBZM were examined.

RESULTS

A significant correlation between seizure frequency and r(20) mosaicism was detected (r=0.903, P<0.05), along with a negative correlation between r(20) mosaicism and binding of [¹²³I]ioflupane in the putamen and in the caudate nucleus (r=-0.692 and r=-807; P<0.05). Seizure frequency was positively correlated with post-synaptic D2 density (r=0.925, P<0.05).

CONCLUSION

Striatal neurons are involved in r(20) epilepsy; the relationship found between r(20) mosaicism and DAT expression suggests that drugs acting on the dopaminergic system could have a place in the treatment of this rare form of epilepsy.

Exploring dopaminergic activity in ring chromosome 20 syndrome: a SPECT study

AIM: Several lines of evidence indicate that the dopaminergic system may play a role in the propagation of epileptic seizures and, indeed, DOPA metabolism impairment has recently been demonstrated in PET studies of ring chromosome 20 [r(20)] patients. We conducted a study looking for correlations between r(20) mosaicism, other clinical variables and both pre-synaptic dopamine transporter (DAT) expression and post-synaptic D2 receptor density. METHODS: Five patients with r(20) and epilepsy were enrolled in the study. DAT expression and D2 density were measured by single photon emission tomography (SPECT) imaging with 185 MBq of [123I]ioflupane and [123I]IBZM, respectively, on different days. Linear correlations between r(20) mosaicism, clinical variables and binding of [123I]ioflupane or [123I]IBZM were examined. RESULTS: A significant correlation between seizure frequency and r(20) mosaicism was detected (r=0.903, P<0.05), along with a negative correlation between r(20) mosaicism and binding of [123I]ioflupane in the putamen and in the caudate nucleus (r=-0.692 and r=-807; P<0.05). Seizure frequency was positively correlated with post-synaptic D2 density (r=0.925, P<0.05). CONCLUSION: Striatal neurons are involved in r(20) epilepsy; the relationship found between r(20) mosaicism and DAT expression suggests that drugs acting on the dopaminergic system could have a place in the treatment of this rare form of epilepsy.

Imaging of neuroendocrine tumours with gamma-emitting radiopharmaceuticals

Nuclear medicine can image some tumors by means of receptor specific radiopharmaceuticals, and offers the possibility to characterize cancer through the detection of its receptor expression. This is the case of neuroendocrine tumours (NETs), that are visualized by different radiolabelled somatostatin analogues that bind 5 distinct somatostatin receptor types (named sstr1-5) that show different tissue distribution. The subtypes sstr2 and sstr5 are the most commonly expressed in NETs. Until now the most widely used radiolabelled somatostatin analogue for planar and single photon emission computed tomography (SPECT) has been [(111)In]pentetreotide, because of its commercial availability. Other analogues labelled with gamma emitting radionuclides are [(99m)Tc]EDDA/HYNIC-TOC, [(99m)Tc]P829, [(111)In]DOTA-lanreotide, [(111)In]DOTA-NOC-ATE, [(111)In]DOTA-BOC-ATE. However, these compounds have not been successful for the routine use. Moreover, NETs express various receptors that can be depicted by different radiopharmaceuticals, such as [(123)I]VIP and [(111)In]GLP-1. Besides this, some precursors of the catecholamines metabolism, as meta-iodo-benzyl-guanidine (MIBG), labelled with (123)I or (131)I, accumulates in neuroendocrine tissues, in particular those of sympathoadrenal lineage. MIBG scintigraphy is currently indicated for neuroblastoma, paraganglioma and phaeocromocitoma. An impressive technological progress has been achieved recently with PET and, in particular, with the development of hybrid instrumentations (PET/CT) combining nuclear imaging with radiological imaging providing both functional and morphologic information. Among positron emitting tracers, the [(18)F]FDG is the most diffuse in oncology, but other more effective tracers are available for NETs, such as the analogues labelled with 68Ga. The diagnostic sensitivity and accuracy of these technology is superior to that of gamma emitting radiopharmaceuticals, but the fact that they are not still registered limits their use in the clinical practice. This overview summarizes the state of art of NETs imaging, focusing the attention mainly on gamma-emitting tracers.

Differences in hippocampal metabolism between amnestic and non-amnestic MCI subjects: automated FDG-PET image analysis

AIM

The aim of this study was to assess whether 18F-fluorodeoxyglucose positron emission tomography differentiates amnestic (aMCI) from single-non-amnestic mild cognitive impairment (snaMCI) with executive dysfunction.

METHODS

Sixteen aMCI subjects (62% females, age 75+/-8 years) and 14 snaMCI subjects (71% females, age 74+/-6 years) underwent [18F]FDG-PET and clinical follow-up. Comparisons between MCI subgroups and with seven cognitively normal elderly subjects were performed using SPM2.

RESULTS

At baseline aMCI and snaMCI exhibited a similar pattern of hypometabolism, mostly in the posterior cingulate gyrus, as compared with controls. In the comparison between the MCI subtypes, the aMCI subjects showed reduced metabolism in the medial temporal lobes (MTL) (hippocampus, fusiform gyrus and amygdala). At follow-up 12 aMCI developed Alzheimer's disease (AD), while snaMCI had a heterogeneous course, including five subjects who developed Lewy body dementia.

CONCLUSIONS

The patterns of altered brain metabolism in aMCI and snaMCI subjects compared to controls are similar and do not provide evidence for making clinical distinctions between them. Comparison between the two MCI subtypes showed MTL hypometabolism in aMCI subjects, possibly reflecting the fact that most had prodromal AD.

Instrumentation and probes for molecular and cellular imaging

Molecular and cellular imaging is a branch of biomedical sciences that combines the use of imaging instrumentation and biotechnology to characterize molecular and cellular processes in living organisms in normal and pathologic conditions. The two merging areas of research behind molecular and cellular imaging are detection technology, i.e. scanners and imaging devices, and development of tracers, contrast agents and reporter probes that make imaging with scanners and devices possible. Several in vivo imaging instruments currently used in human studies, such as computer tomography, ultrasound, magnetic resonance, positron emission tomography and single photon emission computed tomography, have been rescaled for small animal studies, while other methods initially used for in vitro evaluation, such as bioluminescence and fluorescence, have been refined for in vivo imaging. Conventional imaging relies on the use of non specific contrast agents and classical probes; however, newly developed targeted contrast agents and activable ''smart'' imaging probes for so-called ''targeted imaging'' have demonstrated high specificity and high signal to noise ratio in small animal studies. This review focuses on basic recent findings in the technical aspects of molecular and cellular imaging modalities (equipment, targeted probe and contrast agents and applied combinations of instrumentation and probe) with particular attention to the choice of the future: the multimodal imaging approach.

The dynamics of estrogen receptor activity

In the latest few years, the merging of imaging and animal engineering technologies has led to the generation of innovative tools that provide the opportunity to look into the dynamics of specific molecular events in living animals during their entire life under a completely renewed perspective. These tools will have a profound impact not only on basic research, but also on drug discovery and development allowing to depict the activity of any therapeutic agents in all their designed targets as well as in the organs where they may cause undesired effects. Along this research line, our laboratory has recently described the first animal model reporting the state of activity of estrogen receptors (ERs) in real time: the ERE-luc reporter mouse. The application of optical imaging to the ERE-luc has allowed an unprecedented in depth view of estrogen signaling in all of its target tissues. For example, the analysis of the state of activity of ERs in the physiological setting of the estrous cycle has provided compelling evidence that hormone-independent mechanisms are responsible for activating ERs in non-reproductive organs. This discovery may pave the way to a rational basis for the development of novel, more selective and effective treatments for menopause.

Molecular imaging: a new way to study molecular processes in vivo

Non-invasive imaging of reporter gene expression using different imaging modalities is increasing its role for the in vivo assessment of molecular processes. Multimodality imaging protocols overcome limitations to a single imaging modality and provide a thorough view of specific processes, often allowing a quantitative measurement and direct visualization of the process in a specific target organ or tissue. The use of the right reporter gene for the development of animal models and the characterization of its expression in different conditions and tissues is fundamental for basic, translational and future pharmacological applications of a given model. This paper summarizes the major steps in the development and evaluation of a specific animal model for in vivo molecular imaging studies and describes the first example of an animal model designed for the in vivo assessment of a specific receptor activity and its possible evolution towards multimodality imaging analysis.

Dementia with Lewy bodies with supranuclear gaze palsy: a matter of diagnosis

Description of a case of probable dementia with Lewy bodies featuring parkinsonism, dementia and supranuclear gaze palsy. This is the first patient to our knowledge affected with vertical gaze palsy receiving clinical diagnosis of DLB when alive and to be treated with cholinesterase inhibitors.

Why does the agonist [18F]FP-TZTP bind preferentially to the M2 muscarinic receptor?

PURPOSE

Preferential binding of FP-TZTP at the M(2) receptor in vivo led to investigation of [(18)F]FP-TZTP as a potential PET tracer for Alzheimer's disease, in which a substantial reduction of M(2) receptors has been observed in autopsy studies. We hereby investigated in vitro the FP-TZTP behavior to further elucidate the properties of FP-TZTP that lead to its M(2) selectivity.

METHODS

Chinese hamster ovarian cells expressing the five subtypes of human muscarinic receptor as well as the wild type were harvested in culture to assess equilibrium binding. Specific binding was calculated by subtraction of non-specific binding from total binding. Internal specific binding was calculated by subtraction of external specific binding from the total specific binding. Saturation assays were also performed to calculate B(max), K(i), and IC(50). In addition, equilibrium binding and dissociation kinetic studies were performed on rat brain tissue. Selected regions of interest were drawn on the digital autoradiograms and [(18)F]FP-TZTP off-rates were determined by measurement of the rate of release into a buffer solution of [(18)F]FP-TZTP from slide-bound cells that had been preincubated with [(18)F]FP-TZTP.

RESULTS

At equilibrium in vitro, M(2) subtype selectivity of [(18)F]FP-TZTP was not evident. We demonstrated that ATP-dependent mechanisms are not responsible for FP-TZTP M(2) selectivity. In vitro off-rate studies from rat brain tissue showed that the off-rate of FP-TZTP varied with the percentage of M(2) subtype in the tissue region.

CONCLUSION

The slower dissociation kinetics of FP-TZTP from M(2) receptors compared with the four other muscarinic receptor subtypes may be a factor in its M(2) selectivity.

Assessing cell trafficking by noninvasive imaging techniques: applications in experimental tumor immunology

Tracer methods are increasingly being exploited to examine the trafficking patterns of cells transferred into recipient models of diseases, to optimize immune cell therapies, and to assess cancer gene therapy and vaccines in various cancer models. In animal cancer models, noninvasive monitoring by imaging tumor response could significantly facilitate the development of immune cell therapies against cancer. Currently, ex vivo lymphocyte labeling is primarily done by direct labeling. Major advances in cell labeling procedures have led to the use of reporter constructs to assess gene expression in vivo. With this novel technique, the reporter gene marks the cell with a specific protein that distinguishes the cell and its cellular progeny from other cells after migration, homing and mitosis. Several in vivo imaging procedures, including positron emission tomography, single photon emission tomography and magnetic resonance imaging, have been rescaled for studies in small animals. Other methods initially used for in vitro bioluminescence and fluorescence studies have also been refined for in vivo studies. When combined, these methods allow to assess cell trafficking in a noninvasive fashion, beyond lymphocyte response to inflammation, including metastatic diffusion and stem cell transplantation.

Accuracy and clinical correlates of two different methods for chromogranin A assay in neuroendocrine tumors

Measurement of chromogranin A (CgA) plays a major role in the management of neuroendocrine tumors (NET); however, reliable assaying of CgA is made difficult by the rapid hydrolysis following its release into the bloodstream. This study was aimed at the assessment of two assays for CgA in NET patients. CgA was measured in 93 patients by means of an enzyme-linked immunosorbent assay (ELISA) and an immunoradiometric assay (IRMA). The specificity and sensitivity of CgA were evaluated in relation to tumor histology. The clinical accuracy of the two assays was evaluated by receiver-operating characteristic (ROC) curve analysis. Regression analysis demonstrated different immunoreactivity for CgA of the antibodies used in the two kits (r = 0.61). The two assays had different accuracy also in classifying patients according to their clinical condition (91% vs 64% specificity and 79% vs 79% sensitivity for the ELISA and IRMA assay, respectively) and tumor histology (81% vs 85% sensitivity for the ELISA and IRMA assays, respectively, in carcinoids; 92% vs 67% sensitivity for the ELISA and IRMA assays, respectively, in pancreatic islet cell tumors). The different clinical accuracy of the two assays was confirmed by the ROC analysis (AUC = 0.90 vs AUC = 0.87 for the ELISA and IRMA assays, respectively). In conclusion, because of the poor standardization of the commercially available measurement tools the clinical accuracy of CgA measurement depends on the assay used. This makes it difficult to compare CgA values measured with different kits and affects the clinical accuracy of the different assays for CgA.

The use of standardized uptake values for assessing FDG uptake with PET in oncology: a clinical perspective

Among clinicians who use positron emission tomography (PET), the standardized uptake value (SUV) is a popular semi-quantitative value that can be easily assessed whenever a PET study is performed under physiological and pathological conditions. It provides an index of regional tracer uptake normalized to the administered dose of tracer. The simplicity of SUV assessment contrasts with the complexity of full quantitative procedures requiring blood sampling and possibly dynamic scanning, which limits patient throughput and significantly increases the workload of a PET centre. Two main clinical conditions/variables affect the significance and usefulness of the SUV: the type and stage of the disease being assessed. Diagnosis, prognosis and therapy monitoring represent the possible uses of SUV. In the above clinical conditions an SUV may provide information about the single lesion in which it is assessed, but the utility of such information depends largely on its integration with all the available clinical and instrumental data.

Comparative evaluation of two methods to assay thyroglobulin serum concentrations in patients with differentiated thyroid carcinomas

AIM

This study was aimed at the comparative assessment of the analytical and clinical performances of 2 tests for thyroglobulin (Tg) assays: the Dynotest Tg-Plus immunoradiometric assay (IRMA), a new method that might be of interest for its claimed superior sensitivity compared to other methods, and the HTGK-2 IRMA, one of the test currently used in clinical routine.

METHODS

The study was performed in serum samples from 157 patients with differentiated thyroid carcinoma (DTC). The clinical sensitivity of the test was evaluated in patients with and without thyroid stimulating hormone (TSH) suppression.

RESULTS

The lowest detectable Tg concentration values and the within-assay coefficient of variation (CV) were 0.4 and 0.8 microg/L and 5% and 3% for the Dynotest Tg-Plus assay and the HTGK-2 assay, respectively; the between-assay CV was 6% for both assays. The clinical results of the Dynotest Tg-Plus and those of the HTGK-2 kit were similar in both DTC patient populations, either under or off the TSH suppressive treatment. In spite of the manufacturer's statement that the calibrators of both assays had been standardized against the same common reference (standard CRM 457 of the Community Bureau of References), the Dynotest Tg-Plus test underrated by a factor of 0.5 the Tg values measured by means of HTGK-2 IRMA.

CONCLUSION

The sensitivity of the Dynotest Tg-Plus IRMA appears to be similar to that of the HTGK-2 assay.

Position of nuclear medicine techniques in the diagnostic work-up of brain tumors

Although any patient with a suspected brain tumor, either primary or metastatic, should be studied with anatomic imaging modalities such as angiography, computerized tomagraphy (CT) or magnetic resonance imaging (MRI), nuclear medicine techniques are available to further characterize some biological features of brain lesions and help in diagnosis and therapy planning. Bloob-brain-barrier disruption can be easily assessed with single-photon emission tomography (SPET), whereas focal metabolic changes can be better demonstrated by positron emission tomography (PET) as specific radiopharmaceuticals are available to detect changes in glucose utilization and aminoacid uptake with this technique. Expression of specific tumoral antigens is the basis of imaging with radioimmunoscintigraphy, a promising technique that can be applied to brain tumor therapy. The major clinical applications of nuclear medicine in the study of brain tumors -- evaluation of the extension of a tumoral mass, differential diagnosis and evaluation of therapy and prognosis -- are discussed.

Economic analyses on the use of positron emission tomography for the work-up of solitary pulmonary nodules and for staging patients with non-small-cell-lung-cancer in Italy

AIM

Increasing ageing of the population and tumor incidence, along with worldwide rationing of the resources for public health systems, spur the use of economic analyses for the choice of strategies and technologies in the assessment and management of cancer patients. Incidence and clinical managing of tumors vary in different countries even if positron emission tomography (PET) with 2-deoxy-2-[18F]-fluoro-D-glucose (FDG) is becoming a routine clinical method for diagnosis, staging, treatment monitoring and follow-up in a variety of tumors. Available data indicate that PET can be considered a superior alternative or complementary tool to other well-established methods. However, in spite of the above and of the rapidly increasing number of PET centers in Europe, USA and Japan, only a few studies have dealt with some of the economic aspects raised by the clinical use of PET because of differences in values of reimbursements and health costs. The main aim of this study is to propose and discuss an economic model of analysis for PET applications in the field of detection and management of pulmonary tumors.

METHODS

In this study 2 assessments were performed by decision tree analysis on the economic impact of the availability of PET on decision-making processes for 2 conditions: solitary pulmonary nodules assessment and non-small-cell lung cancer (NSCLC) staging. In order to define a methodology consistent with the system of reimbursement and the prevalent clinical views of the Italian National Health Service, data on costs, death probability, and life expectancy were gathered from the literature and from the Italian system of reimbursement (ROD-DRGs).

RESULTS

The results of the cost minimization analysis demonstrate that the use of PET in the diagnostic path for the workup of patients with SPN reduces the overall diagnostic costs, by approximately 50 Euro per patient, by reducing inappropriate invasive diagnostic investigation and their complications. The results of the cost effectiveness analysis demonstrate that the use of PET in the diagnostic path for the staging of patients with NSCLC reduces the overall diagnostic costs by approximately 108 Euro for added year, by reducing inappropriate surgical interventions and their complications.

CONCLUSION

Both analyses are based on standard methods used in the literature, so our conclusions can be compared with results and assessments of similar studies in different countries and health care systems. Also in the Italian case, the use of an economic assessment provides relevant information on the efficacy and effectiveness of PET.

The feasibility of statistical parametric mapping for the analysis of positron emission tomography studies using 11C-2-beta-carbomethoxy-3-beta-(4-fluorophenyl)-tropane in patients with movement disorders

Movement disorders, including Parkinson's disease and parkinsonian syndromes, e.g. progressive supranuclear palsy, multiple system atrophy, and Lewy body dementia, may be difficult to differentiate among each other at an early stage, since they may share similar clinical features and response to dopaminergic drugs. As new tracers for imaging the dopamine transporters become available, the use of positron emission tomography (PET) for the differential diagnosis of movement disorders is gaining clinical relevance. Visual interpretation is generally used for PET image analysis. However, the use of some form of less subjective analysis is desirable in order to detect subtle changes that may be difficult to identify by visual interpretation and to achieve an operator independent analysis. To this end this study was aimed at assessing the feasibility of using statistical parametric mapping (SPM) for the clinical evaluation of single PET scans performed with 2-beta-carbomethoxy-3-beta-(4-fluorophenyl)-tropane ( C-beta-CIT-FE). Eleven healthy volunteers and five patients with movement disorders (Parkinson's disease, essential tremor, PSP and Lewy body dementia) were included in this study. Each subject underwent a PET study after i.v. injection of C-beta-CIT-FE. The PET images of C-beta-CIT-FE distribution acquired between 60 and 90 min were spatially fitted into the Talairach and Tournoux space. A template of normal C-beta-CIT-FE distribution was derived from studies in the 11 normal control subjects. Different patterns of reduction of the uptake of the tracer were detected in the basal ganglia of the five patients, in relation to each pathological condition. The patterns of distribution were all consistent with the severity and type of disease. The results of this study demonstrate the feasibility of differentiating among different states of dopaminergic impairment, due to Parkinson's disease and parkinsonian syndromes, by using PET scans with C-beta-CIT-FE and by using the SPM procedure for analysis of the data.

Anatomical and biochemical investigation of primary brain tumours

Cancerous transformation entails major biochemical changes including modifications of the energy metabolism of the cell, e.g. utilisation of glucose and other substrates, protein synthesis, and expression of receptors and antigens. Tumour growth also leads to heterogeneity in blood flow owing to focal necrosis, angiogenesis and metabolic demands, as well as disruption of transport mechanisms of substrates across cell membranes and other physiological boundaries such as the blood-brain barrier. All these biochemical, histological and anatomical changes can be assessed with emission tomography, X-ray computed tomography (CT), magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS). Whereas anatomical imaging is aimed at the diagnosis of brain tumours, biochemical imaging is better suited for tissue characterisation. The identification of a tumoural mass and the assessment of its size and vascularisation are best achieved with X-ray CT and MRI, while biochemical imaging can provide additional information that is crucial for tumour classification, differential diagnosis and follow-up. As the assessment of variables such as water content, appearance of cystic lesions and location of the tumour are largely irrelevant for tissue characterisation, a number of probes have been employed for the assessment of the biochemical features of tumours. Since biochemical changes may be related to the growth rate of cancer cells, they can be thought of as markers of tumour cell proliferation. Biochemical imaging with radionuclides of processes that occur at a cellular level provides information that complements findings obtained by anatomical imaging aimed at depicting structural, vascular and histological changes. This review focusses on the clinical application of anatomical brain imaging and biochemical assessment with positron emission tomography, single-photon emission tomography and MRS in the diagnosis of primary brain tumours, as well as in follow-up.

Cardiovascular outcomes after kidney-pancreas and kidney-alone transplantation

BACKGROUND

This study retrospectively assessed, with an intention-to-treat analysis, the effect of kidney-pancreas transplantation (KP) on survival and cardiovascular outcome in type 1 diabetic uremic patients.

METHODS

A total of 351 uremic type 1 diabetic patients were enrolled on a waiting list for KP: 130 underwent KP transplantation, 25 underwent kidney transplantation alone (KA), whereas 196 patients remained on dialysis (WL). The three populations had similar cardiovascular conditions. Actuarial survival rates and causes of death were recorded over a period of seven years. Finally, 23 KP and 13 KA patients underwent left radionuclide ventriculography, during a follow-up of four years.

RESULTS

In the entire group of 351 patients the seven-year survival rate was 77.4% for KP, 56.0% for KA and 39.6% for WL (KP vs. WL, P = 0.01). Cardiovascular death rate was 7.6% in KP, 20.0% in KA and 16.1% in WL (KP versus WL, P = 0.03; KP vs. KA, P = 0.16). In the subsample studied with radionuclide ventriculography, left ventricular ejection fraction improved in KP, but did not in KA, with significant differences between groups at two and four years. At four years only the KP patients presented normal values of diastolic parameters, including the peak filling rate, time-to-peak filling rate, and peak filling rate/peak ejection rate ratio. Glycated hemoglobin was negatively associated with the ejection fraction, peak filling rate and peak filling rate/peak ejection rate ratio, and positively associated with the time-to-peak filling rate.

CONCLUSIONS

Normalization of blood glucose metabolism and improvement of blood pressure control obtained with KP transplant is associated with positive effects on survival, cardiovascular death rate, and left ventricular function.