Objective: Large aperiodic bursts of activations named neuronal avalanches have been used to characterize whole-brain activity, as their presence typically relates to optimal dynamics. Epilepsy is characterized by alterations in large-scale brain network dynamics. Here we exploited neuronal avalanches to characterize differences in electroencephalography (EEG) basal activity, free from seizures and/or interictal spikes, between patients with temporal lobe epilepsy (TLE) and matched controls. Method:We defined neuronal avalanches as starting when the z-scored sourcereconstructed EEG signals crossed a specific threshold in any region and ending when all regions returned to baseline. This technique avoids data manipulation or assumptions of signal stationarity, focusing on the aperiodic, scale-free components of the signals. We computed individual avalanche transition matrices to track the probability of avalanche spreading across any two regions, compared them between patients and controls, and related them to memory performance in patients. Results:We observed a robust topography of significant edges clustering in regions functionally and structurally relevant for the TLE, such as the entorhinal cortex, the inferior parietal and fusiform area, the inferior temporal gyrus, and the anterior cingulate cortex. We detected a significant correlation between the centrality of the entorhinal cortex in the transition matrix and the long-term memory performance (delay recall Rey-Osterrieth Complex Figure Test). Significance: Our results show that the propagation patterns of large-scale neuronal avalanches are altered in TLE during the resting state, suggesting a potential diagnostic application in epilepsy. Furthermore, the relationship between specific patterns of propagation and memory performance support the neurophysiological relevance of neuronal avalanches.

The pancreas is easily investigated in children thanks to the relative lack of fat tissue and the large left hepatic lobe with an optimal acoustic window. The use of high frequency, even linear transducers, usually results in detailed images of all pancreatic areas. A wide spectrum of pancreatic pathologic conditions can be identified and monitored at ultrasound although they are relatively uncommon during childhood compared to the adult. In this paper we briefly review the anatomy, technique, and sonographic aspects of normal and pathological pediatric pancreas. Keywords Pancreas • Children • Ultrasound SommarioLo studio ecografico del pancreas in età pediatrica è molto performante grazie alla scarsa presenza di tessuto adiposo sottocutaneo e all'ipertrofia della piccola ala epatica che fornisce una ottimale finestra acustica. L'utilizzo di sonde ad alta frequenza, spesso con il ricorso a trasduttori lineari, consente di ottenere un buon dettaglio anatomico di tutta la regione pancreatica. Diverse sono le patologie che interessano il pancreas in questa fascia di età e che possono essere identificate e monitorizzate con l'indagine ecografica sebbene siano relativamente poco comuni rispetto all'adulto. In questo articolo descriviamo l'anatomia, la tecnica di indagine e gli aspetti ecografici normali e patologici della ghiandola pancreatica in età pediatrica.

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Objective Large aperiodic bursts of activations named neuronal avalanches have been used to characterize whole-brain activity, as their presence typically relates to optimal dynamics. Epilepsy is characterized by alterations of large-scale brain network dynamics. Here, we exploited neuronal avalanches to characterize differences in the electroencephalography (EEG) basal activity, free from seizures and/or interictal spikes, between patients with temporal lobe epilepsy (TLE) and matched controls. Method We defined neuronal avalanches as starting when the z-scored source-reconstructed EEG signals crossed a specific threshold in any region and ending when all regions went back to baseline. This technique avoids data manipulation or assumptions of signal stationarity, focusing on the aperiodic, scale-free components of the signals. We computed individual avalanche transition matrices, to track the probability of avalanche spreading across any two regions, compared them between patients and controls, and related them to memory performance in patients. Results We observed a robust topography of significant edges clustering in regions functionally and structurally relevant for the TLE, such as the entorhinal cortex, the inferior parietal and fusiform area, the inferior temporal gyrus, and the anterior cingulate cortex. We detected a significant correlation between the centrality of the entorhinal cortex in the transition matrix and the long-term memory performance (delay recall Rey figure test). Significance Our results show that the propagation patterns of large-scale neuronal avalanches are altered in TLE during resting state, suggesting a potential diagnostic application in epilepsy. Furthermore, the relationship between specific patterns of propagation and memory performance supports the neurophysiological relevance of neuronal avalanches.

Pseudoprogression (PP) is a diagnostic dilemma in the follow-up of brain high grade gliomas (HGG), and the introduction of new therapies has further complicated its identification in Magnetic Resonance Imaging (MRI). We report a case of pseudoprogression after intraoperative radiotherapy (ioRT) and Regorafenib therapy in a patient with anaplastic astrocytoma recurrence. A 65-year-old man, treated in August 2017 for a right frontal anaplastic astrocytoma, with surgical resection and following radiotherapy and Temozolomide, in October 2019 was again treated for peri-surgical bed recurrence with resection and ioRT followed by Regorafenib therapy, interrupted in February 2020, after the onset of adverse reactions. MRI examination showed a large irregular alteration posterior to the surgical bed, T2 weighted hypointense featuring strong diffusion restriction (low ADC values), with an irregular contrastenhancement (CE) pattern, and surrounded by a vast vasogenic oedema; Dynamic Susceptibility Contrast (DSC) perfusion imaging (PWI) showed no increase of relative cerebral blood volume (rCBV). Particularly, lesion appeared markedly hypointense and dusty-like on susceptibility weighted images (SWI) probably due to a constant hemorrhagic diapedesis promoted by Regorafenib. Therefore, pseudoprogression was suspected. Follow-up MRI exams showed gradual reduction of SWI and CE abnormalities, but a persistent DWI restriction. Unfortunately, the last MRI control showed a secondary cerebellar localisation of the disease. New therapies are changing MRI pattern in HGG imaging and this case underlines how a multimodality approach is increasingly necessary. In particular, when using anti-VEGF drugs, SWI can have a crucial role in identifying therapy-related haemorrhagic changes.