Local sleep-like cortical reactivity in the awake brain after focal injury.

The functional consequences of focal brain injury are thought to be contingent on neuronal alterations extending beyond the area of structural damage. This phenomenon, also known as diaschisis, has clinical and metabolic correlates but lacks a clear electrophysiological counterpart, except for the long-standing evidence of a relative EEG slowing over the injured hemisphere. Here, we aim at testing whether this EEG slowing is linked to the pathological intrusion of sleep-like cortical dynamics within an awake brain. We used a combination of transcranial magnetic stimulation and electroencephalography (TMS/EEG) to study cortical reactivity in a cohort of 30 conscious awake patients with chronic focal and multifocal brain injuries of ischaemic, haemorrhagic and traumatic aetiology. We found that different patterns of cortical reactivity typically associated with different brain states (coma, sleep, wakefulness) can coexist within the same brain. Specifically, we detected the occurrence of prominent sleep-like TMS-evoked slow waves and off-periods-reflecting transient suppressions of neuronal activity-in the area surrounding focal cortical injuries. These perilesional sleep-like responses were associated with a local disruption of signal complexity whereas complex responses typical of the awake brain were present when stimulating the contralesional hemisphere. These results shed light on the electrophysiological properties of the tissue surrounding focal brain injuries in humans. Perilesional sleep-like off-periods can disrupt network activity but are potentially reversible, thus representing a principled read-out for the neurophysiological assessment of stroke patients, as well as an interesting target for rehabilitation

Italian registry of cardiac computed tomography

Cardiac CT (CCT) is an imaging modality that is becoming a standard in clinical cardiology. We evaluated indications, safety, and impact on patient management of routine CCT in a multicenter national registry. MATERIALS AND METHODS: During a period of 6 months, 47 centers in Italy enrolled 3,455 patients. RESULTS: CCT was performed mainly with 64-slice CT scanners (73.02 %). Contrast agents were administrated in 3,185 patients (92.5 %). Mean DLP changes with type of scanner and was lower in >64 row detector scanner. The most frequent indication for CCT was suspected CAD (44.8 %), followed by calcium scoring (9.6 %), post-angioplasty/stenting (8.3 %), post-CABGs (7.5 %), study of cardiac anatomy (4.22 %) and assessment in patients with known CAD (4.1 %) and acute chest pain (1.99 %). Most of the CCTs were performed in outpatient settings (2,549; 74 %) and a minority in inpatient settings (719, 20.8 %). Adverse clinical events (mild-moderate) occurred in 26 examinations (0.75 %). None of them was severe. In 45.3 % of the cases CCT findings impacted patient management. CONCLUSION: CCT is performed with different workloads in participating centers. It is a safe procedure and its results have a strong impact on patient management