Encoding of Oscillations by Axonal Bursts in Inferior Olive Neurons

Inferior olive neurons regulate plasticity and timing in the cerebellar cortex via the climbing fiber pathway, but direct characterization of the output of this nucleus has remained elusive. We show that single somatic action potentials in olivary neurons are translated into a burst of axonal spikes. The number of spikes in the burst depends on the phase of subthreshold oscillations and, therefore, encodes the state of the olivary network. These bursts can be successfully transmitted to the cerebellar cortex in vivo, having a significant impact on Purkinje cells. They enhance dendritic spikes, modulate the complex spike pattern, and promote short-term and long-term plasticity at parallel fiber synapses in a manner dependent on the number of spikes in the burst. Our results challenge the view that the climbing fiber conveys an all-or-none signal to the cerebellar cortex and help to link learning and timing theories of olivocerebellar function

Delirium detection using relative delta power based on 1 minute single-channel EEG : a multicentre study

Background: Delirium is frequently unrecognised. EEG shows slower frequencies (i.e. below 4 Hz) during delirium, which might be useful in improving delirium recognition. We studied the discriminative performance of a brief single-channel EEG recording for delirium detection in an independent cohort of patients. Methods: In this prospective, multicentre study, postoperative patients aged ≥60 yr were included (n=159). Before operation and during the first 3 postoperative days, patients underwent a 5-min EEG recording, followed by a video-recorded standardised cognitive assessment. Two or, in case of disagreement, three delirium experts classified each postoperative day based on the video and chart review. Relative delta power (1–4 Hz) was based on 1-min artifact-free EEG. The diagnostic value of the relative delta power was evaluated by the area under the receiver operating characteristic curve (AUROC), using the expert classification as the gold standard. Results: Experts classified 84 (23.3%) postoperative days as either delirium or possible delirium, and 276 (76.7%) non-delirium days. The AUROC of the relative EEG delta power was 0.75 [95% confidence interval (CI) 0.69–0.82]. Exploratory analysis showed that relative power from 1 to 6 Hz had significantly higher AUROC (0.78, 95% CI 0.72–0.84, P=0.014). Conclusions: Delirium/possible delirium can be detected in older postoperative patients based on a single-channel EEG recording that can be automatically analysed. This objective detection method with a continuous scale instead of a dichotomised outcome is a promising approach for routine detection of delirium. Clinical trial registration: NCT02404181

Delirium detection using relative delta power based on 1 minute single-channel EEG : a multicentre study

Background: Delirium is frequently unrecognised. EEG shows slower frequencies (i.e. below 4 Hz) during delirium, which might be useful in improving delirium recognition. We studied the discriminative performance of a brief single-channel EEG recording for delirium detection in an independent cohort of patients. Methods: In this prospective, multicentre study, postoperative patients aged ≥60 yr were included (n=159). Before operation and during the first 3 postoperative days, patients underwent a 5-min EEG recording, followed by a video-recorded standardised cognitive assessment. Two or, in case of disagreement, three delirium experts classified each postoperative day based on the video and chart review. Relative delta power (1–4 Hz) was based on 1-min artifact-free EEG. The diagnostic value of the relative delta power was evaluated by the area under the receiver operating characteristic curve (AUROC), using the expert classification as the gold standard. Results: Experts classified 84 (23.3%) postoperative days as either delirium or possible delirium, and 276 (76.7%) non-delirium days. The AUROC of the relative EEG delta power was 0.75 [95% confidence interval (CI) 0.69–0.82]. Exploratory analysis showed that relative power from 1 to 6 Hz had significantly higher AUROC (0.78, 95% CI 0.72–0.84, P=0.014). Conclusions: Delirium/possible delirium can be detected in older postoperative patients based on a single-channel EEG recording that can be automatically analysed. This objective detection method with a continuous scale instead of a dichotomised outcome is a promising approach for routine detection of delirium. Clinical trial registration: NCT02404181

The Cerebellum, Cerebellar Disorders, and Cerebellar Research—Two Centuries of Discoveries

Research on the cerebellum is evolving rapidly. The exquisiteness of the cerebellar circuitry with a unique geometric arrangement has fascinated researchers from numerous disciplines. The painstaking works of pioneers of these last two centuries, such as Rolando, Flourens, Luciani, Babinski, Holmes, Cajal, Larsell, or Eccles, still exert a strong influence in the way we approach cerebellar functions. Advances in genetic studies, detailed molecular and cellular analyses, profusion of brain imaging techniques, emergence of behavioral assessments, and reshaping of models of cerebellar function are generating an immense amount of knowledge. Simultaneously, a better definition of cerebellar disorders encountered in the clinic is emerging. The essentials of a trans-disciplinary blending are expanding. The analysis of the literature published these last two decades indicates that the gaps between domains of research are vanishing. The launch of the society for research on the cerebellum (SRC) illustrates how cerebellar research is burgeoning. This special issue gathers the contributions of the inaugural conference of the SRC dedicated to the mechanisms of cerebellar function. Contributions were brought together around five themes: (1) cerebellar development, death, and regeneration; (2) cerebellar circuitry: processing and function; (3) mechanisms of cerebellar plasticity and learning; (4) cerebellar function: timing, prediction, and/or coordination? (5) anatomical and disease perspectives on cerebellar function.Historical ArticleJournal ArticleReviewSCOPUS: re.jinfo:eu-repo/semantics/publishe