Hans Berger (1873-1941)

Cycling reduces the entropy of neuronal activity in the human adult cortex

Brain Complexity (BC) have successfully been applied to study the brain electroencephalographic signal (EEG) in health and disease. In this study, we employed recurrence entropy to quantify BC associated with the neurophysiology of movement by comparing BC in both resting state and cycling movement. We measured EEG in 24 healthy adults and placed the electrodes on occipital, parietal, temporal and frontal sites on both the right and left sides of the brain. We computed the recurrence entropy from EEG measurements during cycling and resting states. Entropy is higher in the resting state than in the cycling state for all brain regions analysed. This reduction in complexity is a result of the repetitive movements that occur during cycling. These movements lead to continuous sensorial feedback, resulting in reduced entropy and sensorimotor processing.

Berger and the Breakthrough: A Centennial Celebration of the Human Electroencephalogram

A century ago, it was a challenge for neuroscientists to decipher the mysteries of human brain functioning until German psychiatrist Hans Berger discovered what is now one of the most well-known electrophysiological recording techniques to examine brain function, EEG. He is rightly regarded as the Father of The Electroencephalogram (EEG), since he performed the first human electroencephalogram in 1924. Berger attempted to investigate the connection between psychology and physiology and to solve the "psychic energy" enigma. Despite turbulence in his professional life and slow progress in his research, he persevered and succeeded in giving humankind an indispensable technique that is now widely used in clinical and research practice. His publications on EEG provide valuable insight into our current understanding of several of the brain's responses to physiological and pathological phenomena. In July 2024, it will be 100 years since Berger recorded the first human EEG, and that calls for a celebration among EEG researchers, neuroscientists, psychiatrists, and neurologists. This article presents a brief account of his journey and commemorates Hans Berger's contributions to the field of neurodiagnostics.

An appraisal to Hans Berger by the time of his 150th birthday: the human EEG and tales of blood flow, heat and brain waves

More than 100 years of research have passed by and still the human electroencephalogram (EEG) remains a puzzle to be solved. Starting from his studies on plethysmography until his theories on brain thermodynamics, Hans Berger was able to refine his method of recording cortical signs with the apparatus at his disposal in an ordinary neuropsychiatric yard towards an early account of human EEG. This review is an appraisal of his contribution to the field of modern neurophysiology.

Sleep Neurology's Toolkit at the Crossroads: Challenges and Opportunities in Neurotherapeutics Lost and Found in Translation

We find ourselves at our present crossroads with a well-traveled toolkit, perhaps too well worn but with aspirational hopes and dreams for the field of sleep neurotherapeutics. This volume is organized thematically into six topical domains that parallel the major subspecialty areas of contemporary clinical sleep neurology practice, as well as novel directions and opportunities. The issue begins with an overview of the central disorders of hypersomnolence, including narcolepsy, idiopathic hypersomnia and other hypersomnia disorders, and the related use of the entire broad range of stimulant and wake-promoting pharmacotherapies. Next, the range of behavioral therapies, application of light and light restriction and melatonin therapies, and hypnotic pharmacotherapies useful in insomnia and circadian sleep-wake rhythm disorders are reviewed, followed by an overview of treatment options for sleep-related breathing disorders including positive airway pressure and the novel approach of hypoglossal neurostimulation for obstructive sleep apnea. The parasomnias and sleep-related movement disorders, including NREM disorders of arousal, REM parasomnias (nightmares and isolated sleep paralysis and idiopathic/isolated REM sleep behavior disorder, and restless legs syndrome are then discussed, and the applications of sleep neurotherapeutics in sleep and neurological disease are reviewed, including neurodevelopmental, epileptic, autoimmune encephalopathies, and neurodegenerative diseases. Last, the novel directions and opportunities in sleep neurology offered by cannabinoid therapies and machine learning/artificial intelligence methodology conclude this comprehensive survey of contemporary sleep neurology. We hope that you find this volume to be a useful and inspirational support tool for the work that matters most, your care of all our sleep neurology patients in the clinics.

Cerebral Cortical Activity Following Non-invasive Cerebellar Stimulation-a Systematic Review of Combined TMS and EEG Studies

The cerebellum sends dense projections to both motor and non-motor regions of the cerebral cortex via the cerebellarthalamocortical tract. The integrity of this tract is crucial for healthy motor and cognitive function. This systematic review examines research using transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS) to the cerebellum with combined cortical electroencephalography (EEG) to explore the temporal features of cerebellar-cortical connectivity. A detailed discussion of the outcomes and limitations of the studies meeting review criteria is presented. Databases were searched between 1 December 2017 and 6 December 2017, with Scopus alerts current as of 23 July 2019. Of the 407 studies initially identified, 10 met review criteria. Findings suggested that cerebellar-cortical assessment is suited to combined TMS and EEG, although work is required to ensure experimental procedures are optimal for eliciting a reliable cerebellar response from stimulation. A distinct variation in methodologies and outcome measures employed across studies, and small sample sizes limited the conclusions that could be drawn regarding the electrophysiological signatures of cerebellar-cortical communication. This review highlights the need for stringent protocols and methodologies for cerebellar-cortical assessments via combined TMS and EEG. With these in place, combined TMS and EEG will provide a valuable means for exploring cerebellar connectivity with a wide range of cortical sites. Assessments have the potential to aid in the understanding of motor and cognitive function in both healthy and clinical groups, and provide insights into long-range neural communication generally.

A Mixed Methods Exploration of Electrical Stimulation in Veterans with Fibromyalgia Symptoms & Affective Disorders

INTRODUCTION

Past research has shown that electrical stimulation has modest beneficial effects on symptoms of fibromyalgia, which is also commonly associated with anxiety and depression. The purpose of the current study was to evaluate the effectiveness and utilization of electrical stimulation (AID or M units) at-home by Veterans.

METHODS

Sixty Veterans were identified using the Fibromyalgia Symptoms Questionnaire for an electrical stimulation trial during January 1-December 31, 2016 at a Midwestern VA Medical Center. Each patient completed a brief, semi-structured phone interview, which included an inquiry about the benefits of the units on affective symptoms.

RESULTS

Quantitative findings suggest that participants who were given any kind of unit (AID or M units) did not have a significant change in pain level from baseline to follow-up. Participants who were given any kind of unit (AID or M units) did not report a significant change in anxiety, depressive, or insomnia symptoms from baseline to follow-up. Qualitative findings produced three thematic maps: utilization, effectiveness, and satisfaction.

LIMITATIONS

This study used a quasi-experimental, one group, pre-/post-test design, and explored the benefits of programming when based on patient self-selection. The instruments used in this study were self-report measures, and the lack of change may have been due to the use of binary versus continuous measures. The findings may differ among other Veterans as the current sample had a larger representation of minority groups compared to the typical Veteran profile.

CONCLUSIONS

This information is invaluable in helping patients who suffer from fibromyalgia symptoms and affective disorders and for the providers aiding in their treatment.

Do Brain Oscillations Orchestrate Memory?

Rhythmicity and oscillations are common features in nature, and can be seen in phenomena such as seasons, breathing, and brain activity. Despite the fact that a single neuron transmits its activity to its neighbor through a transient pulse, rhythmic activity emerges from large population-wide activity in the brain, and such rhythms are strongly coupled with the state and cognitive functions of the brain. However, it is still debated whether the oscillations of brain activity actually carry information. Here, we briefly introduce the biological findings of brain oscillations, and summarize the recent progress in understanding how oscillations mediate brain function. Finally, we examine the possible relationship between brain cognitive function and oscillation, focusing on how oscillation is related to memory, particularly with respect to state-dependent memory formation and memory retrieval under specific brain waves. We propose that oscillatory waves in the neocortex contribute to the synchronization and activation of specific memory trace ensembles in the neocortex by promoting long-range neural communication.

Spontaneous activity forms a foundation for odor-evoked activation maps in the rat olfactory bulb

Fluctuations in spontaneous activity have been observed by many neuroimaging techniques, but because these resting-state changes are not evoked by stimuli, it is difficult to determine how they relate to task-evoked activations. We conducted multi-modal neuroimaging scans of the rat olfactory bulb, both with and without odor, to examine interaction between spontaneous and evoked activities. Independent component analysis of spontaneous fluctuations revealed resting-state networks, and odor-evoked changes revealed activation maps. We constructed simulated activation maps using resting-state networks that were highly correlated to evoked activation maps. Simulated activation maps derived by intrinsic optical signal (IOS), which covers the dorsal portion of the glomerular sheet, significantly differentiated one odor's evoked activation map from the other two. To test the hypothesis that spontaneous activity of the entire glomerular sheet is relevant for representing odor-evoked activations, we used functional magnetic resonance imaging (fMRI) to map the entire glomerular sheet. In contrast to the IOS results, the fMRI-derived simulated activation maps significantly differentiated all three odors' evoked activation maps. Importantly, no evoked activation maps could be significantly differentiated using simulated activation maps produced using phase-randomized resting-state networks. Given that some highly organized resting-state networks did not correlate with any odors' evoked activation maps, we posit that these resting-state networks may characterize evoked activation maps associated with odors not studied. These results emphasize that fluctuations in spontaneous activity form a foundation for active processing, signifying the relevance of resting-state mapping to functional neuroimaging.

New revelations about Hans Berger, father of the electroencephalogram (EEG), and his ties to the Third Reich

Hans Berger was a German neuropsychiatrist and head of the neurology department at the University of Jena, who discovered the human electroencephalogram (EEG). Many sources state that Berger was forced into retirement and suicide by the Nazis because he was at odds with the regime. In fact, Berger helped select his Nazi successor Berthold Kihn (complicit in "euthanasia" murders), financially supported the Nazi Schutzstaffel (SS), and was a willing participant on Nazi genetic health higher courts that reviewed appeals for forced sterilizations of neuropsychiatric patients. His motivations could be related to avoiding Nazi harassment, indoctrination by Nazi ideology, or less likely, career opportunism. His actions stand in contrast to colleagues who partially resisted the Nazis, and hopefully will serve as an example to future generations of neurologists regarding the danger of allowing one's professional standing to be used as a tool to support the policies of tyranny and oppression.