Handbook of clinical neurology
January 1, 2025
G Bryan Young, Loretta Norton
Consciousness depends on the brain and has two main aspects: wakefulness and awareness. Awareness includes perception, abstract thought, selection, judgment, motivation, and emotion. The brain can process information and influence behavior without conscious awareness. Advances in science and technology have deepened understanding of the neural functions and brain region interactions underlying conscious experience. Studies of disorders from brain death to delirium have shaped knowledge of regional and global brain functions. Behavioral responses alone are insufficient to determine conscious level; some unresponsive-wakeful patients retain cognitive capacity detectable by fMRI and electrophysiology. Much remains unknown about how full awareness and self-awareness arise and how best to assess and manage disorders of consciousness.
Handbook of clinical neurology
January 1, 2026
Amos D Korczyn, Lea Tenenholz Grinberg
The brainstem is essential for wakefulness, sleep regulation, and consciousness, orchestrating alertness via the ascending reticular activating system, which integrates sensory information and projects to the cortex. Consciousness arises from intricate brainstem interactions, though the brainstem alone does not generate it. Brainstem lesions produce clinical syndromes that distinguish wakefulness, alertness, and consciousness. Disorders such as sleep paralysis, parasomnias, vegetative state, minimally conscious state, coma, and locked-in syndrome illustrate how brainstem dysfunction affects consciousness and behavior. Unique states like lucid dreaming and hypnagogia reveal a distinct form of internally directed consciousness, termed consciousness II, highlighting the brainstem's essential role in the neural network underlying human consciousness and cognitive function.
Handbook of clinical neurology
January 1, 2022
Ikuo Homma, Anthony G Phillips
Breathing can be classified into metabolic and behavioral categories, with metabolic and voluntary behavioral breathing controlled in the brainstem and cerebral motor cortex, respectively. This chapter emphasizes the reciprocal influences between breathing and emotional processes. Emotions are generated by multiple forebrain control networks, and a respiratory rhythm generator has been investigated in the limbic system. The amygdala receives respiratory-related input from the piriform cortex, where excitatory recurrent branches produce periodic oscillations similar to those in the hippocampus during slow-wave sleep.
Handbook of clinical neurology
January 1, 2019
Ambra Stefani, Evi Holzknecht, Birgit Högl
REM sleep behavior disorder (RBD), sleep paralysis, and nightmare disorder are the three REM sleep parasomnias. Most neurophysiologic research has focused on RBD, with fewer studies on nightmare disorder or isolated sleep paralysis. Studies primarily used polysomnography (PSG) or animal models to understand pathophysiology, while fewer employed electroencephalography, electromyography outside PSG, evoked potentials, or autonomic assessments. The chapter describes key neurophysiologic findings and their implications.
Handbook of clinical neurology
January 1, 2016
Q Deeley
Suggestion—the intentional communication of beliefs or ideas to produce convincing changes in experience and behavior—has been used to treat functional neurologic symptoms since hypnosis was first described in the 19th century. Hypnosis derived from earlier healing practices, including animal magnetism and exorcism, which involved unintentionally suggestive stimuli. Nineteenth-century practitioners used hypnosis, imperative commands, medical clairvoyance, and suggestion without hypnosis. Modern treatments combine suggestion with cognitive-behavioral, rehabilitative, or psychodynamic therapy. The evidence base consists mostly of case studies and series, with few randomized controlled trials. The concept of suggestion highlights how clinical interactions can alter patients' expectancies and beliefs, influencing symptom onset, course, and remission.