Brainstem dysfunction in critically ill patients

Abstract

The brainstem conveys sensory and motor inputs between the spinal cord and the brain, and contains nuclei of the cranial nerves. It controls the sleep-wake cycle and vital functions via the ascending reticular activating system and the autonomic nuclei, respectively. Brainstem dysfunction may lead to sensory and motor deficits, cranial nerve palsies, impairment of consciousness, dysautonomia, and respiratory failure. The brainstem is prone to various primary and secondary insults, resulting in acute or chronic dysfunction. Of particular importance for characterizing brainstem dysfunction and identifying the underlying etiology are a detailed clinical examination, MRI, neurophysiologic tests such as brainstem auditory evoked potentials, and an analysis of the cerebrospinal fluid. Detection of brainstem dysfunction is challenging but of utmost importance in comatose and deeply sedated patients both to guide therapy and to support outcome prediction. In the present review, we summarize the neuroanatomy, clinical syndromes, and diagnostic techniques of critical illness-associated brainstem dysfunction for the critical care setting.

Early discrimination of cognitive motor dissociation from disorders of consciousness: pitfalls and clues

“…Earlier studies from our group suggested that the MBT, which detects subtle motor behaviors missed by the CRS-R, can clinically discriminate patients with potential [19,20] Cranial nerve palsies Imaging (MRI)-brain-stem nuclear or nerve lesions Non convulsive status epilepticus Staring, eye deviations, neglect, myoclonus EEG-epileptic potentials Cortical blindness [12,13] Absence of visual interaction, absence of menace reflex, absence of visual pursuit Imaging (MRI)-bilateral occipital lesions Akinetic (frontal) Syndrome [18] Marked reduction of spontaneous movement and speech production with inconstant visual fixation and tracking, inconstant commandfollowing and vocalization…”

Hemodynamic response during endotracheal suctioning predicts awakening and functional outcome in subarachnoid hemorrhage patients

“…4 The increase of mean arterial pressure (MAP) during endotracheal suctioning (total N = 1080 episodes) was not significantly different across patients with good or poor outcome (P > 0.2). mRS, modified Rankin Scale Score value of comatose patients [29]. In a recent study conducted in patients after cardiac arrest, reduced quantitative pupillary light reflex performed well in mortality prediction [30].…”

“…Surface EEG in unresponsive patients may help to identify patients with brain activity despite missing motor behavior [3]. Besides that, neurophysiological studies with evoked potentials and brain imaging such as MRI are used to estimate patients' outcomes [29]. Testing of ANS is a further cornerstone in prognostication of severely brain-injured patients.…”

Single Virus Targeting Multiple Organs: What We Know and Where We Are Heading?

“…Measuring the peripheral oxygen level is very important for any COVID-19 patient, as several reports suggest patients with minimal symptoms but with very critical oxygen level (49,50). Brainstem dysfunction also results in altered sleep-wake cycles and compromised autonomous control of the immune, circulatory, digestive, and respiratory systems (51). Brain inflammation encephalitis accompanied with seizures has also been reported (52).…”