Recovery Of Consciousness In Patients Research Articles

A Multimodal Magnetic Resonance Imaging Study of Recovery of Consciousness in Severe Traumatic Brain Injury: Preliminary Results.

Accurate and reliable assessment of the conscious state of patients with severe traumatic brain injury (TBI) is vital for their future management. The purpose of the present study is to find an effective and accurate magnetic resonance imaging (MRI) method for predicting recovery of consciousness in patients with severe TBI. Multimodal MR techniques, including structural MRI, MR spectroscopy (MRS), diffusion tensor imaging (DTI), were used to evaluate brain damage in 58 patients with severe TBI. Statistical analysis compared imaging results and recovery over a relatively long period to find the most potent prognostic indicators and predictive method. A total 33 patients gained recovery of consciousness (RC), and 25 did not (NRC). Compared with the RC group, those in the NRC group had a significantly lower N-acetylaspartate to creatine (NAA/Cr) ratio of pons (1.43 ± 0.54 vs. 1.70 ± 0.42), more fiber lines (1046.3 ± 100.8 vs. 975.6 ± 128.1), less peripheral grey matter (pgrey) (579.23 ± 78.85 vs. 638.23 ± 61.16), lower fractional anisotropy (FA) of fibers (0.42 ± 0.04 vs. 0.45 ± 0.03), older age (43.08 ± 14.61 vs. 30.57 ± 12.89), and higher apparent diffusion coefficient (ADC) of fibers (0.99 ± 0.14 vs. 0.89 ± 0.06); all p < 0.05. Age, pgrey, ADC of fibers, NAA/Cr of pons were selected by logistic regression analysis to predict RC, with p values of 0.033 and 0.031, 0.035, 0.030, respectively. Age, pgrey, ADC of fibers, NAA/Cr of pons are effective indicators in the predictive model of RC.

Factors affecting recovery of consciousness in patients with disorders of consciousness following brain trauma: a logistic regression analysis

To explore the factors that affect the recovery of consciousness in patients with disorders of consciousness following brain trauma. We analyzed the data of 114 patients with disorders of consciousness following brain trauma admitted for rehabilitation. Bilateral logistic regression analysis was used to explore the factors that affected the recovery of the patients' consciousness. A logistic regression model was established and the ROC curve was drawn to obtain the optimal threshold of the prognostic model. Univariate analysis showed that vegetative state duration (P<0.001), CRS-R scores (P<0.001), hydrocephalus (P=0.037), hypertonia (P=0.034), central fever (P=0.035), paroxysmal sympathetic hyperactivity (PSH) (P=0.004), and epilepsy seizures were correlated with the recovery of consciousness. Logistic multivariate analysis showed that central fever (OR=3.493, P=0.044), vegetative state duration (OR=1.016, P=0.008), PSH (OR=4.223, P=0.034) and CRS-R scores (OR=0.640, P=0.002) all significantly affected the recovery of consciousness. The χ2 value of the Hosmer-Lemeshow test was 10.214 (P=0.250), and the goodness of fit of this model indicated an outstanding fitting (c=0.91). The presence of PSH is the one of the most important factor followed by centric fever to affect the outcome of patients with disorders of consciousness. A lower CRS-R score and a longer duration of vegetative state also predict a poor recovery of consciousness in these patients.

Vegetative State: Difficulty in Identifying Consciousness and Predicting Outcome

Article consists of literature review, authors experience of the application of neurovisualization and neurophysiological research methods to predict the recovery of consciousness in patients in vegetative state (VS). According to the literature data PET with FDG has higher sensitivity in the detection of signs of consciousness, then functional MRI (fMRI). The method fMRI allows assessing the functional activity of the brain in a state of rest and in response to stimulation with different modalities ― visual, auditory, etc (with the application of active and passive paradigm). A higher specificity in the detection of signs of consciousness have the methodology of fMRI with the active paradigm, at the same time, the absence of signs of consciousness according to the fMRI can not be charged as a basis for the conclusion of a poor prognosis in a particular patient. Neurophysiological tests (EEG, TMS, EP, etc) are more readily available and quite effective. Based on the literature analysis, the authors comes to the conclusion that neurovisualization and neurophysiological tests used in the prediction of the outcome of VS reflects the residual functional activity of different brain areas, in a context of diffuse brain damage, and the recovery of consciousness is usually combined with the restoring of the functional activity off the thalamocortical tracts, which activity, indirectly, is evaluated using these methods. In the authors' opinions, the main disadvantage in the interpretation of the is the lack of a common pathophysiological concept of the organization of brain functions in VS patients. The authors offer for the discussion their concept of stable pathological states of the brain, which is based on the works of Russian pathophysiologists.

The cholinergic deficiency syndrome in patients with depressed consciousness after severe brain injury

To determine the clinical and electrophysiological (EEG) signs of cholinergic deficiency in the process of recovery of consciousness in patients with severe brain injury. Thirty-seven people (24 men and 13 women, mean age 32±14 years) were studied. A comprehensive study included assessment of neurological status, mental activity, and EEG. A set of neurological symptoms, including reduced muscle tone, autonomic disorders (dry mucous membranes and skin, tachycardia, hypotension, gastrointestinal tract), eye movement disorders, that were,in accordance with the literature, characteristicof the cholinergic deficiency syndrome was found. This syndrome was detected against the background of a comatose state, akinetic mutism and mutism with understanding of speech, disintegration of speech, disorientation and amnestic decline. EEG revealed stable over time (months) characteristic changes: slowing and asymmetric alpha activity, equivalent dipole sources of hippocampal and stem localization, persistent strengthening of intra-hemispheric coherent connections, especially on the left side. The regression of the cholinergic deficiency syndrome was accompanied by an increase of regularity, capacity and frequency of alpha-activity (from 7-8 to 9-10 Hz), prevalence of equivalent dipole sources in the hippocampus with their appearance in the occipital cortex, normalization of connections with right-brain coherence with the preservation of their pathologically high values on the left side.

Mechanisms that Regulate Recovery of Consciousness in Patients in Vegetative State/Unresponsive Wakefulness Syndrome: A New Model

Mechanisms that Regulate Recovery of Consciousness in Patients in Vegetative State/Unresponsive Wakefulness Syndrome: A New Model

Predicting outcome from subacute unresponsive wakefulness syndrome or vegetative state.

Predicting recovery of consciousness in patients who survive their coma but evolve to a vegetative state (recently coined unresponsive wakefulness syndrome) remains a challenge. Most previous prognostic studies have focused on the acute coma phase. A novel outcome scale (combining behavioural, aetiology, electroencephalographic, sleep electroencephalographic and somatosensory evoked potential data) has been proposed for patients in subacute unresponsive wakefulness syndrome. The scale’s clinical application awaits validation in a larger population.

A New Index Derived from the Cerebrovascular Pressure Transmission and Correlated with Consciousness Recovery in Severely Head-Injured Intensive Care Patients

In patients with serious head trauma, a moderate (20-25 mm Hg) mean level of intracranial pressure (ICP) may fail to distinguish patients with a real deteriorated intracranial status from those who are stable or improving. Because of these limitations, we analyzed the ICP curve in search of other relevant information regarding cerebrovascular pressure transmission. We looked for parameters with physiological meaning extracted from spectral analysis of cerebrovascular pressure transmission and correlated with consciousness recovery in patients with severe head injuries. A prospective cohort study was conducted in an intensive care unit of the University Hospital, Montpellier, France, from December 2003 to December 2005. Thirty consecutive patients admitted for severe head trauma were subjected to sedatives, mechanical ventilation, and intraparenchymatous recording of ICP and were evaluated with Glasgow Outcome Scale score. Simultaneous 60-s recordings of ICP and arterial blood pressure (BP) signals, beginning as soon as possible after head trauma, were repeated until death or clinical stabilization, every 15 min, with physicians blinded to the patients' data. Spectra of ICP and BP waveforms were computed with Fourier transform. Amplitudes of cardiac and respiratory harmonics were analyzed. Cardiac (or respiratory) gain was defined as the ratio of amplitudes of cardiac (or respiratory) harmonic of ICP to BP signals and referred to as Gc and Gr, respectively. Twenty of the 30 enrolled patients recovered consciousness (Glasgow Outcome Scale score = 3, 4, or 5). Gr/Gc averaged over the whole recording period performed better in discriminating consciousness recovery (area under receiver operating characteristic [ROC] curve: 0.98; 95% confidence interval [CI]: 0.91-1) than ICP (0.76; 95% CI: 0.54-0.97), cerebral perfusion pressure (0.75; 95% CI: 0.53-0.97) and Gc (0.77; 95% CI: 0.57-0.99) (P < 0.001 for each comparison). When considering the recording period 30 h posttrauma (hpt), 162 hpt, a value of Gr/Gc > or =4 was always associated with consciousness recovery, and the relative risk was equal to 9 (95% CI: 1.42-57.12). Gr/Gc, which characterizes the cerebrovascular transmission, better discriminates bad evolution than high values of ICP or low values of cerebral perfusion pressure in patients with severe head trauma. A reduction in Gr/Gc ratio might be an early alarm signaling worsening intracranial hemodynamic conditions.

Time to Recover Consciousness in Patients with Diffuse Axonal Injury : Assessment with Reference to Magnetic Resonance Grading

This study was conducted to investigate the correlation between the degrees of injury on brain magnetic resonance imaging (MRI) and the time interval to recovery of consciousness in patients with diffuse axonal injury. From January 2004 to December 2008, 25 patients with diffuse axonal injury were treated at our hospital. We retrospectively investigated the patients' medical records and radiological findings. We divided the patients into three groups according to the grade of MRI finding : grade I, small scattered lesions on the white matter of the cerebral hemisphere; grade II, focal lesions on the corpus callosum; and grade III, additional focal lesions on the brain stem. Seven patients belonged to the grade I group; 10 to the grade II group; and 8 to the grade III group. The mean Glasgow Coma Scale (GCS) score of all patients at the time of admission was 7.28. Recovery of consciousness was observed in 23 of the 25 patients; the remaining two patients never regained consciousness. The time interval to recovery of consciousness (awake status) ranged from 1 day to 125 days (mean 22.1 days) : grade I group patients, within approximately 1 week (mean 3.7 days); grade II group patients, within approximately 2 weeks (mean 12.5 days); and grade III group patients, within approximately 2 months (mean 59.5 days). Our study results suggest a correlation between the mean time interval to recovery of consciousness in patients with diffuse axonal injuries and the degrees of brain injuries seen on MRI. Patients with grade I and II diffuse axonal injuries recovered consciousness within 2 weeks, while patients with grade III injuries required approximately 2 months.

Mismatch negativity to the patient’s own name in chronic disorders of consciousness

Previous studies implicated potential value of mismatch negativity (MMN) in predicting recovery of consciousness in patients with disorders of consciousness (DOC). We have adopted a novel MMN evoked by subject’s own name (SON), a self-referential stimulus thought to be powerful in evoking residual brain activity, and examined the correlation between the MMN and recovery of consciousness in patients with chronic (>1 month) DOC. Twelve patients and 12 age-matched healthy controls were investigated. The patients were diagnosed as coma (n=4), vegetative state (VS, n=6), and minimally conscious state (MCS, n=2), mainly based on the JFK Coma Recovery Scale-Revised. The SON-evoked MMN (SON-MMN) was present in seven patients. Critically, the presence of SON-MMN was significantly correlated with recovery of consciousness. While four of the five patients (three VS and two coma) showing SON-MMN changed to MCS 3 months later, the rest of the patients (three VS and two coma) without SON-MMN failed to show any clinical improvement. Our study thus illustrates that the subject’s own name is effective in evoking MMN in patients with DOC, and that SON-MMN has potential prognostic values in predicting recovery of consciousness.

COMPARISON OF PROPOFOL AND MIDAZOLAM FOR SEDATION IN CRITICALLY ILL PATIENTS

101 critically ill patients admitted to five intensive-care units were allocated randomly to receive a continuous intravenous infusion of either propofol or midazolam for sedation for up to 24 h. In addition, morphine was given to provide analgesia. The mean duration of infusion was 20-2 h (range 3·0-24·5) in the propofol group and 21·3 h (4·0-47·0) in the midazolam group and infusion rates were 1·77 mg/kg/h (range 0·40 -5·00) and 0·10 mg/kg/h (0·01-0·26), respectively. The infasion rates were adjusted as necessary, and the desired level of sedation was achieved easily in most patients in both groups. There were slight falls in arterial pressure, but there were no significant differences between the groups. Heart rate was lower in patients who received propofol. Some small changes occurred in biochemical and haematological variables in both groups, but they were not clinically significant. There was no indication that either drug substantially impaired adrenal steroidogenesis. When the infusion was discontinued, there was less variability in recovery of consciousness in patients who had received propofol. In a subgroup of patients, weaning from mechanical ventilation was achieved significantly faster after discontinuation of propofol than of midazolam. Propofol proved to be a satisfactory agent for sedation of these critically ill patients and compared favourably with midazolam.