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Sangare A, Rohaut B, Borden A, Zyss J, Velazquez A, Doyle K, Naccache L, Claassen J. A Novel Approach to Screen for Somatosensory Evoked Potentials in Critical Care. Neurocrit Care 2024; 40:237-250. [PMID: 36991177 DOI: 10.1007/s12028-023-01710-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Accepted: 02/27/2023] [Indexed: 03/31/2023]
Abstract
BACKGROUND Somatosensory evoked potentials (SSEPs) help prognostication, particularly in patients with diffuse brain injury. However, use of SSEP is limited in critical care. We propose a novel, low-cost approach allowing acquisition of screening SSEP using widely available intensive care unit (ICU) equipment, specifically a peripheral "train-of-four" stimulator and standard electroencephalograph. METHODS The median nerve was stimulated using a train-of-four stimulator, and a standard 21-channel electroencephalograph was recorded to generate the screening SSEP. Generation of the SSEP was supported by visual inspection, univariate event-related potentials statistics, and a multivariate support vector machine (SVM) decoding algorithm. This approach was validated in 15 healthy volunteers and validated against standard SSEPs in 10 ICU patients. The ability of this approach to predict poor neurological outcome, defined as death, vegetative state, or severe disability at 6 months, was tested in an additional set of 39 ICU patients. RESULTS In each of the healthy volunteers, both the univariate and the SVM methods reliably detected SSEP responses. In patients, when compared against the standard SSEP method, the univariate event-related potentials method matched in nine of ten patients (sensitivity = 94%, specificity = 100%), and the SVM had 100% sensitivity and specificity when compared with the standard method. For the 49 ICU patients, we performed both the univariate and the SVM methods: a bilateral absence of short latency responses (n = 8) predicted poor neurological outcome with 0% FPR (sensitivity = 21%, specificity = 100%). CONCLUSIONS Somatosensory evoked potentials can reliably be recorded using the proposed approach. Given the very good but slightly lower sensitivity of absent SSEPs in the proposed screening approach, confirmation of absent SSEP responses using standard SSEP recordings is advised.
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Affiliation(s)
- Aude Sangare
- Brain Institute, ICM, CNRS, Sorbonne Université, Inserm U1127, UMR 7225, Paris, France.
- Department of Neurophysiology, Pitié-Salpêtrière, Groupe Hospitalier Universitaire Assistance Publique-Hôpitaux de Paris Sorbonne Université, Paris, France.
- Sorbonne University, Paris, France.
| | - Benjamin Rohaut
- Brain Institute, ICM, CNRS, Sorbonne Université, Inserm U1127, UMR 7225, Paris, France
- Department of Neurophysiology, Pitié-Salpêtrière, Groupe Hospitalier Universitaire Assistance Publique-Hôpitaux de Paris Sorbonne Université, Paris, France
- Neurological Intensive Care Unit, Department of Neurology, Pitié-Salpêtrière, Groupe Hospitalier Universitaire Assistance Publique-Hôpitaux de Paris Sorbonne Université, Paris, France
- Department of Neurology, Columbia University, New York, NY, USA
- New York Presbyterian Hospital, New York, NY, USA
| | - Alaina Borden
- Department of Neurophysiology, Pitié-Salpêtrière, Groupe Hospitalier Universitaire Assistance Publique-Hôpitaux de Paris Sorbonne Université, Paris, France
| | - Julie Zyss
- Department of Neurophysiology, Pitié-Salpêtrière, Groupe Hospitalier Universitaire Assistance Publique-Hôpitaux de Paris Sorbonne Université, Paris, France
| | | | - Kevin Doyle
- Department of Neurology, Columbia University, New York, NY, USA
| | - Lionel Naccache
- Brain Institute, ICM, CNRS, Sorbonne Université, Inserm U1127, UMR 7225, Paris, France
- Department of Neurophysiology, Pitié-Salpêtrière, Groupe Hospitalier Universitaire Assistance Publique-Hôpitaux de Paris Sorbonne Université, Paris, France
- Sorbonne University, Paris, France
| | - Jan Claassen
- Department of Neurology, Columbia University, New York, NY, USA
- New York Presbyterian Hospital, New York, NY, USA
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Carter BG, Butt W, Taylor A. Bilaterally Absent Pupillary Responses: Not Always a Bad Sign. Anaesth Intensive Care 2019; 35:984-7. [DOI: 10.1177/0310057x0703500623] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Pupillary responses are a simple test commonly used as a predictor of outcome after severe brain injury. It is also common for clinicians to associate bilaterally absent pupillary responses with very poor prognosis. We report a series of cases of severely brain injured children with bilaterally absent pupillary responses who had favourable outcomes. From a group of 89 patients with brain injury, 32 had bilaterally absent pupillary responses and six (four with traumatic brain injury and two with infective brain injury) subsequently had favourable outcomes. This represents 18.8% of patients and should be a reminder to clinicians that the clinical sign of bilaterally absent pupillary responses is not always associated with a hopeless outcome.
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Affiliation(s)
- B. G. Carter
- Intensive Care Unit, Royal Children's Hospital, Melbourne, Victoria, Australia
| | - W. Butt
- Intensive Care Unit, Royal Children's Hospital, Melbourne, Victoria, Australia
| | - A. Taylor
- Intensive Care Unit, Royal Children's Hospital, Melbourne, Victoria, Australia
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André-Obadia N, Zyss J, Gavaret M, Lefaucheur JP, Azabou E, Boulogne S, Guérit JM, McGonigal A, Merle P, Mutschler V, Naccache L, Sabourdy C, Trébuchon A, Tyvaert L, Vercueil L, Rohaut B, Delval A. Recommendations for the use of electroencephalography and evoked potentials in comatose patients. Neurophysiol Clin 2018; 48:143-169. [DOI: 10.1016/j.neucli.2018.05.038] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Accepted: 05/07/2018] [Indexed: 12/21/2022] Open
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Mende KC, Gelderblom M, Schwarz C, Czorlich P, Schmidt NO, Vettorazzi E, Regelsberger J, Westphal M, Abboud T. Somatosensory evoked potentials in patients with high-grade aneurysmal subarachnoid hemorrhage. Neurosurg Focus 2017; 43:E17. [PMID: 29088953 DOI: 10.3171/2017.7.focus17427] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECTIVE The aim of this prospective study was to investigate the value of somatosensory evoked potentials (SEPs) in predicting outcome in patients with high-grade aneurysmal subarachnoid hemorrhage (SAH). METHODS Between January 2013 and January 2015, 48 patients with high-grade SAH (Hunt and Hess Grade III, IV, or V) who were admitted within 3 days after hemorrhage were enrolled in the study. Right and left median and tibial nerve SEPs were recorded on Day 3 after hemorrhage and recorded again 2 weeks later. Glasgow Outcome Scale (GOS) scores were determined 6 months after hemorrhage and dichotomized as poor (Scores 1-3) or good (Scores 4-5). Results of SEP measurements were dichotomized (present or missing cortical responses or normal or prolonged latencies) for each nerve and side. These variables were summed and tested using logistic regression and a receiver operating characteristic curve to assess the value of SEPs in predicting long-term outcome. RESULTS At the 6-month follow-up visit, 29 (60.4%) patients had a good outcome, and 19 (39.6%) had a poor outcome. The first SEP measurement did not correlate with clinical outcome (area under the curve [AUC] 0.69, p = 0.52). At the second measurement of median nerve SEPs, all patients with a good outcome had cortical responses present bilaterally, and none of them had bilateral prolonged latencies (p = 0.014 and 0.003, respectively). In tibial nerve SEPs, 7.7% of the patients with a good GOS score had one or more missing cortical responses, and bilateral prolonged latencies were found in 23% (p = 0.001 and 0.034, respectively). The second measurement correlated with the outcome regarding each of the median and tibial nerve SEPs and the combination of both (AUC 0.75 [p = 0.010], 0.793 [p = 0.003], and 0.81 [p = 0.001], respectively). CONCLUSIONS Early SEP measurement after SAH did not correlate with clinical outcome, but measurement of median and tibial nerve SEPs 2 weeks after a hemorrhage did predict long-term outcome in patients with high-grade SAH.
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Affiliation(s)
| | | | | | | | | | - Eik Vettorazzi
- Medical Biometry and Epidemiology, University Medical Center Hamburg-Eppendorf, Hamburg; and
| | | | | | - Tammam Abboud
- Department of Neurosurgery, University Medical Center Göttingen, Germany
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Sullivan EG, Guernon A, Blabas B, Herrold AA, Pape TLB. Familiar auditory sensory training in chronic traumatic brain injury: a case study. Disabil Rehabil 2017; 40:945-951. [DOI: 10.1080/09638288.2016.1277403] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- Emily Galassi Sullivan
- Physical Medicine and Rehabilitation Service, Edward Hines, Jr. Hospital, Hines, IL, USA
| | - Ann Guernon
- Department of Research, Marianjoy Rehabilitation Hospital/Northwestern Medicine, Wheaton, IL, USA
- Research Service, Edward Hines, Jr. VA Hospital, Hines, IL, USA
| | - Brett Blabas
- Research Service, Edward Hines, Jr. VA Hospital, Hines, IL, USA
| | - Amy A. Herrold
- Research Service, Edward Hines, Jr. VA Hospital, Hines, IL, USA
- Department of Psychiatry and Behavioral Sciences, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Theresa L.-B. Pape
- Research Service, Edward Hines, Jr. VA Hospital, Hines, IL, USA
- Department of Physical Medicine and Rehabilitation, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
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Abstract
To determine the optimal use and indications of electroencephalography (EEG) in critical care management of acute brain injury (ABI). An electronic literature search was conducted for articles in English describing electrophysiological monitoring in ABI from January 1990 to August 2013. A total of 165 studies were included. EEG is a useful monitor for seizure and ischemia detection. There is a well-described role for EEG in convulsive status epilepticus and cardiac arrest (CA). Data suggest EEG should be considered in all patients with ABI and unexplained and persistent altered consciousness and in comatose intensive care unit (ICU) patients without an acute primary brain condition who have an unexplained impairment of mental status. There remain uncertainties about certain technical details, e.g., the minimum duration of EEG studies, the montage, and electrodes. Data obtained from both EEG and EP studies may help estimate prognosis in ABI patients, particularly following CA and traumatic brain injury. Data supporting these recommendations is sparse, and high quality studies are needed. EEG is used to monitor and detect seizures and ischemia in ICU patients and indications for EEG are clear for certain disease states, however, uncertainty remains on other applications.
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Schmitt S, Dichter MA. Electrophysiologic recordings in traumatic brain injury. HANDBOOK OF CLINICAL NEUROLOGY 2015; 127:319-339. [PMID: 25702226 DOI: 10.1016/b978-0-444-52892-6.00021-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Following a traumatic brain injury (TBI), the brain undergoes numerous electrophysiologic changes. The most common techniques used to evaluate these changes include electroencepalography (EEG) and evoked potentials. In animals, EEGs immediately following TBI can show either diffuse slowing or voltage attenuation, or high voltage spiking. Following a TBI, many animals display evidence of hippocampal excitability and a reduced seizure threshold. Some mice subjected to severe TBI via a fluid percussion injury will eventually develop seizures, which provides a useful potential model for studying the neurophysiology of epileptogenesis. In humans, the EEG changes associated with mild TBI are relatively subtle and may be challenging to distinguish from EEG changes seen in other conditions. Quantitative EEG (QEEG) may enhance the ability to detect post-traumatic electrophysiologic changes following a mild TBI. Some types of evoked potential (EP) and event related potential (ERP) can also be used to detect post-traumatic changes following a mild TBI. Continuous EEG monitoring (cEEG) following moderate and severe TBI is useful in detecting the presence of seizures and status epilepticus acutely following an injury, although some seizures may only be detectable using intracranial monitoring. CEEG can also be helpful for assessing prognosis after moderate or severe TBI. EPs, particularly somatosensory evoked potentials, can also be useful in assessing prognosis following severe TBI. The role for newer technologies such as magnetoencephalography and bispectral analysis (BIS) in the evaluation of patients with TBI remains unclear.
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Affiliation(s)
- Sarah Schmitt
- Department of Neurology, University of Pennsylvania, Philadelphia, PA, USA
| | - Marc A Dichter
- Department of Neurology, University of Pennsylvania, Philadelphia, PA, USA.
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Ordek G, Proddutur A, Santhakumar V, Pfister BJ, Sahin M. Electrophysiological monitoring of injury progression in the rat cerebellar cortex. Front Syst Neurosci 2014; 8:197. [PMID: 25346664 PMCID: PMC4191519 DOI: 10.3389/fnsys.2014.00197] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2014] [Accepted: 09/23/2014] [Indexed: 12/05/2022] Open
Abstract
The changes of excitability in affected neural networks can be used as a marker to study the temporal course of traumatic brain injury (TBI). The cerebellum is an ideal platform to study brain injury mechanisms at the network level using the electrophysiological methods. Within its crystalline morphology, the cerebellar cortex contains highly organized topographical subunits that are defined by two main inputs, the climbing (CFs) and mossy fibers (MFs). Here we demonstrate the use of cerebellar evoked potentials (EPs) mediated through these afferent systems for monitoring the injury progression in a rat model of fluid percussion injury (FPI). A mechanical tap on the dorsal hand was used as a stimulus, and EPs were recorded from the paramedian lobule (PML) of the posterior cerebellum via multi-electrode arrays (MEAs). Post-injury evoked response amplitudes (EPAs) were analyzed on a daily basis for 1 week and compared with pre-injury values. We found a trend of consistently decreasing EPAs in all nine animals, losing as much as 72 ± 4% of baseline amplitudes measured before the injury. Notably, our results highlighted two particular time windows; the first 24 h of injury in the acute period and day-3 to day-7 in the delayed period where the largest drops (~50% and 24%) were observed in the EPAs. In addition, cross-correlations of spontaneous signals between electrode pairs declined (from 0.47 ± 0.1 to 0.35 ± 0.04, p < 0.001) along with the EPAs throughout the week of injury. In support of the electrophysiological findings, immunohistochemical analysis at day-7 post-injury showed detectable Purkinje cell loss at low FPI pressures and more with the largest pressures used. Our results suggest that sensory evoked potentials (SEPs) recorded from the cerebellar surface can be a useful technique to monitor the course of cerebellar injury and identify the phases of injury progression even at mild levels.
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Affiliation(s)
- Gokhan Ordek
- Department of Biomedical Engineering, New Jersey Institute of Technology Newark, NJ, USA
| | - Archana Proddutur
- Department of Neurology and Neurosciences, Rutgers Biomedical and Health Sciences Newark, NJ, USA
| | | | - Bryan J Pfister
- Department of Biomedical Engineering, New Jersey Institute of Technology Newark, NJ, USA
| | - Mesut Sahin
- Department of Biomedical Engineering, New Jersey Institute of Technology Newark, NJ, USA
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Prognostic Value of Somatosensory-evoked Potentials and CT Scan Evaluation in Acute Traumatic Brain Injury. J Neurosurg Anesthesiol 2014; 26:299-305. [DOI: 10.1097/ana.0000000000000040] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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10
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Schorl M, Valerius-Kukula SJ, Kemmer TP. Median-evoked somatosensory potentials in severe brain injury: Does initial loss of cortical potentials exclude recovery? Clin Neurol Neurosurg 2014; 123:25-33. [DOI: 10.1016/j.clineuro.2014.05.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2013] [Revised: 04/27/2014] [Accepted: 05/03/2014] [Indexed: 11/28/2022]
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Sun Y, Yu J, Wu J, Wu X, Yuan Q, Wu X, Mao Y, Zhou L, Hu J. Predictive Value of Somatosensory Evoked Potentials for Patients With Severe Traumatic Brain Injury. Neurosurgery 2014; 61 Suppl 1:171-4. [DOI: 10.1227/neu.0000000000000404] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
- Yirui Sun
- Department of Neurosurgery, Huashan Hospital, Fudan University, Shanghai, China
| | - Jian Yu
- Department of Neurosurgery, Huashan Hospital, Fudan University, Shanghai, China
| | - Jianyue Wu
- Department of Neurosurgery, The Affiliated Hospital of Hangzhou Normal University, Hangzhou, China
| | - Xing Wu
- Department of Neurosurgery, Huashan Hospital, Fudan University, Shanghai, China
| | - Qiang Yuan
- Department of Neurosurgery, Huashan Hospital, Fudan University, Shanghai, China
| | - Xuehai Wu
- Department of Neurosurgery, Huashan Hospital, Fudan University, Shanghai, China
| | - Ying Mao
- Department of Neurosurgery, Huashan Hospital, Fudan University, Shanghai, China
| | - Liangfu Zhou
- Department of Neurosurgery, Huashan Hospital, Fudan University, Shanghai, China
| | - Jin Hu
- Department of Neurosurgery, Huashan Hospital, Fudan University, Shanghai, China
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Prediction of minimally conscious state with somatosensory evoked potentials in long-term unconscious patients after traumatic brain injury. J Trauma Acute Care Surg 2012; 72:1024-9. [DOI: 10.1097/ta.0b013e31824475cc] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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13
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Hansen HC. Sooner or later...? In search of the most useful components of the somatosensory evoked potential to define prognosis in critically ill patients with acute stroke. Clin Neurophysiol 2011; 122:1482-4. [PMID: 21330201 DOI: 10.1016/j.clinph.2011.01.038] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2010] [Revised: 12/31/2010] [Accepted: 01/05/2011] [Indexed: 10/18/2022]
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Early somatosensory evoked potential grades in comatose traumatic brain injury patients predict cognitive and functional outcome. Crit Care Med 2010; 38:167-74. [PMID: 19829103 DOI: 10.1097/ccm.0b013e3181c031b3] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES To relate early somatosensory evoked potential grades from comatose traumatic brain injury patients to neuropsychological and functional outcome 1 yr later; to determine the day (within the first week after traumatic brain injury) that somatosensory evoked potential grade best correlates with outcome; to determine whether somatosensory evoked potential grade improvement in the first week after traumatic brain injury is associated with improved outcome. DESIGN Prospective cohort study. SETTING Critical care unit at a university hospital. PATIENTS Median nerve somatosensory evoked potentials were obtained from 81 comatose patients with traumatic brain injury. Somatosensory evoked potential grades were calculated from results obtained on days 1, 3, and 7 after traumatic brain injury. Glasgow Outcome Scale, Barthel Index, Rivermead Head Injury Follow-up Questionnaire, General Health Questionnaire, Stroop Color-Word Test, Paced Auditory Serial Addition Task, and Symbol-Digit Modalities Test scores were obtained 1 yr after injury. INTERVENTIONS None. MEASUREMENTS AND MAIN RESULTS Somatosensory evoked potential grade on days 1, 3, and 7 related significantly with Glasgow Outcome Scale and Barthel scores (day 3 better than day 1) but did not relate with Rivermead Head Injury Follow-up Questionnaire or General Health Questionnaire scores. Day 3 and day 7 somatosensory evoked potential grades related significantly with Stroop scores. Day 3 somatosensory evoked potential grades related significantly with Symbol-Digit Modalities Test scores. Patients with bilaterally present but abnormal somatosensory evoked potentials, whose somatosensory evoked potential grade improved between days 1 and 3, had marginally better functional outcome than those without somatosensory evoked potential grade improvement. CONCLUSIONS Day 3 somatosensory evoked potential grade related to information-processing speed, working memory, and the ability to attend to tasks 1 yr after traumatic brain injury. Day 3 somatosensory evoked potential grade had the strongest relationship with functional outcome. Somatosensory evoked potential grades were not related to emotional well-being.
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Abstract
OBJECTIVE To review the current understanding of the medical management of severe brain injury. DATA SOURCE The MEDLINE database, bibliographies of selected articles, and current English-language texts on the subject. STUDY SELECTION Studies related to management of intracranial hypertension, traumatic brain injury, and brain edema. DATA EXTRACTION All studies relevant to the subject under consideration were considered, with a focus on clinical studies in adults. DATA SYNTHESIS Basic rules of resuscitation must apply, including adequate ventilation, appropriate fluid administration, and cardiovascular support. The control of intracranial pressure can be considered in three steps. The first step should be initial slight hyperventilation with a target PaCO2 of 35 mm Hg and cerebrospinal fluid drainage for intracranial pressure of >15-20 mm Hg. The second step should be mannitol or hypertonic saline and hyperventilation to target PaCO2 of 28-35 mm Hg. The third step should be barbiturate coma or decompressive craniectomy. Additional management issues, including seizure prophylaxis, sedation, nutritional support, use of hypothermia, and corticosteroids, are also discussed. CONCLUSIONS Brain injury is frequently associated with the development of brain edema and the development of intracranial hypertension. However, with a coordinated, stepwise, and aggressive approach to management, focusing on control of intracranial pressure without adversely affecting cerebral perfusion pressure, outcomes can be good.
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Affiliation(s)
- Jean-Louis Vincent
- Department of Intensive Care, Erasme Hospital, Free University of Brussels, Belgium
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Payen JF, Francony G, Fauvage B, Le Bas JF. [Contribution of magnetic resonance spectroscopy in predicting severity and outcome in traumatic brain injury]. ACTA ACUST UNITED AC 2005; 24:522-7. [PMID: 15904731 DOI: 10.1016/j.annfar.2005.03.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Nuclear magnetic spectroscopy (MRS) is a useful method for noninvasively studying intracerebral metabolism. Proton MRS can identify markers of the neuronal viability (N-acetyl-aspartate, NAA), of the metabolism of cellular membranes (choline), of the cellular energy metabolism (creatine, lactate). In Phosphorus MRS, the peaks most readily identified are involved in the high-energy cellular metabolism (ATP, phosphocreatine, inorganic phosphate), and intracellular pH (pHi) can be determined using this method. MRS has been used in experimental models of traumatic brain injury (TBI), primarily to study the cellular metabolism and the relation between biochemical and histological changes after trauma. In trauma patients, significant changes in NAA, choline and pHi were found in both grey and white matter comparing with controls, and these alterations correlated with injury severity. Correlations have been reported between these biochemical changes (reduction in NAA, increase in choline) measured at 1 to 6 months after TBI and the clinical outcome of the patients. However, there are methodological issues which still impede to recommend MRS as a tool for predicting neurological outcome in the clinical setting.
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Affiliation(s)
- J-F Payen
- Département d'anesthésie-réanimation 1, hôpital Michallon, BP 217, 38043 Grenoble cedex 9, France.
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Maurer E, Milewski P, Ulrich C. [Value of early somatosensory evoked potentials in intubated and mechanically ventilated patients with craniocerebral trauma]. Unfallchirurg 2005; 108:102-8. [PMID: 15729587 DOI: 10.1007/s00113-004-0820-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The objective of this study was to evaluate the prognostic value of early somatosensory evoked potentials (SEP) in patients with brain injury. A total of 85 patients who had been intubated and mechanically ventilated were investigated retrospectively. The results were compared to the Glasgow Coma Scale (GCS). The Glasgow Coma Scale as determined by the emergency doctor at the accident site, an SEP score, and the outcome of the patient were compared. There was no correlation of the Glasgow Coma Scale with the outcome. Probably the reason for this finding is the short interval of time between accident and evaluation of the GCS so that an awakening of the patient a short time after the accident is not reflected by the GCS. On the other hand, there was a significant correlation of the SEP score in the first examination after the accident with the outcome (p<0.001). SEP gave no false pessimistic prognoses. All patients without cortical responses either in one hemisphere or both hemispheres remained in coma vigile or died because of their brain injury. If cortical responses over both hemispheres remained normal, it was highly probable that the patients were later not severely handicapped. A reliable prognosis based on SEP is possible at a time when the clinical examination of the patient is limited due to sedating drugs. Repetitive examinations can monitor the course of recovery and correct false optimistic prognoses. The method may be applied at bedside and requires minimal time and little financial effort.
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Affiliation(s)
- E Maurer
- Abteilung für Anästhesiologie, Operative Intensivmedizin und Schmerztherapie, Klinik am Eichert, Göppingen.
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18
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Abstract
Three-modality evoked potentials (EPs) have been used for several years in association with the electroencephalogram (EEG) as a diagnostic and prognostic tool in acute traumatic or nontraumatic coma. In 1993 we proposed to combine these in two indices: the index of global cortical function (IGCF) and the index of brain-stem conduction (IBSC). Four EP patterns based on both indices emerge at the acute stage of severe head trauma. These are easily explainable by pathophysiology. Pattern 1 corresponds to alterations in the index of global cortical function without changes in the index of brain-stem conduction. Its prognosis is good (80 to 90% of these patients recover). Pattern 2 is characterized by alterations of somatosensory EPs that are suggestive of midbrain dysfunction. The prognosis depends both on the reversibility of the midbrain dysfunction and on the extent of associated diffuse axonal lesions, whose evaluation requires MRI. Patients who recovered from Pattern 2 sometimes did so after a long interval during which they remained vegetative. Pattern 3 is characterized by alterations of brain-stem auditory EPs that are suggestive of pontine involvement. It usually follows uncontrolled intracranial hypertension and corresponds to evolving transtentorial herniation. All patients with that transient pattern eventually died. Pattern 4 is categorized by the disappearance of all activities of intracranial origin, contrasting with the preservation of all activities of retinal, spinal-cord, and peripheral-nerve origin. This pattern corresponds to brain death. In our experience, three-modality EPs are currently the best bedside brain-death confirmatory tool.
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Amantini A, Grippo A, Fossi S, Cesaretti C, Piccioli A, Peris A, Ragazzoni A, Pinto F. Prediction of ‘awakening’ and outcome in prolonged acute coma from severe traumatic brain injury: evidence for validity of short latency SEPs. Clin Neurophysiol 2005; 116:229-35. [PMID: 15589201 DOI: 10.1016/j.clinph.2004.07.008] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/06/2004] [Indexed: 11/24/2022]
Abstract
OBJECTIVE To evaluate the prognostic value of somatosensory evoked potentials (SEPs) in severe traumatic brain injury (TBI) considering both 'awakening' and disability. METHODS SEPs were recorded in 60 severe TBI with duration of acute coma>7 days. N20-P25 amplitudes, their side-to-side asymmetry and CCT were measured. SEPs on each hemisphere were classified as normal (N), pathological (P) or absent (A). 'Awakening' and disability were assessed after at least 12 months using Glasgow Outcome Scale (GOS). SEP predictive value was compared with GCS and EEG reactivity RESULTS Seventy-five percent regained consciousness. 29/60 had a good outcome (GOS 4-5) and 31/60 had a bad outcome (GOS 1-3). According to the ROC curve, SEP findings were classified in 3 grades. Grade I (NN, NP) had PPV of 93.1% for 'awakening' and 86.2% for good outcome. Grade III (AA) had PPV of 100% for bad outcome and 72.7% for 'awakening'. Grade II (PP, NA, PA) was associated with the wider range of outcome. A multivariate analysis including SEP grading, GCS and EEG reactivity did not increase the percentage of cases prognosticated by SEP alone. CONCLUSIONS We confirm the high predictive value of SEPs in TBI, which is greater than GCS and EEG reactivity. Indeed, SEP grades I and III were able to predict the correct prognosis in more than 80% of severe TBI. Therefore, SEPs should be used more widely in the prognosis of severe TBI. SIGNIFICANCE Differently from post-anoxic, in post-traumatic coma the presence of normal SEPs has a favourable predictive value both for 'awakening' and disability. We think that in literature enough attention has still not been paid to this finding.
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Affiliation(s)
- Aldo Amantini
- Department of Neurological and Psychiatric Sciences, University of Florence, Az. Ospedaliera Careggi, V. le Morgagni 85, Firenze 50134, Italy.
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Abstract
SEPs provide useful prognostic information regarding outcome after coma. Use of the summary data presented here should allow clinicians caring for these patients to provide families with a greater degree of certainty regarding outcome than previously has been available.
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Affiliation(s)
- Lawrence R Robinson
- Department of Rehabilitation Medicine, University of Washington, Harborview Medical Center, Box 359740, 325 Ninth Avenue, Seattle, WA 98104-2499, USA.
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Logi F, Fischer C, Murri L, Mauguière F. The prognostic value of evoked responses from primary somatosensory and auditory cortex in comatose patients. Clin Neurophysiol 2003; 114:1615-27. [PMID: 12948790 DOI: 10.1016/s1388-2457(03)00086-5] [Citation(s) in RCA: 104] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
OBJECTIVE To evaluate somatosensory and auditory primary cortices using somatosensory evoked potentials (SEPs) and middle latency auditory evoked potentials (MLAEPs) in the prognosis of return to consciousness in comatose patients. METHODS SEPs and MLAEPs were recorded in 131 severe comatose patients. Latencies and amplitudes were measured. Coma had been caused by transient cardiac arrest (n=49), traumatic brain injury (n=22), stroke (n=45), complications of neurosurgery (n=12) and encephalitis (n=3). One month after the onset of coma patients were classified as awake, still comatose or dead. Three months after (M3), they were classified into one of the 5 categories of the Glasgow outcome scale (GOS). RESULTS At M3, 41.2% were dead, 47.3% were conscious (GOS 3-5) and 11.5% had not recovered consciousness. None of the patients in whom somatosensory N20 and auditory Pa were absent did return to consciousness and in the post-anoxic group, reduced cortical amplitude too was always associated with bad outcome. Conversely, N20 and Pa were present, respectively, in 33/69 and 34/69 patients who did not recover. CONCLUSIONS The prognostic value of SEPs and MLAEPs in comatose patients depends on the cause of coma. Measurement of response amplitudes is informative. Abolition of cortical SEPs and/or cortical MLAEPs precludes post-anoxic comatose patients from returning to consciousness (100% specificity). In any case, the presence of short latency cortical somatosensory or auditory components is not a guarantee for return to consciousness. Late components should then be recorded.
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Affiliation(s)
- F Logi
- Neurologie Fonctionnelle and EA1880, Hôpital Neurologique, 59, Boulevard Pinel, 69003 Lyon, France
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Lew HL, Dikmen S, Slimp J, Temkin N, Lee EH, Newell D, Robinson LR. Use of somatosensory-evoked potentials and cognitive event-related potentials in predicting outcomes of patients with severe traumatic brain injury. Am J Phys Med Rehabil 2003; 82:53-61; quiz 62-4, 80. [PMID: 12510186 DOI: 10.1097/00002060-200301000-00009] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE This study was performed to evaluate the usefulness of somatosensory-evoked potentials (SEPs) and cognitive event-related potentials (ERPs) in predicting functional outcomes of severe traumatic brain injury patients. DESIGN Prospective study of 22 patients with severe traumatic brain injury. Demographic information, Glasgow Coma Scale, and electrophysiologic measurements were recorded. Functional outcomes, as quantified by the Glasgow Outcome Scale-Extended, were obtained. RESULTS Bilateral absence of median nerve SEP was strongly predictive of the worst functional outcome. The specificity and positive predictive value of absent SEP for predicting death or persistent vegetative state at 6 mo after traumatic brain injury were as high as 100%. If the definition of unfavorable outcome was expanded to include Glasgow Outcome Scale-Extended 1-4, absence of ERP was equivalent to the absence of SEP in specificity and positive predictive value. On the other hand, normal ERPs showed higher sensitivity and negative predictive value for prognosticating the best outcomes compared with normal SEPs. If the definition of favorable outcome was expanded to include Glasgow Outcome Scale-Extended 5-8, ERP was still superior to SEP for prognosticating good outcome. Interestingly, the highest sensitivity and negative predictive value for favorable outcomes were associated with the presence of any discernible waveform. CONCLUSIONS Although median nerve SEP continues to make reliable prediction of ominous outcome in severe traumatic brain injury, the addition of the speech-evoked ERPs may be helpful in predicting favorable outcomes. The strength of the latter test seems to complement the weakness of the former.
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Affiliation(s)
- Henry L Lew
- Physical Medicine and rehabilitation Service, VA Palo Alto, Health Care System, Stanford University School of Medicine, Palo Alto, California 94304, USA
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Hoppe U, Schnabel K, Weiss S, Rundshagen I. Representation of somatosensory evoked potentials using discrete wavelet transform. J Clin Monit Comput 2002; 17:227-33. [PMID: 12455741 DOI: 10.1023/a:1020783313428] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
OBJECTIVE Somatosensory evoked potentials (SEP) have been shown to be a useful tool in monitoring of the central nervous system (CNS) during anaesthesia. SEP analysis is usually performed by an experienced human operator. For automatic analysis, appropriate parameter extraction and signal representation methods are required. The aim of this work is to evaluate the discrete wavelet transform (DWT) as such a method for an SEP representation. METHODS Median nerve SEP were derived in 52 female patients, scheduled for elective surgery with SEP monitoring, under clinically proven conditions in the awake state. The discrete wavelet transform implemented as the multiresolution analysis was adopted for evaluating SEP. The suitability of the wavelet coefficients was investigated by calculating the error between the averaged response and the corresponding wavelet reconstructions. RESULTS SEP can be represented by a very small number of wavelet coefficients. Although the individual SEP waveform has an influence on the number and selection of wavelet coefficients, in all subjects more than 84% of the SEP waveform energy can be represented by a set 16 wavelet coefficients. CONCLUSIONS The discrete wavelet transformation provides an efficient tool for SEP representation and parameterisation. Depending on the specific problem the DWT, can be adjusted to the desired accuracy, which is important for the subsequent development of automatic SEP analysers.
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Affiliation(s)
- Ulrich Hoppe
- Department of Phoniatrics and Pediatric Audiology, University of Erlangen-Nürnberg, Erlangen, Germany.
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Pajeau AK. Somatosensory evoked potentials as predictors of outcome in patients with acute diffuse axonal injury. Crit Care Med 2001; 29:675-7. [PMID: 11373446 DOI: 10.1097/00003246-200103000-00043] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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