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Evoked potentials in the ICU

Published online by Cambridge University Press:  01 February 2008

A. Amantini*
Affiliation:
University of Florence, Azienda Ospedaliero–Universitaria Careggi, Department of Neurological and Psychiatric Sciences, *UO Neurophysiopatology, Firenze, Italy
A. Amadori
Affiliation:
University of Florence, Azienda Ospedaliero–Universitaria Careggi, Department of Neurological and Psychiatric Sciences, Neuro-intensive Care Unit, Firenze, Italy
S. Fossi
Affiliation:
University of Florence, Azienda Ospedaliero–Universitaria Careggi, Department of Neurological and Psychiatric Sciences, *UO Neurophysiopatology, Firenze, Italy
*
Correspondence to: Aldo Amantini, Department of Neurological and Psychiatric Sciences, University of Florence – Az. Ospedaliera Careggi V.le Morgagni 85 50134 Firenze, Italy. E-mail: [email protected]; Tel: +39 055 4279410; Fax: +39 –055 4279409
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Summary

The most informative neurophysiological techniques available in the neurosurgical intensive care unit are electroencephalograph and somatosensory evoked potentials. Such tools, which give an evaluation of cerebral function in comatose patients, support clinical evaluation and are complementary to neuroimaging. They serve both diagnostic/prognostic and monitoring purposes. While for the former, discontinuous monitoring is sufficient, for the latter, to obtain increased clinical impact, continuous monitoring is necessary. To perform and interpret these examinations in the neurosurgical intensive care unit, both the technician and the neurophysiologist need specific training in the intensive care field. There is sufficient evidence to show that somatosensory evoked potentials are the best single indicator of early prognosis in traumatic and hypoxic-ischaemic coma compared to the Glasgow Coma Score, computed tomography scan and electroencephalograph. Indeed, somatosensory evoked potentials should always be combined with clinical examination to determine the prognosis of coma. Despite widespread use of somatosensory evoked potentials and their prognostic utility in acute brain injury, few studies exist on continuous somatosensory evoked potential monitoring in the intensive care unit. We carried out a pilot study of continuous electroencephalograph-somatosensory evoked potential monitoring in the neurosurgical intensive care unit (traumatic brain injury and intracranial haemorrhage, Glasgow Coma Score <9, intracranial pressure monitoring). All patients stable from a clinical and computed tomography scan point of view showed no significant somatosensory evoked potential modifications, while in the case of clinical deterioration (23%), somatosensory evoked potentials always showed significant modifications. While somatosensory evoked potentials correlated with short-term outcome, intracranial pressure showed a poor correlation. We believe neurophysiological monitoring is an ideal complement to the other parameters monitored in the neurosurgical intensive care unit. Whereas intracranial pressure is simply a pressure index, electroencephalograph-somatosensory evoked potential monitoring reflects to what extent cerebral parenchyma still remains metabolically active during acute brain injury.

Type
Original Article
Copyright
Copyright © European Society of Anaesthesiology 2008

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References

1.Regan, D. Human brain electrophysiology: evoked potentials and evoked magnetic fields. In: Science and Medicine. New York: University of Toronto, Elsevier, 1989.Google Scholar
2.Guérit, JM. Medical technology assessment EEG and evoked potentials in the intensive care unit. Neurophysiol Clin 1999; 29: 301317.CrossRefGoogle ScholarPubMed
3. Guèrit JM, Amantini A, Amodio P et al. Proposal of Guidelines on the Use of Neurophysiological Tests in the Intensive Care Unit (ICU). XXVII International Congress of Clinical Neurophysiology, Stockholm, 8–12 May 2005.Google Scholar
4.Kraft, GH, Litchy, WJ, Aminoff, MJ, Baran, EM, Eisen, AA, Stolov, WC. American Association of Electrodiagnostic Medicine (AAEM) somatosensory evoked potentials subcommittee. Guidelines for somatosensory evoked potentials.. Muscle Nerve Suppl 1999; 8: S123S138.Google Scholar
5.Amantini, A, Grippo, A, Fossi, S et al. . Prediction of “awakening” and outcome in prolonged acute coma from severe traumatic head injury: evidence for validity of short latency SEPs. Clin Neurophysiol 2004; 116: 229235.CrossRefGoogle Scholar
6.Guerit, JM, Fischer, C, Facco, E et al. . Standards of clinical practice of EEG and EPs in comatose and other unresponsive states. The International Federation of Clinical Neurophysiology. Electroencephalogr Clin Neurophysiol Suppl 1999; 52: 117131.Google ScholarPubMed
7.Fischer, C, Mutschler, V. Traumatic brain injuries in adults: from coma to wakefulness. Neurophysiological data. Ann Readapt Med Phys 2002; 45: 448455.CrossRefGoogle ScholarPubMed
8.Facco, E, Munari, M, Gallo, F et al. . Role of short latency evoked potentials in the diagnosis of brain death. Clin Neurophysiol 2002; 113: 18551866.CrossRefGoogle ScholarPubMed
9.Zandbergen, EG, de Haan, RJ, Stoutenbeek, CP, Koelman, JH, Hijdra, A. Systematic review of early prediction of poor outcome in anoxic-ischaemic coma. Lancet 1998; 352: 18081812.CrossRefGoogle ScholarPubMed
10.Attia, J, Cook, DJ. Prognosis in anoxic and traumatic coma. Crit Care Clin 1998; 14: 497511.CrossRefGoogle ScholarPubMed
11.Rothstein, TL. The role of evoked potentials in anoxic-ischemic coma and severe brain trauma. J Clin Neurophysiol 2000; 17: 486497.CrossRefGoogle ScholarPubMed
12.Carter, BG, Butt, W. Review of the use of somatosensory evoked potentials in the prediction of outcome after severe brain injury. Crit Care Med 2001; 29: 178186.CrossRefGoogle ScholarPubMed
13.Robinson, LR, Micklesen, PJ, Tirschwell, DL, Lew, HL. Predictive value of somatosensory evoked potentials for awakening from coma. Crit Care Med 2003; 31: 960967.CrossRefGoogle ScholarPubMed
14.Carter, BG, Butt, W. Are somatosensory evoked potentials the best predictor of outcome after severe brain injury: a systematic review. Intensive Care Med 2005; 31: 765775.CrossRefGoogle ScholarPubMed
15.Bassetti, C, Bomio, F, Mathis, J, Hess, CW. Early prognosis in coma after cardiac arrest: a prospective clinical, electrophysiological, and biochemical study of 60 patients. J Neurol Neurosurg Psychiatry 1996.; 61: 610615.CrossRefGoogle ScholarPubMed
16.Zandbergen, EG, de Haan, RJ, Koelman, JH, Hijdra, A. Prediction of poor outcome in anoxic-ischemic coma. J Clin Neurophysiol 2000; 17: 498501.CrossRefGoogle ScholarPubMed
17.Wijdicks, EF, Hijdra, A, Young, GB, Bassetti, CL, Wiebe, S. Quality Standards Subcommittee of the American Academy of Neurology. Practice parameter: prediction of outcome in comatose survivors after cardiopulmonary resuscitation (an evidence-based review): report of the Quality Standards Subcommittee of the American Academy of Neurology. Neurology 2006; 67: 203210.CrossRefGoogle Scholar
18.Logi, F, Fischer, C, Murri, L, Mauguiere, F. The prognostic value of evoked responses from primary somatosensory and auditory cortex in comatose patients. Clin Neurophysiol 2003; 114: 16151627.CrossRefGoogle ScholarPubMed
19.Facco, E, Munari, M. The role of evoked potentials in severe head injury. Intensive Care Med 2000; 26: 9981005.CrossRefGoogle ScholarPubMed
20.Claassen, J, Mayer, SA, Hirsch, LJ. Continuous EEG monitoring in patients with subarachnoid hemorrhage. J Clin Neurophysiol 2005; 22: 9298.CrossRefGoogle ScholarPubMed
21.Konasiewicz, SJ, Moulton, RJ, Shedden, PM. Somatosensory evoked potentials and intracranial pressure in severe head injury. Can J Neurol Sci 1994; 21: 219226.CrossRefGoogle ScholarPubMed
22.Moulton, RJ, Brown, JI, Konasiewicz, SJ. Monitoring severe head injury: a comparison of EEG and somatosensory evoked potentials. Can J Neurol Sci 1998; 25: S7S11.CrossRefGoogle ScholarPubMed
23.Forsyth, R, Baxter, P, Elliot, T. Routine intracranial pressure monitoring in acute coma. Cochrane Database Syst Rev 2001; 3: CD002043.Google Scholar
24.Fossi, S, Amantini, A, Grippo, A et al. . Continuous EEG-SEP monitoring of severely brain injured patients in NICU: methods and feasibility. Neurophysiol Clin 2006; 36: 195205.CrossRefGoogle ScholarPubMed