Recommendations for the use of electroencephalography and evoked potentials in comatose patients.

Predicting the outcome of a comatose or poorly responsive patient is a major issue for intensive care unit teams, in order to give the most accurate information to the family and to choose the best therapeutic option. However, determining the level of cortical activity in patients with disorders of consciousness is a real challenge. Reliable criteria are required to help clinicians in the decision-making process, especially in the acute phase of coma.

Neurophysiological assessment of brain dysfunction in critically ill patients: an update.

The aim of this review was to provide up-to-date information about the usefulness of clinical neurophysiology testing in the management of critically ill patients. Evoked potentials (EPs) and electroencephalogram (EEG) are non-invasive clinical neurophysiology tools that allow an objective assessment of the central nervous system's function at the bedside in intensive care unit (ICU). These tests are quite useful in diagnosing cerebral complications, and establishing the vital and functional prognosis in ICU.

Somatosensory evoked potentials in the assessment of peripheral neuropathies: Commented results of a survey among French-speaking practitioners and recommendations for practice.

Background: Somatosensory evoked potentials (SSEPs) are increasingly performed for the assessment of peripheral neuropathies, but no practical guidelines have yet been established in this specific application.

Study Aim: To determine the relevant indication criteria and optimal technical parameters for SSEP recording in peripheral neuropathy investigation.

Methods: A survey was conducted among the French-speaking practitioners with experience of SSEP recording in the context of peripheral neuropathies.

Neurophysiological testing in neurocritical care.

Purpose Of Review: To summarize a consensus of European authorities about the applications of clinical neurophysiology in the ICU and, particularly, for a clinically useful management of individual patients.

Recent Findings: Clinical neurophysiology is useful for diagnosis (epilepsy, brain death, and neuromuscular disorders), prognosis (anoxic ischemic encephalopathy, head trauma, and neurological disturbances of metabolic and toxic origin), and follow-up. The prognostic significance of each test varies as a function of coma etiology.

Neurophysiological investigations of hepatic encephalopathy: ISHEN practice guidelines.

By studying neuronal activity through neuronal electrogenesis, neurophysiological investigations provide a functional assessment of the nervous system and, therefore, has been used for quantitative assessment and follow-up of hepatic encephalopathy (HE). The different clinical neurophysiological approaches can be classified depending on the function to explore and their sensitivity to HE. The reliable techniques are those that reflect cortical function, i.

Consensus on the use of neurophysiological tests in the intensive care unit (ICU): electroencephalogram (EEG), evoked potentials (EP), and electroneuromyography (ENMG).

Study Aim: To provide a consensus of European leading authorities about the optimal use of clinical neurophysiological (CN) tests (electroencephalogram [EEG]; evoked potentials [EP]; electroneuromyography [ENMG]) in the intensive care unit (ICU) and, particularly, about the way to make these tests clinically useful for the management of individual patients.

Methods: This study gathered together several European clinical neurophysiologists and neurointensivists whose leading contributions in the adult or paediatric ICU and in continuous neuromonitoring had been peer-acknowledged. It was based on both a literature review and each participant's own experience.

How clinical neurophysiology may contribute to the understanding of a psychiatric disease such as schizophrenia.

Introduction: The increasing knowledge about anatomical structures and cellular processes underlying psychiatric disorders may help bridge the gap between clinical manifestations and basic physiological processes. Accordingly, important insights have been brought these last years into a main psychiatric affection, i.e.

Recommendations for the clinical use of somatosensory-evoked potentials.

The International Federation of Clinical Neurophysiology (IFCN) is in the process of updating its Recommendations for clinical practice published in 1999. These new recommendations dedicated to somatosensory-evoked potentials (SEPs) update the methodological aspects and general clinical applications of standard SEPs, and introduce new sections dedicated to the anatomical-functional organization of the somatosensory system and to special clinical applications, such as intraoperative monitoring, recordings in the intensive care unit, pain-related evoked potentials, and trigeminal and pudendal SEPs. Standard SEPs have gained an established role in the health system, and the special clinical applications we describe here are drawing increasing interest.

Lateralisation of intranasal trigeminal chemosensory event-related potentials.

Aim Of The Study: To determine whether or not chemosensory event-related brain potentials (CSERP) elicited by nociceptive unilateral intranasal (CO2) trigeminal stimulation are lateralized and, if they are, whether this hemispheric lateralization is related to the side of the stimulated nostril.

Methods: Nine healthy right-handed subjects participated to the study. CSERPs were recorded after left or right monorhinal CO2 stimulation.

Stump pressure and somatosensory evoked potentials for predicting the use of shunt during carotid surgery.

The aim of this study is to compare measurement of stump pressure (SP) and somatosensory evoked potentials (SSEP) made during carotid surgery as criteria upon which to base the decision whether or not to use a shunt. We included 288 patients who underwent for carotid surgery under general anaesthesia. We performed 247 endarterectomies with patch closure (85.

The EEG assessment of low-grade hepatic encephalopathy: comparison of an artificial neural network-expert system (ANNES) based evaluation with visual EEG readings and EEG spectral analysis.

Objective: The EEG provides an objective staging of hepatic encephalopathy (HE), but its interpretation may be biased by inter-observer variability. This study aims at comparing an entirely automatic EEG classification of HE based on an artificial neural network-expert system procedure (ANNES) with visual and spectral analysis based EEG classifications.

Methods: Two hundred and thirty-eight consecutive cirrhotic patients underwent closed-eye EEG.

Assessment of olfactory and trigeminal function using chemosensory event-related potentials.

Goals: To give an overview on the theoretical and practical applications of chemosensory event-related potentials.

Methods: Chemosensory event-related potentials (ERPs) may be elicited by brief and precisely defined odorous stimuli. Based on the principles of air-dilution olfactometry, a stimulator was developed in the late 1970s, which allows stimulation of the olfactory neuroepithelium and the nasal mucosa with no concomitant mechanical stimulation.

Analysis of EEG tracings in frequency and time domain in hepatic encephalopathy.

Spectral EEG analysis in hepatic encephalopathy (HE) is usually performed disregarding the effect of epoch length, statistical errors and equipment noise. A study on these items was carried out. In addition, spectral analysis and a new analysis, performed in time domain, were compared in the assessment of HE.

Neurophysiological patterns of vegetative and minimally conscious states.

This paper reviews the possible usefulness of electroencephalogram (EEG) and evoked potential (EP) recording in vegetative and poorly-responsive patients. There is a marked inter-individual EEG and EP variability, which reflects the state heterogeneity. Four clinical applications are described: (1) the identification of primary midbrain dysfunction--and, therefore, a possible reversibility--in post-traumatic states; (2) the identification of the permeability of sensory channels; (3) quantitative follow-up; and (4) individual assessment of cognitive functions and/or consciousness.

Recording click-evoked myogenic potentials (CEMPs) with a setup for brainstem auditory evoked potentials (BAEPs).

Aim Of The Study: Click-evoked myogenic potentials (CEMPs) originate in the sternocleidomastoid (SCM) muscle through a reflex loop involving the sacculus and the vestibular nerve. In this study we suggest that they can be picked up from the mastoid reference used for auditory evoked potential (AEP) recording by using standard filters for brainstem AEPs (BAEPs). They consist of a P13-N20 complex.

Evoked potentials in severe brain injury.

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.