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Objective To evaluate the accuracy of automated interictal low-density electrical source imaging (LD-ESI) to define the insular irritative zone (IZ) by comparing the concomitant interictal ESI localization with the SEEG interictal activity. Methods Long-term concomitant scalp electroencephalography (EEG) and stereo-EEG (SEEG) with at least one depth electrode exploring the operculo-insular region(s) were analyzed. Automated interictal ESI was performed on the scalp EEG using standardized low-resolution brain electromagnetic tomography and individual head models. A two-step analysis was performed: i) sublobar concordance between cluster-based ESI localization and SEEG-based IZ; ii) time-locked ESI-/SEEG analysis. Diagnostic accuracy values were calculated using SEEG as reference standard. Subgroup analysis was carried out, based on the involvement of insular contacts in the seizure onset and patterns of insular interictal activity. Results Thirty patients were included in the study. ESI showed an overall accuracy of 53% (C.I. 29-76%). Sensitivity and specificity were calculated as 53% (C.I. 29-76%), 55% (C.I. 23-83%) respectively. Higher accuracy was found in patients with frequent and dominant interictal insular spikes. Conclusions LD-ESI defines with good accuracy the insular implication in the IZ, which is not possible with classical interictal scalp EEG interpretation. Significance Automated LD-ESI may be a valuable additional tool to characterize the epileptogenic zone in epilepsies with suspected insular involvement.

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Purpose To determine the diagnostic accuracy of ictal Electrical source imaging (ESI) and subsequent Functional connectivity (FC) to localize the seizure onset zone from classical 19-21 electrodes scalp EEG, in a cohort of extratemporal lobe epilepsy (ETLE) patients. Methods STARD guidelines were adopted for reporting the present study. The epilepsy surgical database of St.Luc Hospital, Brussels, Belgium was retrospectively screened for consecutive patients with: (1) resective surgery for ETLE (2) availability of structural MRI and scalp EEG monitoring (3) 1-year follow-up available. The epileptologist marked seizure onsets characterized by: (1) rhythmical discharges in the delta, theta or alpha band (2) rhythmical spiking activity, (3) fast paroxysmal low voltage activity. Spasms and seizures presenting a non-rhythmic or electrodecremental pattern were excluded. We developed a semi-automated analysis of rhythmic ictal EEG. First, a spectrogram-based algorithm was applied to automatically select the epoch length and the frequency of interest. For ESI power method, we considered as SOZ the source with the highest power (SPOW). For ESI+FC, we used the source with the highest out-degree (SCONN) based on Granger causality FC analysis. Sublobar concordance was determined between SPOW, SCONN and the resection zone, used as reference standard, and diagnostic accuracy was evaluated based on surgical outcome. Results We could analyze 98 seizures from 25 patients. At a seizure level, the overall accuracy was 42% for ESI power (C.I. 17-53%) and 66% for ESI+FC (C.I. 54-78%), at p = 0,0042 (chi-square test). Sensitivity was 36% for ESI power and 54% for ESI+FC. Test specificity was 57% for ESI power and 86% for ESI+FC. Positive predictive value reached 90,2% for ESI+FC. Conclusion Ictal FC analysis may be a valuable tool in the pre-surgical evaluation of ETLE cases. FC significantly improves SOZ localization compared to ESI solely, and is readily applicable on a classic 19-21 ch

Intra-operative electrocorticography (ECoG) has been traditionally used in the surgical management of medically refractory partial epilepsies to identify the limits of the epileptogenic zone. This retrospective study had as goal to evaluate whether tailored surgery based on the presurgical evaluation completed by intra-operative post-resection ECoG improves outcome. We reviewed 94 cases of epilepsy surgery with intra-operative ECoG and determined how many had an ECoG-guided surgical procedure in addition to the initial planned surgery. We also reviewed the presence of specific recurrent ECoG patterns of interictal epileptiform discharges (IED) in the exposed cortical surface, such as: electrographic seizures, bursts, intermittent spike waves, polyspikes or fast rhythms and continuous or quasi-continuous spiking. When performing a post-resection ECoG-tailored surgery, outcome did not improve in lesional or non-lesional epilepsy. Postoperative residual IED did not correlate with a poorer outcome. In our study, the persistence of post-resection IED on ECoG is not correlated with outcome in patients with lesional or non-lesional epilepsy.

Many epilepsy patients treated with vagus nerve stimulation additionally use an "on-demand" function, triggering an extra stimulation to terminate a seizure or diminish its severity. Nevertheless, a substantial number of patients are not able to actively trigger stimulations by use of a magnet, due to the absence of an aura or inability for voluntary actions in the early phase of a seizure. To address this need, a novel implantable pulse generator, the AspireSR VNS system, was developed to provide automated ictal stimulation triggered by a seizure-detecting algorithm. We report our experience with three patients in assessing the functionality of ictal stimulation, illustrating the detection system in practice. Detection of ictal tachycardia and variable additional detections of physiological tachycardia depended on the individual seizure-detecting algorithm settings.

Motor cortex stimulation (MCS) is considered to be an effective treatment in some types of chronic refractory neuropathic pain. The aim of this study is to evaluate and confirm the feasibility, efficacy and security of our surgical technique for subdural motor cortex stimulation (SD MCS) on 18 consecutive cases with follow-up of at least 3 years.

BACKGROUND: To describe a case of auto-immune encephalitis in an adolescent with favorable outcome despite prolonged status epilepticus. METHODS: A 17 year old Asian man without previous medical history developed alteration of consciousness and partial seizures. The diagnosis of anti-N-methyl-D-aspartate receptor encephalitis was confirmed by the detection of specific antibodies in both cerebrospinal fluid and serum. RESULTS: The clinical course was complicated by prolonged status epilepticus which was refractory to a large number of antiepileptic drugs, including barbiturate coma. Immunomodulatory therapy included steroids, plasma exchanges, and intravenous immunoglobulins. After 86 days of intensive therapy, the patient regained consciousness progressively. Brain magnetic resonance imaging never demonstrated any lesion. Extensive search for a tumor was negative. At 12 month follow-up, the patient had made an excellent recovery. CONCLUSION: Auto-immune encephalitis is likely underdiagnosed in adolescents. In their most severe presentation, seizures may be resistant to a large number of anti-epileptic drugs, and the clinical improvement seems to be mainly because of the immunomodulatory therapy. Relapse is possible, as well as the delayed development of a teratoma or other tumor.

This paper proposes therapeutic guidelines for the management of some epileptic syndromes in infants, children, and adolescents, based on available medical literature and clinical practice in the French Community of Belgium. The guidelines address both epileptic encephalopathies (West syndrome, Lennox-Gastaut syndrome, and Dravet syndrome) and idiopathic epilepsies (typical absence seizures, epilepsy with centro-temporal spikes and juvenile myoclonic epilepsy).

This paper proposes therapeutic guidelines for the management of some epileptic syndromes in infants, children, and adolescents, based on available medical literature and clinical practice in the French Community of Belgium. The guidelines address both epileptic encephalopathies (West syndrome, Lennox-Gastaut syndrome, and Dravet syndrome) and idiopathic epilepsies (typical absence seizures, epilepsy with centro-temporal spikes and juvenile myoclonic epilepsy)., Journal Article, Review, info:eu-repo/semantics/published

This paper proposes therapeutic guidelines for the management of some epileptic syndromes in infants, children, and adolescents, based on available medical literature and clinical practice in the French Community of Belgium. The guidelines address both epileptic encephalopathies (West syndrome, Lennox-Gastaut syndrome, and Dravet syndrome) and idiopathic epilepsies (typical absence seizures, epilepsy with centro-temporal spikes and juvenile myoclonic epilepsy)., Journal Article, Review, info:eu-repo/semantics/published

Objective: Verify and explore unexpected results suggesting an effect of deviance direction (shorter or longer deviants) on the amplitude of MMNs evoked by sound duration contrasts. Methods: MMNs were recorded using the oddball paradigm on ten adults. Four standard stimulus durations (100, 150, 200 and 250 ms) were used and deviants were 50% shorter or longer. Behavioral data (hit rates, d', and reaction times) were collected after the electrophysiological sessions. Results: MMNs were larger for short than for long deviants. There was no effect on MMN latencies. Hit rates and d' data were almost at ceiling level for all conditions even for the longest standard - long deviant combination in which the MMN was abolished. Conclusions: We argue that the deviance direction effect on MMN amplitudes can be explained by the delay between the moment of deviance detection and the end of the deviance quantification process. Significance: A major effect of deviance direction on amplitudes was confirmed. This effect, which was confined to electrophysiological data, is to be taken into account when using duration contrasts to probe the processing of temporal information. (C) 2008 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

OBJECTIVE: Verify and explore unexpected results suggesting an effect of deviance direction (shorter or longer deviants) on the amplitude of MMNs evoked by sound duration contrasts. METHODS: MMNs were recorded using the oddball paradigm on ten adults. Four standard stimulus durations (100, 150, 200 and 250ms) were used and deviants were 50% shorter or longer. Behavioral data (hit rates, d', and reaction times) were collected after the electrophysiological sessions. RESULTS: MMNs were larger for short than for long deviants. There was no effect on MMN latencies. Hit rates and d' data were almost at ceiling level for all conditions even for the longest standard - long deviant combination in which the MMN was abolished. CONCLUSIONS: We argue that the deviance direction effect on MMN amplitudes can be explained by the delay between the moment of deviance detection and the end of the deviance quantification process. SIGNIFICANCE: A major effect of deviance direction on amplitudes was confirmed. This effect, which was confined to electrophysiological data, is to be taken into account when using duration contrasts to probe the processing of temporal information., Journal Article, Research Support, Non-U.S. Gov't, SCOPUS: ar.j, info:eu-repo/semantics/published

OBJECTIVE: Verify and explore unexpected results suggesting an effect of deviance direction (shorter or longer deviants) on the amplitude of MMNs evoked by sound duration contrasts. METHODS: MMNs were recorded using the oddball paradigm on ten adults. Four standard stimulus durations (100, 150, 200 and 250ms) were used and deviants were 50% shorter or longer. Behavioral data (hit rates, d', and reaction times) were collected after the electrophysiological sessions. RESULTS: MMNs were larger for short than for long deviants. There was no effect on MMN latencies. Hit rates and d' data were almost at ceiling level for all conditions even for the longest standard - long deviant combination in which the MMN was abolished. CONCLUSIONS: We argue that the deviance direction effect on MMN amplitudes can be explained by the delay between the moment of deviance detection and the end of the deviance quantification process. SIGNIFICANCE: A major effect of deviance direction on amplitudes was confirmed. This effect, which was confined to electrophysiological data, is to be taken into account when using duration contrasts to probe the processing of temporal information., Journal Article, Research Support, Non-U.S. Gov't, SCOPUS: ar.j, info:eu-repo/semantics/published

PURPOSE: To present our results using multiple subpial transections (MST) for the treatment of pharmacologically refractory epilepsy (PRE) with epileptogenic foci in eloquent areas. METHOD: Between January 2003 and March 2006, we treated 33 patients with PRE with epileptogenic foci in eloquent areas by MST "in rays", either isolated (MSTs group) or completing resection or disconnection of other cortical areas (MST+ group). Our first 30 patients had a follow-up of at least 24 months: eight in the MSTs group and 22 in the MST+ group. Four postoperative grades were distinguished based on a modified Engel classification: seizure-free (100% seizure reduction equals to Grade I), substantial significant seizure reduction (75% to 99% seizure reduction equals to Grade II), moderate significant reduction (50% to 74% seizure reduction equals to Grade III) and finally no significant reduction (seizure reduction less than 50% equals to Grade IV). RESULTS: In the MSTs group, two patients (25%) were in grade I and five (62%) in grade II or III. In the MST+ group, six patients (27%) were in grade I and 13 (59%) in grade II or III. All patients showed some seizure reduction and some improvement in behavior or cognitive function with no permanent neurological deficit. CONCLUSION: This series supports the notion that multiple subpial transections are associated with a significant seizure reduction (in 86.6% of the cases reported herein) and that the risk of permanent neurological deficit can be very low.

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FLWIN, info:eu-repo/semantics/published

A 79-year-old man with end-stage renal disease treated by automated peritoneal dialysis was referred to the emergency department for altered consciousness. The first investigations, including toxicology screening, failed to reveal the precise etiology. The patient was treated for a possible seizure. After the progression of central nervous system depression with bradypnea, the patient was intubated and mechanically ventilated. It appeared later on that he had ingested by mistake one of his wife's medications, baclofen. Baclofen was detected in the blood sampled on admission at a level above the therapeutic range. Baclofen is mainly excreted by the kidney. A short-term administration of low-dose of baclofen is not effectively removed by peritoneal dialysis and may result in prolonged but reversible coma.

Seizures starting in patients over 60 years old are frequent. Diagnosis is sometimes difficult and frequently under- or overrated. Cerebrovascular disorders are the main cause of a first seizure. Because of more frequent comorbidities, physiologic changes, and a higher sensitivity to drugs, treatment has some specificity in elderly people. The aim of this paper is to present the result of a consensus meeting held in October 2004 by a Belgian French-speaking group of epileptologists and to propose guidelines for the management and the treatment of epilepsy in elderly people.

The authors propose to define the epileptic syndromes with continuous spikes and waves during slow sleep (CSWS) as a cognitive or behavioral impairment acquired during childhood, associated with a strong activation of the interictal epileptiform discharges during NREM sleep--whatever focal or generalized--and not related to another factor than the presence of CSWS. The type of syndrome will be defined according to the neurological and neuropsychological deficit. These syndromes have to be classified among the localization-related epileptic syndromes. Some cases are idiopathic and others are symptomatic. Guidelines for work-up and treatment are proposed., Journal Article, Review, SCOPUS: ar.j, info:eu-repo/semantics/published

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Seizures starting in patients over 60 years old are frequent. Diagnosis is sometimes difficult and frequently under- or overrated. Cerebrovascular disorders are the main cause of a first seizure. Because of more frequent comorbidities, physiologic changes, and a higher sensitivity to drugs, treatment has some specificity in elderly people. The aim of this paper is to present the result of a consensus meeting held in October 2004 by a Belgian French-speaking group of epileptologists and to propose guidelines for the management and the treatment of epilepsy in elderly people., Journal Article, Practice Guideline, info:eu-repo/semantics/published

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The authors propose to define the epileptic syndromes with continuous spikes and waves during slow sleep (CSWS) as a cognitive or behavioral impairment acquired during childhood, associated with a strong activation of the interictal epileptiform discharges during NREM sleep--whatever focal or generalized--and not related to another factor than the presence of CSWS. The type of syndrome will be defined according to the neurological and neuropsychological deficit. These syndromes have to be classified among the localization-related epileptic syndromes. Some cases are idiopathic and others are symptomatic. Guidelines for work-up and treatment are proposed., Journal Article, Review, SCOPUS: ar.j, info:eu-repo/semantics/published

Seizures starting in patients over 60 years old are frequent. Diagnosis is sometimes difficult and frequently under- or overrated. Cerebrovascular disorders are the main cause of a first seizure. Because of more frequent comorbidities, physiologic changes, and a higher sensitivity to drugs, treatment has some specificity in elderly people. The aim of this paper is to present the result of a consensus meeting held in October 2004 by a Belgian French-speaking group of epileptologists and to propose guidelines for the management and the treatment of epilepsy in elderly people., Journal Article, Practice Guideline, info:eu-repo/semantics/published

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This report illustrates the usefulness and safety of very early hemispherotomy in an infant with Ohtahara syndrome (OS) secondary to left parieto-occipital megalencephaly. It provides evidence that surgical intervention might provide promising results in selected cases, and that young age is not a contraindication for this type of surgery.

PURPOSE: To our knowledge, the epileptic and nonepileptic electroencephalographic (EEG) discharges recorded within the human mammillary body (MB) and mammillothalamic tract (MTT) areas have never been published. Herein, we present the EEG recordings from these structures in patients with refractory epilepsy (RE). METHODS: Three men (ages 41-43 years) were enrolled in a clinical trial for deep brain stimulation (DBS) of MB-MTT in RE. Previous evaluations had demonstrated a low likelihood of successful response to medication or resective surgery. DBS macroelectrodes were bilaterally implanted within the MB-MTT under general anesthesia and their location checked by magnetic resonance imaging (MRI). We obtained a surface-depth EEG for a 2- to 4-day period, including monitoring of the cardiorespiratory and mnemonic functions. RESULTS: The background pattern of EEG recorded from MB-MTT was low-amplitude (usually <25 microv for MB and <20 microv for MTT) waves with a variable combination of theta-beta rhythms. In two patients, pseudoperiodic slow spikes were unilaterally recorded with or without clinical signs. For one patient, several focal ictal discharges were recorded in the right MB without scalp EEG changes. CONCLUSIONS: The analysis of our depth EEG revealed that the theta-beta pattern represents the predominant physiologic profile of MB. Paroxysmal epileptiform discharges can be observed in human MB. These data supplement those available from animal observations.

We report the case of a patient who received two infusions of dimethylsulfoxide (DMSO) cryopreserved autologous peripheral blood progenitor cells (PBPCs) after myeloablative chemotherapy for a relapsing lymphoma. A 49-year-old man presented an episode of tonic-clonic seizure over a few minutes after the start of each infusion and developed a profound and sustained but reversible encephalopathy with coma after the second infusion. The patient's neurological condition correlated well with the electrophysiological findings (electroencephalogram and multimodality evoked potentials) and, to a lesser extent, with the radiological abnormalities (magnetic resonance imaging). Severe but reversible neurological complications may occur with the infusion of PBPCs cryopreserved with DMSO.

This report illustrates the usefulness and safety of very early hemispherotomy in an infant with Ohtahara syndrome (OS) secondary to left parieto-occipital megalencephaly. It provides evidence that surgical intervention might provide promising results in selected cases, and that young age is not a contraindication for this type of surgery. © 2005 BEA Trading Ltd. Published by Elsevier Ltd. All rights reserved., SCOPUS: ar.j, info:eu-repo/semantics/published

Epilepsy and psychiatric diseases are frequent comorbidities. Psychoses in patients with epilepsy have special physiopathology and several clinical presentations and prognoses. Their treatments are also specific, according to the specific diagnosis. This paper represents the summary of a consensus meeting held in November 2003 by a Belgian French-speaking group of neurologists, neuropediatricians and psychiatrists and proposes guidelines for the recognition and treatment of those entities., SCOPUS: ar.j, info:eu-repo/semantics/published

This report illustrates the usefulness and safety of very early hemispherotomy in an infant with Ohtahara syndrome (OS) secondary to left parieto-occipital megalencephaly. It provides evidence that surgical intervention might provide promising results in selected cases, and that young age is not a contraindication for this type of surgery. © 2005 BEA Trading Ltd. Published by Elsevier Ltd. All rights reserved., SCOPUS: ar.j, info:eu-repo/semantics/published

Epilepsy and psychiatric diseases are frequent comorbidities. Psychoses in patients with epilepsy have special physiopathology and several clinical presentations and prognoses. Their treatments are also specific, according to the specific diagnosis. This paper represents the summary of a consensus meeting held in November 2003 by a Belgian French-speaking group of neurologists, neuropediatricians and psychiatrists and proposes guidelines for the recognition and treatment of those entities., SCOPUS: ar.j, info:eu-repo/semantics/published

Approximately 20% of people with epilepsy are of childbearing potential and about 3 to 5 births per thousand will be to women with epilepsy. Both epilepsy and antiepileptic drugs can cause specific problems in women and embryos (less than 8 weeks of gestational age) or foetuses (more than 8 weeks of gestational age). The aim of this paper is to discuss therapeutic issues for the management of women with epilepsy: initiation of antiepileptic therapy, contraception, pregnancy, breast feeding and menopause. Some fertility issues are also discussed., Guideline, Journal Article, Practice Guideline, SCOPUS: re.j, info:eu-repo/semantics/published

Approximately 20% of people with epilepsy are of childbearing potential and about 3 to 5 births per thousand will be to women with epilepsy. Both epilepsy and antiepileptic drugs can cause specific problems in women and embryos (less than 8 weeks of gestational age) or foetuses (more than 8 weeks of gestational age). The aim of this paper is to discuss therapeutic issues for the management of women with epilepsy: initiation of antiepileptic therapy, contraception, pregnancy, breast feeding and menopause. Some fertility issues are also discussed., Guideline, Journal Article, Practice Guideline, SCOPUS: re.j, info:eu-repo/semantics/published

PURPOSE: To present a method of predicting spinal cord ischemia before deployment of an endograft in the thoracoabdominal aorta. CASE REPORT: A 76-year-old high-risk patient presented with an aneurysm of the distal thoracic and proximal abdominal aorta. An endovascular treatment was scheduled, but before deployment of the endograft, occlusion of the aneurysmal segment was monitored for 15 minutes using multilevel somatosensory evoked potentials (SEP). An external axillofemoral bypass was necessary during the test period to prevent distal ischemia; transesophageal echocardiography verified the absence of flow inside the aneurysm during occlusion. Because no SEP changes occurred during the 15-minute test, a 20-cm-long endograft was deployed. No postoperative neurological event was encountered, and the aneurysm has remained successfully excluded with shrinkage of the sac diameter by 1 cm at 6 months. CONCLUSIONS: An occlusion test to detect spinal cord ischemia before deployment of an endograft could be useful in lowering the risk of paraplegia associated with endovascular treatment of thoracoabdominal aneurysm.

The choice of treatment of newly diagnosed epilepsy involves many factors such as age, sex, life style, general health and concomitant medication. The seizure type, syndrome, and the pharmacology, efficacy and safety of the antiepileptic drugs (AEDs) should also be considered. Some of the new AEDs appear to provide at least equivalent efficacy with better tolerability. Some of these drugs have the potential to become drugs of first choice in newly diagnosed epilepsy. At the present time, we also must consider the criteria of reimbursement of these drugs. In this paper, we try to describe common and practical strategies to start a treatment of newly diagnosed epilepsy., Guideline, Journal Article, Practice Guideline, info:eu-repo/semantics/published

The choice of treatment of newly diagnosed epilepsy involves many factors such as age, sex, life style, general health and concomitant medication. The seizure type, syndrome, and the pharmacology, efficacy and safety of the antiepileptic drugs (AEDs) should also be considered. Some of the new AEDs appear to provide at least equivalent efficacy with better tolerability. Some of these drugs have the potential to become drugs of first choice in newly diagnosed epilepsy. At the present time, we also must consider the criteria of reimbursement of these drugs. In this paper, we try to describe common and practical strategies to start a treatment of newly diagnosed epilepsy., Guideline, Journal Article, Practice Guideline, info:eu-repo/semantics/published

Recent data have focused on the peripheral nerve myelin glycoprotein P0 as a putative autoantigen involved in the autoimmune etiology of some cases of Meniere's disease, idiopathic sensorineural hearing loss and sudden deafness. To determine whether antibodies to myelin P0 can alter cochlear function, 13 healthy guinea pigs were immunized with purified porcine myelin P0 while 10 controls were injected with saline water. The animals were then evaluated for evidence of evolving inner ear disease using immunological, electrophysiological and morphological methods. Twenty-six experimental ears were tested weekly with a brainstem auditory evoked potential technique for a period of 4 months and were compared to 20 control ears. Uniformly, all P0-sensitized guinea pigs showed antibodies to myelin protein P0 as evidenced by ELISA. Clinical signs of inflammatory demyelination were not discernible in P0-sensitized guinea pigs and all the animals were qualitatively normal. No significant increase of evoked potential thresholds was found in the P0-sensitized animals when compared to controls (P>0.05). Peak latencies of waves I, II, III, IV and V and inter-peak latencies in P0-sensitized guinea pigs did not significantly differ from those of controls (P>0.05). Histological sections of inner ear and peripheral nerves were free of disease in both groups. These findings indicate that the sole presence of antibodies to myelin P0 in the sera of guinea pigs or patients suspected of having autoimmune inner ear diseases is unlikely to elicit auditory abnormalities and that additional factors are necessary for the pathogenic development of these disorders.

OBJECTIVE: To study the event related potentials (ERPs) in coma and altered states of consciousness, their relationship with the clinical status and coma outcome. METHODS: ERPs were recorded with a passive auditory oddball paradigm in 103 patients. Their probability of occurrence and the peak latencies and amplitudes were studied as a function of the Glasgow Coma Score (GCS). Their relationship with outcome was studied in a subset of 83 patients examined within the first 4 days, and expressed in terms of sensitivity, specificity, and negative or positive prognostic values. RESULTS: When present, the ERPs to rare stimuli consisted of a fronto-central negativity (N(endog), mean latency: 330 ms) and a fronto-central positivity (P(endog), mean latency: 431 ms) following the exogenous N100-P200 complex. Both their probability of occurrence and their latencies and amplitudes were related with the GCS in anoxic and traumatic comas. The N(endog) and P(endog) had high sensitivity with a negative predictive value of 70% and 100%, respectively, but a low specificity, with a positive predictive value of 44% and 41%, respectively. CONCLUSIONS: ERPs can be recorded in some comatose patients and are likely to reflect implicit orienting processes rather than preserved consciousness. Their presence implies a good prognosis but no conclusion can be drawn from their absence.

OBJECTIVE: To present results of electrophysiologic investigations of the visual toxicity observed during the early stage of methanol poisoning. DESIGN: Retrospective, clinical study. SETTING: A 7-bed intensive care unit in a university hospital. PATIENTS: Nineteen patients admitted with a diagnosis of acute methanol poisoning. INTERVENTIONS: Visual evoked potentials were obtained within the first 48 hrs after admission; a clinical follow-up examination was performed in 11 patients, and 12 patients were followed up by visual evoked potentials beyond the same delay. Correlations between the occurrence of an optic neuropathy and clinical, biological, and electrophysiological data were studied. MEASUREMENTS AND MAIN RESULTS: A significant correlation was found between arterial pH and blood formate concentration (r2 = 0.58, p = .003), between blood formate and bicarbonate concentrations (r2 = 0.36, p = .02), and between delay from ingestion and blood formate concentration (r2 = 0.44, p = .017). Clinical outcome was correlated not only with the bicarbonate (p = .007), formate (p = .018), and methanol (p = .03) concentrations and arterial pH (p = .004) but also with a well-defined electrophysiologic pattern during the acute stage. An index of global cortical functioning > or =3 was associated with death, whereas a global cortical functioning index < or =2 was associated with survival (p = .0058). Moreover, a statistically significant difference in long-term visual impairment was found between the subgroup with abnormal wave III morphology or a global cortical functioning index of 1-2 and the subgroup with normal wave III morphology and a global cortical functioning index <1 (p = .015). Results of the electrophysiologic studies were expressed as retinal dysfunction and optic nerve injury. Five patients had normal findings on electrophysiologic examination. Ten patients had early signs of retinal dysfunction that were fully reversed in the eight patients who were followed.

BACKGROUND: We evaluated the efficiency of median-nerve somatosensory evoked potentials (SEPs) monitoring in determining the optimal level of hypothermia in 62 consecutive patients operated on under deep hypothermic circulatory arrest (CA). METHODS: CA was started at 1 degree C below the temperature at which both brainstem and cortical SEP components disappear. No additional method of cerebral protection was used. RESULTS: New neurological complications were observed in 15 patients: long-lasting in 11 and transient in 4. A retrospective analysis of SEP monitoring identified the origin of the complications in 12 cases: early CA with incomplete cooling due to emergency (3 cases); inefficient retrograde perfusion through the femoral artery during cooling due to the dissection flap effect (4 cases); embolism during rewarming (2 cases); delayed embolism (2 cases); hemorrhagic shock (1 case). In 2 cases, neurological sequelae involved the lower limbs (extracerebral origin). One case without intraoperative SEP changes was neurologically abnormal preoperatively and did not change postoperatively. There were no cases with sequelae due to excessive CA duration. CONCLUSIONS: The use of SEP monitoring to determine the optimal level of hypothermia efficiently prevents neurological sequelae of CA. It helps in monitoring the degree of cerebral protection during cooling (flap effect), and rewarming.