Epilepsy and tobacco smoking: a cross-sectional study.

There is little data concerning the prevalence of smoking in the population of people with epilepsy. The present study addresses this aspect in a sample of 429 unselected adults with epilepsy living in French-speaking Switzerland. The criterion of at least one cigarette per day for the past 6 months was used to define the status of "current" smoker. The questionnaires included questions about the type of epilepsy and tobacco consumption and were prospectively filled by attending neurologists in the presence of their patient, ensuring a reliable diagnosis of epilepsy. Data were compared with those of the "Tabakmonitoring" data collection, which gives annually detailed information about tobacco use habits in the Switzerland's population according to the different linguistic regions. Among patients suffering from epilepsy, the prevalence of current smoking was 32.1 % (28.8 % among women and 35 % among men), while the prevalence of smoking was 19.0 % in the general population in French-speaking Switzerland in the same period [OR 2.0, confidence interval (CI) 1.6-2.5, p < 0.001]. The subgroup of patients with epilepsy suffering from idiopathic (genetic) generalized epilepsy had the highest prevalence of smoking: 44.3 versus 27.8 % in the other types of epilepsy-p = 0.03. Epilepsy appears significantly correlated to smoking. The possible causal relationship, such as common genetic susceptibility to epilepsy and to nicotine addiction, indirect comorbidity through stress or depression associated with epilepsy, beneficial effect of nicotine on epilepsy, still remains unclear and deserves further studies.

Ictal bradycardia and asystole: an uncommon cause of syncope.

We report on two patients with recurrent syncope secondary to ictal bradyarrhythmias, triggered by partial epileptic seizures with atypical, stereotyped auras. Ictal bradyarrhythmias are potentially lethal, and likely originate from the involvement of limbic autonomic regions. The appropriate treatment is double-headed, including an antiepileptic drug and the implantation of a pacemaker.

Subcortical nuclei volumetry in idiopathic generalized epilepsy.

PURPOSE: The exact anatomic and neurophysiologic correlates of idiopathic generalized epilepsy (IGE) in humans are still not well understood, although the thalamus has frequently been invoked as the crucial structure in the generation of primary generalized seizures. The few in vivo magnetic resonance (MR)-based studies in IGE patients suggest an altered cortical/subcortical gray matter ratio, but with no evidence of structural alterations of the thalamus. In this study, we sought to determine the volumes of the other subcortical structures. METHODS: The volumes of the caudate nucleus, putamen, pallidum as well as the thalamus were each determined in both hemispheres in 11 patients with various IGE syndromes, normalized for whole-brain volumes and then compared with 15 age-matched controls. RESULTS: No differences were noted in thalamic volumes, confirming previous reports. However, smaller subcortical volumes were noted in the IGE patients (p < 0.009), mainly due to smaller putamen bilaterally (p < or = 0.015). CONCLUSIONS: It is speculated that the presence of discrete frontal dysfunction, as noted in neuropsychological studies in IGE patients, indirectly supports our results because the putamen projects predominantly to the frontal cortex. Larger studies with more homogeneous patient populations are needed to determine the robustness of these findings and whether they are specific for particular IGE syndromes.

Ultrasound measurement of the fibrous cap in symptomatic and asymptomatic atheromatous carotid plaques.

BACKGROUND: Fibrous cap thickness (FCT) is an important determinant of atheroma stability. We evaluated the feasibility and potential clinical implications of measuring the FCT of internal carotid artery plaques with a new ultrasound system based on boundary detection by dynamic programming. METHODS AND RESULTS: We assessed agreement between ultrasound-obtained FCT values and those measured histologically in 20 patients (symptomatic [S]=9, asymptomatic [AS]=11) who underwent carotid endarterectomy for stenosing (>70%) carotid atheromas. We subsequently measured in vivo the FCT of 58 stenosing internal carotid artery plaques (S=22, AS=36) in 54 patients. The accuracy in discriminating symptomatic from asymptomatic plaques was assessed by receiver operating characteristic curves for the minimal, mean, and maximal FCT. Decision FCT thresholds that provided the best correct classification rates were identified. Agreement between ultrasound and histology was excellent, and interobserver variability was small. Ultrasound showed that symptomatic atheromas had thinner fibrous caps (S versus AS, median [95% CI]: minimal FCT=0.42 [0.34 to 0.48] versus 0.50 [0.44 to 0.53] mm, P=0.024; mean FCT=0.58 [0.52 to 0.63] versus 0.79 [0.69 to 0.85] mm, P<0.0001; maximal FCT=0.73 [0.66 to 0.92] versus 1.04 [0.94 to 1.20] mm, P<0.0001). Mean FCT measurement demonstrated the best discriminatory accuracy (area under the curve [95% CI]: minimal 0.74 [0.61 to 0.87]; mean 0.88 [0.79 to 0.97]; maximal 0.82 [0.71 to 0.93]). The decision threshold of 0.65 mm (mean FTC) demonstrated the best correct classification rate (82.8%; positive predictive value 75%, negative predictive value 88.2%). CONCLUSIONS: FCT measurement of carotid atheroma with ultrasound is feasible. Discrimination of symptomatic from asymptomatic plaques with mean FCT values is good. Prospective studies should determine whether this ultrasound marker is reliable.

Transitory sleep spindles impairment in deep cerebral venous thrombosis.

Sleep spindles may be affected by thalamic or hemispheric ischemic stroke. However, spindles reduction and their relationship with K-complexes following deep cerebral venous thrombosis have not been reported. An 18-year-old woman suffered from a deep cerebral venous thrombosis with vasogenic oedema located predominantly in the thalami. Stage 2 sleep EEG recorded in acute setting showed preservation of K-complexes but absent 12-14 Hz sleep spindles, which were replaced by spindle-like theta oscillations. One month later, the patient having completely recovered, sleep spindles were normally seen on the control EEG. This case illustrates that deep cerebral venous thrombosis, through a vasogenic oedema, may transiently affect thalamic functions such as spindles generation. Furthermore, thalamic impairment may lead to dissociation of spindle and K-complex activity.

Survey of management of first-ever seizures in a hospital based community.

BACKGROUND: Epidemiological studies focusing on first-ever seizures have been carried out mainly on community based populations. However, since hospital populations may display varying clinical features, we prospectively analysed patients with first-ever seizure in a hospital based community to evaluate prognosis and the role of complementary investigations in the decision to administer antiepileptic drugs (AED). METHODS: Over one year, we recruited 177 consecutive adult patients with a first seizure acutely evaluated in our hospital. During six months' follow-up data relating to AED treatment, recurrence of seizures and death were collected for each patient. RESULTS: Neurological examination was abnormal in 72.3%, neuroimaging in 54.8% and biochemical tests in 57.1%. Electroencephalogram (EEG) showed epileptiform features in 33.9%. Toxicity represented the most common aetiology. AED was prescribed in 51% of patients. Seizure recurrence at six months involved 31.6% of patients completing the follow-up; mortality was 17.8%. Statistical analysis showed that brain CT, EEG and neurological examination are independent predictive factors for AED administration, but only CT scan is associated with outcome. CONCLUSIONS: Patients evaluated acutely for first-ever seizure in a hospital setting have severe underlying clinical conditions apparently related to their relatively poor prognosis. Neuroimaging represents the most important paraclinical test in predicting both treatment administration and outcome.

Solid or gaseous circulating brain emboli: are they separable by transcranial ultrasound?

High-intensity transient signals (HITS) detected by transcranial Doppler (TCD) ultrasound may correspond to artifacts or to microembolic signals, the latter being either solid or gaseous emboli. The goal of this study was to assess what can be achieved with an automatic signal processing system for artifact/microembolic signals and solid/gas differentiation in different clinical situations. The authors studied 3,428 HITS in vivo in a multicenter study, i.e., 1,608 artifacts in healthy subjects, 649 solid emboli in stroke patients with a carotid stenosis, and 1,171 gaseous emboli in stroke patients with patent foramen ovale. They worked with the dual-gate TCD combined to three types of statistical classifiers: binary decision trees (BDT), artificial neural networks (ANN), and support vector machines (SVM). The sensitivity and specificity to separate artifacts from microembolic signals by BDT reached was 94% and 97%, respectively. For the discrimination between solid and gaseous emboli, the classifier achieved a sensitivity and specificity of 81% and 81% for BDT, 84% and 84% for ANN, and 86% and 86% for SVM, respectively. The current results for artifact elimination and solid/gas differentiation are already useful to extract data for future prospective clinical studies.

Propofol treatment of refractory status epilepticus: a study of 31 episodes.

PURPOSE: Refractory status epilepticus (RSE) is a critical medical condition with high mortality. Although propofol (PRO) is considered an alternative treatment to barbiturates for the management of RSE, only limited data are available. The aim of this study was to assess PRO effectiveness in patients with RSE. METHODS: We retrospectively considered all consecutive patients with RSE admitted to the medical intensive care unit (ICU) between 1997 and 2002 treated with PRO for induction of EEG-monitored burst suppression. Subjects with anoxic encephalopathy showing pathological N20 on somatosensory evoked potentials were excluded. RESULTS: We studied 31 RSE episodes in 27 adults (16 men, 11 women; median age, 41.5 years). All patients received PRO, and six also subsequently thiopental (THP). Clonazepam (CZP) was administered with PRO, and other antiepileptic drugs (AEDs) concomitant with PRO and THP. RSE was successfully treated with PRO in 21 (67%) episodes and with THP after PRO in three (10%). Median PRO injection rate was 4.8 mg/kg/h (range, 2.1-13), median duration of PRO treatment was 3 days (range, 1-9), and median duration of ICU stay was 7 days (range, 2-42). In 24 episodes in which the patient survived, shivering after general anesthesia was seen in 10 episodes, transient dystonia and hyperlipemia in one each, and mild neuropsychological impairment in five. The seven deaths were not directly related to PRO use. CONCLUSIONS: PRO administered with CZP was effective in controlling most of RSE episodes, without major adverse effects. In this setting, PRO may therefore represent a valuable alternative to barbiturates. A randomized trial with these drug classes could definitively assess their respective role in RSE treatment.

Controlled contrast transcranial Doppler and arterial blood gas analysis to quantify shunt through patent foramen ovale.

BACKGROUND AND PURPOSE: A right-to-left shunt can be identified by contrast transcranial Doppler ultrasonography (c-TCD) at rest and/or after a Valsalva maneuver (VM) or by arterial blood gas (ABG) measurement. We assessed the influence of controlled strain pressures and durations during VM on the right-to-left passage of microbubbles, on which depends the shunt classification by c-TCD, and correlated it with the right-to-left shunt evaluation by ABG measurements in stroke patients with patent foramen ovale (PFO). METHODS: We evaluated 40 stroke patients with transesophageal echocardiography-documented PFO. The microbubbles were recorded with TCD at rest and after 4 different VM conditions with controlled duration and target strain pressures (duration in seconds and pressure in cm H2O, respectively): V5-20, V10-20, V5-40, and V10-40. The ABG analysis was performed after pure oxygen breathing in 34 patients, and the shunt was calculated as percentage of cardiac output. RESULTS: Among all VM conditions, V5-40 and V10-40 yielded the greatest median number of microbubbles (84 and 95, respectively; P<0.01). A significantly larger number of microbubbles were detected in V5-40 than in V5-20 (P<0.001) and in V10-40 than in V10-20 (P<0.01). ABG was not sensitive enough to detect a shunt in 31 patients. CONCLUSIONS: The increase of VM expiratory pressure magnifies the number of microbubbles irrespective of the strain duration. Because the right-to-left shunt classification in PFO is based on the number of microbubbles, a controlled VM pressure is advised for a reproducible shunt assessment. The ABG measurement is not sensitive enough for shunt assessment in stroke patients with PFO.

Facial expressions modulate the time course of long latency auditory brain potentials.

Long latency auditory brain potentials were recorded while subjects listened to bi-syllabic words spoken with an emotional expression and concurrently viewed congruent or incongruent facial expressions. Analysis of the auditory waveforms suggests the existence of a positive deflection around 240 ms post-stimulus with a clear posterior topography (the P2b component). This potential is subsequent upon the modality-specific auditory N1-P2 components and precedes the amodal N2-P3 complex. Congruent face-voice trials elicited an earlier P2b component than incongruent trials suggesting that auditory processing is delayed in the presence of an incongruent facial context. These electrophysiological results are consistent with previous behavioural studies showing an acceleration of reaction times for rating voice expressions that are part of congruent bimodal stimulus pairs. A source localisation analysis performed on the scalp EEG during the time-window corresponding to the P2b component disclosed a single dipole solution in the anterior cingulate cortex.