Psychiatric comorbidity in patients evaluated for chronic epilepsy: a differential role of the right hemisphere?

INTRODUCTION: Psychiatric disorders are known to occur frequently in chronic epilepsy. The aim of this study is to investigate the prevalence of psychiatric comorbidity and its relationship to regional cerebral dysfunction in patients admitted to a tertiary epilepsy center for epilepsy surgery. METHODS: 217 patients were investigated. A presurgical workup was performed and allowed precise localization of the epileptogenic focus in 156 patients. Sixty-one patients had multifocal or generalized discharges. After 1-3 psychiatric interviews, a psychiatric diagnosis was made (DSM-IV classification). RESULTS: Psychiatric comorbidity was found in 85 patients (39%), more often in those with right or bilateral hemispheric dysfunction (74%, p = 0.04) with no difference between temporal or extratemporal foci location frequency. Additionally, patients with psychiatric disorders were less likely to undergo epilepsy surgery compared to 'epilepsy-only' patients (p = 0.003), despite similar good outcome in patients with and without psychiatric comorbidity. CONCLUSIONS: Right-sided or bilateral foci seem to represent a risk factor for psychiatric comorbidity in epilepsy, although we did not find any particular association between a psychiatric syndrome and focus localization. Recognition and treatment of psychiatric comorbidity is of major importance since its presence may interfere with patient's decision making for epilepsy surgery treatment.

Prior automatic posture and activity identification improves physical activity energy expenditure prediction from hip-worn triaxial accelerometry.

Accelerometry is increasingly used to quantify physical activity (PA) and related energy expenditure (EE). Linear regression models designed to derive PAEE from accelerometry-counts have shown their limits, mostly due to the lack of consideration of the nature of activities performed. Here we tested whether a model coupling an automatic activity/posture recognition (AAR) algorithm with an activity-specific count-based model, developed in 61 subjects in laboratory conditions, improved PAEE and total EE (TEE) predictions from a hip-worn triaxial-accelerometer (ActigraphGT3X+) in free-living conditions. Data from two independent subject groups of varying body mass index and age were considered: 20 subjects engaged in a 3-h urban-circuit, with activity-by-activity reference PAEE from combined heart-rate and accelerometry monitoring (Actiheart); and 56 subjects involved in a 14-day trial, with PAEE and TEE measured using the doubly-labeled water method. PAEE was estimated from accelerometry using the activity-specific model coupled to the AAR algorithm (AAR model), a simple linear model (SLM), and equations provided by the companion-software of used activity-devices (Freedson and Actiheart models). AAR-model predictions were in closer agreement with selected references than those from other count-based models, both for PAEE during the urban-circuit (RMSE = 6.19 vs 7.90 for SLM and 9.62 kJ/min for Freedson) and for EE over the 14-day trial, reaching Actiheart performances in the latter (PAEE: RMSE = 0.93 vs. 1.53 for SLM, 1.43 for Freedson, 0.91 MJ/day for Actiheart; TEE: RMSE = 1.05 vs. 1.57 for SLM, 1.70 for Freedson, 0.95 MJ/day for Actiheart). Overall, the AAR model resulted in a 43% increase of daily PAEE variance explained by accelerometry predictions. NEW & NOTEWORTHY Although triaxial accelerometry is widely used in free-living conditions to assess the impact of physical activity energy expenditure (PAEE) on health, its precision and accuracy are often debated. Here we developed and validated an activity-specific model which, coupled with an automatic activity-recognition algorithm, improved the variance explained by the predictions from accelerometry counts by 43% of daily PAEE compared with models relying on a simple relationship between accelerometry counts and EE.

An original piecewise model for computing energy expenditure from accelerometer and heart rate signals.

OBJECTIVE: Activity energy expenditure (EE) plays an important role in healthcare, therefore, accurate EE measures are required. Currently available reference EE acquisition methods, such as doubly labeled water and indirect calorimetry, are complex, expensive, uncomfortable, and/or difficult to apply on real time. To overcome these drawbacks, the goal of this paper is to propose a model for computing EE in real time (minute-by-minute) from heart rate and accelerometer signals. APPROACH: The proposed model, which consists of an original branched model, uses heart rate signals for computing EE on moderate to vigorous physical activities and a linear combination of heart rate and counts per minute for computing EE on light to moderate physical activities. Model parameters were estimated from a given data set composed of 53 subjects performing 25 different physical activities (light-, moderate- and vigorous-intensity), and validated using leave-one-subject-out. A different database (semi-controlled in-city circuit), was used in order to validate the versatility of the proposed model. Comparisons are done versus linear and nonlinear models, which are also used for computing EE from accelerometer and/or HR signals. MAIN RESULTS: The proposed piecewise model leads to more accurate EE estimations ([Formula: see text], [Formula: see text] and [Formula: see text] J kg-1 min-1 and [Formula: see text], [Formula: see text], and [Formula: see text] J kg-1 min-1 on each validation database). SIGNIFICANCE: This original approach, which is more conformable and less expensive than the reference methods, allows accurate EE estimations, in real time (minute-by-minute), during a large variety of physical activities. Therefore, this model may be used on applications such as computing the time that a given subject spent on light-intensity physical activities and on moderate to vigorous physical activities (binary classification accuracy of 0.8155).

Personalization of a compartmental physiological model for an artificial pancreas through integration of patient's state estimation.

Artificial Pancreas (AP) are developed for patients with Type 1 diabetes. This medical device system consists in the association of a subcutaneous continuous glucose monitor (CGM) providing a proxy of the patient's glycaemia and a control algorithm offering the real-time modification of the insulin delivery with an automatic command of the subcutaneous insulin pump. The most complex algorithms are based on a compartmental model of the glucoregulatory system of the patient coupled to an approach of MPC (Model-Predictive-Control) for the command. The automatic and unsupervised control of insulin regulation constitutes a major challenge in AP projects. A given model with its parameterization on the shelf will not directly represent the patient's data behavior and the personalization of the model is a prerequisite before using it in a MPC. The present paper focuses on the personalization of a compartmental showing a method where taking into account the estimation of the patient's state in addition to the parameter estimation improves the results in terms of mean quadratic error.

Wearable impedance monitoring system for dialysis patients.

This paper describes the development and the validation of a prototype wearable miniaturized impedance monitoring system for remote monitoring in home-based dialysis patients. This device is intended to assess the hydration status of dialysis patients using calf impedance measurements. The system is based on the low-power AD8302 component. The impedance calibration procedure is described together with the Cole parameter estimation and the hydric volume estimation. Results are given on a test cell to validate the design and on preliminary calf measurements showing Cole parameter variations during hemodialysis.

Localised impedance monitoring device for the remote clinical assessment of home-based dialysis patients.

BioImpedance Spectroscopy (BIS) has been clinically used to determine the hydrational status of patients undergoing haemodialysis (HD). In the present project we are developing a calf-localised, integrated impedimetric device to periodically and conveniently measure and transmit information on the hydrational status of home-based patients to a remote clinic. Surprisingly, we have found that simple postural changes before or during measurement lead to significant fluid shifts in the lower leg that are as important and as long lasting as the effects of haemodialysis. These must be taken into account if potentially hazardous errors are not to be made in assessing a patient's hydrational status.

[Current epilepsy treatment in adults]. / Le traitement actuet des épitepsies chez l'adulte.

The prevalence of epilepsy is about 1%. Only two thirds of these patients respond satisfactorily to an antiepileptic drug (AED) treatment. New AED did not clearly improve this overall efficacy, but often show a better tolerability as compared to old AED. This may allow a more targeted choice, especially in some delicate clinical situations, such as for the treatment of women in childbearing age, or patients receiving other drugs with possible pharmacokinetic interactions. Invasive approaches should be considered early in the course of treatment-resistant epilepsy, and may offer a complete seizure remission in selected cases. On the background of recent acquisitions from the literature, the pros and cons of different treatment options are presented. This is followed by the discussion of some clinical relevant situations.

A wireless patch for sleep respiratory disorders applications.

This paper presents a conformable wireless patch and its mobile application for physical activity, spO2 and pCO2 recording associated to digital biomarkers that aim at providing the clinicians with a reliable computer-aided diagnosis tool for rapid and continuous monitoring of sleep respiratory disorders. Each part of the system is described and results are presented and discussed. The reflectance sp02 sensor has been tested in vivo on several body sites and several subjects then compared to a reference device. The electrochemical tcpO2 sensor has been validated in vitro. Based on these physiological parameters, the proposed algorithms to automatically identifying sleep respiratory events are compared to a reference index.

An epidemiological reconsideration of the Geschwind-Galaburda theory of cerebral lateralization.

To contribute to the Geschwind-Galaburda theory of cerebral lateralization, we examined the relationship of left-handedness to allergic disorders and stuttering, using epidemiological data of two French samples, one of which (N = 9591) is representative of the French male population between 17 and 24 years of age. Results showed a higher frequency of stuttering but not of allergic disorders in left-handers. Extreme right-handedness was observed to be significantly associated with a lower frequency of allergic disorders; response bias might explain such a relationship. Findings were confirmed after allowing for potential confounding factors, such as age and education. In both samples, stuttering and allergic disorders were significantly related.

Incidence of status epilepticus in French-speaking Switzerland: (EPISTAR).

BACKGROUND: To determine the incidence, risk factors, and case fatality rate of status epilepticus (SE) in the French-speaking part of Switzerland. METHODS: Between October 1, 1997 and September 30, 1998 all cases of SE referred to all the hospitals in the six cantons of the French-speaking part of Switzerland were identified by physicians working in emergency rooms, intensive care units, and electroencephalography departments; neurologists; and pediatricians from all hospitals in the area. Each case was validated and classified according to seizure type and etiology. RESULTS: Over 1 year, 172 cases were identified, of whom 74 had a history of epilepsy (42.4%). The crude and standardized annual incidence rate were 9.9/100,000 (95% CI, 8.4 to 11.4) and 10.3/100,000 (95% CI, 8.7 to 11.9). The incidence rate was higher among children < 1 year of age and adults > 65 years, and among men than women. There were 108 cases of acute symptomatic SE (incidence: 6.2 per 1000), 49 cases of remote symptomatic SE, and 15 cases of unknown etiology. Case fatality rate was 7.6%. CONCLUSIONS: The standardized incidence rate of SE in the French-speaking part of Switzerland was lower than that reported in Rochester, MN (18.3/100,000) and in the white population of Richmond, VA (20/100,000). The discrepancy may stem from the lack of a homogeneous, rigorous, and pragmatic definition of SE and the efficient management of acute repetitive seizures in this area.

Propofol in the management of refractory status epilepticus: a case report.

Status epilepticus is one of the most frequent neurological emergencies in the intensive care unit. Standard treatment includes intravenous barbiturates, benzodiazepines and phenytoin. However, drug coma is sometimes necessary to control refractory status epilepticus. We report such a case, successfully treated by intravenous propofol coma to EEG burst suppression.

Bodyweight gain and anticonvulsants: a comparative review.

Bodyweight gain is a common and frequent undesirable effect associated with the use of anticonvulsant drugs. This has been observed for many years with valproic acid (sodium valproate) and carbamazepine, and also, more recently, with some of the newer anticonvulsants such as vigabatrin and gabapentin. Very often bodyweight gain in children, adolescents and adults with epilepsy taking such anticonvulsants results in cosmetic adverse effects. On the other hand, bodyweight gain is disturbing to general health, with a possible increase in the risk of diabetes mellitus or heart disease. Other potential adverse effects, such as the association of obesity with polycystic ovaries, have been reported with the use of valproic acid. Potential mechanisms of anticonvulsant-associated bodyweight gain are not yet clear and differ between drugs used. The involvement of lowered blood glucose level, which may stimulate eating through an effect on the hypothalamus, constitutes one of the possible mechanisms. Lowered blood glucose levels may result from a competition between the binding of the drug and long chain fatty acids. An increased availability of the latter stimulates insulin production and lowers the serum glucose levels. Another possible explanation for lowered blood glucose may be a deficiency in carnitine directly caused by the drug, that would result in a reduction of fatty acid metabolism and an increase in glucose consumption. An enhancing effect of gamma-aminobutyric acid-mediated neurotransmission may increase appetite for carbohydrates and reduce energy expenditure. An antidiuretic hormone-like effect or effects on norepinephrine (noradrenaline) or serotonin-mediated neurotransmission are more rarely considered. Many studies on anticonvulsant-associated bodyweight gain illustrate how we could better define the risk factors for the development of anticonvulsant-induced bodyweight gain and uncover the mechanisms behind it.

Arrhythmogenic seizures.

Arrhythmogenic seizures may represent one of the mechanisms implicated in sudden unexpected death in epilepsy. Various cardiac changes can be observed during epileptic seizures. However, reports of well-documented, life-threatening cardiac arrhythmias in the literature are scarce. The pathogenesis of these arrhythmias and speculations about the cortical localization of cardioarrhythmogenic triggers are reviewed.

EEG-mediated diagnosis of an unusual presentation of SSPE.

OBJECTIVE: To highlight the role of EEG in the diagnosis of SSPE. METHODS: EEG was performed in an 18 month old girl who had a 1 week history of repeated episodes of sudden flexion of the head and trunk and frequent falls. RESULTS: EEG abnormalities consisted of stereotyped, generalized and synchronous high amplitude periodic complexes. These abnormalities correlated with brief episodes of axial and upper limb atonia on electromyogram examination. They persisted during sleep although abnormal movements disappeared. Biological results and cerebral MRI confirmed the diagnosis of subacute sclerosing panencephalitis. CONCLUSIONS: This case is exceptional because of the age of the patient, the clinical presentation and the mode of contamination and it highlights the role of EEG in this diagnosis.

Clinical correlates and prognosis in early spindle coma.

OBJECTIVE: To determine the prognostic significance of spindle coma (SC) according to etiology and EEG reactivity. METHODS: We reviewed 15 patients with SC due to various causes within 8 days of coma to determine the prognostic significance of this EEG pattern. RESULTS: The outcome among survivors was favorable: among 13 survivors, 9 were independent in all activities of daily living (ADLs) at 6 months; 3 were dependent in all ADLs; and one remained in coma. EEG reactivity to noxious stimuli best predicted outcome: All patients (whatever the coma etiology) with EEG reactivity survived; conversely, not all patients without EEG reactivity died. CONCLUSION: In our patients, EEG reactivity independent of etiology predicted survival, neurological examination did not predict outcome. Most SC survivors had a meaningful recovery achieving all ADLs. From the literature, the cause of SC was predictive of outcome: encephalopathy, seizures and trauma had the best prognosis while hypoxia, CRA and structural lesions carried the worst. Literature review revealed that 23% of patients [56/242] died or remained in a persistent vegetative state (PVS). Best outcomes occurred when SC was due to drugs, encephalopathy or seizures: (0/14 died or were in a PVS). With trauma 15% [25/169] died or were in a PVS). Intermediate outcomes occurred with hypoxia and cardio-respiratory arrest (CRA): 33% [7/21] died or were in a PVS. The gravest outcomes occurred with brain-stem and cerebral infarctions, and tumors: 73% [22/30] died or were in a PVS.

Etiology, neurologic correlations, and prognosis in alpha coma.

OBJECTIVE: To determine the factors affecting prognosis in alpha coma (AC). METHODS: Retrospective review of 36 study patients, 36 control coma patients matched for age and etiology, and meta-analysis of 335 cases in the world literature. RESULTS: Principal causes were cardiorespiratory arrest (CRA) (21 patients); infection, metabolic dysfunction, head trauma (3 each); and drugs, stroke and hypoxia (2 each). Outcome was predicated by EEG reactivity to noxious stimuli. Fourteen of the 15 patients with reactive EEGs, had measurable outcome, 8 awoke - all but two had etiologies other than CRA. Fourteen of 19 patients without EEG reactivity died; two had support discontinued and 3 awoke. Following CRA, 16/21 patients died and 3 had support discontinued. Only 3 patients made a good recovery - all with toxic or metabolic etiologies. Literature meta-analysis of 335 cases showed that overall, AC carried a poor prognosis (76% died). CRA (226 cases) had an 88% mortality; strokes (29 cases), a 90% mortality; hypoxia without cardiac arrest (28 cases), a 61% mortality; drug-induced AC (25 cases), an 8% mortality. CONCLUSIONS: Although the cause of AC largely predicts outcome, EEG reactivity in AC predicted survival: most patients with reactivity awoke; most of those without, died. Few survivors had meaningful recovery.

[Iatrogenic myoclonic encephalopathies caused by bismuth salts]. / Encéphalopathies myocloniques iatrogènes aux sels de bismuth

Since the beginning of 1974, we have studied 17 cases of iatrogenic encephalopathy due to the ingestion of bismuth taken for the treatment of chronic digestive disorders. More than 100 similar cases have been reported in France within the same period. The clinical picture is remarkably consistent: there is a relatively long prodromal phase with difficulties in gait and writing, followed by a phase characterised by four signs, namely a severe confusional syndrome, myoclonus, astasia-abasia and sisorders of language. In our cases, after withdrawal of bismuth, recovery invariably began within 2 to 3 weeks but fatal cases have been described. All our patients had taken, for periods of between 3 weeks and 20 years, bismuth subnitrate. The levels of bismuth in the blood and urine in these patients were between 10 and 100 times as great as those in patients who had taken the same treatment without ill effect. The exact mechanism by which bismuth causes this complication, described only recently, is totally unknown.

Semantically-triggered reading epilepsy: an experimental case study.

Primary reading epilepsy (PRE) is a rare syndrome in which epileptic seizures are electively provoked by reading. Cognitive neuropsychology has demonstrated the existence of at least two pathways for reading, the sublexical pathway involved in converting graphemes to phonemes, and the lexical pathway used when meaning is conveyed. Which of these specific pathways is relevant in triggering epileptic discharges remains largely unknown. We report the case of a patient suffering from PRE in which the two routes were distinguished on the basis of the reading material employed. Significantly less epileptic discharges were observed when the patient read non-words than words. In view of our findings, we tentatively contrast a lexical form of PRE, triggered by the activation of semantic knowledge structures, with a sublexical form, triggered by non-word reading. Evidence from the literature suggests that the former is characterized by bilateral EEG activating patterns, whereas the latter involves preferentially the left hemisphere.

[The difficulty of defining and classifying status epilepticus]. / Des difficultés de définir et de classifier l'état de mal épileptique.

Status epilepticus (SE) can theoretically be described using a simple definition based on physiopathological mechanisms: any seizure of epileptic nature, partial or generalized, convulsive or non-convulsive, lasting over a period of more than 30 minutes; or repeated seizures lasting for a period of over 30 minutes without recovery of consciousness. In the context of a historical review of various definitions, the validity of this definition is assessed and questioned. The heterogeneous nature of this condition is evidenced in daily clinical practice and by the results of epidemiologic studies. In the present study, the authors propose a more pragmatic and heuristic classification, taking into account not only clinical but also electroencephalographic data, as well as the particular nature of the epileptic syndrome when this is known.

[Drug resistant status epilepticus]. / L'état de mal résistant aux antiépileptiques.

Refractory epileptic state (RES) is defined by severe seizures that are resistant to antiepileptic drug treatment. Diagnostic errors such as pseudo-seizures and encephalopathies with triphasic waves must be distinguished at an early stage from cases of RES. The latter are symptomatic of a focal brain lesion or severe systemic disease, most frequently metabolic in origin. The treatment of such conditions is aimed at correction of the underlying cause. A nosographic issue that is still a subject of discussion and which requires further study, i.e., PLEDS, will also be discussed in this article.