Genetic diversity analysis in Tunisian perennial ryegrass germplasm as estimated by RAPD, ISSR, and morpho-agronomical markers.

Tunisia is rich in diverse forage and pasture species including perennial ryegrass. In order to enhance forage production and improve agronomic performance of this local germplasm, a molecular analysis was undertaken. Random amplified polymorphic DNA (RAPD), inter simple sequence repeats (ISSR) and morpho-agronomical traits markers were used for genetic diversity estimation of ryegrass germplasm after screening 20 spontaneous accessions, including a local and an introduced cultivars. Same mean polymorphism information content values were obtained (0.37) for RAPD and ISSR suggesting that both marker systems were equally effective in determining polymorphisms. The average pairwise genetic distance values were 0.57 (morpho-agronomical traits), 0.68 (RAPD), and 0.51 (ISSR) markers data sets. A higher Shannon diversity index was obtained with ISSR marker (0.57) than for RAPD (0.54) and morpho-agronomical traits (0.36). The Mantel test based on genetic distances of a combination of molecular markers and morpho-agronomical data exhibited a significant correlation between RAPD and ISSR data, suggesting that the use of a combination of molecular techniques was a highly efficient method of estimating genetic variability levels among Tunisian ryegrass germplasm. In summary, results showed that combining molecular and morpho-agronomical markers is an efficient way in assessing the genetic variability among Tunisian ryegrass genotypes. In addition, the combined analysis provided an exhaustive coverage for the analyzed diversity and helped us to identify suitable accessions showed by Beja and Jendouba localities, which present large similarities with cultivated forms and can be exploited for designing breeding programmes, conservation of germplasm and management of ryegrass genetic resources.

Variation and genetic structure of Tunisian Festuca arundinacea populations based on inter-simple sequence repeat pattern.

Tunisian tall fescue (Festuca arundinacea Schreb.) is an important grass for forages or soil conservation, particularly in marginal sites. Inter-simple sequence repeats were used to estimate genetic diversity within and among 8 natural populations and 1 cultivar from Northern Tunisia. A total of 181 polymorphic inter-simple sequence repeat markers were generated using 7 primers. Shannon's index and analysis of molecular variance evidenced a high molecular polymorphism at intra-specific levels for wild and cultivated accessions, showing that Tunisian tall fescue germplasm constitutes an important pool of diversity. Within-population variation accounted for 39.42% of the total variation, but no regional differentiation was discernible to designate close relationships between regions. Most of the variation (GST = 67%) occurred between populations, rather than within populations. The ɸST (0.60) revealed high population structuring. Additionally, the population structure was independent of the geographic origin and was not affected by environmental factors. The unweighted pair group method with arithmetic mean tree based on genetic similarity and principal coordinate analysis based on coefficient similarity illustrated that continental populations from the proximate localities of Beja and Jendouba were genetically closely related, while the wild Skalba population from the littoral Tunisian locality was the most diverse from the others. Moreover, great molecular similarity of the spontaneous population Sedjnane originated from the mountain areas was revealed with the local cultivar Mornag. The observed genetic diversity can be used to implement conservation strategies and breeding programs for improving forage crops in Tunisia.

Epileptic syndromes: differential treatment in infants, children, and adolescents.

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).

Topiramate in childhood epileptic encephalopathy with continuous spike-waves during sleep: A retrospective study of 21 cases.

OBJECTIVE: Encephalopathy with continuous spike-wave during sleep (CSWS) is a particularly difficult-to-treat childhood epileptic syndrome. This study sought to present the EEG improvement and clinical efficacy of topiramate (TPM), a broad spectrum antiepileptic drug (AED), in a series of 21 children with CSWS encephalopathy. METHODS: We retrospectively reviewed the EEG results and clinical data of children with CSWS followed-up in our institution and treated with TPM. Sleep EEGs were performed 0-3 months prior to TPM introduction and then at 3 and 12 months. The exclusion criteria were (1) introduction of another AED and (2) withdrawal of a potentially aggravating AED during the first 3 months of treatment. In addition to spike index (SI), the severity of EEG abnormalities was rated using an original scale that also considered the spatial extent of interictal epileptiform discharges. RESULTS: 21 patients were included (18 males, 4-14y, three symptomatic cases). At 3 months, sleep EEG was improved in 14 and normalized in four (TPM doses: 2-5.5 mg/kg/day). Among these 18 patients, 16 manifested cognitive or behavioural improvement. In a subgroup of seven patients with frequent seizures, five became seizure-free and one had over 75% decrease in seizure frequency. At the one-year follow-up, 20 children were still on TPM and 10 exhibited persistent EEG improvement without any other AED being introduced, most of them with clinical benefits. CONCLUSION: TPM can decrease EEG abnormalities in epileptic encephalopathy with CSWS, achieving clinical improvement in the majority of patients. However, relapse may occur in the long-term in nearly half of cases. Otherwise, TPM has proven particularly useful in reducing seizure frequency in refractory cases.

The epileptic syndromes with continuous spikes and waves during slow sleep: definition and management guidelines.

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.

Prophylaxis of the epilepsies: should anti-epileptic drugs be used for preventing seizures after acute brain injury?

In many circumstances antiepileptic drugs are used in patients who have never presented any clinical epileptic seizures. These substances are administered on the assumption of a potential risk for the patients of developing acute or delayed chronic seizures after brain injuries such as trauma, stroke, hemorrages or even neurosurgical interventions. The aim of this paper is to propose therapeutic guidelines for the management of this prophylactic attitude in epilepsy based on basic research and clinical practice in the French community in Belgium. We will distinguish between the prevention of acute (early onset-provoked) seizures and a delayed truly post-lesional (unprovoked) epilepsy. Some therapeutic goals can be achieved under the former circumstances whereas in the latter situation we all agree for the absence of any coherent antiepileptic prophylactic behaviour.

Retrospective study of somatosensory evoked potential monitoring in deep hypothermic circulatory arrest.

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.

Intra- and postoperative factors determining neurological complications after surgery under deep hypothermic circulatory arrest: a retrospective somatosensory evoked potential study.

OBJECTIVES: Intraoperative median nerve SEP monitoring uses the disappearance of cortical and brain stem activities as the criterion to determine that brain cooling is sufficient in deep hypothermic circulatory arrest (CA) surgery. This study presents the results of a retrospective SEP analysis of intraoperative events that engendered neurological complications. METHODS: Median nerve SEP monitoring was performed on 58 consecutive patients who underwent surgery under deep hypothermic CA. The monitoring was retrospectively analyzed and compared with intraoperative events, and postoperative symptoms. RESULTS: Intraoperative SEP abnormalities were observed in 9 out of the 16 patients who presented neurological complications. Among the 7 others, the abnormalities either were present preoperatively (n = 2), occurred postoperatively (n = 3) or only involved the lower limbs (n = 2). Although the mere inspection of the intraoperative SEPs was insufficient to determine the origin of the alterations, their comparison with intraoperative events facilitated the identification of hemodynamic factors in 7 cases and embolism in two cases. There were no patients in whom CA per se caused neurological complications. CONCLUSIONS: Intraoperative SEP monitoring helps identify intraoperative events responsible for neurological complications and prevent these in subsequent procedures. However, the neurological complications of deep hypothermic CA can also be due to pre- or postoperative factors that escape the domain of intraoperative monitoring.

[Sensitivity, specificity, and impact on the surgical strategy of the perioperative neuromonitoring of somatic evoked potentials in vascular surgery performed with circulatory arrest under deep hypothermia]. / Sensibilité, spécificité et impact sur la stratégie chirurgicale du neuromonitorage peropératoire par potentiels évoqués somesthésiques en chirurgie vasculaire pratiquée avec arrêt circulatoire sous hypothermie profonde.

AIM: Median nerve somatosensory evoked potentials (SEP) monitoring performed in deep hypothermic circulatory arrest is useful in determining when brain cooling may sufficiently permit circulatory arrest, and to immediately indicate when brain injury occurs. The aim of this retrospective study, including 58 patients, is to determine SEP sensitivity, specificity and impact on the surgical strategy. METHOD: Sensitivity was determined on patients presenting new neurological complications. Specificity was measured on the patients without any new neurological defect. The impact of intraoperative SEP on the surgical strategy was determined when the occurrence of SEP alterations had provoked a modification of the surgical procedure. RESULTS: Five patients died intraoperatively due to non-neurological complications. Fourteen patients presented new neurological complications. SEP sensitivity reaches 64.3% when all the complications are included, but increases to 100% in our series if late postoperative complications, paraplegia and tibial posterior nerve lesion are excluded because median nerve SEP are not able to detect such complications. SEP monitoring was uneventful in the 39 patients whose did not present neurological complication: thus SEP specificity is absolute in our series. SEP had an impact on the surgical procedure whenever neurological complications due to hemodynamic disturbances occurred. CONCLUSION: This retrospective study shows the interest of intraoperative SEP as an useful tool for promptly identifying and preventing the neurological complication of hypothermic circulatory arrest.

Delayed-onset hemidystonia and chorea following contralateral infarction of the posterolateral thalamus. A case report.

A 68 year-old man developed progressive hemidystonia and chorea 8 months after a contralateral thalamic stroke. The neurological examination also showed a right pyramidal syndrome without hemiparesis, a right horizontal sectoranopia, and a right hemihypesthesia for all sensory modalities. The MRI revealed infarctions in the left medial temporo-occipital lobes and left posterolateral thalamus, corresponding to the vascular territories of both the thalamo-geniculate and posterolateral choroidal arterial pedicles. The thalamic lesion involved the pulvinar, the lateral geniculate body, and the ventro-postero-lateral, dorso-lateral, posterolateral, and dorso-medial nuclei, but apparently did not extent to the ventrolateral thalamic nucleus, and the subthalamic and midbrain regions. Thalamic and striatopallidal dystonia have not a common pathophysiological mechanism. The involvement of the pulvinar nucleus and of the strategic crossing of proprioceptive, cerebellar, pyramidal, and subthalamic pathways may play a role in the genesis of the posterolateral thalamic dystonia.

Therapeutic strategies in the choice of antiepileptic drugs.

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.

Therapeutic issues in women with epilepsy.

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.

[Cerebral cysticercosis treated by albendazole: development of cerebral magnetic resonance imaging]. / Cysticercose cérébrale traitée par albendazole: évolution de l'imagerie par résonance magnétique cérébrale.

A 36-year-old Indian man presented with a generalized tonic-clonic seizure. The diagnosis of neurocysticercosis was suspected by the presence of multiple cystic and nodular cerebral lesions on MRI, and was confirmed by serological studies (ELISA). He was treated with albendazole during one week at the daily dose of 15 mg/kg. This case illustrates the advantage of MRI over CT for the detection and the therapeutical follow-up of neurocysticercosis. Moreover, the MRI findings can be correlated to the anatomical stage of neurocysticercosis, proposed by Escobar (1983); four stages are described: I = vesicular stage (living larvae), II = vesicular colloidal stage (degenerating larvae), III and IV, granular nodular and nodular calcified inactive stages respectively.

[Acute encephalomyopathy and persistent cerebellar syndrome after lithium salt and haloperidol poisoning]. / Encéphalomyopathie aiguë et syndrome cérébelleux persistant après intoxication par sel de lithium et halopéridol.

A 44-year-old maniacodepressive woman developed acute encephalopathy due to the association of lithium carbonate and haloperidol. She was treated with lithium salts for many years and the serum level of lithium was within the therapeutic range. The encephalopathy was worsened by hyperthermia, dehydration, and reintroduction of haloperidol, 5 days after the first discontinuation of the neuroleptic. The clinical features were characterized by a persistent cerebellar syndrome, more than one year after the interruption of these medications.

Progressive unilateral hemispheric atrophy in an infant with neurofibromatosis.

INTRODUCTION: Cerebrovascular diseases are rarely seen in neurofibromatosis type 1. These include vascular occlusive disease, moyamoya vessels, aneurysms, arteriovenous malformations and fistulae. CASE REPORT: We describe the case of an infant with genetically proven neurofibromatosis type 1 and progressive brain hemiatrophy over months, due to primary narrowing of intracranial carotid artery branches, as demonstrated by successive brain imaging. She presented with refractory seizures and a progressive hemiparesis associated with developmental delay. Surgical material from hemispherotomy done at 18 months showed severe abnormalities of the small vessels. CONCLUSION: Cerebrovascular changes seen in neurofibromatosis can be diffuse and progressive, with secondary hemiparesis, epilepsy and developmental delay.

Somatosensory evoked potential monitoring in carotid surgery. II. Comparison between qualitative and quantitative scoring systems.

This paper compares the respective yields of our SEP scoring system ('qualitative' criteria), based on the subdivision of SEP abnormalities into mild, moderate, and severe abnormalities, and a quantitative one ('classical' criteria), based on a more than 1 ms CCT increase or 50% decrease of N20 amplitude, for the detection of brain ischemia justifying shunt placement during carotid endarterectomy (CE). For that purpose, we examine the sensitivities of several neurophysiological parameters (the ipsilateral and contralateral CCT, the amplitudes of the ipsilateral and contralateral frontal and parietal SEPs) to carotid cross-clamping or to a drop of blood pressure. Our data first confirm that shunted patients developed a CCT increase and a decrease of N20 amplitude on the ipsilateral hemisphere. They further demonstrate that 50% of the patients who were immediately shunted on the basis of qualitative criteria would not have been shunted or would have been shunted with a longer delay on the basis of quantitative criteria. Simultaneously, the overall percentage of shunted patients was not significantly higher than in studies using the 'classical' criteria. Thus, it was hard to decide between the 'qualitative' and the 'classical' criteria on the basis of patient data. However, our 'qualitative' system appears advantageous in that it smooths out the influence of factors liable to interfere with the quantitative parameters.

Focal seizure-induced premature myelination: speculation from serial MRI.

Local changes in the white matter underlying a focus of cortical thickening were monitored using MRI in an epileptic 2-month-old boy. We hypothesise that these changes reflected seizure-induced premature myelination.

Time dependence of serial diffusion-weighted imaging features in a case of pyogenic brain abscess.

Both signal intensity on trace images and apparent diffusion coefficient measurements on mapped images evolved rapidly on serial diffusion-weighted sequences in a case of pyogenic brain abscess that was monitored primarily by MRI before a biopsy was performed. Considering only the signal intensities on the trace images would have led to an underestimation of the intrinsic tissue changes.

Somatosensory evoked potential monitoring in carotid surgery. I. Relationships between qualitative SEP alterations and intraoperative events.

This paper presents the results of intraoperative median nerve SEP monitoring in 205 successive patients undergoing isolated carotid endarterectomy (CE) (N = 172) or CE followed by coronary bypass (CBP) and/or vascular replacement (VR) (N = 33). The left and right median nerves were alternately stimulated and recordings performed on 4 channels: cervical, ipsi- and contralateral parietal, and frontal. SEPs were qualitatively rated in terms of mild, moderate, or severe ipsilateral, contralateral, or bilateral abnormalities. The SEP abnormalities were subdivided into 5 categories as a function of their relationships with intraoperative events: no alterations (67.3%), early or late SEP alterations after carotid cross-clamping (15.6%), SEP alterations after a drop in blood pressure (occurring outside of or within the cross-clamping period) (15.1%), SEP alterations of a most likely embolic origin (2.4%), SEP changes after head positioning (1%), and SEP changes after a modification of the anesthetic regimen (1.5%). Only moderate to severe SEP alterations occurring soon after carotid cross-clamping justified shunt installation in 16% of the cases. SEP alterations after a drop in blood pressure were reversed merely by restoring blood pressure. The neurological outcome was uneventful in 94.2% of cases. Of the 12 patients who developed neurological sequellae, only one case presented transient sequellae after isolated CE without SEP changes while most cases either had undergone combined CE and CBP and/or VR (6 cases) or had presented SEP alterations of embolic origin (3 cases). We conclude that our system of qualitative rating of SEPs proved very sensitive to intraoperative hemodynamic disturbances or macroembolisms.