University Medical Center Rizk Hospital

Beirut, Lebanon

University Medical Center Rizk Hospital

Beirut, Lebanon
Time filter
Source Type

Mylius V.,University Paris Est Creteil | Mylius V.,University of Marburg | Ayache S.S.,University Paris Est Creteil | Ahdab R.,University Paris Est Creteil | And 13 more authors.
NeuroImage | Year: 2013

The optimization of the targeting of a defined cortical region is a challenge in the current practice of transcranial magnetic stimulation (TMS). The dorsolateral prefrontal cortex (DLPFC) and the primary motor cortex (M1) are among the most usual TMS targets, particularly in its "therapeutic" application. This study describes a practical algorithm to determine the anatomical location of the DLPFC and M1 using a three-dimensional (3D) brain reconstruction provided by a TMS-dedicated navigation system from individual magnetic resonance imaging (MRI) data. The coordinates of the right and left DLPFC and M1 were determined in 50 normal brains (100 hemispheres) by five different investigators using a standardized procedure. Inter-rater reliability was good, with 95% limits of agreement ranging between 7 and 16. mm for the different coordinates. As expressed in the Talairach space and compared with anatomical or imaging data from the literature, the coordinates of the DLPFC defined by our algorithm corresponded to the junction between BA9 and BA46, while M1 coordinates corresponded to the posterior border of hand representation. Finally, we found an influence of gender and possibly of age on some coordinates on both rostrocaudal and dorsoventral axes. Our algorithm only requires a short training and can be used to provide a reliable targeting of DLPFC and M1 between various TMS investigators. This method, based on an image-guided navigation system using individual MRI data, should be helpful to a variety of TMS studies, especially to standardize the procedure of stimulation in multicenter "therapeutic" studies. © 2013 Elsevier Inc.

Chalah M.A.,University Paris Est Creteil | Lefaucheur J.-P.,University Paris Est Creteil | Ayache S.S.,University Paris Est Creteil | Ayache S.S.,University Medical Center Rizk Hospital
Frontiers in Neuroscience | Year: 2015

Essential tremor (ET) is among the most frequent movement disorders. It usually manifests as a postural and kinematic tremor of the arms, but may also involve the head, voice, lower limbs, and trunk. An oscillatory network has been proposed as a neural correlate of ET, and is mainly composed of the olivocerebellar system, thalamus, and motor cortex. Since pharmacological agents have limited benefits, surgical interventions like deep brain stimulation are the last-line treatment options for the most severe cases. Non-invasive brain stimulation techniques, particularly transcranial magnetic or direct current stimulation, are used to ameliorate ET. Their non-invasiveness, along with their side effects profile, makes them an appealing treatment option. In addition, peripheral stimulation has been applied in the same perspective. Hence, the aim of the present review is to shed light on the emergent use of non-invasive central and peripheral stimulation techniques in this interesting context. © 2015 Chalah, Lefaucheur and Ayache.

Chalah M.A.,University Paris Est Creteil | Riachi N.,University Medical Center Rizk Hospital | Ahdabt R.,University Paris Est Creteil | Ahdabt R.,University Medical Center Rizk Hospital | And 3 more authors.
Frontiers in Cellular Neuroscience | Year: 2015

Multiple sclerosis (MS) is a chronic progressive inflammatory disease of the central nervous system (CNS) and the major cause of non-traumatic disability in young adults. Fatigue is a frequent symptom reported by the majority of MS patients during their disease course and drastically affects their quality of life. Despite its significant prevalence and impact, the underlying pathophysiological mechanisms are not well elucidated. MS fatigue is still considered the result of multifactorial and complex constellations, and is commonly classified into “primary” fatigue related to the pathological changes of the disease itself, and “secondary” fatigue attributed to mimicking symptoms, comorbid sleep and mood disorders, and medications side effects. Radiological, physiological, and endocrine data have raised hypotheses regarding the origin of this symptom, some of which have succeeded in identifying an association between MS fatigue and structural or functional abnormalities within various brain networks. Hence, the aim of this work is to reappraise the neural correlates of MS fatigue and to discuss the rationale for the emergent use of noninvasive brain stimulation (NIBS) techniques as potential treatments. This will include a presentation of the various NIBS modalities and a suggestion of their potential mechanisms of action in this context. Specific issues related to the value of transcranial direct current stimulation (tDCS) will be addressed. © 2015 Chalah, Riachi, Ahdab, Créange, Lefaucheur and Ayache.

Ayache S.S.,University Paris Est Creteil | Creange A.,University Paris Est Creteil | Farhat W.H.,University Paris Est Creteil | Zouari H.G.,University Paris Est Creteil | And 6 more authors.
European Journal of Neurology | Year: 2014

Background and purpose: High-dose steroid administration is the usual treatment of multiple sclerosis (MS) relapse, but it remains to determine whether this treatment may act by changing the excitability of cortical circuitry. Methods: The functional cortical effects of high-dose steroids in 21 MS patients before and after 3 days of intravenous administration of methylprednisolone (1 g/day) for the treatment of MS relapse were studied. Investigations included various clinical scales [Kurtzke Functional System Scale (KFSS), Expanded Disability Status Scale and Fatigue Severity Scale, 10-m walk] and transcranial magnetic stimulation (TMS) tests of cortical excitability [resting motor threshold, recruitment curve of motor evoked potentials, short-interval intracortical inhibition (SICI) and intracortical facilitation (ICF) at various interstimuli intervals (ISIs), cortical silent period and interhemispheric inhibition]. Results: Following steroid administration, clinical improvement was significant for the KFSS pyramidal (motor) and total scores, whilst TMS showed a reduction of SICI (mean and maximum values) and an increase of ICF at 10 ms ISI. Conclusions: Very rapid functional changes in the excitability of cortical circuits involved in motor control can be induced by steroids, before any process of remyelination or axonal regeneration has time to occur. The net effect of steroids on the balance between intracortical GABAergic inhibition and glutamatergic facilitation was in favour of weaker inhibition or stronger facilitation, which could lead to improving the motor performance in MS patients. © 2014 EFNS.

Ahdab R.,University Paris Est Creteil | Ahdab R.,University Medical Center Rizk Hospital | Ayache S.S.,University Paris Est Creteil | Farhat W.H.,University Paris Est Creteil | And 5 more authors.
Human Brain Mapping | Year: 2014

Image-guided navigation systems dedicated to transcranial magnetic stimulation (TMS) have been recently developed and offer the possibility to visualize directly the anatomical structure to be stimulated. Performing navigated TMS requires a perfect knowledge of cortical anatomy, which is very variable between subjects. This study aimed at providing a detailed description of sulcal and gyral anatomy of motor cortical regions with special interest to the inter-individual variability of sulci. We attempted to identify the most stable structures, which can serve as anatomical landmarks for motor cortex mapping in navigated TMS practice. We analyzed the 3D reconstruction of 50 consecutive healthy adult brains (100 hemispheres). Different variants were identified regarding sulcal morphology, but several anatomical structures were found to be remarkably stable (four on dorsoventral axis and five on rostrocaudal axis). These landmarks were used to define a grid of 12 squares, which covered motor cortical regions. This grid was used to perform motor cortical mapping with navigated TMS in 12 healthy subjects from our cohort. The stereotactic coordinates (x-y-z) of the center of each of the 12 squares of the mapping grid were expressed into the standard Talairach space to determine the corresponding functional areas. We found that the regions whose stimulation produced almost constantly motor evoked potentials mainly correspond to the primary motor cortex, with rostral extension to premotor cortex and caudal extension to posterior parietal cortex. Our anatomy-based approach should facilitate the expression and the comparison of the results obtained in motor mapping studies using navigated TMS. © 2013 Wiley Periodicals, Inc.

Hammoudeh A.J.,Istishari Hospital | Echtay A.,Lebanese University | Ghanem G.Y.,University Medical Center Rizk Hospital | Haddad J.,Istishari Hospital
Current Medical Research and Opinion | Year: 2014

Background: Several studies that evaluated achieving lipid goals have demonstrated an undertreatment of dyslipidemia. We evaluated the use and efficacy of lipid-lowering agents (LLAs) in reducing low-density lipoprotein cholesterol (LDL-C) to recommended levels in the Levant region. Design and methods: A multi-center, cross-sectional survey enrolled 1002 dyslipidemic patients (August 2010 - January 2011) on LLAs for 3 months. Collection of data and blood samples was done over one visit. Physicians and patients filled out questionnaires pertaining to dyslipidemia diagnosis and treatment. LDL-C target levels were defined according to international guidelines. Results: The full analysis set included 992 patients. Mean age was 58.0 ± 11.6 years (41% women, 65.7% diabetics and 51.5% had history of coronary heart disease). LLAs were prescribed for primary prevention or secondary prevention or familial hypercholesterolemia in 45.8% and 52.8% and 1.4% of patients; respectively. Overall, 64.0% and 56.8% of the patients attained their LDL-C goal recommended by the NCEP ATP III and TJETF guidelines, respectively. According to the 2004 NCEP ATP III updated guidelines, about 24.8% of the very high risk group attained their LDL goal of 70 mg/dL. Smoking, diabetes, metabolic syndrome, history of cardiovascular disease, increased waist circumference, and elevated pre-treatment LDL-C level were all associated with not reaching LDL-C goals. Conclusions: Although the study cohort was a relatively high risk group and might not be representative of the general population, we found that about 60% of enrolled individuals achieved the LDL-C treatment goals and 24.8% of the very high risk group achieved the recommended LDL-C targets of 70 mg/dl; national strategies and aggressive awareness campaigns to effectively control lipid levels to recommended target levels, especially in the high risk groups, are urgently needed. © 2014 Informa UK Ltd.

Almawi W.Y.,Arabian Gulf University | Nemr R.,University Medical Center Rizk Hospital | Keleshian S.H.,Haigazian University | Echtay A.,Rafic Hariri University Hospital | And 3 more authors.
Diabetes Research and Clinical Practice | Year: 2013

Aim: Recent genome-wide association scans (GWAS) and replication studies have expanded the list of validated type 2 diabetes (T2DM) susceptibility loci. We replicated T2DM association of 19 SNPs from 15 candidate loci in Lebanese Arabs. Methods: Case-control association study, comprising 995 T2DM patients and 1076 control participants. We genotyped by the allelic discrimination method 19 SNPs in/near ADAM30, NOTCH2, THADA, TMEFF2, COL8A1, ADAMTS9-AS2, WFS1, JAZF1, SLC30A8, KCNQ1, LOC387761, ALX4, TSPAN8, FTO, and HNF1. Results: Allele frequencies of the tested SNPs were comparable with those of Caucasians. COL8A1 rs792837 (P=2.9×10-9), KCNQ1 rs2237892 (P=1.8×10-18) and rs2237895 (P=0.002), ALX4 rs729287 (Pc=7.5×10-5), and HNF1 rs4430796 (P=0.003) were significantly associated with T2DM, with similar effect sizes to those of Europeans. While FTO rs8050136 and rs17817449, ADAMTS9 rs4607103, and WFS1 rs10010131 were initially associated with T2DM, this was lost upon multiple testing correction. The remaining variants were not associated with T2DM, possibly resulting from insufficient power to detect smaller allele effects. Conclusion: In addition to previous findings on the association of IGF2BP2, CDKAL1, TCF7L2 variants with T2DM among Lebanese, here we extend these by validating the association of five additional loci with T2DM in Lebanese Arabs. © 2013 Elsevier Ireland Ltd.

Nemr R.,University Medical Center Rizk Hospital | Almawi A.W.,Arabian Gulf University | Echtay A.,Rafic Hariri University Hospital | Sater M.S.,Arabian Gulf University | And 2 more authors.
Diabetes Research and Clinical Practice | Year: 2012

We investigated the association of CDKAL1 (rs7754840 and rs7756992) and CDKN2A/2B (rs10811661) variants with T2DM. Higher MAF of rs7754840 and rs7756992 were seen in patients, and both were associated with T2DM under additive, dominant, and recessive models. CDKAL1 rs7754840 and rs7756992, but not CDKN2A/2B rs10811661, are associated with T2DM in Lebanese. © 2011 Elsevier Ireland Ltd.

Aouad M.T.,American University of Beirut | Yazbeck-Karam V.G.,University Medical Center Rizk Hospital | Mallat C.E.,American University of Beirut | Esso J.J.,American University of Beirut | And 2 more authors.
Paediatric Anaesthesia | Year: 2012

Summary Intubation without prior administration of muscle relaxants is a common practice in children. However, succinylcholine may be considered as the golden standard for optimizing intubating conditions. We conducted a systematic review of the literature to identify drug combinations that included induction of anesthesia with sevoflurane or propofol. Our aim was to select drug combinations that yield excellent intubating conditions ≥80%; we identified six combinations in children aged 1-9 years. Sevoflurane with remifentanil (1 or 2 μg·kg -1), lidocaine (2 mg·kg -1), or propofol (2 mg·kg -1) as the adjuvant shared the following characteristics: premedication with midazolam and/or ketamine, long sevoflurane exposure time, high inspired and endtidal sevoflurane concentration, and assisted ventilation. One combination using sevoflurane with propofol (3 mg·kg -1) without premedication, with shorter sevoflurane exposure time, and spontaneous breathing indicated that propofol may be the adjuvant of choice for a rapid sevoflurane induction. The only adjuvant identified in propofol induction was remifentanil (4 μg·kg -1). No serious adverse events were reported with these combinations. © 2012 Blackwell Publishing Ltd.

Ahdab R.,University Medical Center Rizk Hospital | Riachi N.,University Medical Center Rizk Hospital
European Neurology | Year: 2014

Objective: Investigate the added value of hyperventilation (HV) and intermittent photic stimulation (IPS) to the routine electroencephalogram (EEG). Method: This is a retrospective review of 1,172 successive EEGs. The records with evidence of epileptogenic activity were identified and further analyzed to identify if the activation techniques could trigger the expression of epileptic activity not seen otherwise in the nonactivated tracing. Results: Activation procedures provided additional information in 9.5% of the abnormal EEG files. They helped establish the diagnosis of an epileptic disorder or further characterize the epileptic syndrome. This occurred exclusively in the younger age group (age <36 years), and predominantly in women. Conclusion: IPS and HV are easy to perform and remain important adjuncts to routine EEG. They may trigger the expression of epileptogenic activity in an otherwise uneventful EEG. Whereas their diagnostic value was obvious in the younger age group, we found no evidence to support their usefulness in the middle-age and elderly groups. © 2013 S. Karger AG, Basel.

Loading University Medical Center Rizk Hospital collaborators
Loading University Medical Center Rizk Hospital collaborators