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4 ème Journée et Prix de la Recherche Clinique – 19 mai 2011 Présentations posters
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P18
STATUS EPILEPTICUS IN FRAGILE X SYNDROME
Magali Gauthey1, Claudia B Poloni2, Gian-Paolo Ramelli3, Eliane Roulet-Perez2, Christian M Korff4
1Pediatric Emergencies Service, Child and Adolescent Department, University Hospital, Geneva, Switzerland
2Pediatric Neurology and Neurorehabilitation Unit, Pediatric Medico-surgical Department, University Hospital,
Lausanne, Switzerland 3Pediatric Neurology, Children’s Hospital, Bellinzona, Switzerland 4Pediatric Neurology,
Pediatric Specialties Service, Child and Adolescent Department, University Hospital, Geneva, Switzerland
Introduction: Fragile X syndrome (FXS) is the most common cause of inherited mental retardation. The
clinical spectrum includes dysmorphological signs, behavioral peculiarities, and epilepsy. Seizures are rare
and EEG findings resemble those found in benign epilepsy with centro-temporal spikes (BECTS). Status
epilepticus (SE) seems exceptional in FXS.
Méthode: Case series.
Résultats: We report the clinical features, EEG and MRI findings of five FXS children who presented with
SE as their initial seizure. Interestingly, two of our patients had clinical manifestations and EEG findings
more suggestive of Panayiotopoulos syndrome than of benign rolandic epilepsy.
Conclusion: Despite this initial severity, our patients did not evolve to refractory epilepsy, and presented
only rare additional seizures, suggesting that long-term antiepileptic drugs might not be necessary. Epilepsy
is a frequent manifestation in FXS (prevalence 13% -50%). Various mechanisms have been proposed.
Various seizure types may be noted. The EEG frequently reveals a pattern found in BECTS. The natural
course is often favorable. Two of our patients and one of the previously reported children, had clinical
seizures and EEG findings more suggestive of Panayiotopoulos syndrome (PS) than of BECTS (prolonged
seizures with vegetative symptoms). The etiology of PS is unknown, but some authors suspect it to be
genetic. The link with FXS remains to be demonstrated. As observed in PS, one of our patients exhibited
severe respiratory complications after receiving rectal Diazepam, suggesting that a reduction in the dosage
of emergency benzodiazepines may be necessary in FXS patients presenting with predominantly vegetative
ictal symptoms.
P19
WHAT DIFFERENCES ARE DETECTED BY SUPERIORITY TRIALS OR RULED OUT BY
NONINFERIORITY TRIALS? A CROSS-SECTIONAL STUDY ON A RANDOM SAMPLE OF TWO-
HUNDRED TWO-ARMS PARALLEL GROUP RANDOMIZED CLINICAL TRIALS
Thomas Agoritsas, Christophe Combescure, Krisztina Bagamery, Delphine S Courvoisier, Angèle
Gayet-Ageron,Thomas Perneger.
Division of Clinical Epidemiology, University Hospitals of Geneva and Faculty of Medicine, University of Geneva,
Geneva, Switzerland
Introduction: The smallest difference to be detected in superiority trials or the largest difference to be
ruled out in noninferiority trials is a key determinant of sample size, but little guidance exists. The
objectives were to examine the distribution of differences used by researchers and to verify that those
differences are smaller in noninferiority compared to superiority trials.
Méthode: Cross-sectional study based on a random sample of 200 two-arm, parallel group superiority
(100) and noninferiority (100) randomized clinical trials published between 2004 and 2009 in 27
leading medical journals. The main outcome measure was the smallest difference in favor of the new
treatment to be detected (superiority trials) or largest unfavorable difference to be ruled out
(noninferiority trials) used for sample size computation, expressed as standardized difference in
proportions, or standardized difference in means. Student test and analysis of variance were used.
Résultats: In superiority trials, the standardized difference in means ranged from 0.007 to 0.87, and
the standardized difference in proportions from 0.04 to 1.56. On average, superiority trials were
designed to detect larger differences than noninferiority trials (standardized difference in proportions:
mean 0.37 versus 0.27, P=0.001; standardize d difference in means: 0.56 versus 0.40, P=0.006).
Standardized differences were lower for mortality than for other outcomes, and lower in cardiovascular
trials than in other research areas.
Conclusion: Superiority trials are designed to detect larger differences than noninferiority trials are
designed to rule out. The variability between studies is considerable and partly explained by the type
of outcome and the medical context.
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