Frédérique Archambaud

Unité Inserm U1077, Caen, Lower Normandy, France

Are you Frédérique Archambaud?

Claim your profile

Publications (20)46 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Focal cortical dysplasia (FCD) is the most frequent etiology for drug-resistant epilepsy in young children. Complete removal of the lesion is mandatory to cure the epilepsy. Stereo-EEG (SEEG) is an excellent method to delimitate the zone to be resected in older children and adults. We studied its feasibility in younger children.
    Child s Nervous System 11/2014; 30(11):1875-83. DOI:10.1007/s00381-014-2464-x · 1.16 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Background: Anti NMDA receptor (anti NMDAR) encephalitis is a well-characterized entity in children associating movement disorders, psychiatric features and speech difficulties. Novel phenotypes have been described in adults. Methods and Results: A 4-year-old girl presented partial seizures which evolved towards sudden and isolated Broca's aphasia. Anti NMDAR antibodies were positive in CSF and serum confirming anti NMDAR encephalitis. Clinical recovery was observed after a specific treatment. Conclusion: This case widens the clinical spectrum of anti-NMDAR encephalitis in children and awareness of this newly identified symptom is important as early treatment is a predictor of good outcome
    European Journal of Paediatric Neurology 11/2014; 18(6). DOI:10.1016/j.ejpn.2014.06.002 · 1.93 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The aim was to localize the interictal cerebral perfusion abnormalities of focal cortical dysplasia (FCD) in children with Arterial Spin Labeling MRI (ASL) in a retrospective study of nine consecutive children explored with multimodal investigation during interictal periods. We analyzed brain morphology with a 1.5T MRI and a dedicated protocol for epilepsy. Brain perfusion was quantified with pseudo continuous ASL. Brain metabolism was imaged with (18)FDG-PET in six patients. Microvessel histology was studied in five children who underwent epilepsy surgery with CD34 immunostaining on FCD and control samples. Localized decrease of cerebral blood flow (CBF) was found on visual analysis in all patients with ASL. It was co-localized with the structural MRI abnormalities in every case, with PET hypo-metabolism in 5/6 cases, and with histologically proven FCD type IIb in 5/5 cases (all seizure free after surgery). CBF was lower (Kruskal-Wallis test, p=0.001) in FCD than in normal cortex. The total count of CD34+ microvessels was similar in FCD and control cases, but microvasculature showed disorganized architecture. Interictal ASL is a non-invasive method that may help to localize the epileptogenic zone showing hypo-perfusion in FCD. Whether this finding could be generalized to MRI-negative FCD needs to be further studied. Copyright © 2014 Elsevier B.V. All rights reserved.
    Epilepsy Research 10/2014; 108(10). DOI:10.1016/j.eplepsyres.2014.09.029 · 2.19 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Previous studies investigating cerebral metabolic changes associated with continuous spike-wave during sleep (CSWS) compared the metabolism of children with CSWS with that of healthy adults, precluding any assessment in brain areas showing physiologic age-related metabolic changes. Here, we investigated the metabolic and connectivity changes characterizing the acute phase of CSWS activity by comparing awake brain metabolism of children with CSWS with that of pediatric pseudo-controls. Positron emission tomography using [18F]-fluorodeoxyglucose (FDG-PET) was performed in 17 awake children with cryptogenic CSWS (5 girls, age: 5 to 11 years). Voxel-based analyses identified significant metabolic changes in CSWS patients compared with 18 pediatric pseudo-controls (12 girls, age: 6 to 11 years, non-CSWS focal cryptogenic epilepsy with normal FDG-PET). CSWS-induced changes in the contribution of brain areas displaying metabolic changes to the level of metabolic activity in other brain areas were investigated using pathophysiological interaction. Hypermetabolism in perisylvian regions bilaterally and hypometabolism in lateral and mesial prefrontal cortex, precuneus, posterior cingulate cortex and parahippocampal gyri characterized the acute phase of CSWS (p < 0.05 FWE). No change in thalamic metabolism was disclosed. Altered functional connectivity was found between hyper- and hypometabolic regions in CSWS patients compared with pediatric pseudo-controls. This study demonstrates hypometabolism in key nodes of the default mode network (DMN) in awake patients with CSWS, in relation with a possible phenomenon of sustained remote inhibition from the epileptic foci. This hypometabolism might account for some of the acquired cognitive or behavioral features of CSWS epileptic encephalopathies. This study failed to find any evidence of thalamic metabolic changes, which supports the primary involvement of the cortex in CSWS genesis.
    Epilepsy research 07/2014; 108(5). DOI:10.1016/j.eplepsyres.2014.03.014 · 2.19 Impact Factor
  • Medecine Nucleaire 05/2014; 38(3):150. DOI:10.1016/j.mednuc.2014.03.081 · 0.16 Impact Factor
  • 04/2014; DOI:10.1530/endoabs.35.P276
  • Revue Neurologique 04/2014; 170:A143-A144. DOI:10.1016/j.neurol.2014.01.384 · 0.60 Impact Factor
  • Neurochirurgie 12/2013; 59(6):232. DOI:10.1016/j.neuchi.2013.10.027 · 0.47 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Background Statistical parametric mapping (SPM) procedure is an objective tool to analyze 18F-fluoro-2-deoxy-d-glucose-positron-emission tomography (FDG-PET) images and a useful complement to visual analysis. However, SPM requires a comparison to control data set that cannot be obtained in healthy children for ethical reasons. Using adults as controls showed some limitations. The purpose of the present study was to generate and validate a group of pseudo-normal children as a control group for FDG-PET studies in pediatrics. Methods FDG-PET images of 47 children (mean ± SD age 10.2 ± 3.1 years) with refractory symptomatic (MRI-positive, n = 20) and cryptogenic (MRI-negative, n = 27) focal epilepsy planned for surgery were analyzed using visual and SPM analysis. Performances of SPM analysis were compared using two different control groups: (1) an adult control group consisting of healthy young adults (n = 25, 30.5 ± 5.8 years, adult PET template) and (2) a pediatric pseudo-control group consisting of patients (n = 24, 10.6 ± 3.1 years, children PET template) with refractory focal epilepsy but with negative MRI and with PET considered normal not only on visual analysis but also on SPM. Results Among the 47 children, visual analysis succeeded detecting at least one hypometabolic area in 87% of the cases (interobserver kappa = 0.81). Regarding SPM analysis, the best compromise between sensitivity and specificity was obtained with a threshold of p less than 0.001 as an extent of more than 40 voxels. There was a significant concordance to detect hypometabolic areas between both SPM analyses [kappa (K) = 0.59; p < 0.005] and between both SPM and visual analyses (K = 0.45; p < 0.005), in symptomatic (K = 0.74; p < 0.005) as in cryptogenic patients (K = 0.26; p < 0.01). The pediatric pseudo-control group dramatically improved specificity (97% vs. 89%; p < 0.0001) by increasing the positive predictive value (86% vs. 65%). Sensitivity remained acceptable although it was not better (79% vs. 87%, p = 0.039). The main impact was to reduce by 41% the number of hypometabolic cortical artifacts detected by SPM, especially in the younger epileptic patients, which is a key point in clinical practice. Conclusions This age-matched pseudo-control group is a way to optimize SPM analysis of FDG-PET in children with epilepsy. It might also be considered for other brain pathologies in pediatrics in the future.
    01/2013; 3(1):2. DOI:10.1186/2191-219X-3-2
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: For patients with focal epilepsy scheduled for surgery, including MRI-negative cases, (18)FDG-PET was shown to disclose hypometabolism in the seizure onset zone. However, it is not clear whether grey matter hypometabolism is informative of the integrity of the surrounding white matter cerebral tissue. In order to study the relationship between metabolism of the seizure onset zone grey matter and the integrity of the surrounding white matter measured by diffusion tensor imaging (DTI), we performed a monocentric prospective study (from 2006 to 2009) in 15 children with pharmacoresistant focal epilepsy, suitable for interictal (18)FDG-PET, T1-, T2-, FLAIR sequence MRI and DTI. Children had either positive or negative MRI (eight with symptomatic and seven with cryptogenic epilepsies, respectively). Seven children subsequently underwent surgery. Standardised uptake values of grey matter PET metabolism were compared with DTI indices (fractional anisotropy [FA], apparent diffusion coefficient [ADC], parallel diffusion coefficient [PDC], and transverse diffusion coefficient [TDC]) in grey matter within the seizure onset zone and adjacent white matter, using regions of interest automatically drawn from individual sulcal and gyral parcellation. Hypometabolism correlated positively with white matter ADC, PDC, and TDC, and negatively with white matter FA. In the cryptogenic group of children, hypometabolism correlated positively with white matter ADC. Our results demonstrate a relationship between abnormalities of grey matter metabolism in the seizure onset zone and adjacent white matter structural alterations in childhood focal epilepsies, even in cryptogenic epilepsy. This relationship supports the hypothesis that microstructural alterations of the white matter are related to epileptic networks and has potential implications for the evaluation of children with MRI-negative epilepsy.
    Epileptic disorders: international epilepsy journal with videotape 12/2012; 14(4). DOI:10.1684/epd.2012.0547 · 0.90 Impact Factor
  • L. Vija, F. Archambaud, P. Chaumet-Riffaud
    [Show abstract] [Hide abstract]
    ABSTRACT: Growth delay in adults with GH (growth hormone) or insulin-like growth factor 1 (IGF1) deficiency is often associated to low bone mineral density (BMD), osteoporosis and a higher risk of fractures (Tritos et al., 2011 [1]; Wüster et al., 2001 [2]; Bex et Bouillon, 2003 [3]). However to date, the risk of fractures in children with GH or IGF1 deficiency is not clearly evaluated (Högler and Shaw, 2010 [4]). This is the case of a young woman aged 21, with a syndrome including a severe mental, growth and weight retardation (–4 SD), facial dysmorphism and partial epilepsy, who recently presented walking and muscle strength loss, without history of trauma. Bone scan revealed several hot spots related to cortical bone fractures and biological data showed an IGF1 deficiency. Through this case, we discuss the role played by GH and IGF1 in bone growth, and the basic procedures to follow in children when measuring BMD with dual absorptiometry X ray technique (DXA).
    Medecine Nucleaire 07/2012; 36(7):399–402. DOI:10.1016/j.mednuc.2012.05.010 · 0.16 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Fever-induced refractory epileptic encephalopathy in school-age children (FIRES) is a recently described epileptic entity whose etiology remains unknown. Brain abnormalities shown by MRI are usually limited to mesial-temporal structures and do not account for the catastrophic neuropsychologic findings. We conducted FIRES studies in 8 patients, aged 6-13 y, using 18F-FDG PET to disclose eventual neocortical dysfunction. Voxel-based analyses of cerebral glucose metabolism were performed using statistical parametric mapping and an age-matched control group. Group analysis revealed a widespread interictal hypometabolic network including the temporoparietal and orbitofrontal cortices bilaterally. The individual analyses in patients identified hypometabolic areas corresponding to the predominant electroencephalograph foci and neuropsychologic deficits involving language, behavior, and memory. Despite clinical heterogeneity, 18F-FDG PET reveals a common network dysfunction in patients with sequelae due to fever-induced refractory epileptic encephalopathy.
    Journal of Nuclear Medicine 01/2011; 52(1):40-7. DOI:10.2967/jnumed.110.077214 · 5.56 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Intrapancreatic accessory spleen (IPAS) is ectopic splenic tissue distinct from the main spleen. A 46-year-old man with chronic hepatitis C, presented in 2006 with low right chest pain which led to a diagnosis of tuberculosis pleurisy. CT scan and MRI showed a round, homogenous, well limited mass of 3cm in the pancreas tail. Tc-99m heat-damaged red blood cell scintigraphy with SPECT-CT was performed to confirm the diagnosis of IPAS. Most cases of IPAS described in the literature were diagnosed by pathologists after distal pancreatectomy and splenectomy performed for a suspicion of pancreatic tumor. However, heat-damaged red blood cell scintigraphy remains the most commonly used diagnostic procedure for IPAS, even if superparamagnetic iron oxide MRI contrast agent may be used in the future.
    Clinical nuclear medicine 10/2009; 34(9):642-4. DOI:10.1097/RLU.0b013e3181b06b42 · 2.86 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Erdheim-Chester disease (ECD) is a rare form of non-Langerhans' cell histiocytosis. The aim of this study was to assess the value of whole-body scanning with (18)F-fluorodeoxyglucose-positron emission tomography (FDG-PET) in a large cohort of ECD patients from a single center. We retrospectively reviewed all PET scans performed on 31 patients with ECD who were referred to our department between 2005 and 2008. PET images were reviewed by 2 independent nuclear medicine specialist physicians and were compared with other imaging modalities performed within 15 days of each PET scan. Thirty-one patients (10 women and 21 men; median age 59.5 years) underwent a total of 65 PET scans. Twenty-three patients (74%) were untreated at the time of the initial PET scan, whereas 30 of the 34 followup PET scans (88%) were performed in patients who were undergoing immunomodulatory therapy. Comparison of the initial and followup PET scans with other imaging modalities revealed that the sensitivity of PET scanning varied greatly among the different organs studied (range 4.3-100%), while the specificity remained high (range 69.2-100%). Followup PET scans were particularly helpful in assessing central nervous system (CNS) involvement, since the PET scan was able to detect an early therapeutic response of CNS lesions, even before magnetic resonance imaging showed a decrease in their size. PET scanning was also very helpful in evaluating the cardiovascular system, which is a major prognostic factor in ECD, by assessing the heart and the entire vascular tree during a single session. The results of our large, single-center, retrospective study suggest that the findings of a FDG-PET scan may be interesting in the initial assessment of patients with ECD, but its greater contribution is in followup of these patients.
    Arthritis & Rheumatology 10/2009; 60(10):3128-38. DOI:10.1002/art.24848 · 7.87 Impact Factor
  • NeuroImage 07/2009; 47. DOI:10.1016/S1053-8119(09)71043-2 · 6.13 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: (18)F-fluorodeoxyglucose-positron emission tomography (FDG-PET) scanning has been proposed as a new way of assessing disease activity in Takayasu arteritis (TA), but previous studies have used the nonvalidated National Institutes of Health (NIH) global activity criteria, and thus might be biased. This study was undertaken to determine the value of PET scanning for assessment of disease activity in TA, by comparing PET scan data with clinical, biologic, and magnetic resonance imaging (MRI) data assessed separately. Twenty-eight patients with TA (according to the American College of Rheumatology criteria) underwent a total of 40 PET scans. Images were reviewed by 2 pairs of independent nuclear medicine physicians and assessed for pattern and intensity of vascular uptake. TA activity data were obtained within 15 days of the PET scans. PET scanning revealed abnormal vascular uptake in 47% of the 40 examinations. The uptake intensity grade was 0 in 7 scans, grade 1 in 7 scans, grade 2 in 13 scans, and grade 3 in 13 scans. Morphologic analysis was conducted by grading the pattern of the vascular uptake as diffuse (73%), segmental (20%), or focal (13%). There was a trend toward an association between clinically active disease and the semiquantitative assessment of FDG uptake (P = 0.08). We found no statistical association between levels of acute-phase reactants and intensity of uptake. There was no significant association between the semiquantitative assessment of FDG uptake and the presence of vascular wall thickening (P = 0.23), gadolinium uptake (P = 0.73), or the presence of vascular wall edema (P = 0.56). Our findings indicate that there is no association between FDG vascular uptake intensity and clinical, biologic, or MRI assessment of disease activity. Previous studies using the nonvalidated NIH global activity criteria are likely biased.
    Arthritis & Rheumatology 04/2009; 60(4):1193-200. DOI:10.1002/art.24416 · 7.87 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: A 2-year-old child underwent liver transplant and was referred for postsurgical abdominal pain. Hepatobiliary scintigraphy with Tc-99m iminodiacetic acid (IDA) was performed and with the help of 24-hour delayed images, the diagnosis of biliary leak at the site of anastomosis was made possible. This case report confirms the value of delayed images to facilitate the diagnosis in unequivocal situations and reminds us of the usefulness of this noninvasive method, especially in pediatrics.
    Clinical Nuclear Medicine 02/2008; 33(1):44-5. DOI:10.1097/RLU.0b013e31815c5115 · 2.86 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The patient, a two-year-old child, underwent liver transplant and was referred for postsurgical abdominal pain. Hepatobiliary scintigraphy with 99mTc-iminodiacetic acid (IDA) showed a biliary leak at the site of anastomosis. As this investigation method is little known and rarely performed in France, this case report aims to provide valuable information for next referral, especially in paediatrics. This case report stresses the interest of delayed images to facilitate the diagnosis in univocal situations.
    Medecine Nucleaire 07/2007; 31(7):345-349. DOI:10.1016/j.mednuc.2007.05.002 · 0.16 Impact Factor
  • Source
    Psychiatry and Clinical Neurosciences 05/2007; 61(2):206. DOI:10.1111/j.1440-1819.2007.01643.x · 1.62 Impact Factor
  • La Revue de Médecine Interne 12/2006; 27. DOI:10.1016/j.revmed.2006.10.099 · 1.32 Impact Factor

Publication Stats

96 Citations
46.00 Total Impact Points

Institutions

  • 2014
    • Unité Inserm U1077
      Caen, Lower Normandy, France
    • Hôpital Bicêtre (Hôpitaux Universitaires Paris-Sud)
      Lutetia Parisorum, Île-de-France, France
  • 2012–2014
    • Université Paris-Sud 11
      Orsay, Île-de-France, France
  • 2013
    • Cea Leti
      Grenoble, Rhône-Alpes, France
  • 2009
    • Assistance Publique – Hôpitaux de Paris
      Lutetia Parisorum, Île-de-France, France