Hypermetabolism was found in the executive network in narcolepsy at baseline in fully awake condition. Wake state assessment during scanning appears critical to avoid results showing altered functional neurocircuitry secondary to sleepiness and not to the underlying neurological disorder per se. Finally, cataplexy attacks were characterised by a hypometabolism in the hypothalamus associated with wide bilateral brain area hypermetabolisms.

BackgroundNo reliable biomarkers are identified in KLS. However, few functional neuroimaging studies suggested hypoactivity in thalamic and hypothalamic regions during symptomatic episodes. Here, we investigated relative changes in regional brain metabolism in Kleine-Levin syndrome (KLS) during symptomatic episodes and asymptomatic periods, as compared to healthy controls.MethodsFour drug-free male patients with typical KLS and 15 healthy controls were included. 18-F-fluorodeoxy glucose positron emission tomography (PET) was obtained in baseline condition in all participants, and during symptomatic episodes in KLS patients. All participants were asked to remain fully awake during the whole PET procedure.ResultsBetween state-comparisons in KLS disclosed higher metabolism in paracentral, precentral, and postcentral areas, supplementary motor area, medial frontal gyrus, thalamus and putamen during symptomatic episodes, and decreased metabolism in occipital and temporal gyri. As compared to healthy control subjects, KLS patients in the asymptomatic phase consistently exhibited significant hypermetabolism in a wide cortical network including frontal and temporal cortices, posterior cingulate and precuneus, with no detected hypometabolism. In symptomatic KLS episodes, hypermetabolism was additionally found in orbital frontal and supplementary motor areas, insula and inferior parietal areas, and right caudate nucleus, and hypometabolism in the middle occipital gyrus and inferior parietal areas.ConclusionOur results demonstrated significant hypermetabolism and few hypometabolism in specific but widespread brain regions in drug-free KLS patients at baseline and during symptomatic episodes, highlighting the behavioral state-dependent nature of changes in regional brain activity in KLS.

Purpose:The main goal of sentinel lymph node (SLN) detection in head and neck squamous cell carcinomas is to limit neck dissections to pN+ cases only. However, intraoperative + diagnosis cannot be routinely done using the current gold standard, serial step sectioning with immunohistochemistry. Real-time quantitative reverse transcription-PCR (RT-PCR) is potentially compatible with intraoperative use, proving highly sensitive in detecting molecular markers. This study postoperatively assessed the accuracy of quantitative RT-PCR in staging patients from their SLN. Experimental Design: A combined analysis on the same SLN by serial step sectioning with immunohistochemistry and quantitative RT-PCR targeting cytokeratins 5, 14, and 17 was done in 18 consecutive patients with oral or oropharyngeal squamous cell carcinoma and 10 control subjects. Results: From 71lymph nodes examined, mRNA levels (KRT) were linked to metastasis size for the three cytokeratins studied (Pearson correlation coefficient, r = 0.89, 0.73, and 0.77 for KRT 5, 14, and 17 respectively; P < 0.05). Histopathology-positive SLNs (macro-and micrometastases) showed higher mRNA values than negative SLNs for KRT 17 (P < 10 À4) and KRT 14 (P < 10 À2 ). KRT 5 showed nonsignificant results. KRT17 seemed to be the most accurate marker for the diagnosis of micrometastases of a size >450 Am. Smaller micrometastases and isolated tumor cells did not provide results above the background level. Receiver operating characteristic curve analysis for KRT17 identified a cutoff value where patient staging reached 100% specificity and sensitivity for macro-and micrometastases. Conclusion: Quantitative RT-PCR for SLN staging in cN 0 patients with oral and oropharyngeal squamous cell carcinoma seems to be a promising approach.The extent of lymph node involvement in clinically and computed tomography scan N 0 (cN 0 ) oral and oropharyngeal squamous cell carcinomas is f30% to 40% and is one of the main prognostic factors (1). Until recently, a neck dissection was advocated routinely both to assess nodal involvement and to remove occult minimal residual cancer (2). A more recent approach consists of limiting lymph node surgery to a staging procedure by taking only the sentinel lymph nodes (SLN) which are representative of the whole neck node system (3). Such a strategy aims to permit more thorough analysis of only a few lymph nodes to enhance the sensitivity and the specificity of the diagnosis of lymph node invasion and thus select only pN+ patients on whom to perform a neck dissection. Intraoperative diagnosis must therefore have a predictive negative value close to 100%. At present, many methods of SLN analysis are used. The reference method for pathologic analysis is histopathologic examination by serial step sectioning with immunohistochemistry, staining with anticytokeratin antibodies in cases of squamous cell carcinoma (4, 5). Such analysis is able to diagnose three levels of nodal invasion (6): isolated tumor cells <0.2 mm, micrometastases V2 mm, and macromet...

The aim of this preliminary study was to evaluate the accuracy of left and right ventricular output computed from a semi-automatic processing of tomographic radionuclide ventriculography data (TRVG) in comparison with the conventional thermodilution method. Twenty patients with various heart diseases were prospectively included in the study. Thermodilution and TRVG acquisitions were carried out on the same day for all patients. Analysis of gated blood pool slices was performed using a watershed-based segmentation algorithm. Right and left ventricular output measured by TRVG correlated well with the measurements obtained with thermodilution (r = 0.94 and 0.91 with SEE = 0.38 and 0.46 l/min, respectively, P < 0.001). The limits of agreement for TRVG and thermodilution measurements were -0.78-1.20 l/min for the left ventricle and -0.34-1.16 l/min for the right ventricle. No significant difference was found between the results of TRVG and thermodilution with respect to left ventricular output (P = 0.09). A small but significant difference was found between right ventricular output measured by TRVG and both left ventricular output measured by TRVG (mean difference = 0.17 l/min, P = 0.04) and thermodilution-derived cardiac output (mean difference = 0.41 l/min, P = 0.0001). It is concluded that the watershed-based semi-automatic segmentation of TRVG slices provides non-invasive measurements of right and left ventricular output and stroke volumes at equilibrium, in routine clinical settings. Further studies are necessary to check whether the accuracy of these measurements is good enough to permit correct assessment of intracardiac shunts.