Appropriate use criteria for dementia amyloid imaging in Switzerland – mini-review and statement on behalf of the Swiss Society of Nuclear Medicine and the Swiss Memory Clinics

While FDG-PET imaging of the brain for the differential diagnosis of dementia has been covered by the compulsory health insurance in Switzerland for more than a decade, beta-amyloid-PET just recently has been added to the catalogue of procedures that have been cleared for routine use, provided that a set of appropriate use criteria (AUC) be followed. To provide guidance to dementia care practitioners, the Swiss Society of Nuclear Medicine and the Swiss Memory Clinics jointly report a mini-review on beta-amyloid-PET and discuss the AUC set into effect by the Swiss Federal Office of Public Health, as well as their application and limitations.Die Beta-Amyloid-PET-Bildgebung des Gehirns ist mit der Zulassung für die klinische Routineanwendung durch Swissmedic von 3 EU-weit bereits länger kommerziell verfügbaren Amyloid-β-PET-Radiopharmaka nun auch in dem Nicht-EU-Land Schweiz allgemein verfügbar geworden. Seit dem 01.04.2020 unterliegt die Anwendung von Beta-Amyloid-PET der gesetzlichen Leistungspflicht durch die obligatorische Schweizer Krankenversicherung für die Differenzialdiagnose demenzieller Erkrankungen unter bestimmten Voraussetzungen.Im Namen der Schweizer Gesellschaft für Nuklearmedizin (SGNM) und der Schweizer Memory-Kliniken publiziert die AG Neuronuklearmedizin der SGNM die aktuell gültigen Anwendungskriterien im Rahmen der gesetzlichen Leistungspflicht in der Schweiz, um sowohl den verordnenden Demenzspezialisten, Gerontopsychiatern und Neurologen, als auch den durchführenden Nuklearmedizinern Handlungsempfehlung an die Hand zu geben und einen aktuellen Kurzüberblick über Möglichkeiten und Grenzen der Beta-Amyloid-Bildgebung im klinischen Alltagskontext zu geben

Brain areas involved in medial temporal lobe seizures: a principal component analysis of ictal SPECT data

The study describes brain areas involved in medial temporal lobe (mTL) seizures of 12 patients. All patients showed so-called oro-alimentary behavior within the first 20 s of clinical seizure manifestation characteristic of mTL seizures. Single photon emission computed tomography (SPECT) images of regional cerebral blood flow (rCBF) were acquired from the patients in ictal and interictal phases and from normal volunteers. Image analysis employed categorical comparisons with statistical parametric mapping and principal component analysis (PCA) to assess functional connectivity. PCA supplemented the findings of the categorical analysis by decomposing the covariance matrix containing images of patients and healthy subjects into distinct component images of independent variance, including areas not identified by the categorical analysis. Two principal components (PCs) discriminated the subject groups: patients with right or left mTL seizures and normal volunteers, indicating distinct neuronal networks implicated by the seizure. Both PCs were correlated with seizure duration, one positively and the other negatively, confirming their physiological significance. The independence of the two PCs yielded a clear clustering of subject groups. The local pattern within the temporal lobe describes critical relay nodes which are the counterpart of oro-alimentary behavior: (1) right mesial temporal zone and ipsilateral anterior insula in right mTL seizures, and (2) temporal poles on both sides that are densely interconnected by the anterior commissure. Regions remote from the temporal lobe may be related to seizure propagation and include positively and negatively loaded areas. These patterns, the covarying areas of the temporal pole and occipito-basal visual association cortices, for example, are related to known anatomic paths