ITALIAN CONSENSUS RECOMMENDATIONS FOR THE ETIOLOGICAL DIAGNOSIS IN MEMORY CLINICS

Biomarkers support the etiological diagnosis of dementing neurodegenerative disorders in vivo. Aim of this study is to define a biomarker-based diagnostic algorithm for Italian memory clinics based on available literature and expert consensus. Representatives of five Italian Scientific Societies (SINDEM; AINR; SIBioC; AIP; AIMN) defined context of use (diagnosis of Mild Cognitive Impairment, MCI, in Italian memory clinics), theoretical framework (2011 NIA-AA criteria) and identified relevant literature and the diagnostic issues to be addressed. A Delphi procedure was held and consensus achieved with an 80% majority. Panelists were experienced clinicians making heterogeneous use of biomarkers in clinical practice. The algorithm was defined in seven Delphi rounds and comprises detailed clinical and cognitive assessment, blood examination and MRI with both exclusionary and inclusionary diagnostic value [I, 5-0] at baseline. The choice of biomarker then depends on diagnostic hypothesis. With suspected Dementia with Lewy Bodies with clear parkinsonism, I-123 MIBG cardiac scintigraphy was voted as the most specific marker [VII, 3-1, 1 abstained], and FDG-PET as second choice [VII, 3-1, 1 abstained]; without clear parkinsonism, the panelists recommend I-123 MIBG cardiac scintigraphy or DAT-SPECT [VII, 3-1, 1 abstained]. In patients with suspected Alzheimer's disease (AD), rachicentesis was voted as the first-choice etiological biomarker [I, 5-0], to be accompanied with FDG-PET if previous MRI was negative [III, 5-0]. In patients over age 75 and consistent clinical and MRI findings, rachicentesis prescription should depend on the plausible clinical impact [IV, 5-0]. Amyloid-PET should be prescribed if rachicentesis cannot be performed, or provided borderline inconclusive values. Finally, with suspected Frontotemporal Lobar Degeneration (FTLD) and very low diagnostic confidence of AD, the panelists suggest FDG-PET to assess the pattern of hypometabolism [VII, 4-0, 1 abstained]. We generated consensual recommendations for a cost-effective biomarker-based etiological diagnosis of MCI in memory clinics based on available evidence and expert opinion. These can guide clinicians in the use of biomarkers while the quantitative assessment of their comparative and combined diagnostic value is limited. Acknowledgements: This work was supported by the Italian Health Ministry grant NET-2011-02346784 and the EU-EFPIA Innovative Medicines Initiative 2 Joint Undertaking grant 115952 (AMYPAD).