Michael Lassi

publications

1. Connectivity Measures Differentiate Cortical and Subcortical Sub-Acute Ischemic Stroke Patients

   Fanciullacci, Chiara, Panarese, Alessandro, Spina, Vincenzo,  Lassi, Michael, Mazzoni, Alberto, Artoni, Fiorenzo, Micera, Silvestro, and Chisari, Carmelo

   Frontiers in Human Neuroscience 2021

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   Brain lesions caused by cerebral ischaemia lead to network disturbances in both hemispheres, causing a subsequent reorganization of functional connectivity both locally and remotely with respect to the injury. Quantitative electroencephalography (qEEG) methods have long been used for exploring brain electrical activity and functional connectivity modifications after stroke. However, results obtained so far are not univocal. Here, we used basic and advanced EEG methods to characterize how brain activity and functional connectivity change after stroke. Thirty-three unilateral post stroke patients in the sub-acute phase and ten neurologically intact age-matched right-handed subjects were enrolled. Patients were subdivided into two groups based on lesion location: cortico-subcortical (CS, n=18) and subcortical (S, n=15), respectively. Stroke patients were evaluated in the period ranging from 45 days since the acute event (T0) up to 3 months after stroke (T1) with both neurophysiological (resting state EEG) and clinical assessment (Barthel Index, BI) measures, while healthy subjects were evaluated once. Brain power at T0 was similar between the two groups of patients in all frequency bands considered (δ, θ, α and β). However, evolution of θ-band power over time was different, with a normalization only in the CS group. Instead, average connectivity and specific network measures (Integration, Segregation and Small-worldness) in the β-band at T0 were significantly different between the two groups. The connectivity and network measures at T0 also appear to have a predictive role in functional recovery (BI T1-T0), again group-dependent. The results obtained in this study showed that connectivity measures and correlations between EEG features and recovery depend on lesion location. These data, if confirmed in further studies, on the one hand could explain the heterogeneity of results so far observed in previous studies, on the other hand they could be used by researchers as biomarkers predicting spontaneous recovery, to select homogenous groups of patients for the inclusion in clinical trials.

2. Loss of speech and functional impairment in Alzheimer’s disease-related primary progressive aphasia: predictive factors of decline

   Mazzeo, Salvatore, Polito, Cristina,  Lassi, Michael, Bagnoli, Silvia, Mattei, Marta, Padiglioni, Sonia, Berti, Valentina, Lombardi, Gemma, Giacomucci, Giulia, De Cristofaro, Maria Teresa, Passeri, Alessandro, Ferrari, Camilla, Nacmias, Benedetta, Mazzoni, Alberto, Sorbi, Sandro, and Bessi, Valentina

   Neurobiology of Aging Sep 2022

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   We aimed to identify features associated with different disease trajectories in Alzheimer’s disease (AD)-related primary progressive aphasia (PPA). We considered 23 patients diagnosed with AD-related PPA. All patients underwent neuropsychological evaluation, 18F-Fluorodeoxyglucose-PET brain scan, CSF biomarkers measurement and APOE genotype analysis at baseline and underwent neurological follow-up for a mean time of 3 years. Patients who progressed to total loss of speech (TLoS+) had greater impairment in writing and higher t-tau concentration as compared to TLoS– patients. Patients who progressed to loss of functional autonomy (LoFA+) had greater impairment in single-word comprehension as compared to patients who maintained autonomy in self-care. Furthermore, 18F-FDG-PET SPM analyses revealed different brain metabolic patterns between TLoS+ and TLoS– and between LoFA+ and LoFA–. In conclusion, linguistic profile, CSF t-tau and brain metabolic pattern might be useful tools to predict progression to total loss of speech and loss of functional autonomy in AD-related PPA patients.