Clinical and metabolic imaging features of late-onset and early-onset posterior cortical atrophy.

BACKGROUND AND PURPOSE: Late-onset (LO) and early-onset (EO) dementia show neurobiological and clinical differences. Clinical and 18 fluoro-deoxy-glucose positron emission tomography (FDG-PET) features of LO and EO posterior cortical atrophy (LO_PCA, EO_PCA), the visual variant of Alzheimer's disease (AD), were compared. LO_PCA patients were also compared with a group of patients with LO typical AD (tAD). METHODS: Thirty-seven LO_PCA patients (onset age ≥ 65 years), 29 EO_PCA patients and 40 tAD patients who all underwent a standard neuropsychological battery were recruited; PCA patients were also assessed for the presence of posterior signs and symptoms. Brain FDG-PET was available in 32 LO_PCA cases, 23 EO_PCA cases and all tAD cases, and their scans were compared with scans from 30 healthy elderly controls. Within the entire PCA sample FDG uptake was also correlated with age at onset as a continuous variable. RESULTS: The main difference between the two PCA groups was a higher prevalence of Bálint-Holmes symptoms in EO cases, which was associated with the presence of severe bilateral occipito-temporo-parietal hypometabolism, whilst LO_PCA patients showed reduction of FDG uptake mainly in the right posterior regions. The latter group also showed mesial temporal hypometabolism, similarly to the tAD group, although with a right rather than left lateralization. Correlation analysis confirmed the association between older age and decreased limbic metabolism and between younger age and decreased left parietal metabolism. CONCLUSIONS: The major involvement of the temporal cortex in LO cases and of the parietal cortex in EO cases reported previously within the AD spectrum holds true also for the visual variant of AD.

Posterior reversible encephalopathy syndrome and COVID-19: A series of 6 cases from Lombardy, Italy.

Posterior reversible encephalopathy cases are increasingly being reported in patients affected by COVID-19, but the largest series so far only includes 4 patients. We present a series of 6 patients diagnosed with PRES during COVID-19 hospitalized in 5 Centers in Lombardia, Italy. 5 out of the 6 patients required intensive care assistence and seizures developed at weaning from assisted ventilation. 3 out of 6 patients underwent cerebrospinal fluid analysis which was normal in all cases, with negative PCR for Sars-CoV-2 genome search. PRES occurrence may be less rare than supposed in COVID-19 patients and a high suspicion index is warranted for prompt diagnosis and treatment.

Primary Whipple disease of the Central Nervous System presenting with rhombencephalitis.

Primary Whipple disease of the Central Nervous System is a rare entity whose outcome might be fatal if not promptly diagnosed and treated. Few cases are reported in the literature with heterogeneous clinical and radiological presentations which often make the diagnosis extremely challenging. We report a case of primary Whipple disease of the Central Nervous System presenting with rhombencephalitis in a female patient in immunosuppressive treatment for rheumatoid arthritis. We describe the management of our patient and discuss the features of this rare clinical entity.