A curable pseudo-dementia related to an atypical presentation of giant cell arteritis.

A 70-year-old patient was admitted with rapidly progressive cognitive decline associated with limitations in activities of daily living, weight loss and cerebellar ataxia. The diagnosis of giant cell arteritis (GCA) with vascular involvement was made, based on the presence of a metabolically active vasculitis of the brachiocephalic trunk on 18FDG-PET imaging. Temporal artery biopsy also revealed pan-arteritis. A progressive regression of cognitive disorders occurred under corticosteroid treatment and immunosuppressive therapy. Previously published case reports concerning this atypical presentation of GCA are scarce. They suggest that numerous cognitive symptoms, such as impairment of short-term memory, disorientation, delirium, impaired attention or visual hallucinations might be related to GCA. Thus, this diagnosis should be considered as a curable cause of unexplained cognitive impairment associated with weight loss and systemic inflammation.

Biomarker profiles of Alzheimer's disease and dynamic of the association between cerebrospinal fluid levels of ß-amyloid peptide and tau.

OBJECTIVE: To investigate the relationship between cerebrospinal fluid (CSF) ß-amyloid peptide (Aß42) and CSF Tau in a large population of patients referred to memory clinics for investigation of cognitive dysfunction. METHODS: We analyzed Alzheimer's disease (AD) biomarkers in CSF taken from 3565 patients referred to 18 French memory clinics. Patients were classified into four profiles according to levels of CSF biomarkers (A: amyloidosis, N: neurodegeneration). The association between CSF Tau and CSF Aß42 were analyzed using general linear regression models, in the overall population and stratified by biomarkers profiles. We compared linear and quadratic models using Akaike information criterion. We also assessed change in biomarker profiles in a subset of patients who had 2 assessments of biomarkers. RESULTS: CSF Tau was negatively associated with CSF Aß42 in the overall population, following a non-linear quadratic model. However, the nature of this association was different in the 4 profiles: positive association in A-N- profile, negative association in A-N+ and A+N+ profiles, lack of association in A+N- patients. When considering patients with longitudinal data on profiles, 36% of those initially classified as A-N+ evolved to an A+N+ profile. CONCLUSIONS: The nature of the association between CSF Aß42 and CFS Tau depends on the A/N profiles of patients. These results suggest an increase in CSF Aß42 early in the disease before its decline while tau pathology progresses, this pattern is particularly observed in non-APOE4 subjects. This phenomenon may explain why some patients with neurodegeneration only markers convert to an AD profile (A+N+) over time.