%0 Journal Article %J J Alzheimers Dis %D 2016 %T Differential Diagnosis of Dementia with High Levels of Cerebrospinal Fluid Tau Protein. %A Grangeon, Lou %A Paquet, Claire %A Bombois, Stephanie %A Quillard-Muraine, Muriel %A Martinaud, Olivier %A Bourre, Bertrand %A Lefaucheur, Romain %A Nicolas, Gaël %A Dumurgier, Julien %A Gerardin, Emmanuel %A Jan, Mary %A Laplanche, Jean-Louis %A Peoc'h, Katell %A Hugon, Jacques %A Pasquier, Florence %A Maltête, David %A Hannequin, Didier %A Wallon, David %K Adult %K Age of Onset %K Aged %K Aged, 80 and over %K Alzheimer Disease %K Biomarkers %K Creutzfeldt-Jakob Syndrome %K Dementia, Vascular %K Diagnosis, Differential %K Female %K France %K Frontotemporal Dementia %K Humans %K Lewy Body Disease %K Male %K Mental Status Schedule %K Middle Aged %K Phosphorylation %K Retrospective Studies %K Sex Factors %K tau Proteins %X

BACKGROUND: Total Tau concentration in cerebrospinal fluid (CSF) is widely used as a biomarker in the diagnosis of neurodegenerative process primarily in Alzheimer's disease (AD). A particularly high Tau level may indicate AD but may also be associated with Creutzfeldt-Jakob disease (CJD). In such situations little is known about the distribution of differential diagnoses.

OBJECTIVE: Our study aimed to describe the different diagnoses encountered in clinical practice for patients with dementia and CSF Tau levels over 1000 pg/ml. We studied the p-Tau/Tau ratio to specify its ability to distinguish AD from CJD.

METHODS: Patients (n = 202) with CSF Tau levels over 1000 pg/ml were recruited in three memory clinics in France. All diagnoses were made using the same diagnostic procedure and criteria.

RESULTS: Patients were diagnosed with AD (n = 148, 73.2%), mixed dementia (n = 38, 18.8%), CJD, vascular dementia (n = 4, 2.0% for each), Lewy body dementia, and frontotemporal dementia (n = 3, 1.5% for each). Dispersion of CSF Tau levels clearly showed an overlap between all diagnoses. Using the p-Tau/Tau ratio suggestive of CJD (<0.075), all CJD patients were correctly categorized and only two AD patients were miscategorized. This ratio was highly associated with CJD compared to AD (p < 0.0001).

CONCLUSION: Our study showed that in clinical practice, extremely high CSF Tau levels are mainly related to diagnosis of AD. CJD patients represent a minority. Our results support a sequential interpretation algorithm for CSF biomarkers in dementia. High CSF Tau levels should alert clinicians to check the p-Tau/Tau ratio to consider a probable diagnosis of CJD.

%B J Alzheimers Dis %V 51 %P 905-13 %8 2016 %G eng %N 3 %1 http://www.ncbi.nlm.nih.gov/pubmed/26890785?dopt=Abstract %R 10.3233/JAD-151111