Who needs cerebrospinal biomarkers? A national survey in clinical practice.

Cerebrospinal fluid (CSF) biomarkers for Alzheimer's disease (AD) are well validated in clinical research but less in clinical practice. Using a questionnaire, we evaluated the reasons for prescriptions and clinician's expectations concerning CSF biomarkers. The results show that CSF AD biomarkers are mainly required in case of atypical dementia and diagnosis uncertainty that are different from indications in clinical research. In the future, clinicians wish to get new biomarkers that could improve differential diagnosis and could have a good pronostic value. Further studies in routine practice are necessary to precise the role of these biomarkers in the management of patients.

Impact of cerebro-spinal fluid biomarkers of Alzheimer's disease in clinical practice: a multicentric study.

CSF biomarkers of Alzheimer's disease are well validated in clinical research; however, their pragmatic utility in daily practice is still unappreciated. These biomarkers are used in routine practice according to Health Authority Recommendations. In 604 consecutive patients explored for cognitive disorders, questionnaires were prospectively proposed and filled. Before and after CSF biomarker results, clinicians provided a diagnosis and an estimate of their diagnostic confidence. Analysis has compared the frequency of diagnosis before and after CSF biomarker results using the net reclassification improvement (NRI) method. We have evaluated external validity comparing with data of French Bank National of AD (BNA). A total of 561 patients [Alzheimer's disease (AD), n = 253; non-AD, n = 308] were included (mean age, 68.6 years; women, 52 %). Clinically suspected diagnosis and CSF results were concordant in 65.2 % of cases. When clinical hypothesis and biological results were discordant, a reclassification occurred in favour of CSF biomarkers results in 76.9 %. The NRI was 39.5 %. In addition, the results show a statistically significant improvement in clinician confidence for their diagnosis. In comparison with BNA data, patients were younger and more frequently diagnosed with AD. Clinicians tend to heavily rely on the CSF AD biomarkers results and are more confident in their diagnoses using CSF AD biomarkers. Thus, these biomarkers appear as a key tool in clinical practice.