Use of CSF α-synuclein in the differential diagnosis between Alzheimer's disease and other neurodegenerative disorders

Background:The etiology and pathogenesis of neurodegenerative disorders has yet to be elucidated, so their differential diagnosis is a challenge. This is especially true in differentiating Alzheimer's disease (AD), dementia with Lewy bodies (DLB), Parkinson disease (PD), and multiple system atrophy (MSA).Methods:A total of 11 eligible articles were identified by search of electronic databases including PubMed, Springer Link, Elsevier, and the Cochrane Library, up to June 2014. In meta-analyses, standardized mean differences (SMD), with 95% confidence intervals (CI), comparing cerebrospinal fluid (CSF) measures of α-synuclein between the above conditions were calculated using random-effects models.Results:CSF α-synuclein concentrations were significantly higher in AD compared to DLB [SMD: 0.32, 95%CI: (0.02, 0.62),z= 2.07,P= 0.038]; PD [SMD: 0.87, 95%CI: (0.15, 1.58),z= 2.38,P= 0.017]; or MSA [SMD: 1.14, 95%CI: (0.15, 2.14),z= 2.25,P= 0.025]. However, no significant difference was found between patients with AD and neurological cognitively normal controls [SMD:0.02, 95%CI: (−0.21, 0.24),z= 0.13,P= 0.894].Conclusions:Results of these meta-analysis suggest that quantification of CSF α-synuclein could help distinguish AD from other neurodegenerative disorders such as DLB, PD, or MSA.