Patent ID: 8778334

Claim:
A method of identifying whether or not an individual has Parkinson's Disease (PD) rather than a neurodegenerative disease which is not PD, which method comprises: (i) measuring the concentration of α-synuclein (α-syn) in a cerebrospinal fluid (CSF) sample taken from the individual; (ii) measuring the concentration of unphosphorylated tau (tau) and/or phosphorylated (p-tau) present in the sample; and (iii) calculating the ratio of: total ⁢ ⁢ concentration ⁢ ⁢ of ⁢ ⁢ tau concentration ⁢ ⁢ of ⁢ ⁢ α ⁢ - ⁢ syn ⁢ ⁢ or ⁢ ⁢ concentration ⁢ ⁢ of ⁢ ⁢ p ⁢ - ⁢ tau concentration ⁢ ⁢ of ⁢ ⁢ α ⁢ - ⁢ syn wherein the total concentration of tau is the cumulative concentration of p-tau and tau measured in the sample; and (iv) thereby determining whether or not the individual has PD according to at least one of the following: (a) a ratio of total tau to α-syn of 19.5:1 or less is indicative that the individual has PD rather than a neurodegenerative disease which is not PD; or (b) a ratio of p-tau to α-syn of 3.1:1 or less is indicative that the individual has PD rather than a neurodegenerative disease which is not PD; or (c) a decreased ratio of total tau to α-syn or p-tau to α-syn relative to the corresponding ratio in a sample taken from an individual having a neurodegenerative disease which is not PD, is indicative that the individual has PD rather than a neurodegenerative disease which is not PD; or (d) a ratio of total tau to α-syn or p-tau to α-syn that is not significantly different to the corresponding ratio in a sample taken from a normal individual is indicative that the individual has PD rather than a neurodegenerative disease which is not PD.