MAPT and dementia: The combination of reduced Aβ42 and increased t-tau and p-tau levels is collectively termed ‘an AD-like profile’ considering its specificity for diagnosing the condition.122 This profile occurs in a larger proportion of synucleinopathy patients with prominent cognitive dysfunction, i.e. Parkinson’s disease dementia (PDD) and dementia with Lewy bodies (DLB).123–125 CSF AD-like biomarkers may, therefore, be useful for differentiating DLB from other parkinsonian disorders, although for some interventional trials this distinction may be somewhat arbitrary.