- The medical doctor (after clinical assessments, cognitive testing, CSF analyses and structural brain imaging) believes the cognitive complaints are caused by an incipient neurocognitive disorder of any sort. This is defined as any case fulfilling the criteria above (i.e. both SCD and MCI) with an abnormal CSF Aβ42/40 ratio, which is strongly associated with brain Aβ pathology and prodromal Alzheimer's disease. Further, cases with MCI (=minor neurocognitive impairment) due to either Parkinson's disease, Lewy body disease, vascular neurocognitive disorder or frontotemporal dementia (please see Appendix below for clinical criteria and references) can also be included.