Abstract: A process for determining an extent of a central nervous system (CNS) specific neurological condition in a subject including collecting a biological sample of biofluid from the subject and measuring a quantity of a first biomarker, or metabolite of or mRNA corresponding to, the first biomarker from the sample from a dried spot or through a microfluidic device. The biofluid is capillary blood or saliva, which affords ease of collection advantages that are attractive for field-, hospital-, and home-based environments. The process being useful in the diagnosis, care, and management of brain specific abnormal neurological conditions in general, and in particular, to traumatic brain injury (TBI) and (TBI-induced) Alzheimer's disease (AD) and Alexander disease, in which a GFAP mutation is implicated in white matter deterioration.