Choroid plexus insufficiency or glymphatic stasis are often classified as prequels to harmful accretion of toxic proteins in neurodegenerative disease. Cognitive decline and disordered neuronal signaling subsequently become cardinal features of Alzheimer's disease (AD), typically progressing with amyloid-ß and tau protein accumulation. For Parkinson's disease (PD), α-synuclein deposits and dopamine depletion are linked to impaired movement, resting tremor, and rigidity. Importantly, both diagnoses feature hyperinflammation and intrathecal cytokine changes. Thus far, numerous clinical trials have produced nothing effective for AD or PD, yet the anti-inflammatory and regenerative potential of autologous platelet-rich plasma (PRP) remains largely unexamined in this context. Our report explores a proposed Phase I study on intrathecal condensed plasma growth factors processed from thrombin-activated PRP as monotherapy for AD or PD. The concept gains support from related work where cytokines of platelet origin successfully lowered inflammation, corrected background fibrosis, deactivated abnormal cells, and recovered local tissue function-all desirable outcomes in AD and PD. While PRP-mediated effects on membrane potentials, cellular signaling, electrolyte balance, and water clearance are less well characterized, experimental data suggest these pathways could likewise influence glymphatic drainage to ameliorate proteinopathies. As a well-tolerated 'orthobiologic' with no hypersensitivity risk, intrathecal PRP and its derivatives bring advantages over synthetic pharmaceuticals. If age-associated neuroinflammation in AD and PD is an upstream event inciting or contributing to neural disruption, then dampening local oxidative stress by a patient's own platelet cytokines (successful in other contexts) could offer therapeutic relevance to these neurodegenerative conditions as well.