Bypassing the Blood-Brain Barrier: A Dual-Axis Framework for Parkinson's Disease Utilizing Glymphatic-Lymphatic Clearance and In Situ Chaperone Synthesis

Parkinson's disease (PD) is characterized neuropathologically by loss of dopaminergic neurons in the substantia nigra pars compacta and by aggregation of misfolded alpha-synuclein into Lewy bodies and Lewy neurites, which is proposed to propagate in a prion-like manner following a stereotyped, stage-dependent pattern described by Braak staging.Because any circulating agent intended to act within the central nervous system (CNS) must cross the blood-brain barrier, this review proposes active craniospinal tensioning (ACT), a mechanical, non-pharmacological route to disease modification acting on cerebrospinal fluid (CSF) and cerebral venous pressure dynamics.ACT combines two concurrent mechanisms converging on a single venous-side target within Monro-Kellie/Queckenstedt pressure continuity: suboccipital venous occlusionrebound, proposed to raise and release craniospinal CSF pressure to accelerate venous-side glymphatic efflux, and dural pull-recoil, a reverse Queckenstedt effect in which spinal elongation is proposed to generate a CSF-side pressure gradient with a coupled venous component.The proposed disease-modifying route is clearance of transiting extracellular alpha-synuclein from the perivascular and interstitial space before it templates a neighboring cell.The claim is scoped to the CNS phase of PD, excluding peripheral vagal or olfactory transport, with its most direct anatomical rationale at the dorsal motor nucleus of the vagus (DMV), one of the two earliest CNS sites of Lewy pathology in Braak staging and adjacent to ACT's craniocervical site of action, where ACT is proposed to act on onward extracellular spread rather than on arrival.A secondary, hypothesis-generating axis, cerebral venous preconditioning (CVPC), proposes that the same cycle produces venule-and capillary-wall strain sufficient to activate heat shock factor 1 (HSF-1) within the neurovascular unit, beginning at the vessel wall, independent of oxygen tension, with a possible contribution from hypoxia-inducible factor 1-alpha (HIF-1α) left open; the mechanical route alone is proposed as sufficient.Validation is staged, with diffusion tensor image analysis along the perivascular space (DTI-ALPS) and neuromelanin-sensitive magnetic resonance imaging with quantitative susceptibility mapping (QSM) of the substantia nigra as dual falsification endpoints over at least two years, and any disease-modification claim deferred to a randomized, delayed-start trial.This framework is entirely theoretical, requires clinical validation, and extends a dual-axis template already applied to Alzheimer's disease (AD) and amyotrophic lateral sclerosis (ALS).