Hydrocephalus 2018 – Bologna

Biomechanical approach of brain aging, neurodegenerative diseases and frailty

Alexandra Vallet1,3, Armelle Lokossou2, Sylvie Lorthois3, Pascal Swider3, Pauline Assemat3, Laurent Risser4, Zofia Czosnyka5, Marek Czosnyka5, Natalia Del Campo6, Laurent Balardy6, Patrice Peran1, Olivier Balédent2, Pierre Payoux 1, Eric Schmidt1,6

1ToNIC UMR 1214, INSERM, Toulouse, France; 2CHIMERE EA 7516, Amiens, France; 3Inst. De Mecanique des Fluides de Toulouse UMR 5502, Toulouse, France; 4Inst. De Mathématiques de Toulouse UMR 5219, Toulouse, France; 5Neurosurg. Unit, Department of Clinical Neurosciences, United Kingdom; 6Ctr. Hospitalier Universitaire de Toulouse, Toulouse, France

Correspondence: Alexandra Valle

Fluids and Barriers of the CNS 2018, 15(Suppl 2):O112

Introduction: Brain aging is a natural process that can become pathological leading to neuronal loss and neurodegenerative diseases. In link with CSF related disorders, intracranial physical constrains like stress, strain or shear should participate to the pathophysiology of neurodegenerative diseases. We propose to explore the frail zone that is the transition region from normal to pathological brain aging with a biomechanical approach.

Methods: A statistical analysis was performed on a database that included 100 patients suspected of normal pressure hydrocephalus with enlarged ventricles or parenchymal atrophy, gait disturbance, modest cognitive decline or urinary incontinence. The frailty was evaluated using the SEGA score, based on cognitive status, nutritional status, risk of depression, level of independence and fall risk.

The cerebrospinal fluid (CSF) dynamics was explored using an infusion test. The intra cranial pressure was recorded while a saline fluid was injected at constant rate through a lumbar puncture. The intracranial fluids (blood and CSF) dynamics were also quantified (at baseline) with phase contrast MRI. A model of the blood and CSF circuit system was fitted on the clinical measurements in order to obtain the brain mechanical properties.

Results: The statistical analysis showed a significant correlation (r = 0.34, p = 0.01) between brain elastance, which describes the brain ability to accommodate to volume changes, and frailty index SEGA.

Conclusion: Our results support the hypothesis that biomechanical characterization of the brain could be valid to identify the transition from normal to pathological aging.