The cerebrospinal fluid (CSF) surrounds and protects the brain and spinal cord offering a cushion against shock and aiding in maintaining physiological balance. Understanding CSF dynamics is crucial for insights into neurological disorders like Chiari 1 Malformation (CM1) and hydrocephalus. CM1 involves the downward displacement of brain tissue through the skull opening, which obstructs the CSF flow. Theories suggest that this altered CSF distribution due to CM1 might contribute to related disorders like syringomyelia, where fluid accumulates within the spinal cord and which has been associated with severe motor and sensory symptoms. However, the source of syringomyelia remains debated. This thesis aims to investigate the effect of an artificial 3D obstruction as present in CMI using both a Computational Fluid Dynamics (CFD) and a poroelastic Fluid Structure Interaction (FSI) approach.