Purpose <p>Physiological head motion is common in daily activities after carotid artery stenting (CAS) and may alter the local biomechanical environment of the treated artery. This study aimed to investigate the effects of different head movements on arterial wall stress after CAS and to explore the potential mechanical role of neointima formation.</p> Methods <p>A carotid bifurcation model with an implanted stent was developed, and numerical simulations were performed to evaluate biomechanical changes under different head-motion conditions, including forward/backward bending, left/right bending, and left/right turning. Additional models with neointima formation were constructed to assess its influence on stress redistribution in the stented artery.</p> Results <p>Head bending induced increased stress concentration in the arterial bending region and at the distal end of the stented segment. Head turning produced elevated stress mainly near the proximal end of the stented segment. Neointima formation did not substantially alter the stress distribution in the motion-deformed regions near the stent ends, but it partially reduced high-stress areas within the relatively less-deformed stented segment.</p> Conclusion <p>Under the modeled conditions, head motion increased local mechanical loading near the stent edges and arterial bending regions after CAS. Neointima formation may locally attenuate stress within the stented segment but does not eliminate motion-induced stress concentrations. These findings provide a biomechanical basis for further investigation of motion-related vascular responses after CAS.</p>