Neuroplasticity is commonly acknowledged as a beneficial phenomenon. However, it should no longer be interpreted dogmatically, as the literature timidly discusses the phenomenon of negative plasticity. Taking up the interdisciplinary dialogue between the humanities and medicine, we recall the thought of French philosopher Catherine Malabou. She accused medicine of focusing only on the positive aspects of neuroplasticity. We therefore look at clinical examples of references to its negative dimension. The substantial advancements in neurosurgical techniques afford the removal of larger tumour volumes, resulting in prolonged patient survival rates, but the quality of life may not consistently result in satisfactory outcomes. Patients may undergo discernible alterations of their identities in a way apparent to both their loved ones and themselves. The neurosurgeon relies on neuroplasticity as a rehabilitative strategy, nevertheless its impact is not entirely predictable. We therefore encourage future discussion on the ethical implications of this phenomenon.