Atypical Charles Bonnet syndrome secondary to frontal meningioma: a case report

BACKGROUND: Charles Bonnet Syndrome (CBS) is a rare clinical entity that is classically composed of visual hallucinations in the context of an altered optic pathway with preservation of reality judgment. This case aims to present the association of visual hallucinations with complex alterations of the nervous structures adjacent to the visual pathway and an atypical clinical presentation, thus explaining the possible mechanisms involved in the generation of these symptoms. CASE PRESENTATION: A 43-year-old man presents seeking care due to visual hallucinations with partial preservation of reality judgment and symptoms compatible with a major depressive disorder, including irritability and diminished hygiene habits. He has a history of complete gradual loss of vision and hyposmia. Due to poor treatment response during hospitalization, an MRI was obtained, which showed a frontal tumor lesion with meningioma characteristics adjacent to the olfactory groove and compression of the optic chiasm. He underwent surgical resection of the lesion, which remitted the psychotic symptoms, but preserving the visual limitation and depressive symptoms. CONCLUSIONS: The presence of visual hallucinations, without other psychotic features as delusions, is a focus of attention for basic structural pathologies in the central nervous system. Affection at any level of the visual pathway can cause CBS. When finding atypical symptoms, a more in-depth evaluation should be made to allow optimization of the diagnosis and treatment.