5th International Conference on Neuroscience and Mental Health

Marcos Temistocles Duarte is a psychiatrist and psychotherapist, with clinical practice in mental health since 2008 in Maceió, Alagoas, Brazil. He has extensive experience providing care to children, adolescents, adults, and older adults, with a clinical focus on Psychiatry, Psychotherapy, and comprehensive mental health care. He graduated in Medicine from the Federal University of Alagoas in 2004 and completed his medical residency in Psychiatry. He holds specialist certification from the Brazilian Medical Association and the Brazilian Psychiatric Association, as well as specialization in Cognitive Behavioral Psychotherapy and Chemical Dependency. He is a member of the Brazilian Psychiatric Association. In 2026, he published two scientific papers in Debates em Psiquiatria, the scientific journal of the Brazilian Psychiatric Association (ABP). He is currently in the final stage of the medical diploma recognition process at the University of Porto, Portugal, which will culminate in the award of a Master’s degree.

Background: Capgras syndrome is a rare delusional misidentification syndrome characterized by the belief that a familiar person has been replaced by an identical impostor. Although commonly associated with psychiatric disorders, it may also occur in association with neurological conditions, particularly lesions involving frontal and frontolimbic networks.

Objective: To present a case of Capgras syndrome following frontal Traumatic Brain Injury (TBI) in a patient with Bipolar II Disorder (BD-II), highlighting the relationship between structural brain injury, neurocognitive changes, and psychopathological manifestations.

Case Report: A 66-year-old man with a previous diagnosis of BD-II experienced multiple TBIs between 2024 and 2025. Following the injuries, he developed a predominantly frontal acquired neurocognitive disorder and fluctuating episodes of Capgras syndrome directed toward his primary caregiver. Despite the delusional misidentification, semantic and professional memory remained relatively preserved. After the second TBI, a qualitative change in personality was observed, with reduced aggressiveness and increased affability. Computed tomography revealed frontal gliosis and encephalomalacia, increased extra-axial spaces, compensatory ventriculomegaly, and hypodense white matter lesions. The episodes were more evident in contexts of emotional distress and showed partial improvement with non-confrontational psychotherapeutic interventions and atypical antipsychotic treatment.

Conclusion: This case illustrates the complex interaction between frontal brain injury, acquired neurocognitive dysfunction, affective disorder, and Capgras syndrome. The findings reinforce the relevance of integrating neuropsychiatric evaluation, neuroimaging, longitudinal cognitive assessment, and individualized psychotherapeutic and pharmacological approaches when evaluating delusional misidentification after brain injury.