Bilateral Amygdala Radio-Frequency Ablation for Refractory Aggressive Behavior Alters Local Cortical Thickness to a Pattern Found in Non-refractory Patients

Author(s)

Gouveia, Flavia Venetucci ^{[1, 2]} ; Germann, Jurgen ^{[3, 4, 5]} ; Devenyi, Gabriel A. ^{[5, 6]} ; Fonoff, Erich T. ^[7] ; Morais, Rosa M. C. B. ^{[2, 8]} ; Brentani, Helena ^[8] ; Chakravarty, M. Mallar ^{[9, 5, 6]} ; Martinez, Raquel C. R. ^{[2, 8]}

Affiliation

^[1] Sunnybrook Res Inst, Biol Sci Platform, Toronto, ON - Canada

^[2] Sirio Libanes Hosp, Div Neurosci, Sao Paulo - Brazil

^[3] Univ Toronto, Toronto, ON - Canada

^[4] Univ Hlth Network, Div Neurosurg, Dept Surg, Toronto, ON - Canada

^[5] McGill Univ, Cerebral Imaging Ctr, Douglas Mental Hlth Univ Inst, Montreal, PQ - Canada

^[6] McGill Univ, oDept Psychiat, Montreal, PQ - Canada

^[7] Univ Sao Paulo, Dept Neurol, Div Funct Neurosurg, Med Sch, Inst Psychiat, Sao Paulo - Brazil

^[8] Univ Sao Paulo, Med Sch, Dept Psychiat, LIM 23, Sao Paulo - Brazil

^[9] McGill Univ, Dept Biol & Biomed Engn, Montreal, PQ - Canada

• Document type: Journal article
• Source: FRONTIERS IN HUMAN NEUROSCIENCE; v. 15, JUN 9 2021.
• Web of Science Citations: 0

Abstract

Aggressive behaviors comprise verbal and/or physical aggression directed toward oneself, others, or objects and are highly prevalent among psychiatric patients, especially patients diagnosed with autism spectrum disorder and severe intellectual disabilities. Some of these patients are considered refractory to treatment, and functional neurosurgery targeting the amygdala can result in widespread plastic brain changes that might reflect ceasing of some abnormal brain function, offering symptom alleviation. This study investigated cortical thickness changes in refractory aggressive behavior patients that were treated with bilateral amygdala ablation and compared to control patients presenting non-refractory aggressive behavior {[}three refractory and seven non-refractory patients, all males diagnosed with autism spectrum disorder (ASD) and intellectual disabilities]. The Overt Aggression Scale (OAS) was used to quantify behavior and magnetic resonance imaging was performed to investigate cortical thickness. Before surgery, both groups presented similar total OAS score, however refractory patients presented higher physical aggression against others. After surgery the refractory group showed 88% average reduction of aggressive behavior. Imaging analysis showed that while refractory patients present an overall reduction in cortical thickness compared to non-refractory patients across both timepoints, the local pattern of thickness difference found in areas of the neurocircuitry of aggressive behavior present before surgery is diminished and no longer detected after surgery. These results corroborate the hypotheses on induction of widespread neuronal plasticity following functional neurosurgical procedures resulting in modifications in brain morphology and improvement in behavior. Further studies are necessary to determine the underlying cause of these morphological changes and to better understand and improve treatment options. (AU)

• FAPESP's process: 13/20602-5 - Prospective analyses of the functional results of philanthropist bilateral amygdalectomy in patients with refractory aggression
• Grantee: Flavia Venetucci Gouveia
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 11/08575-7 - The role of dopaminergic modulation in the lateral nucleus of amygdala during active avoidance response
• Grantee: Raquel Chacon Ruiz Martinez
• Support Opportunities: Research Grants - Young Investigators Grants
• FAPESP's process: 17/10466-8 - Towards revealing aggression: imaging the aggressive brain
• Grantee: Flavia Venetucci Gouveia
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate