Case Series: Unilateral Amygdala Ablation Ameliorates Post-Traumatic Stress Disorder Symptoms and Biomarkers

Abstract

Background Post-traumatic stress disorder is a severe psychobiological disorder associated with hyperactivity of the amygdala, particularly on the right side. Highly selective laser ablation of the amygdalohippocampal complex is an effective neurosurgical treatment for medically refractory medial temporal lobe epilepsy that minimizes neurocognitive deficits relative to traditional open surgery. Objective To examine the impact of amygdalohippocampotomy upon symptoms and biomarkers of post-traumatic stress disorder. Methods Two patients with well-documented chronic post-traumatic stress disorder who subsequently developed late-onset epilepsy underwent unilateral laser amygdalohippocampotomy. Prospective clinical and neuropsychological measurements were collected in patient 1. Additional prospective measurements of symptoms and biomarkers were collected pre- and post-surgery in patient 2. Results After laser ablation targeting the nondominant (right) amygdala, both patients experienced not only reduced seizures, but also profoundly abated post-traumatic stress symptoms. Prospective evaluation of biomarkers in patient 2 showed robust improvements in hyperarousal symptoms, fear potentiation of the startle reflex, brain functional magnetic resonance imaging responses to fear-inducing stimuli, and emotional declarative memory. Conclusion These observations support the emerging hypothesis that the right amygdala particularly perpetuates the signs and symptoms of post-traumatic stress disorder and suggests that focal unilateral amydalohippocampotomy can provide therapeutic benefit.