Charles Bonnet Syndrome Following Trans-Sphenoidal Adenomectomy without Optic Nerve Atrophy

Charles Bonnet syndrome (CBS) can develop after trans-sphenoidal adenomectomy (TSA); however, the neural mechanisms remain unknown. Sensory deprivation and releasing phenomenon are both hypothetical explanations for this condition; however, there is no definite evidence that strongly supports either supposition. We report the first case of CBS after TSA without optic nerve atrophy. Postoperatively, the patient's vision seemed to be relatively well preserved, apart from the left-side hemianopsia in the right eye. Distinctive visual hallucinations only appeared when his eyes were closed, and these responded to quetiapine in a dose-dependent manner. Dose dependent change in colors and formation of hallucination was reported. Two weeks after quetiapine initiation, the patient's CBS was completely resolved. This unique case suggests that blocking sensory input from the periphery is more critical than neural damage of the bottom-up connection to the visual association cortex. In addition, quetiapine should be considered as a specific treatment for CBS.