Functional imaging localization of complex organic hallucinations

Area of Science:

• Neuroscience
• Radiology
• Neurology

Background:

• Investigating the neural basis of complex hallucinations is challenging due to patient cooperation and symptom stability.
• Functional MRI (fMRI) and Diffusion Tensor Imaging (DTI) can offer anatomical insights in specific cases of organic hallucinations.

Observation:

• A 14-year-old boy with a left fronto-dorsal tumor experienced chronic, complex visual and auditory hallucinations.
• During presurgical fMRI, the patient reported experiencing these hallucinations, allowing for simultaneous data acquisition.
• The tumor exhibited aberrant structural connectivity to occipital and temporal regions.

Findings:

• fMRI revealed activation in the left inferior frontal gyrus (IFG) and peri-lesional areas during hallucinations.
• DTI tractography showed abnormal connections to occipital and temporal lobes, and via the aslant fasciculus to the IFG.
• Intraoperative EEG indicated epileptic discharges within the tumor and surrounding brain tissue.

Implications:

• This is the first case report combining functional and structural connectivity imaging to map brain networks involved in complex auditory-visual hallucinations.
• Surgical resection of the tumor led to complete cessation of hallucinations, with recurrence at a lower intensity after 90 days.
• The study highlights the potential of advanced neuroimaging in understanding and potentially treating hallucination-generating brain networks.