Complex Visual and Auditory Hallucinations Following Neurosurgical Injury: A Case Series and Systematic Review

TL;DR

This study explores hallucinations after neurosurgery, showing they can result from network-level brain dysfunction and often improve with targeted treatment.

Contribution

The paper reports the first documented cases of concurrent visual and auditory hallucinations following neurosurgery.

Findings

Hallucinations after neurosurgery are often linked to parieto-occipital or temporal/insular lesions.

Concurrent visual and auditory hallucinations post-surgery have not been previously reported.

Symptoms resolved with treatment targeting underlying causes like thrombosis or edema.

Abstract

Hallucinations - perceptions without external stimuli - are complex neuropsychiatric phenomena that remain poorly understood in neurosurgical contexts.

We present two cases of multimodal visual and auditory hallucinations following neurosurgical interventions: a 34-year-old woman with occipital venous stasis following torcular tumor resection and sinus thrombosis, and a 53-year-old man with parieto-occipital edema from a traumatic contusion. Both cases featured vivid, meaningful perceptions without epileptiform activity on electroencephalogram (EEG), suggesting network-level dysfunction rather than focal pathology.

A systematic review of 16 prior non-epileptic cases revealed that visual hallucinations predominated, typically associated with parieto-occipital involvement, while auditory hallucinations were less common and linked to temporal or insular lesions. Notably, concurrent visual and auditory hallucinations, as observed here, have not been previously reported post-neurosurgery. Treatment targeting underlying causes (anticoagulation for venous thrombosis and edema reduction) led to complete symptom resolution within weeks to months, highlighting the importance of etiology-specific management.

These findings demonstrate that hallucinations in neurosurgical patients may result from transient disturbances to association cortices and white matter tracts, with a favorable prognosis when secondary to reversible conditions. The study underscores the need for increased clinical awareness, systematic evaluation to exclude seizures, and tailored therapeutic approaches for this underrecognized complication.

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