An Unusual Presentation of Vivid Hallucinations

Abstract

Visual hallucinations may present secondary to neurologic, psychologic, or physiologic disturbances. Certain features and characteristics of visual hallucination are often attributed to various brain regions; however, with a broad list of causes and multifaceted pathophysiology, it is often hard to accurately localize. Overlapping clinical presentations may be due to the pathology of brain interconnections, rather than isolated brain regions themselves. In this study, we discuss a case of isolated, complex visual hallucinations secondary to occipital seizures in the radiologic absence of an ischemic injury. We propose that a network-based localizing lesion is responsible for this unconventional presentation.

Keywords: charles bonnet syndrome; epilepsy; hallucinations; occipital; peduncular hallucinosis; seizures; visual cortex.

Figure 1. Patient’s MRI imaging sequences

The diffusion-weighted imaging (DWI) sequence in Panel A is without diffusion restriction that would suggest an acute or subacute ischemic infarct. The T2 sequence in Panel B is without significant changes that would suggest prior ischemic infarcts or underlying chronic microvascular white matter disease.

Figure 2. Patient’s double montage electroencephalograms

Double montage EEG in Panel A show unilateral, right-sided occipital spikes in the absence of field spread to surrounding regions (arrows). Normalization of double montage EEG in Panel B is achieved after AED administration indicating successful treatment. EEG: Electroencephalogram; AED: Antiepileptic drug.