Disconnection in Facial Perception: A Tract-based Analysis of Reported Prosopometamorphopsia Cases (1947-2025)
Shweta Kalita1, George Plotkin1, Jordan Larson2
1Neurology, University of Texas Health Science Centre, Tyler, 2Brown University
Objective:
To compile all reported prosopometamorphopsia (PMO) cases with lesion location data and identify commonly affected areas.
Background:
PMO is a disorder of facial perception caused by structural brain lesions. Although multiple cortical regions have been implicated, variability in lesion location has hindered the development of a unified neuroanatomical explanation.
Design/Methods:
A review of PMO cases from 1947-2025 was performed via PubMed and Google Scholar. Inclusion required individual-level clinical and lesion location data. Demographics, etiology, hemisphere, lesion site, and outcome were extracted. Lesion locations were translated into Montreal Neurological Institute (MNI) coordinates using the Harvard-Oxford atlas then mapped onto the Scalable Brain Atlas, resulting in a “heat map” of affected brain regions. Commonly affected regions were cross-referenced with known cortical areas and white-matter tracts involved in the ventral visual pathway.
Results:
Sixty-eight cases were included (55 ± 14 years; 59% male). Etiologies were vascular (53%), neoplastic (20%), epileptogenic (12%), traumatic (7%), and autoimmune or structural (8%). Lesions were predominantly right-sided (72%). Lesions were located in the occipital cortex (41%), splenium/posterior callosal fibers (18%), fusiform or occipitotemporal cortex (18%), and parietal (10%), parahippocampal (9%), and frontal (4%) regions. Heat-map reconstruction revealed strong alignment with the ventral visual pathway, encompassing the vertical occipital, inferior longitudinal, and inferior fronto-occipital fasciculi and forceps major, which link the occipital, fusiform, temporal, and splenial cortices.
Conclusions:
This synthesis of isolated PMO case reports reveals the first tract-based map of facial perception. Lesion clustering unveils a right-sided ventral visual network, with critical white-matter tracts connecting occipital, fusiform, temporal, and splenial hubs. The visual distortions that result from disruption of this network reveal PMO as a “disconnection syndrome” rather than a focal cortical disorder. Recognition of this pattern can prevent misdiagnosis as hallucinations, guide neuroimaging, and provide a framework for understanding how white-matter pathways underlie facial perception and how their disruption distorts it.
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