Hemiprosopometamorphopsia: a Case of Impaired Facial Perception Restricted to the Eye
Prosopometamorphopsia is a rare condition of perceptual facial distortion, with no impairment in facial recognition. We report a case of hemiprosopometamorphopsia restricted only to the eye. A 42-year-old male pilot presented with an acute onset visual disturbance consistent with hemiprosopometamorphopsia. While looking at faces, he observed a distorted image with the left eye appearing lower than the right. Faces resembled the paintings of Picasso. He had preserved insight and could recognize faces. Neurological and ophthalmological examination revealed no abnormalities. A brain MRI performed on day 3 of symptom onset demonstrated an area of acute infarct in the right occipital lobe involving the right posterior cerebral artery territory. Carotid CT angiogram and circle of Willis were unremarkable. Further workup did not reveal an underlying cause. Secondary stroke prevention with aspirin and statin was initiated. An event recorder was implanted. He was discharged on day 8 with near complete resolution of presenting symptom. While various facial distortions have been reported from prosopometamorphopsia, our case was restricted to only the eye and could have been easily overlooked or misdiagnosed as a migraine phenomenon. In patients presenting with perceptual facial distortion, clinicians should consider the possibility of stroke.
KeywordsProsopometamorphopsia Stroke Facial Fusiform Occipital Visual
We present a case of a 42-year-old helicopter pilot who developed sudden onset visual disturbance. When looking at faces, they appeared distorted at the midline such that the left eye was approximately 2 cm lower than the right with slight blurring. Faces resembled the paintings of Picasso.
This was associated with a generalized dull headache and nausea. There was no distortion of the ear, hair, or mouth. The facial distortion was not present when looking at animals, photos, television images, or animations. There was no prosopagnosia, dysgraphia, or dyslexia. The patient did not have a history of migraine.
A “half-face-covering-test” demonstrated persistent hemiprosopometamorphopsia despite the patient covering either eye. On the other hand, when covering the right side of the face of the interlocutor, the facial distortion on the left disappeared immediately .
Initially, the visual distortion was evident when looking at faces up to 5 m. By day 4, he reported improvement such that the facial distortion was apparent only when looking up to 1.5 m. The difference in height between the right and left eye also reduced to 1 cm.
Examination demonstrated visual acuity of 6/6 bilaterally. Saccadic examination and eye pursuit were normal. Visual fields were intact.
Non-contrast CT on day 1 did not demonstrate any abnormality. CT carotid angiogram and circle of Willis were unremarkable. An ophthalmology assessment was normal including Humphrey visual field test.
He was commenced on aspirin and as statin for secondary stroke prevention. An event recorder was implanted and outpatient follow-up was arranged. He was discharged on day 8 with near complete resolution of the presenting symptom.
Prosopometamorphopsia is a rare condition of perceptual facial distortion, which is distinct from prosopagnosia, or inability to recognize faces. While most commonly associated with a structural brain pathology, prosopometamorphopsia has been reported in patients with epilepsy, migraine, tumor, and eye disease .
The perceived visual distortion in prosopometamorphopsia has been reported to be associated with structural brain changes such as a lesion to the fusiform face area and the adjacent occipital face area . Lesions affecting the retina, splenium of the corpus callosum, putamen, temporal, parietal, and occipital lobes have also been implicated [4, 5, 6]. In our case report, the lesion was localized to inferior occipital gyrus in Brodmann’s area 18, often referred to as the occipital face area.
Interestingly, in our case, prosopometamorphopsia was restricted to one side and only the eye, thus more accurately termed hemiprosopometamorphopsia, and occurred ipsilateral to the patient’s ischemic lesion. The explanation for the ipsilateral symptom could be that information from the right visual field projected to the left occipital lobe might have been damaged when being transmitted to the right cerebral hemisphere, where integration of facial information occurs [5, 6]. Previous studies suggest the right cerebral hemisphere is dominant in integrating facial information . Another report suggests prosopometamorphopsia may be a right dominant hemisphere-specific sign .
While various facial distortions have been reported from prosopometamorphopsia, our case and could have been easily overlooked or misdiagnosed as a migraine phenomenon, making the case challenging to diagnose. Although prosopometamorphopsia is usually a transient event, given its impact on social functioning of the affected patient due to perceptual facial distortions, comprehensive diagnostic workup to unravel the underlying etiology is warranted.
In patients presenting with complaint of facial distortion restricted to eyes only, possibility of stroke should be considered.
All authors contributed to the study conception and design. Literature search was performed by all authors. The first draft of the manuscript was written by Dr Chun Seng Phua, and all authors commented on previous versions of the manuscript. All authors read and approved the final manuscript.
Compliance with Ethical Standards
Conflicts of Interest
The authors declare that they have no conflict of interest.
All human and animal studies have been approved by the appropriate ethics committee and have therefore been performed in accordance with the ethical standards laid down in the 1964 Declaration of Helsinki and its later amendments.
Informed consent was obtained from all individual participants included in the study.
- 6.Barghouthi T, El Husseini N. Prosopometamorphopsia secondary to a left splenium of the corpus callosum infarct. BMJ Case Rep. 2018;2018.Google Scholar