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Patient reports difficulty recognizing faces
A 62-year-old female was referred to the eye clinic from the Behavioral Health Department because she had expressed difficulty recognizing faces. The patient described that if she were to spend a significant amount of time with someone and see them later in another place, she would not be able to recognize them.
The patient worked as a waitress in a restaurant and said when patrons would leave without paying, she would be required to provide a description of the people so security could handle the matter. She was unable to provide a description of their facial features, often only being able to relay what they were wearing. She said this caused her high levels of anxiety. Movie plots were also difficult for her to follow, as she was not able to differentiate characters, especially when costumes changed.
These difficulties did not apply to those with whom she was familiar, however. The patient said when her sister entered a room, she immediately recognized her with little difficulty. She said she has had these issues ever since she could remember.
The patient had a positive history of depression, insomnia, personality disorder and anxiety, as well as hyperlipidemia, irritable bowel syndrome and restless leg syndrome. Current medications included 20 mg of omeprazole daily, 7.5 mg of mirtazapine daily, 20 mg of escitalopram daily, 1 mg of ropinirole daily, 20 mg of pravastatin daily and a daily multivitamin.
Unaided visual acuities were 20/30 OD and 20/25 OS. With refraction, her vision was correctable to 20/20 OD and OS. Her pupils were equal, round and reactive to light with no relative afferent pupillary defect. Extraocular movements were full, with no restrictions.
Humphrey visual field testing was performed and showed a scotoma in the superior temporal quadrant in the left eye. The right visual field had no defects. Ishihara color plate testing was 17/17 for both eyes. Contrast sensitivity testing was normal for the left eye but slightly decreased in the right.
Slit lamp exam showed a linear defect in the endothelium, extending limbus-to-limbus in the right eye. The cornea was clear in the left eye. The adnexa and conjunctiva were unremarkable in both eyes. The right lens showed trace posterior subcapsular cataract, 1+ cortical spoking and 1+ nuclear sclerosis. The left lens was clear. Intraocular pressures were 14 mm Hg OD and 12 mm Hg OS. Posterior segment examination was unremarkable.
What’s your diagnosis?
See answer on the next page.
This patient was diagnosed with prosopagnosia, presumably developmental. People with this condition have a neurodevelopmental disorder that impairs their ability to recognize faces. There are no definitive diagnostic criteria or testing protocol for this condition because it has high variability in patient signs and symptoms.
Diagnosis is typically made from the patient’s self-reported difficulties with facial recognition and poor results on standardized facial recognition tests or famous face recognition tests. This patient’s long history of difficulty with facial recognition, without additional neurological comorbidities, was the basis of this diagnosis.
Description, etiology
Prosopagnosia is either developmental (congenital) or acquired. Developmental is most likely hereditary and has a prevalence of 2.5% (Schmidt). It is thought to be a polygenic, autosomal dominant disorder. However, it is also suggested that these cases of developmental prosopagnosia are simply the result of the lower end of a normal distribution curve. The acquired form is rarer and caused by various cerebral pathologies affecting the areas responsible for facial awareness.
The degree of facial awareness deficit is varied in both acquired and developmental forms, ranging from patients being unable to recognize their spouse until he or she speaks to being able to recognize family, but having difficulty with more unfamiliar faces. Patients often suffer from elevated anxiety and chronic stress, as facial recognition plays such an important role in social interaction.
Functional magnetic resonance imaging has identified a network of cerebral areas responsible for facial awareness that exist predominantly on the right hemisphere. This network includes primarily the fusiform gyrus and the inferior occipital gyrus. To a lesser extent, the superior temporal sulcus, lingual gyrus, temporal gyrus and dorsolateral prefrontal cortex are also involved. Developmental prosopagnosia is a result of structural and functional impairment of the network between these areas.
Cerebral anomalies associated with acquired prosopagnosia include stroke, trauma, encephalitis, cerebral tumors or other brain pathologies. Bilateral lesions are the cause of prosopagnosia in 55.64% of patients, while the other 44.35% are unilateral lesions, with 90.0% of the unilateral lesions being on the right side (Schmidt). The lesions may overlap to areas that also can cause cerebral dyschromatopsia and homonymous visual field defects.
In fact, 73% of patients with acquired prosopagnosia have visual field defects, while color vision defects are present in 29.9% of these patients (Schmidt). Cerebral dyschromatopsia has been linked to damage to the lingual and posterior fusiform gyrus, areas predominantly involved in facial recognition. Patients may also exhibit topographagnosia (difficulty with locations) or object agnosia (difficulty identifying objects).
Our patient’s diagnosis
A famous faces test from faceblind.org was performed in the office. During the test, faces of various famous celebrities were shown without hair or attire. The patient performed remarkably well, scoring 29/30 (97%). The average score for normal face recognition was 85% for this particular test. These results coincide with this patient’s description of her symptoms. She is able to recognize her sister and other familiar people. She has been exposed multiple times to these famous people and has had a chance to memorize their faces. We were unable to obtain a diagnostic test to assess ability with unfamiliar faces.
The patient also had no other neurological findings to indicate an acquired prosopagnosia. Visual field testing, color vision and contrast sensitivity testing was done to rule out an acquired prosopagnosia. This testing allows the practitioner to assess the risk of the various neurological conditions that lead to the acquired prosopagnosia.
Her psychiatrist ordered an MRI of the brain with and without contrast. There was no evidence of hemorrhage, mass or mass effect. The ventricles, cerebral sulci and cisterns were all within normal limits for the patient’s age. No abnormal extra-axial fluid collections and no enhancing lesions were identified.
Treatment
There is no treatment for developmental prosopagnosia. However, motivated patients may be able to improve their facial recognition skills. This was first noted in a case study of a man with developmental prosopagnosia who was able to improve his ability to distinguish faces. He practiced classifying hundreds of faces every day, focusing on distances between facial features (DeGutis et al.). The temporary improvement was confirmed by functional MRI testing showing increased connectivity between the face-selective regions of the brain.
Many patients with developmental prosopagnosia are not aware of their deficiency or fail to discover their deficit until later in life. Patients learn to adapt using cues such as hairstyles, clothing, context and voices to recognize people.
Our patient’s unilateral decreased contrast sensitivity can be explained by the incipient cataract in her right eye. The unilateral linear endothelial defect on the right cornea is presumably from a forceps delivery during her birth. The visual field scotoma present in the left eye is presumed to be an artifact attributed to the learning curve of the Humphrey visual field test, as it was not specific to neurologic or retinal pathology.
- References:
- DeGutis JM, et al. J Cogn Neurosci. 2007;19(11):1790-1802;doi:10.1162/jocn.2007.19.11.1790.
- Dinkelacker V, et al. J Neurol. 2011;258:770-782; doi:10.1007/s00415-010-5828-5.
- Duchaine BC, et al. Curr Opin Neurobiol. 2006;16:166-173;doi:10.1016/j.conb.2006.03.003.
- Johnen A, et al. Neuropsychologia. 2014;58:52-63;doi.org/10.1016/j.neuropsychologia.2014.03.013.
- Moroz D, et al. Neuropsychologia. 2016;89:153-160;doi:10.1016/j.neuropsychologia.2016.06.012.
- Rossion B, et al. J Cogn Neurosci. 2000;12:793-802.
- Schmidt D. Graefes Arch Clin Exp Ophthalmol. 2015; 253:333-334;doi.org/10.1007/s00417-014-2890-1.
- Susilo T, et al. Curr Opin Neurobiol. 2013;23:423-429;doi:10.1016/j.conb.2012.12.011.
- For more information:
- Laura Goemann, OD, is a 2017 graduate from Pacific University College of Optometry in Forest Grove, Ore. She can be reached at goem7019@pacificu.edu.
- Leonid Skorin Jr., OD, DO, MS, FAAO, FAOCO, practices at the Mayo Clinic Health System in Albert Lea, Minn., and is a member of the Primary Care Optometry News Editorial Board. He can be reached at skorin.leonid@mayo.edu.
- Edited by Leo P. Semes, OD, FAAO, a professor of optometry, University of Alabama at Birmingham and a member of the Primary Care Optometry News Editorial Board. He may be reached at leopsemes@gmail.com.
Disclosures: Goemann and Skorin report no relevant financial disclosures. Semes is an advisor or on the speakers bureau for Alcon, Allergan, Bausch + Lomb, Genentech, Maculogix, OptoVue, Shire and ZeaVision. He is a stockholder with HPO.