(P41) Acquired Cerebral Achromatopsia Secondary to Occipital Stroke

Chief Complaint : 1 week history of blurry vision, which was proceeded by a right-sided headache.

History of Present Illness : A 51-year-old female presented to the emergency department with a chief complaint of 1 week history of blurry vision, which was proceeded by a right-sided headache. She has a background of type II diabetes mellitus, hypertension, dyslipidemia and a history of breast cancer with cessation of treatment 10 years prior, and is currently in remission. In addition to the blurry vision, she complained of impaired color vision described as desaturation of color appearance in all visual fields. She denied any focal motor weakness, dysarthria, aphasia, gait disturbance, dizziness or sensory loss.

Pertinent Physical Exam: Upon presentation, her vital signs were within normal limits. A general examination was unremarkable. A neurological examination showed complete left homonymous hemianopia, otherwise normal neurological examination.

Pertinent Laboratory Data: Computerized tomography (CT) angiography of head and neck with intravenous (IV) contrast showed moderate narrowing of the right posterior cerebral artery and mild narrowing of the left carotid cavernous artery. Hyperacute MRI of the brain was done in the Emergency Department which revealed a subacute right occipital pole infarct.

Case Discussion: Patients with strokes in the posterior circulation artery often present with non-specific symptoms, which can lead to delayed diagnosis and treatment. Visual field defects are common in posterior cerebral artery (PCA) strokes, as the lower part of the optic radiation is supplied by this artery. Acquired cerebral achromatopsia, the inability to perceive color after acute brain injury, is a rare phenomenon associated with PCA stroke.

A case discussion was presented that compared two cases of acquired cerebral achromatopsia following PCA stroke. The first case involved a 60-year-old female who presented with right hemiachromatopsia, while the second case involved a 74-year-old female who initially had preserved full-field color vision after a stroke on the left hemisphere, but later developed full-field achromatopsia after a stroke on the right hemisphere. The contrast between the two cases suggested that there may be individual differences in the hemispheric laterality of the color centers in the brain, with the right hemisphere potentially being responsible for full-field color processing.

Our patient presented with a subacute occipital stroke on the right hemisphere, yet, developed bilateral achromatopsia. This case may support the hypothesis that the right hemisphere is responsible for full-field color processing. However, more research is needed to fully understand the mechanisms underlying acquired cerebral achromatopsia in PCA stroke. Overall, this discussion highlights the challenges in diagnosing and treating strokes in the posterior circulation artery and the need for further research to better understand the neurological processes involved.

References and Acknowledgements (Optional): 1. Kartika, A., & Dwijayanti, S. (2018, November 13). Different Visual Field Defects in Cerebral Infarction Patients. Perpustakaan Pusat Mata Nasional Rumah Sakit Mata Cicendo.
2. Kuybu, O., Prasanna TadI, P., & Dossani, R. H. (2022, August). Posterior cerebral artery stroke - statpearls - NCBI bookshelf. Posterior Cerebral Artery Stroke. Retrieved from https://www.ncbi.nlm.nih.gov/books/NBK532296/
3. Zobor, D., Zobor, G., & Kohl, S. (2015). Achromatopsia: on the doorstep of a possible therapy. Ophthalmic research, 54(2), 103–108. https://doi.org/10.1159/000435957
4. Harper, D. G., Arsura, E. L., Bobba, R. K., Reddy, C. M., & Sawh, A. K. (2005). Acquired color blindness in an elderly male patient from recurrent metastatic prostate cancer. Journal of the American Geriatrics Society, 53(7), 1265–1267. https://doi.org/10.1111/j.1532-5415.2005.53384_6.x
5. Shaygannejad, V., Golabchi, K., Dehghani, A., Ashtari, F., Haghighi, S., Mirzendehdel, M., & Ghasemi, M. (2012). Color blindness among multiple sclerosis patients in Isfahan. Journal of research in medical sciences: the official journal of Isfahan University of Medical Sciences, 17(3), 254–257.
6. Young, R. S., Fishman, G. A., & Chen, F. (1980). Traumatically acquired color vision defect. Investigative ophthalmology & visual science, 19(5), 545–549.
7. Bartolomeo, P., Bachoud-Lévi, A. C., & Thiebaut de Schotten, M. (2014). The anatomy of cerebral achromatopsia: a reappraisal and comparison of two case reports. Cortex; a journal devoted to the study of the nervous system and behavior, 56, 138–144. https://doi.org/10.1016/j.cortex.2013.01.013