Clinicoradiologic Findings and Prognosis of Cortical Blindness

Kim, Jung Eun; Park, Kee Duk; Oh, Jee Young; Kim, Jee Hyun; Kwon, Young Joo; Kim, Yong Jae; Choi, Kyoung Gyu

Abstract

BACKGROUND: Cortical blindness is one of the less known clinical syndromes caused by bilateral occipital lobe lesions. The most common etiology is bilateral posterior cerebral artery (PCA) infarction, and the prognosis has been reported to be bad and incomplete.
METHODS
We reviewed our registry from January 1999 to March 2002, and found seventeen patients who were diagnosed with cortical blindness. We analyzed their clinical features, neurologic examinations, radiologic findings, electrophysiological studies, and follow up their visual acuities.
RESULTS
Of the sixteen cases, ten were bilateral PCA infarction, three were postpartum eclampsia, two were cyclosporin-induced blindness and the other was the case recovered from cardiac arrest. Most patients' presenting symptoms were headache and sudden visual loss, ranged from finger count to complete blindness. There were two patients with complete blindness. On the follow up examination, twelve patients regained some visual acuity. The wider lesion involved bilateral occipital lobes; the worse was initial visual acuity. The prognosis was better when the lesion size was small and extrastriate cortex was spared. The electroencephalography and visual evoked potential findings were compatible with clinical symptom, but not exactly correlated with the prognosis.
CONCLUSIONS
Contrary to the general concept that cortical blindness is caused by bilateral occipital lobe infarction has a poor prognosis, our cases showed a fair outcome of vision. It was a good predictor for prognosis whether extrastriate cortex was spared or not, suggesting its role in visual recovery.