Muhammad Asad Sheikh
Peterborough City Hospital, UK
Title: Cortical blindness post coronary angiogram, a rare but frightening complication
Biography
Biography: Muhammad Asad Sheikh
Abstract
Cortical blindness is a rare but frightening complication following coronary angiogram probably due to contrast penetration in occipital lobes in susceptible individuals.
A case report of 82 years old man was admitted with collapse. Investigations showed NSTEMI with T wave inversion in lateral leads and Troponin rise. Severe LCX disease was found on coronary angiogram, which was stented with DES with good angiographic results. Patient became blind 30 minutes after the procedure.
Clinical examination showed diminished visual acuity to light perception bilaterally. Light reflex and fundoscopy was unremarkable. Motor, sensory & cerebellar systems were normal. No other abnormality was detected.
CT head scan showed bilateral contrast enhancement in the occipital lobes. Patient was not considered for thrombolysis due to symmetrical bilateral focal neurological presentation, which is uncommon in cerebrovascular accidents. Patient had a partial recovery of vision while in observation ward and had complete recovery within 24 hours. Patient remained asymptomatic at 2 months follow-up post discharge.
A clinical diagnosis of “cortical blindness” was made, however it was thought to be unlikely due to thrombo-embolism secondary to cardiac catheterization so thrombolysis was withheld (symmetrical bilateral focal neurological lesions are very uncommon in cerebrovascular accidents).
A quick literature search showed case reports of cortical blindness linked with coronary angiography and such blindness almost always spontaneously recovers in hours to days time.
Although the exact cause is unknown it is postulated that there is a direct neurotoxic effect of contrast in occipital cortex potentiated by prolonged lying position during coronary angiogram.
Other possible mechanisms includes spasm of the posterior cerebral arteries, dissection of the aortic arch, and contrast-induced hypotension.