Occurrence of seizure during cranial computed tomography.

With the advent of cranial computed tomography, the incidence of contrast-induced convulsion has increased. The reason for this is threefold: (a) Contrast media after the permeability of the blood-brain barrier, enabling toxins, drugs, and perhaps the contrast agent itself to enter the brain; (b) the vessels of neoplasms and their surrounding tissue are already more permeable, enabling contrast medium to leak from these vessels into the brain; (c) since patients coming to contrast-enhanced cranial CT have a relatively high incidence of neoplastic lesions of the brain, they are therefore at greater risk for convulsive episodes.