Having said that, although convulsions or seizures are listed in the long list of side effects in the Physician's Desk Reference, they are certainly not very common. Most textbooks do not list this as a side effect. Corticosteroids seem to exert a number of indirect effects on the central nervous system, through maintenance of blood pressure, plasma glucose concentration and electrolyte concentrations. Improved awareness of the distribution and function of steroid receptors in the brain has led to increasing recognition of direct effects on the central nervous system, including effects on mood, behavior and brain excitability. The most striking effect of corticosteroids on the cardiovascular system is hypertension.
Hypertension is more pronounced with mineralocorticoids and their effect on renal sodium excretion.
The mechanism of glucocorticoid associated hypertension is essentially unknown. On the other hand, it may be related to the endogenous secretion of cortisol. The resultant hypertension can lead to a diverse group of effects on the cardiovascular system including increased atherosclerosis, cerebral hemorrhage, stroke and hypertensive cardiomyopathy. Restricting dietary sodium intake can considerably lower blood pressure secondary to corticosteroids. Adrenocortical steroids also have an effect on carbohydrate, protein and lipid metabolism which can accelerate atherosclerosis.