BACKGOUND: The barrier can be altered by a number of insults to the brain (e.g., hypertension, freezing, trauma, drug). But the effect of the blood brain barrier distruction immediately after the neural change is unknown. In the present study, we focused on the BBBD after cervical sympathetic chain block. METHODS: 13 male Sprague-Dawley rats were divided into 2 groups. Group 1 (N=7) was blocked with 0.5% bupivacaine on the right cervical sympathetic chain and group 2 (N=6) was blocked with 0.5% bupivacaine on the bilateral cervical sympathetic chain. All rats received 37degrees C, 25% mannitol (1.75 g/kg) via right carotid artery and then, the effect of cervical sympathetic chain block on blood-brain barrier disruption of four cerebral compartment using 99mTc-human serum albumin and Evans blue was evaluated. RESULTS: Both groups showed blood-brain barrier disruption and there was no significant difference between group 1 and group 2 in the anterior and posterior hemisphere of the right side brain. But group 2 showed significant blood-brain barrier disruption than group 1 in anterior and posterior hemisphere of the left brain (p<0.01). CONCLUSIONS: This results suggest that cervical sympathetic chain block can increase the degree of mannitol-induced blood-brain barrier disruption via neural arch or blood flow change.