Efficacy of clonidine in patients with essential hypertension with neurovascular contact of the rostral ventrolateral medulla

By Sakuma et al

The goal of this paper is to study the effects of neurovascular compression. This is done by looking at the regions of the brain that experience this condition. One region that was focused on was the rostral ventro lateral medullam (RVLM). It has been shown to be vital in regulating sympathetic and cardiovascular activities. One association that was looked at was between the RVLM and neurovascular contact (NVC), meaning an arterial vessel or vascular loop made contact with the RVLM. It was explained that when NVC was associated with RVLM, hypertension was observed. A technique that could help this condition is microvascuar decompression (MVD). It was shown to decrease BP in patients with NVC of the RVLM. The purpose of the study was to study a different method to treat hypertension in patients with NVC of RVLM because MVD was too risky being it is an invasive procedure. To accomplish this they treated patients with clonidine, which is an alpha 2 adrenergic agonist, and observed whether it lowered BP.

26 patients with NVC of RVLM and 28 patients without NVC of RVLM were studied. All patients were hypertensive. Both groups were treated with 225 ug of clonidine per day for 4 weeks. Both groups were also administered the same antihypertensive drugs in addition to clonidine.

After the conclusion of the study, the results showed that there was a significant decrease in systolic BP in NVC- patients. In NVC+ patients, there was a significant decrease in systolic and diastolic BP. Both decreases were greater in NVC+ patients compared to NVC-. There was no sig. change in HR. NE was significantly decreased in both groups, but more significant in NVC+.

Concluding these results they found out that clonidine did in fact show sig greater reductions in BP and NE levels in patients with NVC compared to without. This indicates that clonidine has effective antihypertensive properties, especially in NVC+ patients. It is key to understand that though after administration of clonidine to the patients showed a decrease in BP, we must also consider the fact that they did gave other antihypertensives with it as well. A suggestion was made that clonidine could be used as a secondary line of treatment. This study also only lasted 4 weeks so a longer study would show if clonidine's affects are sustainable long term.

-Tsetse Fly