Decreases in Blood Pressure and Sympathetic Nerve Activity by Microvascular Decompression of the Rostral Ventrolateral Medulla in Essential Hypertension

Abstract

Background-Neurovascular compression of the rostral ventrolateral medulla, a major center regulating sympathetic nerve activity, may be causally related to essential hypertension. Microvascular decompression of the rostral ventrolateral medulla decreases elevated blood pressure. Case Description-A 47-year-old male essential hypertension patient with hemifacial nerve spasms exhibited neurovascular compression of the rostral ventrolateral medulla and facial nerve. Microvascular decompression of the rostral ventrolateral medulla successfully reduced blood pressure and plasma and urine norepinephrine levels, low-frequency to high-frequency ratio obtained by power spectral analysis, and muscle sympathetic nerve activity. Conclusions-This case suggests not only that reduction in blood pressure by microvascular decompression of the rostral ventrolateral medulla may be mediated by a decrease in sympathetic nerve activity but also that neurovascular compression of this area may be a cause of blood pressure elevation via increased sympathetic nerve activity. (Stroke. 1999;30:1707-1710.)

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

“…We reported a patient with EH and hemifacial nerve spasms who exhibited NVC of RVLM and facial nerve. 27 MVD of RVLM successfully reduced BP and indices of SNA such as plasma and urine NE, low-frequency to high-frequency ratio obtained by power spectral analysis and muscle SNA. 27 Interestingly, Jannetta et al also performed MVD of RVLM in 12 patients with EH without cranial neuralgia and observed a reduction in BP in 10 of them.…”

“…27 MVD of RVLM successfully reduced BP and indices of SNA such as plasma and urine NE, low-frequency to high-frequency ratio obtained by power spectral analysis and muscle SNA. 27 Interestingly, Jannetta et al also performed MVD of RVLM in 12 patients with EH without cranial neuralgia and observed a reduction in BP in 10 of them. 17 Therefore, MVD of RVLM is expected to be a useful therapeutic strategy to reduce BP in these patients.…”

“…It could be worthwhile to select hypotensive agents based on the presence or absence of NVC of RVLM when treating patients with EH. As normalization of BP has been reported in hypertensive patients with NVC of RVLM after MVD, 16,17,27 hypertension due to NVC of RVLM could be classified as secondary hypertension. 31 To establish this condition as a new type of secondary hypertension, it is essential to conduct further studies on its pathophysiology to establish reasonable treatment methods.…”

Efficacy of an L- and N-type calcium channel blocker in hypertensive patients with neurovascular compression of the rostral ventrolateral medulla

“…MVD of the RVLM successfully reduced BP and indices of SNA such as plasma and urine NE levels, low-frequency to high-frequency ratio obtained by power spectral analysis and muscle SNA. 27 Therefore, MVD of the RVLM is expected to be a useful therapeutic strategy to reduce BP in these patients. However, as MVD is a highly invasive therapy, it seems quite unlikely to be applicable in all hypertensive patients with NVC of the RVLM.…”

Blood pressure lowering effects of non-surgical procedures for vascular decompression: good news to be taken with caution

“…3,[8][9][10] The favourable haemodynamic outcome of the surgical intervention is likely to be triggered by a sympathetic deactivation, as several indirect and/or direct markers of adrenergic neural drive, such as plasma and urinary noradrenaline, low-frequency/high-frequency spectral power ratio as well as efferent postganglionic sympathetic nerve firing rate, have all shown a consistent and rather homogeneous reduction of adrenergic cardiovascular drive following surgical decompression. [10][11] In the present issue of the Journal of Human Hypertension, Bakris et al 12 add a new piece of information to the above-mentioned findings, by providing evidence on the favourable blood pressure lowering effects of chiropractic procedures capable to correct misalignment of the Atlas vertebra and thus to induce medullary vascular decompression. According to a double-blind, placebo-controlled study design, hypertensive patients with documented evidence of vertebral misalignment were randomized either to a chiropractic vertebral realignment procedure or to a sham intervention.…”