Hypertension of neurogenic origin: effect of microvascular decompression of the CN IX-X root entry/exit zone and ventrolateral medulla on blood pressure in a prospective series of 48 patients with hemifacial spasm associated with essential hypertension

Abstract

aBBreViatiONS AICA = anterior inferior cerebellar artery; BA = basilar artery; BP = blood pressure; CN = cranial nerve; ENMG = electroneuromyographic; GP = general practitioner; HFS = hemifacial spasm; MVD = microvascular decompression; NVC = neurovascular compression; PICA = posterior inferior cerebellar artery; REZ = root entry/exit zone; VA = vertebral artery. SuBmitted August 1, 2014. accepted December 30, 2014. iNclude wheN citiNg Published online July 31, 2015; DOI: 10.3171/2014.12.JNS141775. diSclOSure The authors report no conflict of interest concerning the materials or methods used in this study or the findings specified in this paper. OBJect In spite of solid anatomical and physiological arguments and the promising results of Jannetta in the 1970s, treating essential hypertension by microvascular decompression (MVD) of the brainstem has not gained acceptance as a mainstream technique. The main reason has been a lack of established selection criteria. Because of this, the authors' attempts have been limited to patients referred for MVD for hemifacial spasm (HFS) who also had hypertension likely to be related to neurovascular compression (NVC). methOdS Of 201 patients referred for HFS, 48 (23.8%) had associated hypertension. All had high-resolution MR images that demonstrated NVC. All underwent MVD of the root exit/entry zone (REZ) of the ninth and tenth cranial nerves (CN IX-X) and adjacent ventrolateral medulla in addition to the CN VII REZ. Effects on hypertension, graded using the WHO classification, were studied up to the latest follow-up, which was 2-16 years from the time of surgery, 7 years on average. Also, effects of MVD on blood pressure (BP) according to the side of vascular compression were evaluated. reSultS Preoperatively, hypertension was severe in all but 1 of the patients; in spite of medical treatment, 47 patients still had WHO Grade 1 or 2 hypertension, and 18 still had unstable BP. After MVD, at latest follow-up, BP had returned to normal (i.e., systolic pressure < 140 mm Hg) in 28 patients; 14 of these patients (29.10% of the whole series) were able to maintain normal BP without any antihypertensive treatment; the other 14 still required some medication to maintain their BP below 140 mm Hg (p < 0.0001). Also, at latest follow-up, BP remained unstable in only 8 of the 18 patients with instability prior to MVD (p < 0.02). Analysis according to side of compression showed that of the 30 patients with left-sided compression, 17 had their BP normalized (without medication in 11 cases), and of the 18 patients with right-sided compression, 11 had their BP normalized (without medication in 3 cases). The difference between sides was not significant. cONcluSiONS These results argue for considering MVD for the treatment of hypertension likely to be due to NVC at the CN IX-X REZ and adjacent ventrolateral medulla. Criteria for selecting patients with hypertension alone still need to be established and could include the following indications: apparently essential hypertension, likely to be neuro...

Microvascular decompression in patients with hemifacial spasm

“…Previous studies have shown that MVD surgery could not only relieve the clinical symptoms of HFS but also improve the blood pressure management in patients with hypertension (Barley & Ellis, ; Sindou et al, ). Symptomatic treatments, such as botulinum toxin injections, medicine, and acupuncture induce, did not cause significant changes in blood pressure.…”

“…Patients with HFS could have concurrent hypertension. Some patients with both of these disorders were considered to share the same etiology (Miller & Selman, ; Sindou et al, ). HFS was caused by the vascular compression of the facial nerve in the REZ area in the brainstem.…”

“…Their hypertension may be due to neurogenic causes from increased sympathetic activities from the vascular compression at the left rostral ventrolateral medulla (RVLM) and REZ of cranial nerve IX, X (Jannetta & Gendell, ; Naraghi et al, ; Sandell, Holmen, & Eide, ; Solar, Ceral, Zizka, & Elias, ). Studies have shown that MVD surgery could improve the clinical symptoms of HFS and, at the same time, could also decrease the blood pressure in patients with refractory hypertension (Barley & Ellis, ; Sindou, Mahmoudi, & Brinzeu, ). However, it is unknown whether MVD surgery only lowers the blood pressure in patients with hypertension or also alters the blood pressure in patients without hypertension.…”

“…Studies have shown that MVD surgery could improve the clinical symptoms of HFS and, at the same time, could also decrease the blood pressure in patients with refractory hypertension (Barley & Ellis, 2013;Sindou, Mahmoudi, & Brinzeu, 2015). However, it is unknown whether MVD surgery only lowers the blood pressure in patients with hypertension or also alters the blood pressure in patients without hypertension.…”

New onset persistent refractory hypertension after medulloblastoma excision in children—an indicator of poor prognosis: A case series

“…Moreover, studies by Jannetta et al .,[ 8 ] Geiger et al .,[ 9 ] and Sindou et al . [ 10 ] have implicated rostral VLM and root entry zone (REZ) of IX–X cranial nerves as the sites of neurogenic hypertension. [ 8 9 10 ] A significant benefit was observed by concomitant MVD of nerve V along with IX–X and VLM in patients with trigeminal neuralgia.…”