Compression of the rostral ventrolateral medulla by a vagal schwannoma of the cerebellomedullary cistern presenting with refractory neurogenic hypertension: case report.
OBJECTIVE
The rostral ventrolateral medulla is thought to serve as a final common pathway for the integration of central cardiovascular information and to be important for the mediation of central pressor responses. An association between essential hypertension and neurovascular compression of the rostral ventrolateral medulla has been reported. This may be mediated by an increase in sympathetic tone.


METHODS
Schwannomas arising from the lower cranial nerves (Cranial Nerves IX-XI) are rare, constituting only 3% of all intracranial schwannomas unassociated with neurofibromatosis. The majority of these tumors present as jugular foramen lesions and, less commonly, they occur along the extracranial course of these nerves. An intracisternal location is extremely rare. Fewer than 15 cases of pathologically proven intracisternal vagal schwannomas in the absence of neurofibromatosis have been reported.


METHODS
We report a case of vagal schwannoma in the cerebellomedullary cistern causing distortion of the vagal root entry zone and presenting with refractory neurogenic hypertension. Total microsurgical excision of this tumor, arising from one of the rootlets of the vagus nerve, was achieved. Immediately postoperatively, blood pressure decreased markedly, and despite our effort to maintain the blood pressure with fluids, the patient developed a cerebral infarction in the watershed zone.


CONCLUSIONS
We discuss the proposed mechanism of hypertension, and the perioperative management, stressing blood pressure control. A review of the literature regarding vagal schwannomas is also presented. To the best of our knowledge, this is the first case report of a cerebellomedullary cistern vagal schwannoma presenting with neurogenic hypertension.
Kamel
Mahmoud H
MH
National Department of Neurology, Beaumont Hospital, Dublin, Ireland. mahmoudhamdy@yahoo.com
Mansour
Nassir H
NH
Mascott
Chris
C
Aquilina
Kristian
K
Young
Steven
S
D000368:Aged; D003390:Cranial Nerve Neoplasms / Q000150:complications* / Q000175:diagnosis / Q000503:physiopathology* / Q000601:surgery; D006801:Humans; D006973:Hypertension / Q000209:etiology*; D008279:Magnetic Resonance Imaging; D008297:Male; D008526:Medulla Oblongata / Q000503:physiopathology*; D009442:Neurilemmoma / Q000150:complications* / Q000175:diagnosis / Q000503:physiopathology* / Q000601:surgery; D014057:Tomography, X-Ray Computed; D014630:Vagus Nerve