title: Overt and Subclinical Baroreflex Dysfunction After Bilateral Carotid Body Tumor Resection: Pathophysiology, Diagnosis, and Implications for Management.
abstract: BACKGROUND
  Carotid body paragangliomas are rare, usually benign, tumors arising from glomus cells of the carotid body. Bilateral involvement is present in ∼5% of sporadic cases and up to one third of familial cases. In most patients undergoing bilateral resection of carotid body tumors, a condition known as baroreflex failure syndrome (BFS) develops after resection of the second tumor characterized by headache, anxiety, emotional lability, orthostatic lightheadedness, hypertension, and tachycardia. This condition is believed to result from damage to the carotid baroreceptor apparatus. Patients without overt cardiovascular abnormalities may have subclinical baroreceptor dysfunction evident only on specific testing, measuring heart rate and sympathetic nerve responses to baroloading (e.g., phenylephrine) and barounloading (e.g., Valsalva maneuver). Given the high incidence of BFS in patients undergoing bilateral resection of carotid body tumors, it is suggested that operation is limited to unilateral resection of the dominant/symptomatic lesion and nonsurgical intervention (i.e., embolization, radiotherapy) on the contralateral side. Alternatively, refinement of surgical technique to prevent injury to elements of the baroreceptor apparatus may prevent this complication of bilateral tumor resection.
  
  
  RESULTS
  We present a case of a 16-year-old girl with bilateral jugular vagale and carotid body tumors who developed hypertension after surgical resection of her left jugular vagale tumor and worsening of hypertension concurrent with progression, requiring intensity-modulated radiation therapy and a resection for significant progression of her left jugular vagale tumor. Additional case studies and series of bilateral carotid body tumors and BFS were identified through a comprehensive literature search in the PubMed database.
  
  
  CONCLUSIONS
  Our case shows the generalizability of BFS to patients with tumors involving the vagal baroafferent fibers.
authors.affiliation: Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, Pennsylvania, USA. Electronic address: mgzghali@gmail.com.
authors.forename: Michael G Z
authors.initials: MGZ
authors.lastname: Ghali
authors.affiliation: Department of Neurosurgery, Baylor College of Medicine, Houston, Texas, USA.
authors.forename: Visish M
authors.initials: VM
authors.lastname: Srinivasan
authors.affiliation: Department of Head and Neck Surgery, The University of Texas M. D. Anderson Cancer Center, Houston, Texas, USA.
authors.forename: Ehab
authors.initials: E
authors.lastname: Hanna
authors.affiliation: Department of Neurosurgery, Baylor College of Medicine, Houston, Texas, USA; Department of Neurosurgery, The University of Texas M. D. Anderson Cancer Center, Houston, Texas, USA. Electronic address: fdemonte@mdanderson.org.
authors.forename: Franco
authors.initials: F
authors.lastname: DeMonte
mesh_terms: D000293:Adolescent; D017704:Baroreflex / Q000502:physiology*; D002345:Carotid Body Tumor / Q000000981:diagnostic imaging* / Q000601:surgery*; D019468:Disease Management; D005260:Female; D006801:Humans; D011183:Postoperative Complications / Q000000981:diagnostic imaging / Q000209:etiology; D011311:Pressoreceptors / Q000503:physiopathology*
keywords: Baroreflex dysfunction; Baroreflex failure syndrome; Carotid body tumors; Paraganglioma