title: Rational Roots of Sympathetic Overactivity by Neurogenic Pulmonary Edema Modeling Arising from Sympathyco-Vagal Imbalance in Subarachnoid Hemorrhage: An Experimental Study.
abstract: BACKGROUND
  Autonomous innervations of the lungs are maintained by cervical sympathetic and vagal nerves. Sympathetic overactivity-induced neurogenic pulmonary edema (NPE) is known as a serious complication of subarachnoid hemorrhage, but the rational neuronal mechanism of that overactivity has not yet been clarified fully. The aim of this study was to examine whether there is a relationship between vagal nerve ischemia related sympathetic overactivity and neurogenic pulmonary edema in subarachnoid hemorrhage.
  
  
  METHODS
  This study was conducted on 27 rabbits. A control group was formed of 5 animals, a sham group of 7 to which saline was administered, and a study group of 15 animals that were injected with homologous arterial blood into the cisterna magna. Electrocardiography and respiratory rhythm parameters were monitored for 3 weeks and the animals were then decapitated. Statistical analysis was made of the numbers of degenerated axons in the pulmonary branches of the vagal nerves, the neuron density of stellate ganglions and the vasospasm index of the pulmonary arteries.
  
  
  RESULTS
  In the control group, the normal respiration rate was 34 ± 6 bpm, total axon number was 1600 ± 270/mm(2), degenerated axon number was 10 ± 3/mm(2), and vasospasm index was 1.34 ± 0.25. The sham group values were 30 ± 3 bpm, 163 ± 47/mm(2), and 1.95 ± 0.45 and the study group values were 45 ± 8 bpm, 530 ± 92/mm(2), and 2.76 ± 0.83. The mean stellate ganglion neuron density was evaluated as 8.112 ± 1.230/mm(3) in all animals, as 7.420 ± 4.10/mm(3) in animals with slight NPE, and as 12.512 ± 1.236/mm(3) in animals that developed severe NPE.
  
  
  CONCLUSIONS
  High neuron density of stellate ganglion may have important roots in sympathetic overactivity-related NPE development in subarachnoid hemorrhage.
authors.affiliation: Department of Neurosurgery, Umraniye Teaching and Research Hospital, Istanbul, Turkey. Electronic address: mresid@gmail.com.
authors.forename: Mehmet Resid
authors.initials: MR
authors.lastname: Onen
authors.affiliation: Department of Neurosurgery, Sisli Teaching and Research Hospital, Istanbul, Turkey.
authors.forename: Ilhan
authors.initials: I
authors.lastname: Yilmaz
authors.affiliation: Department of Neurology, FSM Teaching and Research Hospital, Istanbul, Turkey.
authors.forename: Leyla
authors.initials: L
authors.lastname: Ramazanoglu
authors.affiliation: Department of Neurosurgery, Bakirkoy Teaching and Research Hospital, Istanbul, Turkey.
authors.forename: Osman
authors.initials: O
authors.lastname: Tanrıverdi
authors.affiliation: Department of Neurosurgery, Atatürk University, Erzurum, Turkey. Electronic address: nmda11@hotmail.com.
authors.forename: Mehmet Dumlu
authors.initials: MD
authors.lastname: Aydin
authors.affiliation: Department of Neurosurgery, Rize recep Tayyip Erdogan University, Rize, Turkey.
authors.forename: Ayhan
authors.initials: A
authors.lastname: Kanat
authors.affiliation: Department of Neurosurgery, Atatürk University, Erzurum, Turkey.
authors.forename: Coskun
authors.initials: C
authors.lastname: Yolas
authors.affiliation: Department of Pathology, Atatürk University, Erzurum, Turkey.
authors.forename: Sare
authors.initials: S
authors.lastname: Sipal
mesh_terms: D000818:Animals; D011654:Pulmonary Edema / Q000209:etiology / Q000473:pathology / Q000503:physiopathology*; D011817:Rabbits; D013233:Stellate Ganglion / Q000473:pathology / Q000503:physiopathology*; D013345:Subarachnoid Hemorrhage / Q000150:complications / Q000473:pathology / Q000503:physiopathology*; D013564:Sympathetic Nervous System / Q000473:pathology* / Q000503:physiopathology*; D014630:Vagus Nerve / Q000473:pathology / Q000503:physiopathology*
keywords: Respiration; Subarachnoid hemorrhage; Vagal ischemia