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  • Cerebral Vasospasm
    • M. Christopher Wallace M.D.
    • The Toronto Western Hospital,
    • University Health Network
    • University of Toronto
    • Postgraduate Lecture Series
    • Division of Neurosurgery
    • Friday October 20, 2000
  • Subarachnoid Hemorrhage
    • Delayed presentation
    • Headache, no deficit
    • Minimal subarachnoid blood
  • Cause of Subarachnoid Hemorrhage?
  • Post surgical CT
  • Post-op Angiography
  • Comparison Angiograms
  • Post surgical CT’s
  • History
    • 1927 Moniz - angiography
    • 1937 Dandy describes the clipping of intracranial aneurysm
    • 1949 Robertson described post-mortem lesions after aneurysmal SAH.
            • Brain 72:150, 1949
    • 1951 Ecker & Reimenschneider angiographic spasm
  • Time Course
    • After aneurysmal subarachnoid hemorrhage
    • Delayed onset
    • Rarely present before Day 3
    • Peak Day 6-7
  • Significance
    • 1970’s Does it exist?
    • Time course in humans
        • Kwak, Niizuma Surg Neurol 11:257, 1979
        • Niizuma, Kwak Surg Neurol 11:263, 1979
    • Cause of death or disability in 13.5% in co-operative study
        • J. Neurosurgery 73:18-36, 1990
  • Vasospasm and SAH
    • Relationship to the amount of subarachnoid hemorrhage
    • Fisher CT Grade
      • I 2/11 angiographic spasm, 0/11
      • II 0/7
      • III 23/24 clinical vasospasm
          • Fisher, Kistler, Davis Neurosurgery 6:1 1980
  • Etiology
    • Reversible?
    • Smooth muscle contraction vs morphological change in vascular wall
    • Weir, Findlay, MacDonald
      • Demonstration of role of oxyhemoglobin leads to documented contraction of smooth muscle
      • Delayed thickening of intima and adventitia day 28
  • Etiology
    • Fresh serum and platelet rich plasma are vasoreactive
    • Washed rbc’s are inert
    • Contractility of rbc’s linked to incubation with plasma
    • Trapped rbc’s in subarachnoid space
      • day 7
  • Treatment of cerebral vasospasm
    • Diagnosis
    • Hypervolemic-hypertensive therapy
    • Calcium channel blockers
    • Cerebral angioplasty
    • Intracisternal thrombolytic therapy
  • Diagnosis
    • Clinical suspicion: patient/time period
    • Transcranial doppler
    • Cerebral angiography
    • Neurological deficit
  • Hypervolemic-hypertensive therapy
    • Prophylactic use of euvolemia in patients with aneurysmal hemorrhage post-therapy
    • Kosnik & Hunt J Neurosurg 45:148, 1976
    • Kassell, Peerless et al Neurosurgery 11:337, 1982
      • Reversal of deficit in 43/58 patients
      • Use of colloids and inotropes
      • Clinical detection of deficit and angiographic proof of spasm
  • Calcium channel blockers
    • Use of nimodipine 60mg q4h x 3 weeks
    • Reduces morbidity/poor outcomes but does not alter the incidence of angiographic spasm….?mechanism
    • Allen NEJM 308:619, 1983
    • Petruk J Neurosurg 68:505, 1988
    • Pickard Br Med J 298:636, 1989
  • Cerebral angioplasty
    • Mechanical vs chemical (papaverine)
    • Early, minimal deficit, radiological contraindications
    • Permanence
    • Risk of rupture
    • ?prophylaxis
    • Polin et al Neurosurgery 42:1256-1264, 1998
    • Eskridge et al Neurosurgery 42:510-516, 1998
  • Intracisternal thrombolytic therapy
    • Cisternal clot removal
    • Laboratory evidence
    • Prospective study failed to demonstrate efficacy
          • N=100, high risk patients in main centre (p=0.02)
      • mild/no spasm severe
      • Placebo 42% 23%
      • rt-PA 69% 15%
      • Findlay et al Neurosurgery 37:168-176, 1995
  • Endothelin and Vasospasm
    • Isolated from endothelial cells, 1988
    • Three isoforms: ET-1, -2, -3, 21 AA
    • Prepro ET-1 gene, conversion to proendothelin then Big-ET
    • ET-1 most vasoactive
    • Vasoconstriction, elevates arterial pressure, bronchoconstriction
    • Endothelin receptors: ET A, ET B1 , ET B2
    • Neurosurgery 43:863-876, 1998
  • Endothelin Receptors
    • ET A
    • localized to smooth muscle
    • mediates vasoconstriction
    • ET B1
    • Localized to vascular endothelial cells
    • Mediates endothelium-dependant vasodilation action of ET
    • ET B2
    • Similar localization and action to ET A
  • Endothelin and Vasospasm
    • Documented in CSF after aneurysmal SAH
    • Marker vs mediator
    • Likely not over expression of ET1
    • Potential for therapy with selective agonists/antagonists to receptors
  • Approach to Patient with Delayed Neurological Deficit
    • Post-op
    • Hemorrhage
    • Ischemia
    • Vessel occlusion
    • Clipping or coiling error
    • Post temporary clipping
  • Approach to Patient with Delayed Neurological Deficit
    • Day1-3
    • Hyponatremia
    • Fever
    • Oxygenation
    • Hydrocephalus
    • Medications
    • Rebleed/unsecured aneurysm
  • Approach to Patient with Delayed Neurological Deficit
    • Day3-10
    • Vasospasm
    • Vasospasm
    • Vasospasm
    • Hydrocephalus
    • Fever/pneumonia