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: ETA, ETB1, ETB2
• Neurosurgery 43:863-876, 1998
Endothelin Receptors
ETA
localized to smooth muscle mediates vasoconstriction
ETB1
Localized to vascular endothelial cells Mediates endothelium-dependant vasodilation action of
ET
ETB2
Similar localization and action to ETA
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