SUBARACHNOID HEMORRHAGE
Vasospasms in subarachnoid hemorrhage
Created 31/03/2021, last revision 10/02/2023
- vasospasms (VSPs) in SAH are provoked by the blood in the subarachnoid space. The breakdown products lead to changes in the arterial wall involving cytokines, inflammatory response, free radical production, and others ⇒ resulting in arterial contraction or structural changes with the thickening of the vessel wall [Dorsch, 1995].
- VSPs appear on days 3-4, with a peak on days 5-9; VSPs may persist for up to 3-4 weeks
- when detected < 3 days after SAH, a previous episode of bleeding can be assumed
- VSPs occur in up to 70% of patients with SAH (usually in the artery with a ruptured aneurysm), about 1/3-1/2 are symptomatic – leading to Delayed Ischemic Deficit (DID), which is the leading cause of neurological deficits (focal deficits, encephalopathy) and mortality in SAH patients [Dorsch, 2002]
- patients at risk for developing spasms:
- at a younger age
- with more blood in the SA space (see Fisher grade)
- with worse baseline clinical status (higher Hunt-Hess score)
- with late initiation of treatment
- early diagnosis and correct treatment of VSP can prevent or at least minimize the development of DID
- a clinical syndrome manifested by cognitive changes and/or focal neurological impairment lasting ≥ 1h and/or cerebral infarction
- present in approximately 30% of patients with SAH (Yamaki, 2019)
- multifactorial etiology
- vasospasms (VSP)
- intracranial hypertension, cerebral edema, and impaired vascular autoregulation
- presence of cortical spreading depression ⇒ microvascular dysfunction
- micro-thrombosis due to activation of the coagulation cascade and due to inhibition of the fibrinolysis (microemboli are detectable by TCD/TCCD)
- vasospasms (VSP)
- exclude other causes of clinical deterioration (rebleeding, hydrocephalus, intracranial hemorrhage, etc.)
Vasospasms Classification
| Content available only for logged-in subscribers (registration will be available soon) |
Clinical presentation
- worsening of headache and neck stiffness
- confusion, disorientation, decreased consciousness
- new focal neurological deficits
- fever
Vasospasms detection
TCD/TCCD
- TCD/TCCD allows repeated bedside monitoring ( → TCCD diagnosis of vasospasms)
- in VSP, a typical velocity increase of > 50 cm/s or 25%/24h can be detected
- progression of intracranial hypertension can be monitored → see here
CT/CTA/CTP or MRI/MRA
- NCCT excludes recurrent bleeding, obstructive hydrocephalus, or progression of edema
- CTA shows the extent and severity of vasospasm
- CT perfusion (CTP) allows assessment of the risk of DID ⇒ in the territory of the affected artery; there is a prolonged transit time (TTP, MTT) and, in severe cases, a decrease in regional perfusion (CBF) or blood volume (CBV) appears → pattern of ischemic injury
[Binaghi, 2007]
- MRI outperforms CT in the evaluation of vasospasm-induced ischemia (DWI)
- it also has better sensitivity for small hemorrhages (GRE/SWI)
- MRA and MR perfusion detect VSPs and assess their hemodynamic significance
DSA
- considered as the “gold standard”
- the typical finding on DSA is segmental narrowing of the artery
- detection of vasospasms in peripheral, less easily visualized vessels remains a limiting factor
Management
- individualized approach is required
- consider these factors:
- the severity of the vasospasm
- presence of significant hypoperfusion in the distal circulation
- dynamics
- number and location of VSP (focal or diffuse, single or multiple VSPs)
- signs of hyperperfusion
- signs of intracranial hypertension
- clinical status
Maintaining Cerebral Perfusion
- effect of 3H therapy (Hypertension, Hypervolemia, and Hemodilution) is not proven
- a review of controlled trials showed no positive impact of 3H therapy or its components on increasing cerebral blood flow) [Dankbaar, 2010]
- a review of controlled trials showed no positive impact of 3H therapy or its components on increasing cerebral blood flow) [Dankbaar, 2010]
- maintain normovolemia with CVP at 10-12 cm H2O (mm Hg) or pulmonary artery wedge pressure (PAWP) at 14-20 mmHg
- maintain the hematocrit at 30-35% to optimize blood viscosity
- SBP should be maintained preoperatively ≤ 130-140 mmHg, postoperatively 150-175 mmHg
- administer inotropes and vasopressors if MAP < 90 mm Hg
Drug therapy
- nimodipine and cilostazol are likely the most effective treatments for preventing morbidity and mortality (Dayyani, 2022)
- clazosentan, nicardipine, and magnesium have beneficial effects on delayed cerebral ischemia and vasospasms, but they were not found to reduce mortality or disability (Dayyani, 2022)
| Content available only for logged-in subscribers (registration will be available soon) |
Angioplasty, local application of vasodilatory drugs
| Content available only for logged-in subscribers (registration will be available soon) |
Thrombolytic therapy
- meta-analysis suggests a clinically relevant beneficial effect of subarachnoid clot removal achieved by intracisternal tPA injections. (Amin-Hanjani, 2004]
- ARR of 14.4% for delayed ischemic neurological deficit
- therapy is associated with an increased risk of intracranial bleeding
- clinical trials are needed to determine the safety and efficacy of this approach
