**2. Clinical presentation of subarachnoid hemorrhage**

The most common clinical reflection of aneurysm is SAH; it can occur in several ways: headache, bilateral temporal hemianopsia and bilateral lower limb weakness, unilateral nerve palsy, facial or orbital pain, nosebleed, progressive vision loss and/or ophthalmoplegia, and symptoms of brain stem dysfunction. Patients with complex middle cerebral artery aneurysms may present with intracranial hemorrhage, mass effects, epilepsy, or cerebral ischemia; in addition, the aneurysm may be incidentally discovered. A high mortality rate of 65–85% within 2 years has been reported, and aneurysm rupture survivors are often left with severe neurological deficits [5–9].

In the presence of rupture, aneurysmal SAH may cause coma in 20–30% of patients. In "poor-grade" patients, neurologic findings may include extensor posturing and loss of upper brain stem reflexes, and further progression may occur in hours from the ictus. A wide light-fixed pupil may indicate oculomotor palsy from a ruptured posterior communicating aneurysm or lateral brain stem displacement from a hematoma in the temporal or frontal lobe. Pinpoint pupils may indicate the presence of an acute hydrocephalus with ventricles often filled with blood. The causes of coma after aneurysmal SAH are shown in **Table 3**.

The severity of SAH is clinically assessed and graded using either the Hunt and Hess classification or the World Federation of Neurosurgeons (WFNS) scale (**Tables 4** and **5**). The WFNS, widely used, is a combination of focal neurological deficits and the Glasgow coma scale (GCS). Higher grades on both scales are


#### **Table 3.** *Causes of coma in aneurysmal subarachnoid hemorrhage.*


*Hypertension, diabetes, arteriosclerosis, chronic pulmonary disease, or vasospasm assigns patient to the next less favorable category.*

#### **Table 4.**

*Modified Hunt and Hess classification [13].*


#### **Table 5.**

*World Federation of neurosurgeons scale.*


#### **Table 6.**

*Fisher and modified fisher grading scale.*

associated with the worst outcomes. The WFNS classification provides a more objective assessment. The first computerized tomography scan uses the Fisher grading scale to determine the amount, localization, prognosis, and severity of bleeding (**Table 6**). The risk of vasospasm is high in patients with Grade III and IV SAH.

The overall mortality in patients with SAH is over 30%, and approximately 10–20% of survivors show functional dependence despite intensive neurological care. Several extensive studies have been conducted to improve intensive neurological care in patients with SAH [12]. Poor-grade aneurysmal SAH (WFNS Grades IV and V)

#### *Intensive Care Management in Cerebral Aneurysm and Arteriovenous Malformations DOI: http://dx.doi.org/10.5772/intechopen.89714*

reflect 20–30% of all aneurysmal SAH. Mortality is commonly associated with neurological injury resulting from the initial bleeding and rebleeding and from delayed cerebral ischemia (DCI). The volume of initial hemorrhage and initial neurological status following SAH remain major factors for mortality. Elderly patients and patients with coexisting medical conditions are at higher risk. The clinical goal is to prevent rebleeding and DCI [13–15].

In general, the prognosis of aneurysmal SAH is considered to be inversely related to grading at first presentation. Aggressive early interventions such as emergency surgical clip application or endovascular treatment of the aneurysm can lead to positive outcomes in poor-grade aneurysmal SAH patients. Subarachnoid hemorrhage patients can be followed with conservative treatment without invasive intervention. External ventricular drainage is a frequently preferred method in the case of hydrocephalus which can be observed during this clinical follow-up. In a multicenter, prospective observational study conducted with 324 patients, the relationship between the potential clinical risk factors and the prognosis of aneurysmal SAH in intracranial aneurysm patients was investigated. Results showed that age, female gender, ventilated respiratory status, pupil dilatation, low GCS, WFNS grade, intraventricular hemorrhage, higher Fisher grade, higher Modified Fisher grade, and a relatively poor outcome in aneurysmal SAH patients receiving conservative treatment play a major role. There are many studies showing that age has a strong relationship with clinical outcomes in aneurysmal SAH patients [16–23]. Global cerebral edema occurs in up to 57% of patients suffering from subarachnoid hemorrhage and is associated with prolonged hospital stay and poor outcome. The pathogenesis of brain injury after intracerebral hemorrhage is thought to be due to mechanical damage followed by ischemic, cytotoxic, and inflammatory changes in the underlying and surrounding tissue. Typically, a sudden rise in intracranial pressure at the moment of rupture reduces cerebral perfusion globally in both hemispheres and results in marked ischemic changes. Intraventricular extension of the hemorrhage and hydrocephalus may be a cause of coma, and thus, an improvement may be seen after ventriculostomy [3, 24, 25].
