Nonaneurysmal Subarachnoid Hemorrhage: A Review of Clinical Course and Outcome in Two Hemorrhage Patterns

Linda L. Herrmann; Joseph M. Zabramski


J Neurosci Nurs. 2007;39(6):135-142. 

In This Article

Assessment and Diagnosis

Patients who present with an SAH will classically describe the sudden onset as the worst headache of their life. However, a gradual onset of the severe headache over several minutes has been reported in patients with NASAH (Brilstra et al., 1997; Rinkel et al., 1990; Rinkel, Wijdicks, Hasan, et al., 1991; Rinkel, Wijdicks, Vermeulen, et al., 1991; van Gijn et al., 1985). Patients may report associated symptoms such as nausea, vomiting, and photophobia. Family may report an altered level of consciousness in the patient.

Objective data assessment should include time, location, and character of headache onset; headache duration; associated symptoms (e.g., altered level of consciousness, extremity weakness, or slurred speech); and exacerbating and alleviating factors. The assessment should also note what type of activity preceded the headache onset (i.e., a headache that came on during rest or sedentary activity, or a headache that started abruptly during intercourse or strenuous exercise). In the authors' experience, onset of severe headache during intercourse or strenuous exercise may be a result of elevated venous sinus pressure (not SAH) from the Valsalva maneuver. Physical assessment data should consist of a comprehensive neurological examination, including documentation of the Glasgow Coma Scale (GCS) score, motor and sensory examination, cranial nerve function, and vital signs. Other pertinent information includes patient history of recent illicit drug use, hypertension, polycystic kidney disease, previous ASAH or aneurysms, use of anticoagulants, or tobacco use, which can increase the risk of aneurysm formation (Juvela, Hillbom, Numminen, & Koskinen, 1993; Schievink, Torres, Piepgras, & Wiebers, 1992). Pertinent family history includes polycystic kidney disease, ASAH, or aneurysms.

Diagnostic assessment usually starts with a CT scan of the brain. This scan can be done quickly after a patient is evaluated in the emergency department. A CT scan is the diagnostic study of choice for SAH and is useful in ruling out other pathologies that may mimic aneurysm rupture, such as hypertensive intracerebral hemorrhage or hemorrhage from a tumor mass. It also allows rapid identification of ventricular size and the presence of intraventricular hemorrhage.

CT angiography (CTA) may be performed to determine the source of hemorrhage. A minimally invasive test, CTA uses a timed bolus of intravenous (IV) contrast to visualize the arteries. In patients with ruptured aneurysms, CTA has a reported sensitivity of 86% (Anderson, Findlay, Steinke, & Ashforth, 1997); however, conventional cerebral angiography remains the "gold standard" for evaluation and is likely to be done when the CTA is negative. A conventional angiogram is performed to evaluate the cerebral circulation for the source of SAH: aneurysm, arteriovenous malformation (AVM), or dural arteriovenous fistula. Conventional catheter-based cerebral angiography is an invasive test requiring significant technical expertise and is best performed at specialized centers where the risk of serious complications is in the range of 0.5% to 1% (Heiserman et al., 1994). When considering conventional angiography or CTA in patients with abnormal renal function, the administration of contrast poses a significant risk of further compromising renal function. These risks can be significantly reduced by pretreating patients with acetylcysteine and IV sodium bicarbonate solution (Liu, Nair, Ix, Moore, & Bent, 2005); a nephrology consult may be useful in managing such patients. Patients allergic to contrast, iodine, or shellfish require pretreatment with steroids, usually 32 mg oral methylprednisolone administered 12 hours and 2 hours before exam, or, if emergent, 100 mg IV methylprednisolone. Patients may also be given IV diphenhydramine, 25–50 mg, before angiography (Greenberg, 2001).

A negative angiogram may be followed by a magnetic resonance imaging (MRI) scan of the brain, and possibly of the cervical spine, to rule out other sources of SAH. A tumor or vascular lesion, such as a cavernous malformation in the posterior fossa or upper cervical spine, would not be visible on a cerebral angiogram.

Repeat cerebral angiography is controversial in patients with a nonfocal neurological examination and a negative invasive workup. At the authors' institution, repeat cerebral angiography is not routinely performed in a patient with a perimesencephalic hemorrhage pattern and a negative initial high-quality cerebral angiogram. Repeat angiography is reserved for patients with an aneurysmal pattern of subarachnoid blood or a suboptimal initial study. If a second cerebral angiogram is recommended, it is usually completed approximately 5 to 7 days after the hemorrhage. This interval allows for repeat evaluation for aneurysm or AVM that may have been obscured and for identification of the presence of vasospasm.