Recognizing aneurysmal subarachnoid hemorrhage

Recognizing aneurysmal subarachnoid hemorrhage

Routson, Janet L

Aneurysmal subarachnoid hemorrhage (SAH) is a highly dangerous illness with an annual incidence rate of 1 per 10,000 people.1 Two-thirds of patients diagnosed with SAH die within the first month, and some do not even reach a hospital. Of those who do survive, one-fourth to onehalf have major neurologic deficits.

Evidence supports the role of genetics and acquired or environmental factors in the development of SAH (see Table 1). Some 20% of patients with aneurysmal SAH have first or second degree relatives with intracranial aneurysms.2,3 Other risk factors include smoking cigarettes, drinking episodically, having hypertension, and being a man under age 50; postmenopausal women and women undergoing hormone replacement therapy have an intermediate risk.4-6

Symptoms usually begin once rupture occurs. The most common presentation is a severe acute headache. The patient may describe the headache as “the worst headache of my life.” A prodromal or sentinel headache caused by minor leaking of blood into the aneurysm or subarachnoid space may develop days, weeks, or months prior to rupture. In addition, signs of meningeal irritation and intraocular hemorrhage are usually present. The patient may also experience lower back pain due to the breakdown of blood products within the subarachnoid space, which are circulated by the cerebral spinal fluid.

Diagnosis and Treatment

The unusual nature of the warning headache stimulates many of those affected to seek medical attention. If symptoms are recognized and prompt referrals are made, the patient may remain in optimal clinical condition for early treatment. Unfortunately, many of these symptoms (see Table 2) are not recognized, and treatment is delayed. This delay is associated with high mortality. The diagnosis at initial consultation usually includes migraine, tension headache, flu, sinusitis, or sprained neck.7,8

If SAH is suspected, the first diagnostic study should be a computed tomography scan, although angiography is the primary method used to detect an intracranial aneurysm. The goal of treatment is to preserve the parent artery while excluding the aneurysm from intracranial circulation. If an aneurysm has ruptured, the patient will need surgery to prevent recurrent hemorrhage within 72 hours. Many patients who survive the initial bleeding experience morbidity and mortality from rebleeding and delayed cerebral ischemia.

An alternative to surgical intervention is endovascular therapy. Soft metallic coils are inserted into the aneurysm to completely obliterate the aneurysmal sac. A thrombus forms around the coils in the aneurysm. Patients may be selected for this intervention based on clinical or surgical status, untreatable surgical aneurysm, or high potential for surgical morbidity or mortality.9

Prognosis

The prognosis for patients with aneurysmal SAH remains poor. Many of these patients die prior to receiving medical attention. Up to 50% of patients who survive may die of complications, and up to 20% may experience permanent neurologic disability.

To lesson the devastation of this disease, primary care providers must accurately diagnose early presentation of symptoms and refer the patient promptly for definitive treatment (see Table 3). Patients should be screened aggressively for both genetic and environmental risk factors. Patient education for the modification of risk factors alone may be beneficial in reducing the morbidity and mortality of aneurysmal SAH.

REFERENCES

1. Schievink WI: Intracranial aneurysms. N Engl J Med 1997;336(1):28-40.

2. Noorgard O, Angquist KA, Fodstad H, et al.: Intracranial aneurysms and heredity. Neurosurgery 1987;20(2):236-39.

3. Schievink l1, Schaid DJ, Michels AT, et al.: Familial aneurysms and subarachnoid hemorrhage: A community based study. J Neurosurg 1995; 83(3)426-29.

4. Longstreth WT, Nelson LM, Koepsell TD, et al.: Cigarette smoking, alcohol use and subarachnoid hemorrhage. Stroke 1993;23(10):1242-49.

5. Juvela S, Hamilton 1I, Numminen H, et al.: Cigarette smoking and alcohol consumption as risk factors for aneurysmal SMA. Stroke 1993;24(5): 639-46.

6. Longstreth l?T, Nelson LM, Koepsell TD, et al.: SAH and hormonal factors in women: A population based case control study. Ann Intern Med 1994;121(3):168-73.

7. Schievink WI, Van der WerfJ, Hageman LM, et al.: Referral pattern of patients with aneurysmal subarachnoid hemorrhage. Surg Neurol 1988; 29(5):367.

8. Ostergard JR. Headache as a warning symptom of impending aneurysmal subarachnoid hemorrhage. Cephalgia 1991;11(1):53-5.

9. Vinuela F, Duckwiler G, Mawad M: Guglielmi detachable coil embolization of acute intracranial aneurysm: Perioperative anatomical and clinical outcome in 403 patients. J Neurosurg 1997; 86(3):475-82.

Janet L. Routson, RN, CS, FNP Department of Veterans Affairs Clovis Primary Care Clinic Clovis, N.M.

Copyright Springhouse Corporation Apr 1999

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