Subarachnoid Hemorrhage

Abstract

Subarachnoid hemorrhage should be suspected in patients with sudden, very severe headache. The neurologic and general examination may be entirely normal except for slight stiffness of the neck. Lumbar puncture with pressure measurement, cell count, and careful attention to the presence or absence of xanthochromic staining of the cerebrospinal fluid supernatant should be carried out in such patients. If there is subhyaloid hemorrhage on fundoscopic examination, or if the diagnosis of subarachnoid hemorrhage is clinically obvious, or if the patient is in poor neurologic condition with stupor, coma, or serious neurologic deficit, lumbar puncture should be deferred until neurologic or neurosurgical consultation is available. The chief use of lumbar puncture is to separate those patients who should be admitted to the hospital for evaluation and treatment of suspected intracranial aneurysm or arteriovenous malformation from those whose headaches should be managed symptomatically. Once the diagnosis is suspected or confirmed by lumbar puncture, CT scanning can sometimes be helpful, if available. CT scanning can sometimes identify a clinically inapparent hematoma, identify a large aneurysm of greater than one or two centimeters, depending on the scanner, and assess ventricular size and brain swelling. Angiography by transfemoral catheter to show both carotids and the vertebral circulation is usually the definitive diagnostic study. Surgery is indicated in patients who are in good or fairly good neurologic condition and is usually carried out seven to ten days following the hemorrhage. Such a delay is usually advisable to reduce the likelihood of producing or worsening disabling vasospasm. Emergency surgery may be indicated in patients, particularly those in the younger age group, who are in poor condition as a result of intracranial hematoma. Shunting operations to relieve hydrocephalus may occasionally be useful. The prognosis of untreated intracranial aneurysm is unfavorable. Forty to fifty per cent of patients die in the first eight weeks and 10 per cent per year subsequently. With surgery, operative results with microsurgical methods are excellent for patients in good neurological condition preoperatively, with mortality in the range of 2 per cent for Grade 1 and 4 per cent for Grade 2 patients. Correct clinical diagnosis by the primary care physician can be the most important step in the treatment of life-threatening subarachnoid hemorrhage. If the possibility is not considered, the diagnosis may not be obvious.