Warning signs in subarachnoid hemorrhage: a cooperative study

Misdiagnosis of symptomatic cerebral aneurysm. Prevalence and correlation with outcome at four institutions

BACKGROUND AND PURPOSE

It is not known what fraction of patients with symptomatic cerebral aneurysms are misdiagnosed at initial medical presentation. It is also not clear whether misdiagnosed patients more frequently deteriorate before definitive aneurysm diagnosis and therapy or achieve a poorer outcome than correctly diagnosed patients.

METHODS

We reviewed records of consecutive patients with symptomatic cerebral aneurysms managed by four tertiary-care neurosurgical services during a recent 19-month period. Clinical course and outcome were analyzed according to misdiagnosis or correct diagnosis at initial medical evaluation.

RESULTS

Fifty-four of 217 patients (25%) were misdiagnosed at initial medical evaluation, including 46 of 121 patients (38%) initially in good clinical condition (clinical grade 1 or 2). Forty-six of 54 patients (85%) in the misdiagnosis group were initially grade 1 or 2 compared with 75 of 163 patients (46%) with correct initial diagnosis (P < .01). Twenty-six of 54 misdiagnosed patients (48%) deteriorated or rebled before definitive aneurysm treatment compared with 4 of 165 correctly diagnosed patients (2%) (P < .001). Among patients initially presenting as clinical grade 1 or 2, overall good or excellent outcome was achieved in 91% of those with correct initial diagnosis and 53% of patients with initial misdiagnosis (P < .001). Deterioration before correct diagnosis accounted for 16 of 67 patients (24%) with poor or worse final outcome in this series.

CONCLUSIONS

Patients in good clinical condition with symptomatic cerebral aneurysms were commonly misdiagnosed. Misdiagnosed patients were more likely than correctly diagnosed patients to deteriorate clinically and had a worse overall outcome. Misdiagnosed cases accounted for a significant fraction of overall poor outcomes among consecutive cases of symptomatic aneurysms.

Will increased awareness among physicians of the significance of sudden agonizing headache affect the outcome of subarachnoid hemorrhage? Coventry and Warwickshire Study: audit of subarachnoid hemorrhage (establishing historical controls), hypothesis, campaign layout, and cost estimation

BACKGROUND AND PURPOSE

The most common symptom associated with aneurysmal minor bleed ("warning leak") is a sudden agonizing headache. Early screening of these patients may improve the outcome of subarachnoid hemorrhage and may be highly cost-effective.

METHODS

We conducted an extensive retrospective audit of subarachnoid hemorrhage over the last 10 years in the region of Coventry and Warwickshire, England, and initiated a continuous campaign among all physicians in the region for early neurosurgical referral of patients with sudden agonizing headache.

RESULTS

Over the last 10 years the incidence of subarachnoid hemorrhage in the region was 8.7/100 000 per year. Surgical activity was 34% and early mortality 45.2%. Functional outcome, both overall and by grade on admission, was within internationally accepted levels. Warning leak symptoms before admission were experienced by 20% of patients. These patients sought medical advice but were not referred immediately to the neurosurgical unit.

CONCLUSIONS

We have established our population as valid historical controls and outlined our campaign strategy. Lowering the clinical threshold at which patients with sudden agonizing headache are screened for aneurysms or arteriovenous malformations will undoubtedly increase diagnostic costs. However, for reasons given in the text, we estimated the cost per quality-adjusted life year gain to be 1000 pounds ($1500).

Diagnostic testing for the evaluation of headaches

Headaches are one of the most common symptoms that neurologists evaluate. Although most are caused by primary disorders, the list differential diagnoses is one of the longest in all of medicine, with over 300 different types and causes. The cause or type of most headaches can be determined by a careful history supplemented by a general and neurologic examination. Reasons for obtaining neuroimaging include medical indications as well as anxiety of patients and families and medico-legal concerns. In the era of managed care, concerns over deselection and negative capitation may dissuade the physician from ordering even a medically indicated scan. The yield of neuroimaging in the evaluation of patients with headache and a normal neurologic examination is quite low. Combining the results of multiple studies performed since 1977 for a total of 3026 scans reveals the overall percentages of various pathologies as: brain tumors, 0.8%; arteriovenous malformations, 0.2%; hydrocephalus, 0.3%; aneurysm, 0.1%; subdural hematoma, 0.2%; and strokes, including chronic ischemic processes, 1.2%. EEG is not useful in the routine evaluation of patients with headache. Similarly, the yield of neuroimaging in the evaluation of migraine is quite low. Combining the results of multiple studies performed since 1976 for a total of 1440 scans of patients with various types of migraine, the overall percentages of various pathologies are: brain tumor, 0.3%; arteriovenous malformation, 0.07%; and saccular aneurysm, 0.07%. WMA have been reported on MRI studies of patients with all types of migraine, with a range from 12% to 46%. The cause of WMA in migraine is not certain. Cerebral atrophy has been variable reported as more frequent and no more frequent in migraineurs compared with controls. The "first or worst" headache has a long list of possible causes and always includes the possibility of acute subarachnoid hemorrhage. Headaches--especially the sentinel type caused by SAH--often are misdiagnosed. The probability of detecting an aneurysmal hemorrhage of CT scans performed at various intervals after the ictus is: day 0.95%; day 3, 74%; 1 week, 50%; 2 weeks, 30%; and 3 weeks, almost nil. The location of a ruptured saccular aneurysm often is suggested by the predominant site of the SAH. The probability of detecting xanthochromia with spectrophotometry in the CSF at various times after a subarachnoid hemorrhage is: 12 hours, 100%; 1 week, 100%; 2 weeks, 100%; 3 weeks, more than 70%; and 4 weeks, more than 40%. The management of thunderclap headaches with normal CT scan and CSF examinations is controversial. Most patients have a benign course but an unruptured saccular aneurysm occasionally may be responsible for the headache. MR angiography may be a reasonable test to obtain instead of a cerebral arteriogram in many of these cases. About 30% to 90% of patients have headaches of various types and causes after mild head injury. Although most headaches are relatively benign, perhaps 1% to 3% of these patients have life-threatening pathology, including subdural and epidural hematomas, that are detected on CT and MRI scans. Headaches caused by subdural hematomas can be nonspecific. When new-onset headaches begin in patients over the age of 50 years, the physician always should consider whether it may be a secondary headache disorder requiring specific diagnostic testing and treatment. Up to 15% of patients 65 years and over who present to neurologists with new-onset headaches may have serious pathology such as stroke, TA, neoplasm, and subdural hematoma. Headaches are the most common symptom of TA, reported by 60% to 90%. The only over the temple. The diagnosis of TA is based on a high index of clinical suspicion that usually but not always is confirmed by laboratory testing. The erythrocyte sedimentation rate can be normal in 10% to 36% of patients with TA. A superficial temporal artery biopsy can give a false-negative result in 5% to 44% of patients.

Seizures at the onset of subarachnoid haemorrhage

In a prospective study of 253 patients with subarachnoid haemorrhage, 16 (6.3%) had seizures at the onset of bleeding. None had a previous history of seizures. One was an alcoholic. None had metabolic imbalance. Hemiparesis, Hunt's grade > 3, the amount of subarachnoid blood and the presence of an aneurysm were significantly more frequent in patients with seizures at the onset of subarachnoid haemorrhage. Although rebleeding and mortality or severe disability at discharge were more frequent in these patients, seizures were not a significant predictor of prognosis. One of the survivors with early seizures developed recurrent epileptic seizures 1 year later.

Subarachnoid hemorrhage: an update of pathogenesis, diagnosis and management

Subarachnoid hemorrhage (SAH) remains a devastating neurological disorder, which most commonly develops after rupture of an intracranial aneurysm. Advances have occurred in the areas of epidemiology, diagnostic imaging, medical management and surgical intervention, related to aneurysmal SAH. Interested physicians must become aware of these and other advances to diagnose and manage this potentially lethal disorder more effectively. This review provides information about the pathogenesis and complications of aneurysmal SAH and an update of new and evolving treatment modalities to provide an in-depth overview for the clinician and researcher involved in this rapidly evolving field.