The value of CT angiography in patients with acute severe headache

Management of patients presenting to the emergency department with sudden onset severe headache: systematic review of diagnostic accuracy studies

Objective

Advances in imaging technologies have precipitated uncertainty and inconsistency in the management of neurologically intact patients presenting to the Emergency Department (ED) with non-traumatic sudden onset severe headache with a clinical suspicion of subarachnoid haemorrhage (SAH). The objective of this systematic review was to evaluate diagnostic strategies in these patients.

Methods

Studies assessing any decision rule or diagnostic test for evaluating neurologically intact adults with a severe headache, reaching maximum intensity within 1 hour, were eligible. Eighteen databases (including MEDLINE and Embase) were searched. Quality was assessed using QUADAS-2. Where appropriate, hierarchical bivariate meta-analysis was used to synthesise diagnostic accuracy results.

Results

Thirty-seven studies were included. Eight studies assessing the Ottawa SAH clinical decision rule were pooled; sensitivity 99.5% (95% CI 90.8 to 100), specificity 24% (95% CI 15.5 to 34.4). Four studies assessing CT within 6 hours of headache onset were pooled; sensitivity 98.7% (95% CI 96.5 to 100), specificity 100% (95% CI 99.7 to 100). The sensitivity of CT beyond 6 hours was considerably lower (≤90%; 2 studies). Three studies assessing lumbar puncture (LP; spectrophotometric analysis) following negative CT were pooled; sensitivity 100% (95% CI 100 to 100), specificity 95% (95% CI 86.0 to 98.5).

Conclusion

The Ottawa SAH Rule rules out further investigation in only a small proportion of patients. CT undertaken within 6 hours (with expertise of a neuroradiologist or radiologist who routinely interprets brain images) is highly accurate and likely to be sufficient to rule out SAH; CT beyond 6 hours is much less sensitive. The CT–LP pathway is highly sensitive for detecting SAH and some alternative diagnoses, although LP results in some false positive results.

Acute headache management in emergency department. A narrative review

Headache is a significant reason for access to Emergency Departments (ED) worldwide. Though primary forms represent the vast majority, the life-threatening potential of secondary forms, such as subarachnoid hemorrage or meningitis, makes it imperative for the ED physician to rule out secondary headaches as first step, based on clinical history, careful physical (especially neurological) examination and, if appropriate, hematochemical analyses, neuroimaging or lumbar puncture. Once secondary forms are excluded, distinction among primary forms should be performed, based on the international headache classification criteria. Most frequent primary forms motivating ED observation are acute migraine attacks, particularly status migrainous, and cluster headache. Though universally accepted guidelines do not exist for headache management in an emergency setting, pharmacological parenteral treatment remains the principal approach worldwide, with NSAIDs, neuroleptic antinauseants, triptans and corticosteroids, tailored to the specific headache type. Opioids should be avoided, for their scarce effectiveness in the acute phase, while IV hydration should be limited in cases of ascertained dehydration. Referral of the patient to a Headache Center should subsequently be an integral part of the ED approach to the headache patients, being ascertained that lack of this referral involves a high rate of relapse and new accesses to the ED. More controlled studies are needed to establish specific protocols of management for the headache patient in the ED.

Diagnostic Neuroimaging in Headache Patients: A Systematic Review and Meta-Analysis

OBJECTIVE

Neuroimaging in headache patients identifies clinically significant neurological abnormalities and plays an important role in excluding secondary headache diagnoses. We performed a systematic review and meta-analysis of the existing guidelines and studies surrounding neuroimaging in headache patients.

METHODS

The research question involved determining the prevalence of detecting clinically significant neurological abnormalities using neuroimaging in patients suspected of primary headache. Searches of the PubMed and Embase databases were conducted on English-language studies published from 1991 to 2016, and the reference lists of the retrieved articles were also checked manually. All headache subtypes and patients aged ≥15 years were included in the analysis.

RESULTS

Ten studies met the selection criteria. The pooled prevalence of detecting clinically significant abnormalities in the neuroimaging of headache patients was 8.86% (95% confidence interval: 5.12-15.33%). Subsequently, diverse subgroup analyses were performed based on the detection method, headache type, study type, study region, age group, and disease type.

CONCLUSION

The present findings indicate that limited neuroimaging methods should be carefully considered for headache diagnostic purposes when there are red flag symptoms. Limitations and suggested directions for future studies on neuroimaging in headache patients are described.

Imaging of Headache in Pregnancy

Pregnant women are most likely to have primary headaches, such as migraine and tension-type headaches, which can be diagnosed and treated without brain imaging. Primary headaches may even start de novo during pregnancy, especially in the first few months. However, when the headache occurs late in pregnancy or in the peripartum period, secondary causes of headaches need to be considered and evaluated by brain and/or vascular imaging, generally using magnetic resonance techniques. There is considerable overlap between the cerebrovascular complications of pregnancy, including preeclampsia/eclampsia, posterior reversible encephalopathy syndrome (PRES), reversible cerebral vasoconstriction syndrome (RCVS), and both hemorrhagic and ischemic strokes; although, their imaging may be distinctive. Imaging is necessary to distinguish between arterial and venous pathology causing headache in the peripartum patient, as there can be similar presenting symptoms. Mass lesions, both neoplastic and inflammatory, can enlarge and produce headaches and neurological symptoms late in pregnancy.