More than 50% of patients who present to the emergency department (ED) with thunderclap headache (TCH), which often signals an underlying serious or life-threatening condition, are inadequately managed, new research shows.
Results of a retrospective study revealed that TCH was common, affecting 1 in every 50 ED patients, yet, for 52.4% of the patients, workup was incomplete. In addition, researchers found that in almost 40% of cases, TCH had a secondary cause.
"Most of the associated conditions are secondary disorders that might threaten patients' lives or cause persistent disability, so the management should be as precise and efficient as possible. If neurologists say that 'time is brain,' then thunderclap should be managed as promptly as code stroke," study investigator David García-Azorín, MD, a neurologist at Hospital Clínico Universitario de Valladolid, in Valladolid, Spain, told Medscape Medical News.
The study was published online January 7 in Cephalalgia.
A Potential Medical Emergency
TCH is primarily associated with subarachnoid hemorrhage (SAH), but there are many other disorders, including cerebral venous sinus thrombosis, intracranial infection, increased intracranial pressure, and reversible cerebral vasoconstriction syndrome (RCVS), that present as TCH.
To evaluate how often clinicians rule out secondary headache disorders for patients with TCH, the investigators examined electronic health records for consecutive patients who visited the ED at a single center between January 2012 and July 2014.
Eligible patients had pain of severe intensity that reached its peak within 1 minute of headache onset, with the headache lasting for at least 5 minutes. Patients who had recently experienced traumatic injury to the head or neck were excluded from the study.
The study's primary endpoint was how often a secondary cause of TCH was adequately ruled and whether patient assessment was in line with International Classification of Headache Disorders (ICHD) recommendations.
ICHD guidance for ruling out secondary causes of TCH include cranial CT, lumbar puncture, CT angiography (CTA), magnetic resonance angiography (MRA), digital subtraction angiography, and MRI.
The researchers also determined the proportion of patients who were examined by a neurologist, who were admitted to hospital, and who were discharged with no further examination.
Secondary Causes Common
Of 2132 patients who visited the ED for headache, 71 patients were eligible, and 29 were excluded. The final analysis included 42 patients. The mean age of the study population was approximately 43 years, and 24 patients (57.1%) were women. Twenty patients (47.6%) had a prior history of headache.
Secondary causes of TCH were insufficiently ruled out for 22 (52.4%) patients with TCH. The most commonly omitted exams were vascular evaluation (38.1% of the entire sample, 72.7% of patients with incomplete workup), cerebrospinal fluid (CSF) evaluation (21.4% of the entire sample, 40.9% of patients with incomplete workup), and MRI (16.7% of the entire sample, 31.8% of patients with incomplete workup).
Multiple examinations were omitted for six patients (27.3%). Eight patients (19.0%) received a diagnosis of primary headache, even though their assessment was incomplete.
All patients underwent cranial CT as an initial investigation. A total of 18 patients (52.9%) underwent lumbar puncture, 10 (29.4%) underwent CTA, and two (5.8%) underwent MRI. A total of 28 (66.7%) patients were evaluated by a neurologist. Four patients (11.7%) did not undergo any further examination.
The investigators found a secondary cause for TCH in 16 of the 20 patients whose assessment was adequate. Of these, eight had SAH, two had RCVS, and two had intracerebral hemorrhage secondary to arteriovenous malformation rupture.
The remaining causes were amyloid angiopathy–associated intracerebral hemorrhage, CSF low-pressure headache, unruptured intracranial aneurysm, and pituitary space-occupying lesion with signs of bleeding on MRI.
Primary headache was diagnosed in the four patients for whom a secondary cause of TCH was adequately ruled out. These diagnoses included primary headache associated with sexual activity (n = 2), primary TCH (n = 1), and primary cough headache (n = 1).
The median time from patient arrival to CT request was 68.0 minutes. The median time from CT request to CT was 66.0 minutes. Imaging was completed within an hour after request in 47.6% of patients and within an hour of patient arrival in 42.8% patients.
The time between patient arrival and lumbar puncture was 262.2 minutes, and the time between the first imaging and lumbar puncture was 83.5 minutes.
Despite the many potential causes of TCH, many clinicians believe that results of imaging and CSF analysis can rule them out, said García-Azorín.
A clear case of TCH is a "red flag" and requires more sophisticated imaging and further investigation, said García-Azorín.
"In these cases, imaging should be requested as urgently as we do in code stroke, and in the case of normal study, the craniocervical arterial and venous system should be directly evaluated in the same study. With this approach, many secondary causes could be detected, with a huge impact on the prognosis of many of them," he said.
Some patients were discharged before their studies were completed, so the frequency of secondary causes may be underrepresented in the current investigation, García-Azorín noted.
"To properly describe all the causes of thunderclap headache, increasing the sample size and combining our efforts with other international centers could give us better insights on the causes and potential consequences of this intriguing syndrome," he said.
Diagnosis Is Key
Commenting on the findings for Medscape Medical News, Stewart J. Tepper, MD, professor of neurology at the Geisel School of Medicine, Dartmouth College, Hanover, New Hampshire, said clinicians aren't taking TCH seriously enough.
The study reveals that EDs are not following through on the recommended workup for the management of TCH, said Tepper. He noted that the ICHD recommendations need to be followed "as quickly as possible" for optimal screening and care. "We cannot either defer workup or elect not to go through workup," he said.
Vascular imaging and MRI can reveal secondary causes of headache, so performing only CT and spinal tap is inadequate, he said. If results of all four of these tests are negative, vascular imaging should be repeated 1 month later to screen for RCVS.
"Getting the diagnosis is key. You need to know why somebody presents with a thunderclap. They need to have this study in every emergency room in the country, because the number of cases they had was quite high and...more than 50% were not adequately worked up," said Tepper.
The study's strengths, he added, include a clear statement of its objectives, the number of patients that the investigators considered for the study, and the assessment of the length of time it took for patients to undergo various tests, said Tepper.
The study's potential limitations include its retrospective design, that fact that it was a single-center study, and the small size of the final sample. A prospective study potentially could provide more meaningful results, Tepper noted.
"I think we have our work cut out for us," he added. "Headache providers and neurology providers who counsel emergency providers need to talk them through this, need to teach them, need to have them adopt this. We also have to teach the neurologists who consulted, because they didn't get it right all the time either," he concluded.
The study was conducted without outside funding. García-Azorín and Tepper have disclosed no relevant financial relationships.
Cephalalgia. Published online January 7, 2021. Abstract
Medscape Medical News © 2021
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Cite this: Thunderclap Headache Often Mismanaged in the ED - Medscape - Feb 04, 2021.