What is Primary Thunderclap Headache? 2023

Primary thunderclap headache is a new name for sudden onset severe headache.  Primary means it has no certain medical cause.  High blood pressure is also called “Primary hypertension.”  Tension Type Headache and Migraine are the two giant types of “Primary Headache.”

If you have ever been in a rainstorm and suddenly startled by a close, high volume shock of thunder, you know that is called a “Thunderclap.”  We jump and sort of want to get away from it.  Then, we realize it is just thunder, and we relax.

Imagine a headache that comes on suddenly like that—out of the blue and for no reason-a horrible spike of knock you to your knees type severe, onset to peak, headache.  Isn’t it appropriate to call it “Thunderclap headache?”  And if later it is worked up by doctors and tests and nothing is found to be wrong, we could call it “primary thunderclap headache.”

This is an article by Britt Talley Daniel MD, member of the American Academy of Neurology, migraine textbook author, podcaster, YouTube video producer, and blogger.

Thunderclap headache is a severe, sudden onset headache that takes seconds to minutes to reach maximum intensity. About 75% of headaches like this are benign and called " primary headache” or “idiopathic thunderclap headache.”  The remaining 25% of headaches in this group are secondary to other causes, which can be dangerous neurologic conditions that require intensive work-up with brain scanning, spinal fluid exam, and cerebral arteriography.

Further defining statement.

The International Classification of Headache Disorders V3 states that Primary Thunderclap Headache is:

A. High-intensity headache, which is of abrupt onset, mimicking that of ruptured cerebral aneurysm, but occurs in the absence of any intracranial pathology.

B. This abrupt onset headache reaches maximum intensity in less than 1 minute.

C.  The headache lasts for 5 minutes or less.

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Related Questions

What are the Signs and Symptoms?

Thunderclap headache strikes suddenly and severely, peaks within 60 seconds, and can be accompanied by nausea or vomiting.

Other signs and symptoms that may occur are: An altered mental state, Fever, Seizures.

The authors of ICDH3 comment that:  Evidence that thunderclap headache exists as a primary disorder is poor; the search for an underlying cause should be expedited and exhaustive.

Pathophysiology

The most important of the secondary causes are subarachnoid hemorrhage, cerebral venous sinus thrombosis, and dissection of an artery in the neck.

In subarachnoid hemorrhage, there may be syncope (transient loss of consciousness), seizures, meningism (neck pain and stiffness), visual symptoms, and vomiting.  50–70% of people with subarachnoid hemorrhage have an isolated headache without decreased level of consciousness. The headache typically persists for several days.

Cerebral venous sinus thrombosis, thrombosis of the veins of the brain, usually causes a headache that reflects raised intracranial pressure and is therefore made worse by anything that makes the pressure rise further, such as coughing.

In 2–10% of cases, the headache is of thunderclap character.  In most cases there are other neurological abnormalities, such as seizures and weakness of part of the body, but in 15–30% the headache is the only abnormality.

Carotid artery dissection and vertebral artery dissection (together cervical artery dissection), in which a tear forms inside the wall of the blood vessels that supply the brain, often causes pain on the affected side of the head or neck.

The pain usually precedes other problems that are caused by impaired blood flow through the artery into the brain; these may include visual symptoms, weakness of part of the body, and other abnormalities depending on the vessel affected.

Epidemiology

Incidence of thunderclap headache has been estimated at 43 per 100,000 people every year. Approximately 75% are attributed to "primary" headaches: headache disorder, non-specific headache, idiopathic thunderclap headache or uncertain headache disorder. The remainder is attributed to secondary causes: vascular problems, infections, and various other conditions.

History of severe headache

The importance of severe headaches in the diagnosis of subarachnoid hemorrhage has been known since the 1920s, when London neurologist Charles Symonds described the clinical syndrome.

The term "thunderclap headache" was introduced in 1986 in a report by John Day and Neil Raskin, neurologists at the University of California, San Francisco, in a report of a 42-year-old woman who had experienced several sudden headaches and was found to have an aneurysm that had not ruptured.

Thunderclap headaches live up to their name, striking suddenly like a clap of thunder.  The pain of these severe headaches peaks within 60 seconds.

Thunderclap headaches are uncommon, but they warn of potentially life-threatening conditions which usually have to do with bleeding in and around the brain.

What is the Cause of Thunderclap headache?

Thunderclap headache most commonly is associated with subarachnoid haemorrhage or reversible cerebral vasoconstriction syndrome.

If all the neurologic tests are normal, what is the cause of this severe type of headache?  The cause of primary thunderclap headache is largely unknown.  It may be related to a spasm of the blood vessels in the brain or some abnormality of the sympathetic nervous system.  Many cases relate to migraine.

Read my article, “What is Migraine?” on my website, www.doctormigraine.com.

Other causes may be:

Subarachnoid hemorrhage (10–25% of all cases of thunderclap headache)

Cerebral venous sinus thrombosis

Cervical artery dissection

Hypertensive emergency (severely raised blood pressure)

Spontaneous intracranial hypotension (unexplained low cerebrospinal fluid pressure)

Stroke (headache occurs in about 25% of strokes but usually not thunderclap character)

Retroclival hematoma (hematoma behind the clivus in the skull, usually due to physical trauma but sometimes spontaneous)

Pituitary apoplexy (infarction or hemorrhage of the pituitary gland)

Colloid cyst of the third ventricle

Meningitis, sinusitis

Reversible cerebral vasoconstriction syndrome

Primary cough headache

primary exertional headache

and primary sexual headache

Read my article, “Primary Headache Associated with Sexual Activity” on my website, www.doctormigraine.com.

Thunderclap Headache does not recur, it is usually a one-time event.  Some persons present with thunderclap headache but later develop primary cough headache, primary exertional headache, or primary sexual headache.

Neurologic work-up

The most important initial investigation is computed tomography of the brain, which is sensitive for subarachnoid hemorrhage.  If this is normal, a lumbar puncture is performed, as a small proportion of SAH is missed on CT and can still be detected as xanthochromia.[1][2]

If both investigations are normal, the specific description of the headache and the presence of other abnormalities may prompt further tests, usually involving magnetic resonance imaging (MRI).  Magnetic resonance angiography (MRA) may be useful in identifying problems with the arteries (such as dissection), and magnetic resonance venography (MRV) identifies venous thrombosis.

It is not usually necessary to proceed to cerebral angiography, a more precise but invasive investigation of the brain's blood vessels, if MRA and MRV are normal.

Primary thunderclap headache should be a diagnosis of last resort, reached only when all organic causes have been demonstrably excluded.  This means the patient has normal brain imaging, such as a brain CT scan and/or brain magnetic resonance imaging (MRI).  Spinal tap should reveal normal CSF.

Treatment

Treatment of such headaches depends on the actual cause, revealed by neurologic work-up.  If the headache is related to subarachnoid hemorrhage the patient would need neurological and/or neurosurgical intervention.

If medical emergencies have been ruled out, treatment is difficult. Persons with Thunderclap Headache generally do not respond well to typical headache pain relievers.

However, the short duration of headache as defined as 5 or less minutes means it does not last long.

Literature review

Linn and Wijdicks writing in 2002 in Neurologist on “Causes and Management of Thunderclap Headache: A Comprehensive Review” found a serious cause in one third of patients in a primary care setting and in two thirds of patients in a hospital setting.  Linn and Wijdicks stated:

Clues in history and physical examination can point to a possible serious underlying cause of thunderclap headache, such as subarachnoid hemorrhage, intracranial hematoma, or cerebral venous thrombosis.

The remaining patients with thunderclap headache, however, have a primary headache disorder, such as migraine or (less frequently) tension headache with an unusual sudden onset, exertional headache, coital headache, cough headache, or cluster headache.

Linn, FH wrote in Handb Clin Neurol. 2010;97:473-81. on “Primary thunderclap headache.  The abstract of this article follows:

Thunderclap headache is an uncommon type of headache, but recognition and diagnosis are important because of the possibility of a serious underlying brain disorder.  In this chapter, primary thunderclap headache in relation to other primary headache disorders and secondary, symptomatic headache disorders are discussed.

Most importantly, subarachnoid hemorrhage should be excluded  . The first investigation is a computed tomography (CT) scan, and, if the CT scan is negative, investigation of the cerebrospinal fluid.

Other symptomatic vascular causes are intracranial hemorrhage, cerebral venous sinus thrombosis, cervical artery dissection, or a reversible vasoconstriction syndrome.  These and other serious underlying intracranial disorders should be detected by magnetic resonance imaging or the appropriate investigations.

The remaining patients with thunderclap headache most likely represent a primary headache disorder, including migraine, primary cough headache, primary exertional headache, or primary headache associated with sexual activity.

Within the group of primary headache disorders, primary thunderclap headache represents a distinct clinical entity; it is characterized by a sudden severe headache lasting from 1h up to 10 days and not attributed to another disorder.  The pathogenesis of primary thunderclap headache is still not known, but the sympathetic nervous system may play an important role.

Schwedt, TJ, Matharu MS, Dodick,DW wrote in Lancet Neurol. 2006 Jul;5(7):621-31 on “Thunderclap headache.”  The abstract of this article states:

Thunderclap headache (TCH) is head pain that begins suddenly and is severe at onset.  TCH might be the first sign of subarachnoid haemorrhage, unruptured intracranial aneurysm, cerebral venous sinus thrombosis, cervical artery dissection, acute hypertensive crisis, spontaneous intracranial hypotension, ischaemic stroke, retroclival haematoma, pituitary apoplexy, third ventricle colloid cyst, and intracranial infection.

Primary thunderclap headache is diagnosed when no underlying cause is discovered.  Patients with TCH who have evidence of reversible, segmental, cerebral vasoconstriction of circle of Willis arteries and normal or near-normal results on cerebrospinal fluid assessment are thought to have reversible cerebral vasoconstriction syndrome.

Herein, we discuss the differential diagnosis of TCH, diagnostic criteria for the primary disorder, and proper assessment of patients. We also offer pathophysiological considerations for primary TCH.

Yang CW and Fuh JL, wrote in Expert Rev Neurother. 2018 Dec;18(12):915-924 on “Thunderclap headache: an update.”  Their abstract follows.

Thunderclap headache (TCH) is an excruciating headache that reaches maximal intensity within a minute.  It has numerous potential etiologies, the most concerning of which is subarachnoid hemorrhage (SAH) due to high morbidity and mortality.

Thus, patients with TCH must be evaluated urgently to identify the underlying cause and initiate prompt therapy. Areas covered:  This paper reviews PubMed-listed research articles and presents an update of the clinical features, diagnostic evaluation, and possible causes of TCH.

Expert commentary: In addition to SAH, TCH has been associated with reversible cerebral vasoconstriction syndrome (RCVS), cervical artery dissection, cerebral venous sinus thrombosis, cerebral infarction, intracerebral hemorrhage, spontaneous intracranial hypotension, intracranial infection, and pituitary apoplexy.

Of note, with advances in knowledge in the past decade, RCVS has become an important cause of TCH, being diagnosed more frequently.  Brain computed tomography (CT) should be performed in all patients with TCH, and lumbar puncture is indicated if the brain CT is nondiagnostic.

Generally, a negative brain CT and lumbar puncture can eliminate SAH diagnosis, in which case brain magnetic resonance imaging and vascular imaging should be performed to evaluate other possible underlying causes.

Schwedt TJ. Wrote in Continuum (Minneap Minn). 2015 Aug;21(4 Headache):1058-71 on “Thunderclap Headache.”

Abstract

PURPOSE OF REVIEW:

A thunderclap headache is a very severe headache that reaches its maximum intensity within 1 minute.  Patients with thunderclap headache must be evaluated emergently and comprehensively to rule out underlying disorders that can be associated with high mortality and morbidity, determine the cause for the thunderclap headache, and initiate targeted therapy.

This review presents an up-to-date summary on the clinical presentation, diagnostic evaluation, and causes of thunderclap headache.

RECENT FINDINGS:

Numerous etiologies for thunderclap headaches have been identified, with the most common causes being subarachnoid hemorrhage and reversible cerebral vasoconstriction syndrome.

Other relatively common causes include cervical artery dissection, cerebral venous sinus thrombosis, and spontaneous intracranial hypotension. Although "primary" thunderclap headache is typically accepted to exist, it may be that such cases represent missed diagnoses of underlying causes.

The urgent evaluation of the patient with thunderclap headache includes brain CT, followed by lumbar puncture if the brain CT is nondiagnostic.  If a diagnosis is not reached following brain CT and lumbar puncture, brain MRI and imaging of the brain and cervical vasculature are indicated.

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SUMMARY:

Patients with thunderclap headache require an emergent and comprehensive evaluation to identify the underlying cause and to initiate appropriate therapy.

Dilli E wrote in Curr Neurol Neurosci Rep. 2014 Apr;14(4):437 on “Thunderclap headache.”  The abstract states:

Thunderclap headache (TCH) is a sudden severe headache that peaks to maximum intensity within 1 minute.  Subarachnoid hemorrhage is the most commonly identified etiology for the headache; however, other secondary etiologies should be considered.

Sentinel headache, reversible cerebral vasoconstriction syndrome, arterial dissection, cerebral venous sinus thrombosis, pituitary apoplexy, intracranial hemorrhage, ischemic stroke, reversible posterior leukoencephalopathy, spontaneous intracranial hypotension, colloid cyst, and intracranial infections are other possible causes of TCH.

Investigations for the etiology of TCH begin with non-contrast CT head and lumbar puncture.  MR brain, CT angiogram, MR angiogram, or CT/MR venogram may need to be performed if the initial investigations are negative. Treatment and prognosis depend on the etiology of the TCH.

Thunderclap headache is a headache that is severe and sudden onset.  It is defined as a severe headache that takes seconds to minutes to reach maximum intensity.  Although approximately 75% are attributed to "primary" headaches—headache disorder, non-specific headache, idiopathic thunderclap headache, or uncertain headache disorder—the remainder are secondary to other causes, which can include some extremely dangerous acute conditions, as well as infections and various other conditions.  Usually, further investigations are performed to identify the underlying cause.

Bottom line-Thunderclap headache is usually benign, but should always be evaluated with neurologic testing for the first occurrence

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All the best.

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Britt Talley Daniel MD