Understanding Thunderclap Headache: A Case Study of Sudden Severe Headache and Its Causes

Table of Contents

• Case Presentation: The Worst Headache of Her Life
• Initial Examination and Test Results
• Imaging Findings
• Differential Diagnosis: What Could Cause This?
• Understanding Thunderclap Headache
• Common Causes of Thunderclap Headache
• Uncommon and Rare Causes
• Final Diagnosis and Explanation
• What This Means for Patients
• Limitations of This Case Study
• Patient Recommendations
• Source Information

Case Presentation: The Worst Headache of Her Life

A 64-year-old woman was evaluated in the emergency department after experiencing a sudden, severe headache that she described as "the worst headache of her life." The symptoms began when she stood up to speak at a condominium association meeting.

The headache developed suddenly with bilateral, frontal, pulsating pain that reached maximal intensity within seconds. The patient rated the pain as 10 out of 10 on the pain scale. The pain was so severe that she couldn't complete her sentence and felt like she might faint.

She experienced nausea without vomiting. When her symptoms didn't improve after 30 minutes, emergency medical services were called, and she was transported to the hospital for evaluation. She repeatedly told her husband, "Something is really wrong," indicating she knew this was different from any previous headache.

Initial Examination and Test Results

The patient's medical history included hypertension and cervical disk disease with chronic neck pain. Her medications included hydrochlorothiazide (a blood pressure medication) and oral conjugated estrogens taken every 3 days for menopause symptoms.

On examination, her vital signs showed:

• Temperature: 36.3°C (normal)
• Blood pressure: 157/77 mm Hg (elevated)
• Heart rate: 77 beats per minute (normal)
• Respiratory rate: 16 breaths per minute (normal)
• Oxygen saturation: 96% on room air (normal)

Neurological examination was normal, including normal speech, cranial nerve function, visual fields, motor strength, sensation, reflexes, and cerebellar function. Blood tests including glucose, electrolytes, complete blood count, kidney function, and coagulation studies were all normal.

Additional test results showed:

• Erythrocyte sedimentation rate: 8 mm per hour (normal range: 0-20)
• C-reactive protein: 2.7 mg per liter (normal: <8.0)
• Troponin T: 0.36 ng per milliliter (elevated, normal: <0.03)

Electrocardiogram showed sinus rhythm with first-degree atrioventricular block and diffuse submillimeter ST-segment depressions.

Imaging Findings

Computed tomography (CT) scan of the head performed without contrast two hours after headache onset revealed subarachnoid hemorrhage along the left superior parietal lobule and paramedian parietal sulci. This pattern is known as convexal subarachnoid hemorrhage, where bleeding occurs over the surface of the brain rather than around the base where it typically occurs with aneurysmal bleeding.

CT angiography of the head performed with contrast showed subtle diffuse segmental narrowing of multiple distal arterial branches of the intracranial vessels. There was no evidence of aneurysm or other vascular abnormalities that would explain the bleeding.

Differential Diagnosis: What Could Cause This?

The medical team considered multiple possible causes for this presentation, focusing on three key elements: the thunderclap headache, the convexal subarachnoid hemorrhage, and the elevated troponin level.

Thunderclap headache refers to a severe headache that reaches peak intensity within minutes. The International Headache Society defines it as headache that is severe in intensity, abrupt in onset (peaking in less than 1 minute), lasts at least 5 minutes, and isn't explained by another diagnosis. However, research shows that approximately 15% of patients with aneurysmal subarachnoid hemorrhage describe headache that peaked after 1 minute, and some up to 60 minutes later.

Understanding Thunderclap Headache

Thunderclap headache represents a medical emergency that requires immediate evaluation. Approximately 2% of all emergency department visits involve evaluation of headache, and 15% of those visits involve evaluation of thunderclap headache.

It's crucial that patients with thunderclap headache undergo immediate and thorough evaluation for underlying causes. The pain relief this patient experienced after treatment with intravenous morphine and promethazine doesn't eliminate the need to identify the underlying cause, as successful pain control shouldn't preclude evaluation for serious conditions.

Common Causes of Thunderclap Headache

The medical team considered these common causes:

Aneurysmal Subarachnoid Hemorrhage: This is the most important "cannot miss" diagnosis because effective treatment exists and outcomes are worse without timely treatment. However, this typically causes bleeding around the base of the brain rather than on the surface. In patients with thunderclap headache and normal neurological examination, 5-7% have aneurysmal subarachnoid hemorrhage.

Reversible Cerebral Vasoconstriction Syndrome (RCVS): This condition involves fluctuating and reversible narrowing of intracranial arteries and occurs more commonly in women. Approximately 8% of patients presenting to the emergency department with thunderclap headache have RCVS. About 35% of patients with RCVS have convexal subarachnoid hemorrhage.

RCVS is often triggered by emotional, physical, medical, or pharmacologic factors. Patients typically experience multiple thunderclap headaches over days to weeks, though every case must begin with a first headache.

Uncommon and Rare Causes

The team also considered these less common possibilities:

Cerebral Venous Sinus Thrombosis (CVST): Thunderclap headache is a presenting symptom in 15% of patients with CVST, which could also cause convexal subarachnoid hemorrhage. The patient's use of conjugated estrogens is a risk factor for CVST.

Arterial Dissection: An uncommon cause of thunderclap headache that can cause convexal subarachnoid hemorrhage. However, this is reported primarily in postpartum women and those with dissection causing ischemic stroke, neither of which fit this patient's presentation.

Posterior Reversible Encephalopathy Syndrome (PRES): Another uncommon cause that can cause convexal subarachnoid hemorrhage, but headache in PRES usually develops gradually rather than abruptly.

Other rare causes considered and ruled out included meningitis/encephalitis, symptomatic unruptured aneurysm, colloid cyst, retroclival hematoma, giant-cell arteritis, transient global amnesia, painless aortic dissection, and acute myocardial infarction.

Final Diagnosis and Explanation

The final diagnosis was reversible cerebral vasoconstriction syndrome (RCVS) with takotsubo cardiomyopathy.

RCVS explained both the thunderclap headache and the convexal subarachnoid hemorrhage. The emotional stress of public speaking likely triggered sympathetic hyperactivity and vasoconstriction. The condition is called "reversible" because the blood vessel narrowing typically resolves within 1-3 months.

The elevated troponin level (0.36 ng/mL, significantly above the normal <0.03 ng/mL) was explained by takotsubo cardiomyopathy, also known as stress-induced cardiomyopathy. This condition has been associated with RCVS, suggesting that vasoconstriction in RCVS may not be limited to cerebral arteries.

This patient fit the typical profile for takotsubo cardiomyopathy: in an international registry of 1,750 patients, 90% were women with a mean age of 67 years. The condition involves temporary weakening of the heart muscle, often triggered by emotional stress.

What This Means for Patients

This case illustrates several important points for patients:

First, any sudden, severe headache that patients describe as "the worst headache of my life" requires immediate medical attention. This is particularly true when the headache is different from previous headaches or reaches maximal intensity within minutes.

Second, emotional stress can trigger serious medical conditions beyond anxiety. The stress of public speaking in this case likely triggered both the cerebral vasoconstriction and the heart muscle weakness.

Third, normal initial test results don't always rule out serious conditions. This patient had normal neurological examination and most blood tests, yet had significant bleeding on her brain surface and heart involvement.

Fourth, postmenopausal women taking estrogen should be aware of potential cardiovascular and cerebrovascular risks, though the relationship is complex and requires individual discussion with healthcare providers.

Limitations of This Case Study

This case report describes a single patient's experience, which means the findings cannot be generalized to all patients with similar symptoms. The diagnosis was based on clinical presentation and imaging findings rather than pathological confirmation.

The patient was followed during her acute presentation, but long-term outcomes aren't described in this report. RCVS typically resolves within weeks to months, but some patients may experience persistent symptoms or complications.

The connection between RCVS and takotsubo cardiomyopathy, while plausible based on similar triggers and pathophysiology, represents an association rather than a proven causal relationship in this individual case.

Patient Recommendations

Based on this case, patients should:

1. Seek immediate medical attention for any sudden, severe headache unlike previous headaches
2. Describe symptoms accurately to medical providers, including timing, intensity, and triggering events
3. Continue prescribed medications unless instructed otherwise by a healthcare provider, even if a potential side effect is suspected
4. Follow up appropriately after emergency department visits for serious symptoms
5. Discuss hormone therapy risks and benefits with their healthcare provider, particularly if they have other cardiovascular risk factors
6. Manage stress effectively through healthy coping mechanisms, recognizing that severe emotional stress can have physical health consequences

Patients should also understand that while pain relief is important, it doesn't eliminate the need to identify the underlying cause of severe symptoms. Comprehensive evaluation should proceed alongside symptomatic treatment.

Source Information

Original Article Title: Case 18-2024: A 64-Year-Old Woman with the Worst Headache of Her Life

Authors: Jonathan A. Edlow, M.D., Aneesh B. Singhal, M.D., and Javier M. Romero, M.D.

Publication: The New England Journal of Medicine, June 13, 2024

DOI: 10.1056/NEJMcpc2402484

This patient-friendly article is based on peer-reviewed research from The New England Journal of Medicine. It maintains all significant medical information from the original case study while making it accessible to educated patients.