“Worst Headache of My Life”
Brain Aneurysm Rupture vs. Primary Benign Thunderclap Headache – Pituitary Apoplexy – Carotid/Vertebral Dissection
“Worst headache of my life” statement normally refers to a sudden, explosive, excruciating headache due to subarachnoid hemorrhage caused by a ruptured cerebral aneurysm. Massive subarachnoid bleeding carries a high risk of death or a significant disability due to stroke even with the most advanced management. On the other hand, more than half of sudden severe headaches are caused by a benign primary thunderclap headache, which is not associated with any complications.
- Subarachnoid Hemorrhage due to Brain Aneurysm Rupture
- Pituitary Apoplexy
- Carotid/Vertebral Dissection
- Primary Benign Thunderclap Headache
Symptoms of Subarachnoid Hemorrhage
A sudden, explosive, excruciating headache reaching maximum within a minute is a trademark of subarachnoid hemorrhage. After initial violent presentation the headache may persist, followed by confusion, vomiting, stiff neck, seizures, coma, or even death. Consequences depend on the amount of the blood leaked from the ruptured aneurysm. In milder cases, the headache may subside by itself or it may respond to pain medications or triptans. Subarachnoid hemorrhage is a true emergency. Missing the diagnosis often translates into a death verdict.
In half of the cases of subarachnoid hemorrhage the headache lacks a thunderclap quality, which complicates diagnostic process a lot.
Statistically, more than half of thunderclap headaches are caused by a benign primary thunderclap headache (see below). This complicates all this even further.
On one hand, you can’t be too paranoid, on the other, missing the diagnosis of subarachnoid hemorrhage is inexcusable!
Causes of Subarachnoid Hemorrhage
The most common cause of a spontaneous (non-traumatic) subarachnoid hemorrhage is a rupture of a brain aneurysm. A brain aneurysm rarely produces any symptoms prior to its rupture and is commonly detected by accident. Close family member history of cerebral aneurysms doubles the chance of having it in the other family members. Some disorders, such as Marfan syndrome and polycystic kidney, smoking and high blood pressure increase the risk of having aneurysms.
What Is an Aneurysm?
Ballooning of a vessel wall is called an aneurysm. Blood vessels may form a great variety of aneurysms. Not all of them carry a high risk of hemorrhage. So called berry-aneurysms are the most dangerous. They form in the site of blood vessel branching. The shared part of the wall between the branches is subjected that most of the blood pressure impact and starts bulging. The bulge becomes larger and larger. Eventually, the wall becomes thin enough to give way and the blood rushes through the opening. It takes years for an aneurysms to reach a dangerous size. Even though it strongly depends on the location, general rule is that the brain berry aneurysms tend to rupture after they surpass the size of 5 to 6 millimeters in diameter.
Aneurysm Rupture Triggers
A common misperception is that subarachnoid hemorrhage occurs mostly during strenuous physical activity. In reality, almost half of the aneurysms rupture cases occur during a non-strenuous activity or even in sleep. Ten percent of orgasmic headaches are caused by subarachnoid hemorrhage. Exertional headache may mimic subarachnoid hemorrhage as well.
Having said that aneurysms are just some time bombs, which reveal themselves only at the time of the “explosion”, they do give some clues about their existence from time-to-time. Besides occasional cranial nerves palsies caused by large aneurysms, they might leak a little blood and cause a sudden bad headache without consequences. These headaches are called sentinel headaches.
Twenty to 50 percent of patients have sentinel headaches from days to weeks prior to the major subarachnoid hemorrhage. Sentinel headache feels like a typical thunderclap headache and is caused by a small leak of the blood, which is not sufficient to cause any complications. Sentinel headache can be a life saver for some patients if it’s paid attention to. Sentinel headache raises a red flag of danger allowing aneurysm diagnosis prior to the clinically significant bleeding.
Complications of an Aneurysm Rupture
Subarachnoid hemorrhage has delayed complications. Brain tissue is enclosed in the cavity inside the skull which has no ability to expand. Extra blood volume in the subarachnoid space increases the total intracranial volume leading to the rise of intracranial pressure. Rising intracranial pressure prevents blood from reaching the brain tissue, circulation stops and the brain is choked to death. Subarachnoid space is filled with constantly circulating cerebrospinal fluid. Blood will clog the pathways and prevents the fluid from normal circulation and absorption. This mechanism also causes intracranial volume expansion with grave consequences.
Surviving patients may develop strokes a few days later. Blood products in the sub-arachnoid space lead to inflammation in the walls of the brain arteries. This inflammation leads to the blood vessel spasm at the base of the brain. Blood supply shortage results in massive strokes.
Cerebral Aneurysm and Subarachnoid Hemorrhage Diagnosis
Suspected subarachnoid hemorrhage is a medical emergency. It requires an immediate hospitalization, a CAT Scan of the head, and a spinal tap as soon as possible if the CAT scan is unrevealing. Once subarachnoid hemorrhage is confirmed, further testing is required in order to find the source of the hemorrhage. Typical work up is a Brain MRI and MRA, CT Angiography or a Conventional Angiography.
In about 15% to 20% of spontaneous sub-arachnoid hemorrhages no aneurysm is found. Those cases usually carry a better prognosis. SAH may be caused by AVMs. Arteriovenous malformations usually leak less blood in the sub-arachnoid space and have better prognosis for this reason.
Treatment is directed to the stroke prevention caused by vasospasm, maintaining an adequate brain circulation and control of the intracranial pressure. Aneurysms are either surgically clipped or plugged utilizing minimally invasive endovascular procedures. Treatment options for a ruptured brain aneurysm is beyond the scope of this web site.
Pituitary apoplexy is a hemorrhage into the pituitary gland (usually caused by a tumor). The thunderclap type of headache is common in pituitary apoplexy. The expanding hematoma damages the optic nerves causing the loss of eyesight. It may compromise nerve supply to the eyeball muscles, which will lead to double vision.
The pituitary controls the whole endocrine system of the body. It is situated in a bone pocket (sella turcica) like in a cage. Pressure from the rushing blood can destroy the gland. Sudden loss of pituitary function may lead to cardiovascular collapse, coma and even death. However, most of the pituitary hemorrhages are not so dramatic.
A typical diagnostic work up for pituitary disease is as follows: Brain MRI with attention to pituitary with a contrast, Brain CT (if MRI is unavailable or contraindicated), and blood work for multiple hormone levels.
Pituitary apoplexy treatment is mostly hormone replacement.
Dissection of the carotid or vertebral arteries in the neck may produce a sudden severe pain on the same side of the neck or in the head in 20%. The rest will have a gradual headache onset. The pain is usually steady and often throbbing. Ninety percent of patients with carotid dissection and 70% with vertebral dissection will have a headache. Neck pain affects 50% of patients with vertebral artery and 25% of patients with carotid artery dissection. The vast majority of carotid dissection associated headaches resolve within a few days, while vertebral dissection headaches might last for a few weeks.
Neck and head injuries or sudden neck movements are often blamed for dissection syndromes but the association is rather anecdotal.
A stroke can develop either immediately or in up to two weeks later. Neck arteries dissection is one of the most common causes of stroke in young adults. Dissection of the carotid artery may also cause multiple cranial nerve palsies and Horner syndrome. Diagnosis of dissection syndrome is often missed.
The following mechanism is believed to be responsible for the blood vessel dissection: a small tear in the innermost layer of the artery fills with the blood stripping off the layer. The expanding “pocket” restricts the normal blood flow. Arterial dissection may cause a stroke by either obstruction of the blood flow or by shooting blood clots (emboli) formed in the pocket.
The diagnostic workup in a suspected dissection syndrome is as follows:
Neck MRA, Conventional Angiography, Carotid duplex, Transcranial Doppler with embolus monitoring, Brain MRI or CT/CTA if MRI is contraindicated.
It is often impractical to see the dissection itself on any type of angiography or an ultrasound. Blood degradation products are seen the best on a soft tissue MRI protocol, especially if the blood has accumulated outside the vessel wall and caused no flow obstruction.
An anticoagulation with Heparin in acute setting followed but Coumadin or an antiplatelet treatment with Plavix, Aspirin, or Aggrenox for a few months are is a typical secondary stroke preventive approach. It is expected that once the vessel wall is restructured, regenerated, or recanalized, there is no risk of stroke any longer. There are no controlled studies favoring any particular treatment approach.
Primary thunderclap headache is a sudden severe headache that reaches its maximum intensity within 1 minute. The pain usually lasts for several hours with milder pain continuing through the next couple of weeks.
Primary thunderclap headache does not have tendency to recur in majority of patients. The attack may be brought by exertion or sexual activity in one third of the patients. Some patients have nausea and vomiting. In this case it is often called a “crash migraine”. Primary thunderclap headache is a benign condition with no known complications.
I intentionally put both headache types in the same web site section because it is simply impossible to differentiate them clinically with a high level of certainty.
The current approach to this type of headache is as follows:
It is a subarachnoid hemorrhage unless proven otherwise. Only after all the diagnostic testing is negative, the “worst headache of my life” is allowed to be called as “benign”.
Some patients experience dramatic and frightening associated symptoms along with the pain syndrome. There might be a temporary confusion, weakness or numbness, loss of coordination, seizures or speech problems. Surprisingly, all those symptoms are transient and resolve without any repercussions.
Thunderclap headache associated with above mentioned symptoms is called a “reversible cerebral vasoconstriction syndrome. Blood vessels of the Circle of Willis constrict during the attack, which may be seen on the brain angiography. Unlike the stroke, there is a complete recovery after the attack is over. There is no permanent damage to the brain. The cause of benign idiopathic thunderclap headache remains unknown.
Diagnostic testing is identical to the described in the subarachnoid hemorrhage section of this page.
No treatment is needed since primary thunderclap headaches almost never recur.
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Disclosure: This Web Site is intended for education purpose only. The information provided on this site must not be perceived as a guide for self-diagnosis or self-treatment. Every effort is made to keep the information current, but there are absolutely no guarantees of timely updates. By Andre Strizhak