One of the most treacherous problems a busy emergency room physician faces is headache.  “Headache” is a very common symptom, different from focal head pains attributable to sinus, eye or ear problems. While very painful and sometimes associated with nausea and vomiting,  the vast majority of headaches, even if frequent and debilitating, are benign.  They do not signify underlying illnesses or impending danger.   But the emergency physician cannot afford to be wrong about the rare headache that predicts oncoming catastrophe and provides a chance to intervene.

Two broad categories

Catastrophic headaches fall into two broad categories. The first category includes “space-occupying lesions” such as tumors, hemorrhages, abscesses, and hydrocephalus (known commonly as “water on the brain”).  The second category involves infectious and autoimmune problems that produce inflammation, triggering pain receptors in the membranes surrounding the brain and its blood vessels. Catastrophes avoided by successful interventions in both categories include death, permanent brain damage and blindness.  

Tumors and abscesses

The most common fear about a bad headache is that it is caused by a brain tumor, but tumors usually produce other symptoms, involving speech, thinking, coordination or vision before they produce headache. Since the brain tissue itself has no pain receptors, tumors cause headache when they distort surrounding membranes or blood vessels, which have pain receptors. Tumor-related headaches worsen with positions and activities that normally cause the pressure in the veins in the head to rise – coughing, sneezing, lying down, straining at a bowel movement or lifting something heavy. As tumor size and pressure increase, nausea and vomiting appear. Occasionally, brain abscesses – pockets of infection surrounded by capsules -may mimic tumors. They usually come from blood infections seeding bacterial or fungal organisms into the brain.

Hemorrhages in the brain

Brain hemorrhages occupy space and increase pressure in the head.  Deep small blood vessels, damaged by high blood pressure or arteriosclerosis, are usually the culprits. While these intracerebral hemorrhages can cause sudden headache, stroke-like symptoms such as paralysis, confusion, trouble speaking and loss of consciousness occur first or soon after the onset of headache.

Hemorrhages outside the brain, but inside the head

Headaches are also a symptom of epidural and subdural hematomas – collections of blood that accumulate over the surface of the brain hours to weeks after some closed head injuries (meaning no skull fracture). The history of injury, even seemingly trivial injury in an elderly patient,  is crucial to correct evaluation of these headaches and there may be no other accompanying neurological symptoms. A head blow in the temple, where the skull is the thinnest is a common history. Young children and older adults are more susceptible to epidural hematomas (located between the inner skull and the the dural membrane over the brain) than those in between those age groups. Both epidural and subdural (between the dural membrane and the surface of the brain) collections of blood usually require surgical removal, sometimes as an emergency if symptoms such as change in level consciousness appear. Actor Liam Neeson’s wife Natasha Richardson did not survive an epidural hematoma incurred in a skiing related fall in 2009.

The “sentinel headache” of the aneurysm

Bleeding from brain aneurysms – weak spots at branch points of arteries – can be immediately catastrophic, even causing sudden death. But a tiny, warning leak before an aneurysm actually ruptures may cause a “sentinel headache” which allows time for life-saving surgical repair to prevent the oncoming, big rupture which typically occurs sometime in the next 10 days.  A sentinel headache is sudden and severe pain involving all or part of the head, It is sometimes described like a “thunderclap.”  As the little warning squirt of blood dissipates in the spinal fluid around the base of the brain, the headache dulls but a peculiar, longer-lasting pain may appear in the middle of the upper back, usually worsened with movement and probably indicating irritation from blood in the spinal fluid around the spinal cord. Diagnosis involves brain imaging with dye to study the arteries, and possibly a spinal tap to make certain bleeding has occurred. Unruptured cerebral artery aneurysms are found incidentally in 2% of autopsies so the problem is not rare.

Hydrocephalus

Hydrocephalus is a rare cause of headache, but one that should never be overlooked. The rise in pressure in the head comes from spinal fluid being trapped in the ventricles, hollow structures in the center of the brain where spinal fluid is made. Normally the spinal fluid circulates out of the ventricles via a very small channel, and bathes the surface of the brain and spinal cord before being absorbed into special veins at the top of the head. If flow is blocked, the ventricles begin to enlarge putting pressure on the surrounding brain. Most times, the onset of hydrocephalus is gradual, with headache, nausea, vomiting and balance problems gradually increasing. Unrecognized and untreated, obstructed spinal fluid flow leads to lethargy, coma and death, within 24 hours if the obstruction is sudden. Causes of obstruction include congenital anatomical abnormalities, tumors blocking the ventricular outflow tracts, scarring of these passages by inflammation from past meningitis or bleeding. Hydrocephalus most often requires surgical intervention to either remove the obstruction or to place a shunt around it, allowing cerebrospinal fluid to escape from the ventricles.

Headache from infection

Headache producing infections mainly involve the meninges, the membranes covering the brain and the spinal cord and are caused by viruses, bacteria or fungi. Viral and bacterial meningitis both cause severe headache, neck pain and rigidity and photophobia – inability to tolerate bright light. Movements of head and trunk and even eye movements are painful. Someone suffering from bacterial meningitis has a high fever, looks extremely ill and deteriorates rapidly. Identification of the infection type requires spinal fluid, obtained via spinal tap – insertion of a large needle into the spinal canal in the low back.  Antibiotics are lifesaving. Viral meningitis, though painful, is less dramatic, and gets better on its own. Fungal meningitis is rare and much slower and less dramatic in its presentation than bacterial meningitis. It most often occurs in people who have impaired immune systems and requires prolonged treatment with antifungal drugs.

Non-infectious inflammatory headache: temporal arteritis

Headache from a non-infectious inflammatory condition called temporal arteritis usually presents itself in the seventh or eighth decade of life as a constant, often one-sided pain. Other symptoms that provide clues to this diagnosis are pain in the jaw muscle, especially with chewing, and tenderness of the artery just under the skin of the temple – the origin of the name for auto-immune inflammation that affects the arteries that supply the skull and brain with blood and can cause blindness and strokes. Diagnosis is confirmed when a blood test called ESR (erythrocyte sedimentation rate) is elevated and a temporal artery biopsy shows characteristic inflammatory cells in the artery wall. Treatment with steroids like prednisone, undertaken soon enough, prevents blindness and takes the headache away, but must be continued for many months.

A very useful question

One of the most useful questions an emergency room physician, or any other professional evaluating a headache complaint can ask the patient is “How worried are you about this headache?” People know themselves and have an innate sense about the nature of their symptoms. They will very often know the difference between a catastrophic headache and all the others.