When a headache is a pain! About primary and secondary headaches
Nitin K. Sethi, MD
Assistant Professor of Neurology
New York-Presbyterian Hospital
Weill Cornell Medical Center
New York, NY 10065
Headaches are a very common reason that patients consult a neurologist like me. The intensity of the headache, its character and duration are some of the factors which determine if and when patients seek medical attention. So in this post I shall go over the different types of headaches and list their main differentiating features.
Broadly speaking we can divide headaches into primary and secondary headaches. Primary headaches are those headaches for which there is no structural/ secondary cause. For example a migraine headache is an example of a primary headache. The migraine may be severe and frequently disabling but if you scan (CT or MRI) the patient’s brain no underlying structural lesion like a tumor is found. Secondary headaches as the name implies are secondary to a another cause. For example headache due to a large brain tumor or headache due to an infection (meningitis) represent secondary headaches.
Types of primary headaches:
1) Migraine: common migraine and classical migraine
2) Tension type headache
3) Cluster headache
Types of secondary headaches:
1) Headache secondary to a brain tumor or other masses (space occupying lesions) in the brain
2) Headache secondary to an infectious and inflammatory process in the brain (example headache associated with meningitis)
Headaches can be a cause of concern and distress. Patients frequently worry that may have a brain tumor. So let us go over some of the signs and symptoms which suggest that the headache is due to a secondary cause . These are the signs and symptoms which should make you seek urgent medical attention:
- Sudden onset of severe headache. When asked patients rate their headache as the “worse headache of their lives”. I shall be concerned if I encounter such as patient in the ER, more so if the patient tells me that they have never had a headache in their life before. When accompanied with other signs such as nuchal (neck) rigidity and depressed sensorium (level of alertness), the question of subarachnoid hemorrhage (SAH) comes to mind. A common cause of non-traumatic SAH is the rupture of an aneurysm or arteriovenous malformation (AVH) in the brain. SAH is associated with high morbidity and mortality especially if the patient presents to medical attention late.
Caveat: Not all “worse headaches of my life” are due to SAH due to rupture of an intracranial aneurysm. Many times (especially if there is a past history of migraine headaches) these patients are suffering from a particularly debilitating/ severe attack of migraine. Thunderclap/ explosive headaches have also been reported at the time of coitus. They are referred to as post coital or orgasmic headache.
- Headaches in extreme of ages: headaches which occur in the extreme of ages (such as in a young child or after middle age especially if there is no past history of headaches) deserve a more closer look. Signs such as neck stiffness or depressed level of sensorium may be masked or difficult to elicit in these age groups. As a neurologist my threshold of investigating these patients with tests such as MRI of the brain and more invasive tests such as spinal tap (lumbar puncture) is lower.
Caveat: small children frequently cannot express headache (meaning they cannot tell you that they are bothered by headache). Primary headaches such as migraine may be missed in children as a result. The child may be agitated and parents may think he is acting up. So a high index of suspicion has to maintained by the physician to timely identify migraines in small children. Also it is well known that migraine is not “typical” in the pediatric age group. Various migraine variants have been identified in children such as abdominal migraine (the child complains of episodic abdominal pain), cyclical vomiting and so forth.
- Onset of headache in middle age (especially if there is no prior history of headaches): when a middle aged patient comes to me and says he is bothered by headaches for the past 3-4 months, never had headaches when he was in his teens, I pay close attention to him. A thorough neurological examination shall frequently tell me if there is anything “brewing” inside the brain aka does he have a mass lesion/ tumor? As a neurologist I have several tools to help me in this endeavor. I can look for signs of asymmetry: weakness/ numbness on one side of the body, problems with coordination on one side of the body, is the gait steady, are the reflexes symmetrical and so forth. I can further look into his eyes with an ophthalmoscope to see if there is increased pressure inside the brain (remember the eyes are the window into the brain). Based on my exam, I may or may not order a MRI scan or CT scan to confirm my suspicion.
- Headaches associated with fever: are always a cause of concern. Various disease processes such as meningitis (bacterial, viral or fungal), brain abscesses and so forth come into the differential. Patients are admitted into the hospital and further management depends upon the underlying etiology.
- Recent onset of headache in an immunocompromised patient: recent onset of headache in a patient who is immunocompromised (example a HIV positive patient or a patient who is receiving chemotherapy for cancer) always warrant a thorough work-up. Such patients are frequently found to have a secondary cause for their headaches. So again my threshold for imaging such patients is low. My threshold for doing a spinal tap in these patients is also low (provided I am confident that the pressure in the brain is normal).
- Headache/ temporal pain in a patient past 65: temporal arteritis (Giant cell arteritis) is a disease entity which is seen in the elderly and is due to inflammation of the temporal arteries. Patients may not complain of headache per-se. When you examine them you find they have tenderness over the temporal arteries and the artery may feel beaded and thickened. It is imperative that temporal arteritis be identified in a timely fashion and treated otherwise the patient may suffer loss of vision.
In the next post I shall talk about the primary headaches.