Headaches: Pathology review

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Case Study 0:00–1:32

At the neurology department, there’s a 34-year old male, named Andrew, who came in due to headache. This is the first time he’s had a headache like this and described the pain as “the worst headache of his life”.
Neurological examination reveals neck stiffness. His medical history is otherwise insignificant.
Next to Andrew, there’s a 30-year old female, named Anna, who complains of recurrent episodes of unilateral, pulsating headaches that usually occur when she’s tired, and last approximately 6 hours each time.
Her mother also suffers from similar episodes of headache. Finally, there’s a 40-year old male, named Evan, who has had recurrent attacks of excruciating headaches for the past two months.
The pain is located behind his eye, typically occurs in the morning, and lasts for about one hour. He also has nasal congestion and lacrimation of the affected eye.
He has no family history of similar episodes. All three people suffer from headaches.
A headache occurs when any of the pain-sensitive structures in the head and neck are stimulated. These include the meninges, blood vessels, nerves, and muscles.
Headaches can be classified into two types. The first are called primary headaches, and they’re more common.
These are chronic or recurrent headaches and include tension headaches, migraines, and cluster headaches. Now, the second type are called secondary headaches, and these are acute headaches from a specific underlying cause like a serious head injury, infection, or a brain tumor.
Alright, now let’s take a closer look at the different types of primary headaches. Tension headaches are the most common type and they’re more common in females.

Tension Headache1:32–2:17

On the exams, the classic description is a headache that is slowly-progressive, bilateral, tight, “band-like” headache with no other associated symptoms.
Typically, they lasts from 30 minutes to up to a week, and is usually triggered by stress and dehydration. It is thought that these headaches are due to an increased sensitivity to pain due to the release of vasoactive neuropeptides like substance-P and calcitonin gene-related peptides.
These headaches can be treated acutely by NSAIDs, and chronic pain can be treated with amitriptyline or other tricyclic antidepressants.
Now, a migraine headache is another primary headache and it’s also more common in females. Family history of migraines is often present.

Migraine2:17–3:43

They usually have triggers, such as specific foods, weather, bright lights, loud noises, physical exertion, or lack of sleep.
For the exams, you have to remember that migraine headaches usually last between 4 to 72 hours, and it’s usually a severe, unilateral, pulsating or throbbing pain that’s aggravated by movement.
Additionally, individuals can have nausea or vomiting. Often, individuals isolate themselves in a dark room to avoid light and sound, and this is called photophobia and phonophobia.
Some migraines can cause an aura before or during the headache, which consists of visual symptoms like seeing bright lights, zigzag lines, or other neurological symptoms like tinnitus, aphasia, or confusion.
Sometimes, the aura can present as a temporary paralysis of one side of the body, in which case the attack would be called a hemiplegic migraine, and can be confused with a stroke.
The difference is strokes don’t usually cause severe headaches. For abortive therapy, NSAIDs and other analgesics can be used.
Sumatriptan is used to treat more severe migraines. For prevention, lifestyle changes can make a difference, but beta-blockers like propranolol, or amitriptyline can also help.
Now, cluster headaches are the rarest form of primary headache and usually occur in males. In the exams, cluster headaches are classically described as an excruciating, stabbing pain located unilaterally behind the eye.

Cluster Headache3:43–4:45

They usually occur every day for about 8 to 10 weeks per year, and not the rest of the year. They also occur at almost the same time every day, and last anywhere between 15 minutes to 3 hours.
Cluster headaches have been linked with cigarettes and alcohol. Oftentimes, individuals with cluster headaches pace around, because there’s nothing that really provides comfort.
Another high yield fact you have to remember for the exams is that they’re usually associated with autonomic symptoms on the affected side, such as ptosis, miosis, lacrimation, and nasal congestion.
For acute pain relief, 100% oxygen and sumatriptan, a selective serotonin receptor agonist, are used. For prophylaxis, verapamil, valproic acid, or lithium are effective.
Okay, now let’s go over some of the causes for secondary headaches. Diagnosing a primary headache is usually based on clinical symptoms alone.

Secondary headaches4:45–11:24

But on the exams and in practice, when an individual presents with a headache, it’s important to think through the secondary causes first to avoid missing something important or life-threatening.
There are some findings that point towards a secondary headache like new or sudden onset of headache, headache that is worsening in severity or frequency, systemic symptoms, such as fever or weight loss, neurological symptoms, like weakness, sensory deficits, or vision loss, and other associated conditions, like history of trauma.
Any of these findings warrant further investigation like brain imaging with a CT scan, or MRI, and in some cases a lumbar puncture.
Also, some clinical features may point towards a specific diagnosis! A high yield cause you’re likely to see on the exams is subarachnoid hemorrhage, that it’s usually caused by rupture of an intracranial aneurysm.
Typically, the headache develops suddenly, and rates 10 out of 10 in terms of pain, right at its onset. It’s often described as the “the worst headache of my life”.
Meningeal signs, like neck stiffness, are often present. If a person’s recently had a head trauma, epidural or subdural hematomas should be considered.
Now, if someone has a sudden headache after a trauma, and it radiates down one side of the neck, and there’s Horner syndrome, which is unilateral ptosis, miosis, and anhidrosis, then it could be due to a carotid or vertebral artery dissection.
This is also associated with pulsatile tinnitus which is a pulsating ringing sensation in the ears. If left untreated, the dissection could extend into the intracranial vessels, leading to a stroke.
Now, the cerebral veins can also become blocked in a condition called cerebral venous sinus thrombosis. This presents with exertional headache, focal neurological deficit, and signs of increased intracranial pressure like papilledema.
This occurs more commonly in individuals with hypercoagulable disorders, or women who are in a hyperestrogenic state, such as pregnancy or taking combined oral contraceptives.
Now, an acute headache that’s associated with fever, photophobia, meningeal signs like neck stiffness, and altered mental status should make you think about meningitis.
Sinusitis can also present with headache and fever, and a characteristic feature is tenderness of the affected sinus on palpation.
Next, a brain abscess can present with headache and focal neurological deficit with or without fever, and there may be signs of increased intracranial pressure like nausea, vomiting and papilledema.
Brain tumors can also present with focal neurological defects or seizures. The headaches they cause are characterized as a chronic, dull headache that is usually worse in the morning and when lying down, improves when sitting up, and is often associated with symptoms of increased intracranial pressure, such as nausea, vomiting or papilledema.
Pituitary tumors can cause headache along with loss of the peripheral visual fields due to compression of the optic chiasm, which is known as bitemporal hemianopsia.
Additionally, since prolactinomas are the most common pituitary tumors, signs of hyperprolactinemia such as galactorrhea, decreased libido, amenorrhea in women, or erectile dysfunction in men may also be present.
Speaking of the pituitary gland, another dangerous cause of headache is pituitary apoplexy, which is bleeding in the pituitary gland.
This occurs when a pituitary tumor outgrows its blood supply, and causes a sudden onset headache associated with visual field loss.
Also, in pregnancy, the pituitary gradually enlarges to meet the demands of breastfeeding after delivery. If women suffers from severe postpartum hemorrhage, ischemia to the pituitary can cause pituitary infarction, a condition called Sheehan syndrome.
Acute angle-closure glaucoma may also present with an acute headache that is more intense in the periorbital region, and is classically associated with a red eye, a fixed mid-dilated pupil, and visual impairment.Okay, now temporal, or giant cell arteritis is a vasculitis that primarily affects the extracranial carotid circulation.
In the exams, the classic presentation is a female individual over age 50 with a superficial, pounding headache along the temple on one side of the head.
In fact, the scalp may be so tender that the patient complains even brushing their hair can cause pain. Other symptoms that can be important clues for the diagnosis include fever, weight loss, and jaw claudication, causing pain when chewing.
Because giant cell arteritis involves the carotid circulation, a worrisome complication is extension of the vasculitis to involve the first branch of the internal carotid artery: the ophthalmic artery.
This could potentially cause irreversible blindness in one of the eyes. Next, a condition called idiopathic intracranial hypertension, or pseudotumor cerebri can cause daily headaches.
This disorder is characterized by an increased intracranial pressure due to an unknown reason. The headache worsens with the valsalva maneuver.
This is because both cerebral blood flow and intracranial pressure changes when the maneuver increases intrathoracic pressure.
Individuals tend to be young, obese women, and other risk factors include oral contraceptive use, as well as tetracycline and vitamin A toxicity.
In addition to headache, individuals may also complain of visual disturbances such as diplopia, which is due to cranial nerve six, or abducens nerve palsy.
On fundoscopic examination, there’s usually bilateral papilledema, or swelling around the optic nerves. There could also be edema of the optic discs due to optic nerve compression.
While CT and MRI of the brain are usually normal, a lumbar puncture is diagnostic, and reveals an elevated opening pressure, with a normal cerebrospinal fluid analysis.
Treatment consists of weight loss along with the carbonic anhydrase inhibitor acetazolamide, which helps lower the intracranial pressure.
If papilledema is extensive and vision-threatening, then a procedure called optic nerve sheath fenestration surgery is done emergently.Okay, now a pain disorder that you have to distinguish from a headache is trigeminal neuralgia, also fancily called tic douloureux.

Neural Lesion 11:24–12:36

Trigeminal neuralgia is a neuropathic pain disorder that is thought to be due to compression of the trigeminal nerve in the brainstem by the superior cerebellar artery.
Individuals classically describe sudden, excruciating, sharp, lightning-like, unilateral facial pain in the V2 and V3 trigeminal nerve branch distribution.
These attacks can be spontaneous, or they can be triggered by irritating activities like chewing, shaving, brushing the teeth, talking on the phone, or even simply smiling.
The pain can be very short-lasting, causing the individual to frequently wince or grimace in response. Therefore, it might actually look like the individual has a tic, hence the name tic douloureux.
Importantly, one of the core features of trigeminal neuralgia is that the neurological examination will be completely normal, despite the localized pain episodes.
The treatment is carbamazepine. Finally, a high yield fact is that trigeminal neuralgia, especially if it occurs bilaterally, can be due to multiple sclerosis or a brainstem tumor, so it’s important to consider these diseases.
Finally, caffeine withdrawal can also cause a mild headache approximately 12 to 24 hours after the last cup of coffee.Alright, as a quick recap, Headaches occur when the pain-sensitive structures in the head and neck are affected and they can be primary or secondary.

Caffeine Withdrawal 12:36–12:46

Review12:46–13:15

Primary headaches include tension headaches, migraines, and cluster headaches, while secondary are due to underlying diseases.
For primary headaches, the diagnosis can be made based on clinical findings. If secondary causes are suspected, further investigation like head CT, MRI, or lumbar puncture must be done.Back to the patients!

Summary13:15–13:41

Due to his description of the headache as “the worst headache of his life” and the presence of meningeal signs, Andrew most likely has secondary headache due to subarachnoid hemorrhage.
In order to confirm the diagnosis, brain imaging with head CT, or MRI, must be ordered. Now, Anna and Evans have recurrent episodes of headaches and so they most probably have primary headaches.
Due to their descriptions, Anna has migraines,