Differential Diagnosis: Headaches

By Adam Thompson, EMT-P

Headaches account for a large volume of EMS responses.  Most are benign, but a few could be an early symptom of a life-threatening cause.   It may be beneficial to differentiate between the presentations.  A good history is by far the most useful tool that any clinician has in determining a headache’s malignancy.


Common types of headaches:

• Tension-type headache
• Migraine headaches
• Cluster headaches

Tension-type  the most common type of headache, and yet its causes aren’t well understood. A tension headache is generally a diffuse, mild to moderate pain that many people describe as feeling as if there’s a tight band around their head.It may feel as though muscle contractions are responsible for your head pain, but experts don’t think that’s the cause, which is why this type of headache is generally referred to as a tension-type headache. (from MayoClinic)

Migraine a common type of headache that may occur with symptoms such as nausea, vomiting, or sensitivity to light. In many people, a throbbing pain is felt only on one side of the head. Some people who get migraines have warning symptoms, called an aura, before the actual headache begins. An aura is a group of symptoms, usually vision disturbances, that serve as a warning sign that a bad headache is coming. Most people, however, do not have such warning signs. (from Google Health)

Cluster The term “cluster headache” refers to a type of headache that recurs over a period of time. People who have cluster headaches experience an episode one to three times per day during a period of time (the cluster period), which may last from two weeks to three months. The headaches may disappear completely (go into “remission”) for months or years, only to recur. A cluster headache typically awakens a person from sleep one to two hours after going to bed. These nocturnal attacks can be more severe than the daytime attacks. Attacks appear to be linked to the circadian rhythm (or “biological” clock). Most people with cluster headaches will develop cluster periods at the same time each year — either in the spring or fall or the winter or summer. (from WebMD)

Symptom	A Tension	B Migraine
Intensity, Duration and Quality of Pain
Mild or moderate pain intensity	√	√
Severe		√
Duration of headache 30 min – 7 days 4-72 hours	√	√
Intense pounding, throbbing and/or debilitating		√
Distracting but not debilitating	√
Steady ache	√
Location of Pain
One side of head		√
Both sides of head	√	√
Associated Symptoms
Nausea/vomiting		√
Sensitivity to light and/or sounds		√
Aura before onset of headache such as visual symptoms		√

Weight-lifters: Just like you’d think, this is a headache that occurs after a strenuous weight-lifting regimen.

Histamine: A headache caused by histamine overload, from a source such a histamine injection or certain wines.

Coital: A headache that occurs suddenly during sex or after orgasm. As if couples nowadays didn’t have enough issues – thankfully, these are very rare and actually occur more often in men.

Analgesic-rebound: That medication you’ve been taking for your headaches could now be the underlying cause of new headaches. Removal of the medication is required.

Hypnic: This is an oddball headache that awakens people from sleep. Clusters can do this as well but the pain of hypnic headaches are not as intense and are not localized around the eye.

• The worst headache someone has ever had
• Headache with stiff neck (especially with a high grade fever)
• A headache associated with loss of consciousness or altered mental status.
• A headache accompanied by severe eye or ear pain.
• A headache that occurs in an individual who has experienced recent head trauma.
• A headache accompanied by sudden, disabling pain or convulsions.
• Headache with parasthesia or paralysis

References:

• American Headache Society – Table 1

The stroke patient is one that is commonly seen and transported by EMS providers.  There tends to be a frustration due to the inability to do much for these critically ill patients.  Their quality of life subsides right before our eyes.  There are two types of stroke as I explained in PART 1.  There are treatments available for ischemic strokes that can tremendously benefit the patients if given soon enough.  Thrombolytic therapy could be very effective in treating the ischemic stroke patient in the prehospital environment.  The only problem is that if this treatment was used on a patient suffering from a hemorrhagic stroke, it could tremendously worsen that patient’s condition.  There is no way to conclusively differentiate between an ischemic or hemorrhagic stroke in the field without the use of diagnostic equipment.  There are, however, many indicators that could clue you in on the probably etiology.

Risk factors for stroke


Most of the risk factors for stroke are the same for both subtypes.  However, some are more indicative of a specific type.  Knowing these may assist you, along with the presenting signs and symptoms.

More associated with ischemic stroke

• Atrial fibrillation 
• History of TIAs
• Increase in Vitamin K
• Carotid artery disease
• High cholesterol
• Diabetes
• Patent Foramen Ovale

More associated with hemorrhagic stroke

• Severe acute hypertension
• Anticoagulant medications
• Smoking

Similar to risk factors, physical findings are not synonymous with a specific subtype, but they are very good indicators.  These signs may indicate either type of stroke, I cannot stress that enough.  


Signs of Hemorrhagic Stroke

• Airway compromise
• Complete unresponsiveness
• Complete aphasia
• Nausea & vomiting

Signs of Ischemic Stroke

• Expressive aphasia
• Unilateral deficits
• Poor coordination

So it is possible to have a fairly good idea weather the stroke patient you are presented with is suffering from a clot or a bleed, based on a fine assessment.  With advancements in technology, this skill, however, may eventually be unneeded.  There is solid evidence supporting the efficacy of paramedics and the use of prehospital diagnostic equipment.  There are portable brain scanners that are being tested in the field right now.  This may sound like something far-fetched or unnecessary, but I believe otherwise.  With stroke being the time is tissue condition, why not use equipment that may facilitate treatment that could subsequently improve the quality of life, of our patients.  With the ability to conclusively diagnose an ischemic stroke, thrombolysis could be preformed much earlier.  There would be an obvious need to provide research and gain evidence to support this process, but with an exponential probability of benefit, there should be a bigger push to get this done.  The studies advocating hypothermia in the presence of a CVA all appear encouraging as well.  Please read some of the research I have provided below.

Set up and run a thrombolysis service for acute stroke. [1]

Abstract 

Intravenous thrombolysis significantly improves the chance of independent recovery from ischaemic stroke but its benefit is strongly time dependent: present evidence supports effectiveness when delivered up to 4.5 h after symptom onset but the chance of recovery is twice as great when it is given within 90 min compared with 3-4.5 h. Delivery of treatment to a high proportion of patients is possible but requires clinicians to optimise systems for patient transfer, clinical and radiological assessment. A high proportion of patients with stroke already present to UK hospitals within the treatment time window even without specific public awareness or prehospital triage. Establishing a service requires dialogue with all those involved in the patient pathway, including ambulance dispatchers, paramedics, emergency department staff, radiology and colleagues in acute medicine. Most acute stroke teams cross traditional medical disciplines. Thrombolysis should ideally be delivered within an integrated service that seamlessly includes acute stroke unit care and rehabilitation.

Stroke care happens to be very near and dear to my heart and was the initial reason that I sought a career in EMS. Watching a person have a stroke or CVA (cerebral vascular accident), has to be one of the worst experiences. These patient’s are very likely going to live a very difficult life after having a stroke. Unfortunately, there is very little that we can do in the prehospital environment for these patients.

New Treatments

Abstract
Hypothermia is considered nature’s “gold standard” for neuroprotection, and its efficacy for improving outcome in patients with hypoxic-ischemic brain injury as a result of cardiac arrest is well-established. Hypothermia reduces brain edema and intracranial pressure in patients with traumatic brain injury. By contrast, only a few small pilot studies have evaluated hypothermia as a treatment for acute ischemic stroke, and no controlled trials of hypothermia for hemorrhagic stroke have been performed. Logistic challenges present an important barrier to the widespread application of hypothermia for stroke, most importantly the need for high-quality critical care to start immediately in the emergency department. Rapid induction of hypothermia within 3 to 6 hrs of onset has been hampered by slow cooling rates, but is feasible. Delayed cooling for the treatment of cytotoxic brain edema does not provide definitive or lasting treatment for intracranial mass effect, and should not be used as an alternative to hemicraniectomy. Sustained fever control is feasible in patients with intracerebral and subarachnoid hemorrhage, but has yet to be tested in a phase III study. Important observations from studies investigating the use of hypothermia for stroke to date include the necessity for proactive antishivering therapy for successful cooling, the importance of slow controlled rewarming to avoid rebound brain edema, and the high risk for infectious and cardiovascular complications in this patient population. More research is clearly needed to bring us closer to the successful application of hypothermia in the treatment for stroke.