DIAGNOSIS — it’s all that really matters. We can’t a treat a patient if we don’t know what they have. And aside from antibiotics, surgery, maybe chemotherapy, much of our therapeutics achieves comparatively little. By all means, do what you can to relieve asthma symptoms, control hypertension, ease gastroesophageal reflux, minimize pain, etc. But please — always think to yourself, “Hey, Dude, what’s the DIAGNOSIS?”
A 44-year-old woman, volunteer at my colleague’s free clinic, mentioned her bad headache requiring lots of ibuprofen. My colleague urged she see her primary, who prescribed an antibiotic for sinusitis. A week later, symptoms unimproved, they changed the antibiotic. The headache persisted another week, they performed a head CT and lumbar puncture, both were normal. Into the fourth week, her cerebral aneurysm ruptured completely, and the lady died.
What went wrong?
When aneurysms rupture, causing a Subarachnoid Hemorrhage (SAH), over half the time patients succumb then-and-there. But up to 50% of patients experience a “warning leak” [a.k.a. “sentinel leak”], which seals over. This is obviously unstable, and will fully burst a few weeks later [rarely, in just 1-2 days], but offers a window period for life-saving surgery. It’s a diagnosis NOT TO MISS.
A non-contrast head CT is virtually 100% sensitive within the first 12 hours, over 90% within the first 24 hours [i.e. no false-negative scans]. But this sensitivity decreases to 60% by the first week, as blood is resorbed. Similarly, a lumbar puncture (LP) is highly sensitive throughout the first week, much less so after two. So if you entertain the diagnosis of SAH at all, don’t delay.
Who warrants this work-up (head CT and LP) for an acute headache? Anyone with both oftwo clinical parameters:
- New onset of the “worst headache ever.” “Worst” is defined by a patient’s prior headaches and pains; the intensity depends on how much blood leaks, but the headache is always the “worst ever.”
- Sudden Onset: Pain often reaches its maximal intensity immediately. Makes sense — a drop of blood spurts out, the pain begins then & there.
If the sudden onset of headache occurred during a valsalva, it should raise suspicion. This includes coughing, lifting, sex, etc. Sadly, some women die of SAH while pushing during labor. Patients with polycystic kidney disease are at high risk of cerebral aneurysms. A family history of SAH [often reported as a “stroke,” but at an age too young for atherosclerosis] may suggest rare genetic syndromes.
Certainly, anybody with a new headache deserves a complete neurologic exam, especially of the cranial nerves. But in most patients with a sentinel leak, this will be normal. The most common clinical error is to assume that patients with SAH look ill — true for the fully ruptured aneurysm, but not for the treatable “sentinel leak.” After all, the patient described above went to work with her “worst headache ever,” to an unpaid volunteer job at that!
MORAL: a patient with the very sudden onset of the “worst headache ever,” even if not appearing in much pain, should get a non-contrast CT & an LP, most expeditiously obtained via an emergency department. If 2 weeks have elapsed since symptom onset, consider a neurologist opinion regarding an angiogram.
MORAL #2: When a patient’s condition isn’t improving, NEVER change an antibiotic without a very specific reason. Instead, question your diagnosis.
This Blog encapsulates over 30 years of experience, anecdotes, pearls, pitfalls, clinical tricks, PubMed searches, & literature reviews. And, occasionally, the very best teacher of all — really bad outcomes [hopefully those of colleagues & others, not one’s own]. It deals primarily with adults and school-age children in an out-patient setting. We’ll explore a comprehensive range of Differential Diagnosis, one “chief-complaint” at a time.
The key to Diagnosis is History-Taking, much more so than physical exam or other testing. A few crucial suggestions:
- Put yourself in a patient’s shoes — truly imagine what’s been going on. Pardon the cliché, but try to “feel their pain” (or vomit, diarrhea, whatever).
- CHRONOLOGY of illness is the key parameter — get it right. Are symptoms new or recurrent; intermittent or continuous? I’ve seen countless clinicians fail here.
- Don’t ask a single question without knowing what you’re trying to rule out or in — obtain data systematically.
- Consider the natural history of each diagnostic entity — is the patient’s presentation a possible course of untreated illness? [or, if they’d tried a therapy, of treated disease].
- Always inquire if the patient’s illness is “getting better,” “getting worse,” or “staying the same”. A progressive course is always more concerning.
Acute symptoms (i.e. recent onset) are the most dangerous. This is counter-intuitive to many of my patients, who think that ten years of pain is worse than a few days’ worth. Keep in mind conditions which can do a person in rapidly [the “DON’T MISS” category].
We’ll begin with “ACUTE HEADACHE” — a very common chief complaint, rarely serious, though occasionally associated with preventable deaths. For this symptom, let’s define “acute” as less than 3-4 weeks duration.
The following table outlines the differential diagnosis of the “acute headache”. Always consider conditions “Not To Miss,” which can invariably be rapidly ruled out. Most of them present within a few days of onset. Then, target your questions and exam to ruling-in a less-serious illness. Even if you’re wrong, those conditions are mostly self-limiting.
Next posting we’ll cover increased Space Occupying Lesions, i.e. increased intracranial pressure, and the essence of a succinct neuro exam for the headache patient (Acute H/A – 2), then go on to rare causes NOT TO MISS (Acute H/A – 3) and more common causes (Acute H/A – 4), followed by Recurrent Headaches, and finally Chronic Headaches.