Back to diagnosing the patient with an ACUTE HEADACHE [defined somewhat arbitrarily as one lasting less than 3-4 weeks]. We’ve already discussed how to address the “worst headache ever” (Acute H/A – 1). A word now about…
Space-Occupying Lesions such as tumors, subdural hematomas, and hydrocephalus, causing Increased Intracranial Pressure, are potentially lethal diagnoses not to be missed. But we can’t image everyone with a headache. We worry mainly about headaches with Red Flags, that:
- Occur daily and progress in severity;
- Are associated with daily nausea / vomiting;
- A softer clue: worsen with valsalvas or bending forward. Contrary to popular thought, early morning exacerbation is not a feature of brain tumors.
- Elderly patients, & anyone taking anticoagulants, can have occult subdural hematomas, caused by the most minor of traumas.
- People over 50 with a completely new headache are more likely to have tumors.
And of course we perform an adequate NEURO EXAM, especially Mental Status and Cranial Nerves. It can be accomplished in a few minutes; today’s topic includes key pearls & pitfalls.
Mental Status: This serves to rule out confusion or delirium. Abnormalities are usually detected through the course of history-taking. Sometimes friends or family will report recent change in behavior. Believe them, even if the patient seems fine at the moment (delirium can fluctuate throughout the day). And sometimes the confusion can be very subtle.
Twice, in normal appearing, cooperative, and apparently alert patients, I’ve diagnosed acute CNS disease (hydrocephalus and hepatic encephalopathy) by simply asking the year. Orientation to time is lost before person or place. Both those patients knew the day of week, the month, and even the date, but not the year. And no matter how uneducated, illiterate, or socially isolated, everyone knows the year. Both had found their way to the clinic on their own. I sent them to the E.D. by ambulance, even though outwardly, they appeared totally calm and normal.
An excellent internist recounted how, as a med student, he presented a detailed two-hour medical history on a patient. His attending ambled to bedside, asked, “Hi, Joe, what year is it today?” “1925.” Joe was an alcoholic with Wernicke-Korsakoff syndrome, an expert at confabulation. Two hours of work down the drain.
Two patients, who knew the year, couldn’t do serial 7’s from 100 — and they couldn’t count backwards from 100 by one’s either! One had a glucose of 30 [no tremor, diaphoresis, or anything of the sort; smiling, as calm as could be]. The other had a subdural hematoma, beginning to herniate.
Pearl from a psychiatrist — If ever you’re getting a history, and the story seems boring, you can’t quite follow the details, and wonder if you need another cup of coffee, don’t doubt yourself. Something’s badly wrong with that patient.
Cranial Nerves — “On Old Olympus’s…” “Oh, Oh, Oh, To Touch And Feel…” or whatever mnemonic you like — systematically approach the 12 cranial nerves. Most are straight-forward; the main difficulties and errors I’ve seen among clinicians deal with the eyes.
A good eye exam for chief complaint of “headache” only requires a penlight and direct ophthalmoscope (as opposed to an exam for “visual loss,” or “eye pain”). The examiner must:
- Assess visual acuity;
- Evaluate visual fields by confrontation
- Examine the pupils, always looking for an afferent pupillary deficit (APD) [see below]
- Visualize both optic disk margins to exclude papilledema
The Fundoscopic Exam — some hints & clues (besides lots of practice):
- Position the patient so you are comfortable at eye level (a rushed exam won’t help anybody, if you have to stand on tiptoes while your back aches).
- In a dark room [but not completely dark], have a spot on the wall where they can focus.
- Get used to holding the ophthalmoscope properly: your left hand for patient’s left eye, right for right [otherwise you’ll block their focusing on that distant spot]. Keep the instrument firmly against your brow, moving your head plus scope as a unit.
- Approach from the lateral side at 15° from midline.
- Get as close to the pupil as possible!!!! It’s OK to rub eyebrows. I put my free hand behind the patient’s shoulder, to pull me in. Don’t place it on the forehead, which makes you keep your distance. An excellent old-time rural ophthalmologist taught me, “It’s like looking through a key hole — get right up there.”
- Know what you’re looking for ahead of time!!!!! Main thing (for “headache”) is the optic disk. As soon as it appears in view, look for the disk’s:
- sharp margins;
- normal creamy color (as opposed to the pallor of optic atrophy); and
- cup-to-disk ratio — the white physiologic cup should be less than half the diameter of the disk [not important for “headache”, but worth noting for undetected, asymptomatic, open-angle glaucoma].
- You can also try focusing on the retinal vein to see if it wiggles — that’s “spontaneous venous pulsation” which absolutely rules out papilledema. But it may be hard to see, & 10%-15% of people naturally lack it.
From there, you can explore the vessels & retinal background if you’ve time before the patient recoils from photophobia, but that’s not so crucial for a complaint of “headache”.
Visual Acuity: You don’t need to do formal Snellen testing unless there’s active mention of visual loss; just see if the patient can read any posters/signs on your wall (one eye at a time). But… what to do if a patient has 20/20 acuity in one eye, 20/100 in the other? It could be due to an organic lesion (neurologic or ocular), or merely simple refractive error (just needs eyeglasses). click here for answer
The Afferent Pupillary Deficit (APD) — present with many forms of organic eye disease. It’s elicited by a “swinging flashlight test” [a medical term, not my own coinage], which should be performed every time you check pupils. A “positive” swinging flashlight (a.k.a. “APD”; a.k.a. “Marcus-Gunn pupil”) looks as follows: In a very dark room, shine a penlight in the right eye, the pupil constricts. Shine it over to the left, pupil dilates!!! Swing back to the right, pupil constricts. Back to the left, pupil dilates!!! Etc. Patient has a Left APD.
Pathology: optic nerve (CN-2) deficit. The entering afferent nerve impulse synapses to the Edinger-Westphal nucleus in midbrain, then the efferent CN-3 provides consensual pupillary constriction. In the above example, right CN-2 is strong, senses lots of light, so both pupils constrict well. The left CN-2 being weak, afferent stimulus is less when penlight swings to it, so both pupils constrict less, i.e. dilate [but the room is dark, so you only see the left side]. Swing back to the right, both constrict more [you see it on the right]. Swing to the left and there’s dilatation. Etc.
A fascinating case in the New England Journal of Medicine discussed the importance of both the pinhole exam and swinging flashlight test. An obscure ultimate diagnosis was initially missed, the main point being how clinicians omitted these two salient tests. At, of all places, the E.D. of Massachusetts Eye and Ear Infirmary. See N Engl J Med 2008;359:2825-33.
Fields by Confrontation: part of the CN-2 exam that shouldn’t be omitted. It’s amazing how patients with a hemispheric field deficit will merely say their vision is “blurry.” You do a Snellen test, it’s 20/20 bilaterally, & you don’t realize you’ve only tested central vision.
Brief comment on extra-ocular movements (EOMs): I’ve seen various clinicians err by asking a patient to move their eyes horizontally & then vertically. The EOMs for CN-3 and -4 include obliques; there’s no vertical.
Technicality on CN-3: don’t chart “PERRLA” unless you can see the “A” (accommodation), which is virtually impossible for dark-brown irises. If I need to check this (e.g. rule out 3° syphilis), I improvise. Darken the room, & dim the otoscope lamp enough to see the pupil but still keep it somewhat dilated. Tell the patient “look at the wall [distant], now look at my finger [near].” With near focus, the light should be right to see a little constriction.
After mental status & cranial nerves, other components of the neuro exam for “headache” can be screened (unless history, like “falls” or “dropping things,” suggests other deficits requiring fuller evaluation):
- Motor System — Don’t test handgrip, since it’s the least sensitive modality of all [it tests flexors, aided by gravity]. Test for pronator drift [large joint against gravity]. Then test elbow & wrist extensors against gravity.
- Coordination: Can test finger-to-nose for the arms; legs are screened as described below.
- Sensory System — Skip it, unless the patient describes focal numbness or paresthesias. A sensory exam is way too laborious, with a very low yield if any.
- Reflexes — tap a few of them.
- Screening the lower extremities — Hopping on each leg, and performing a tandem gait [like a cop does to a drunk driver] will screen motor function, proprioception, and coordination. Can also do a Romberg: patient stands feet together, eyes open. If they sway or fall, it’s a cerebellar problem. Then they close their eyes; loss of balance at that point is either vestibular dysfunction, or loss of position sense.
Various etiologies of Increased Intracranial Pressure can cause a headache. But they also cause confusion, or an objective neurological abnormality. If you can chart “Neuro Exam Normal,” you’ve made a powerful statement, & don’t need to worry about imaging unless there are Red Flags as noted above.