August 6, 2012 by EmerJencyWEBB
A young gentleman made his way to the ED one evening for an unrelenting headache he had been suffering from for 4 days. He was otherwise healthy and his only encounters previously with headaches had been minor, alleviated with a couple Tylenol. The only associated symptoms he endorsed were phono- and photophobia. The patient denied fever, nausea, vomiting, head trauma, or significant neurological deficits at home. He also denied vision loss, eye pain, temporal pain/jaw claudication, tick bite, or CO exposure. He was afebrile in triage, with normal vital signs. On exam, he had mild photophobia, but otherwise his exam was pretty unrevealing. I grabbed the ophthalmoscope off the wall, turned the lights out and got a pretty good view of his fund. They looked like this:
What we are seeing is blurring of the margins of the optic nerve head, called papilledema. This is primarily seen in patients with elevated intracranial pressure.
As an interesting aside, did you know that you can grade the severity of papilledema?
With this exam, unfortunately, a simple uncomplicated headache fell off the differential pretty fast. So what’s the next step? The differential was pretty wide at this point, including meningitis, although the patient looked well. I knew I wanted to perform a lumbar puncture at this point, but with a quick glance at the paper below (stored in my Evernote), I ordered an uninfused CT scan of the patient’s head to assess for contraindications to LP. It also helped me search for other causes of the patient’s headache.
If you look closely at this paper, only one patient in the study had evidence of papilledema…this patient had HIV and cerebral toxoplasmosis and died of brain herniation. Not really the patient in front of me at the time, but I mentally added papilledema to the “Neurologic Findings” list on the table above.
Head CT came back pretty quick, and was normal. Good for the patient, but he still had to have a needle in his back. I gave my risk vs. benefits talk, and listed all potential complications as I always do. (Another aside: I always mention bleeding around the cord as a possibility. In the making of this post, I found THIS image which I had never seen before. Great image, but a little scary looking when dealing with any anti-coagulated patient)
The patient agreed, and we finally got down to performing the LP. To get an opening pressure, you have to lay the patient down in the lateral position. I got into the space and hooked up the manometer first. Click the link below to see attachment of manometry with normal opening pressure.
My result, however, looked a lot like this:
Wowzer! I rarely hook up the manometer in the first place, and to get CSF flowing freely from the top of the apparatus was fascinating. Most LP kits for adults have two-piece 550mm manometers. Normal CSF opening pressure for adults lies somewhere between 70-180 mmH20, but can be as high as 200-250 mmH20 in obese patients or patients who are crying/straining/moving during the procedure. The CSF itself was grossly normal appearing.
After sending the requisite CSF studies off, I went back to tell my attending Dr. Know-it-all the results of the LP. “So what’s the differential diagnosis for elevated opening pressure?”, he asks…
In part 2, we’ll go through the pathophysiology and differential diagnosis of high CSF opening pressures and find out what this patient actually had.
Disclaimer: The Case Report series employs no real life patient data or identifiers. All case descriptions are loosely based on an amalgam of cases encountered in clinical practice, but not on any one case in particular. The primary goal is to set the stage for a clinical question to be answered in sequence.
Figure 96-10 from Fong B, Van Bendegom JM: Lumbar puncture.
In: Reichman EF, Simon RR, ed. Emergency Medicine Procedures, New York: