00:00
In this lecture, we're going to learn about meningitis. Let's start with a case. This is a
76-year-old woman with headache. This 76-year-old woman has insulin-dependent diabetes
mellitus and hypertension. She is on insulin, metformin, lisinopril, amlodipine, and pantoprazole
and presents with a 1- to 2-day history of severe headache and confusion. Her husband says
that she was seen by her primary care physician about 2 weeks ago and diagnosed with a left
middle ear infection and placed on antibiotics. She did well initially, but over the past 2 days
has progressively declined. This has happened quickly over only 2 days. She has complained
of holocephalic headache, headache is important, and has become progressively confused.
00:50
Last night she spiked a fever of 101.9 Fahrenheit. Let's learn a little more. Exam reveals an
uncomfortable-appearing woman who requires tactile stimulation to awaken. You have to
shake her to wake her and will converse for about a minute before returning to a sleeping
state. She groans throughout the exam and this worsens considerably when you try and
bend her neck with flexion or extension suggesting some type of neck stiffness. You're unable
to assess for papilloedema because of lack of participation which is common in these patients.
01:22
There are no focal deficits, no rash, and laboratory assessment shows a leukocytosis. Her
white blood cell count is 21,000 which is substantially elevated. She has normal chemistry
including hepatic and renal function. So what's the diagnosis? Well let's look at some of the
features of this case that tip us off as to what maybe going on. First, this patient has a
history of diabetes and that can increase the risk of infectious processes. It suggests some
relative immune suppression. This process is acute. This has been going on for 1-2 days, it
happened quickly and this points us in the direction of certain processes that happened
acutely. Bacterial processes or strokes or toxic ingestions, we're thinking about things that
happen over a short amount of time. She has a headache and a fever and this suggest
potentially an infectious process and maybe infections in the certain part of the brain.
02:21
Let's look at our examination. She is altered, she requires tactile stimulation to arouse and
awaken. She has neck stiffness or meningismus on exam. That's a really important clinical
examination finding that's going to point us in the direction of this process. So what is the
diagnosis? Is this a meningitis, an encephalitis, a cerebritis, or a brain abscess? Well, it doesn't
sound like an encephalitis. We're going to learn and we've learned that encephalitis is the
triad of headache, fever, and altered mental status. This patient is altered, but she has
meningismus or evidence of a problem in the meningeal layer and compartment and that
points us in the direction of meningitis and not a primary encephalitis. This doesn't sound like
cerebritis. That's headache, fever, and focal neurologic deficit which we don't see on her
exam. The same is true for brain abscess; headache, fever, and focal neurologic deficit which
we also don't see in this patient. So this is the classic presentation of a patient with a
bacterial meningitis. It is acute in onset, the patient has headache, fever, and neck stiffness,
also with increased white blood cells or leukocytosis. And we need to evaluate that process.