Note: This post is open for discussion and by no means does it mean the thought process discussed here is “the correct” one; There are many different thought processes that can go through this call, and each different path is valuable. I found this particular call interesting and worthwhile in sharing.
So given the case study in my last post: What’s Your Differential Diagnosis? Part I. Lets take a look at a possible thought process and what the diagnostic outcome was based on the CT scan done at the hospital (it is recommended you read the first post before reading this post).
So the call came in as a seizure, but we can’t just assume “it’s just a seizure” so we have to think what causes seizures. Some of the causes can be epilepsy, stroke/CVA, brain tumor, hypoglycemia, drug use, head trauma, to name a few. From the history of the bystander, we get the following important clues:
- Tremors right arm started several weeks ago (new)
- Never had a seizure before (new)
- No recent falls
- Has had previous stroke
- Medications: Rabeprazole & plavix
The history of a previous stroke is very important because that puts our patient at a higher risk for a second stroke. Therefore, the possibility of a CVA (cerebral vascular accident, aka stroke) is high on the list in the differential diagnosis. However, the fact that the patient was taking plavix makes it rather suspicious since plavix is an anti-platelet medication (more commonly known as a blood thinner). Why would a doctor prescribe a blood thinner to a patient who has had a CVA? Well there are two main categories of CVAs: One caused by hemorrhage or a bleed, and another is thrombotic or caused by a clot. So most likely his previous CVA was from a clot and was then later prescribed plavix to prevent further strokes. Obviously this doesn’t rule out a CVA, but the plavix does make me lean away from hemorrhagic CVA instead of towards it. Why? Because I’d expect the patient to be much worse condition (instead of just compensated shock) since plavix would cause a serious bleed and its been about 10min since the seizure (although this would depend on the location and size of the bleed, venous vs arterial). I would also expect to possibly see Cushing’s triad from an increase in ICP (intercranial pressure). It is also because of plavix, I would presume a thrombotic CVA as unlikely.
Another clue in the history that makes it questionable whether the patient is having a CVA would be the following new onset of symptoms: Seizure, and right arm tremors. Sure seizures can result from a stroke and so can the possibility of right arm tremors. But the patient has been having right arm tremors which started several weeks ago…unless he’s been bleeding into his brain for the past several weeks (plus he’s on plavix, I wouldn’t expect him to be alive at the moment), that just seems unlikely that it could be from a hemorrhagic CVA (even though it doesn’t rule it out). At this point, suspicion of possibly a brain tumor is pretty high.
The patient also has sudden bouts of vomiting without warning. Generally if one feels nausea and wants to vomit, you’d be able to have a fore-warning that you’ll vomit. However, vomiting without warning is an ominous sign of neurological injury, such as the brain.
The neuro exam didn’t provide all the classic signs of a CVA:
- Equal grip strength
- No arm drift
- Patient confused and needs encouragement to respond to commands GCS 13 (4,4,5)
- Patient can look to the right, but needs encouragement and with difficulty can look to the left, cannot look up or down
- Patient has slightly droopy smile
However, it’s not often that patients present with textbook signs and symptoms in the field. The slightly droopy smile could be from the patient’s previous CVA, or a new one. However, the lack of arm drift and equal grip strength in my opinion further points to a possibility of a brain tumor. It would also make sense that depending on where the tumor is sitting, it could affect the patient’s gaze but perhaps not his motor skills in his arms. It is difficult to explain the vital signs though, perhaps it’s the patient’s fear that’s causing that response or (a guess on my part) perhaps the tumor is affecting certain nerves in the nervous system causing shock. As for the confusion, it could be from the seizure (postictal) he just had or it could very well be something going on in his brain.
Based on the normal temp., infection would go lower on the list of differentials and one can rule out hypoglycemia and epilepsy based on the sugar readings (5.6 mmol/L) and patient history.
Obviously, it’s impossible to come up with a diagnosis without confirmation from a CT scan. It could well have been a CVA or a brain tumor, but the two would be on the top of the differential diagnosis list. Based on the overall picture of the call, I would lean towards brain tumor over CVA. The main clues pulling me in that direction involves the medication plavix, relatively new onset of arm tremors, no previous hx of seizures, and the neurological exam.
(Feel free to respond with your thoughts and comments on this post).
What’s Your Differential Diagnosis Scenario cont’d…
Several hours later, you learn from the doctor that they did perform a CT scan and had found several tumours in your patient’s brain. During your call, your patient and bystander had neglected to tell you that the patient has had esophageal cancer, which had obviously now metastasized.
CVA—Key Differentiating Signs & Symptoms
|– Cushing’s triad
– Severe H/A
– Pinpoint or =/ unequal pupils
– Facial droop
– Slurred speech
Signs & Symptoms of Brain Tumor
Of course there are a lot of signs and symptoms of a brain tumor, but below is a short list of the possible signs and the similarities in the call above:
- Headache progressively worse, severe always in same location
+ blurred/double vision
- Seizures, esp with no history of seizures and older adults
- Decreased movement/sensation in an arm/leg
- Hand tremors
- Weakness, numbness
For more information, you can refer to the following links:
- Brain Tumor–NIH (National Institutes of Health–Medline Plus)
- Brain Cancer–eMedicineHealth
- Brain Tumor–MayoClinic