​Case Study #1: MG

​Let's do a quick review...

​Treatment

​Case Study: Casey

​Casey, a 32 year old male, is a computer programmer and an avid hiker.

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​Casey is hiking with his best friend (who happens to be a third year medical student) when he tells him towards the end of the hike "my tongue feels weird, it's almost like I don't have control over it sometimes".

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​He also tells his friend he feels like one arm is weaker than the other sometimes. His friend is concerned about the report of these symptoms even though they are vague and non-specific. He tells Casey "I think something might be wrong with you man, like maybe you have MS or something".

Visit to PCP​

​Casey has no past medical history and is very healthy but the comment by his friend is enough to scare Casey into going to see his nurse practitioner. He reports his symptoms to his NP which also include fatigue, weight loss, double vision and difficulty swallowing.

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​What types of follow up questions would you want to ask Casey about his symptoms?

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​What diagnostic exams would you anticipate might be ordered?

​Diagnostic Tests

​Casey's NP orders an MRI of the brain without contrast and the results are normal.

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​She also orders a typical round of bloodwork (CBC, CMP, thyroid panel, B12 level, LFTs, etc.) but all the lab work comes back unremarkable.

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​She then orders an antinuclear antibody (ANA) as well as an AQP4 antibody and an MOG-IgG antibody test. These tests come back negative as well.

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​After his NP's diagnostic work up comes back without any answers she refers him to a local neurology specialist for further investigation.

​Neurology Referral

​Casey's neurologist orders an EEG (normal) and EMG (abnormal).

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* Prior to 2018 she may have ordered a Tensilon test: edrophonium chloride is given IV and improved muscle contractility and strength are noted *

​Edrophonium chloride was the drug of choice for diagnosing MG because it is reversible, has a rapid onset and a short duration. It briefly improves symptoms by increasing the amount of acetylcholine in the NMJ synapses. However, the FDA discontinued this medication due to a high false positive rate and development of serological antibody testing that is now the gold standard.

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​AchR antibodies and MuSK antibodies are both present in Casey's serum and he is diagnosed with myasthenia gravis. Next, a CT of the chest is ordered.

​Difficult Diagnosis

​Is Casey typical or an atypical presentation of myasthenia gravis?

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​Why or why not? Explain your rationales.

​Types of Strokes

​Right hemisphere

​Left hemisphere

​Cerebellar

​Brain stem

​Hemorrhagic

​Case Study: Shelby

​Shelby is a 27 year old mother of 2 young children. She works at a bank and her husband owns a landscaping business she helps run.

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​She has no known past medical history other than child birth, she takes OTC cetirizine for occasional seasonal allergies and is prescribed Ortho-Novum for birth control and acne treatment.

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​She is at home gardening one summer morning when she suddenly feels very dizzy. She also feels like she isn't speaking normally and her husband confirms her speech is abnormal. Her gait is unsteady.

​Shelby's Story continued

​Shelby lies down and rests for awhile to try to abate the symptoms but an hour later the symptoms are no better, in fact, they are a little worse.

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​Shelby's husband drives her to the ED (it's a weekend and her PCP office is closed). The ED checks her vital signs: HR 95, BP 145/79, RR 20, SpO2 97%, temp 97.9 F. They ask her questions about her symptom onset, any other associated symptoms, past medical history, medications, etc. A 12 lead ECG is performed.

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​A CT scan of the head without contrast is done and results are normal.

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​She is diagnosed with vertigo, given a prescription for meclizine and discharged.

​Follow Up with PCP

​A few weeks later Shelby follows up with her PCP.

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​Upon entering the exam room, Shelby's nurse practitioner begins asking her questions about her ED visit and her symptoms. The NP notes that her speech is so slurred that "if she didn't know better she would have thought she was drunk."

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​Based on her continued symptoms Shelby's NP arranges for an urgent MRI without contrast. The MRI reveals abnormalities in her cerebellar region and the radiologist suggests another MRI with contrast for full evaluation. It is ordered and performed and the diagnosis of multi-infarct cerebellar CVA is made.