Exam day blues... (the time I wrote about GBS without studying anything about it)

Sitting in my dorm room, I was preparing to read about GBS. I was tired of the long hours of studying and had an intention of skipping this chapter. I argued with myself that probably nothing will be asked about it in the exam. There are only about 1-4 cases for every 100,000 patients and chances are there that I might not even meet one. I was convinced not to read about it and if they ask about it in the exam I know it is an autoimmune disease that attacks the neurons and nerve roots (polyradiculoneuropathy). I can surely spin a story around it.

The day of the exam arrived. Seated in the examination hall I couldn’t wait to get this over with. It was like waiting to rip off a band aid. The examiner started giving the question paper. I took the paper in my hand and skimmed through the paper. It seemed pretty easy. I turned the pages to view the detailed question that was worth 20% of the paper. No surprises there- they wanted a detailed description of GBS. Immediately my brain yelled "You are screwed."

After finishing all the other questions in the exam I started on writing a detailed description of GBS. What did I remember? I remotely remembered that this disease was an autoimmune disease similar to a terrorist attacking a city (sudden and severe in nature.)

That would fetch me two points.

For the remaining 18 points I decided to make 9 more categories. Each category may fetch me at least one point. After spending some thought on it I decided on the following categories “Etiology, Risk factors, Pathophysiology, Types, Clinical features, Diagnosis, Differential diagnosis, Management, Treatment.”

My friend had mentioned that the risk factors are similar to Camping in a Bar with Herpes and HIV singing in a Mega Microphone. I could write about the infectious risk factors now:

1. Campylobacter jejuni (most common)
2. Epstein-Barr virus
3. Herpes
4. HIV
5. CytoMegalovirus
6. My(i)coplasma pneumoniae

Sitting in the audience is Dr.Gregory House saying “It’s lupus” and  Shakira dancing in the background singing “Vacca vacca” and sneezing at the same time. So, the non infectious causes are:

1. Adult men
2. SLE
3. Influenza vaccine

I had successful written about risk factors.

About the pathophysiology I knew nothing about it except the incubation period. GBS can be written in a single word or in three words. That is how I remembered that the incubation period is 1-3 weeks.

I decided to derive the clinical manifestations from the effect.
What happens when neurons and their junctions are destroyed?

1. Nerve damage leads to paralysis (ascending in this case).
2. Nerve root damage leads to pain, numbness, weakness and poor muscle control.
3. Deep tendon reflexes might be absent because of polyradiculoneuropathy.

When our professor was teaching us this chapter I remember that we were making fun of the types... “Aid a MAN, aS(i)AN and a Fish”. Hence the types could be:

• AID (Later I found that it was AIDP)
• AMAN
• ASAN (Later found it to be AMSAN)
• Fisher syndrome (Later found that this was actually Muller Fischer syndrome. Close enough, I guess)

Next I had to write on how to diagnose the disease. Since the disease damages neurons and nerve roots, Nerve conduction velocity could be slow in these patients. Given the infectious nature of most causes of GBS a look at the CSF could give us an idea if its infectious in nature or not. For the non infectious causes- CBC for SLE and knowledge of vaccine history could help us to ascertain the cause. The history, signs and symptoms alone can ascertain whether the disease is GBS or not.

Had no idea about the DDx. Hence skipped writing about it. 

Other diseases that may  resemble GBS are as follows:

• Acute myelopathies
• Diphtheria 
• Lyme polyradiculitis and other tick-borne paralyses
• Porphyria 
• Vasculitic neuropathy 
• Poliomyelitis  
• West Nile virus
• CMV polyradiculitis
• Myasthenia gravis 
• Botulism
• Poisonings with organophosphates, thallium, or arsenic
• Shellfish poisoning

It is quite an extensive list. Isn’t it?

I somehow remembered that the treatment is high dose IVIG. Forgot that plasmapharesis is usually an adjunct treatment.

I don’t know how much I scored on this particular question but I passed the exam and that is all that mattered.