An illustration of the importance of pattern recognition in Neurology. At the outset, let me reveal this is a Myopathy. Try to note how this particular one is different from others. 10 years history
As with most myopathies, limb girdle weakness is present
But wait! Foot drop and prominent distal muscle weakness in a muscle disease??
And look at how strong the Quadriceps are! weak proximal and weakness with selective sparing of the quadriceps!
So this is a 10 year story. Muscle disease with distal weakness(foot drop). Sparing the quadriceps. CPK isn't all that high. This is GNE Myopathy (Nonaka Myopathy)
Not all myopathies are purely proximal. There is a distinct set of Distal Myopathies, GNE being one of the commoner ones seen in India
It classically spares the quadriceps muscle, mostly affects Tibialis Anterior. Inheritance is Autosomal Recessive, usually in 3rd decade of life
The weakness may be asymmetric as well
Muscle biopsy shows rimmed vacuoles, and the CPK may not be excessively elevated.
If you think of it. A distal myopathy, asymmetric, modest CPK elevation, rimmed vacuoles. Sounds familiar?
It's similar to Inclusion Body Myositis!
In fact, GNE was initially known as hIBM-2
Again, pattern recognition!
GNE gene encoded proteins involved in the formation of sialic acid.
There is yet another striking clinical feature of GNE/Nonaka Myopathy. I have alluded to it in an earlier post. Can you remember it?
• • •
Missing some Tweet in this thread? You can try to
force a refresh
In the angstful days of early residency, I used to spend my time between patients with Rage Against blaring through my headphones. The song became the steadfast soundtrack to the trips to and from Ward 23.
A man’s mood is dictated by his favourite song that day. And the student physician’s diagnosis by the disease he studied the previous night.
Those days, my mind was wild like an elephant in rut.
Often, obsession seizes the fledgling doctor’s mind, biased by the unrelenting pursuit of knowledge. Once the young physician reads about an illness, it is seen everywhere. The Baader-Meinhoff Effect.
One can read about Absence Seizures from a plethora of Neurology textbooks, but the best description of the semiology of absence seizures I have ever read is not from a neurology textbook but Russian literature! (1/n)
The great Fyodor Dostoevsky himself unfortunately suffered from epilepsy and indeed epilepsy comes up in most of his stories. He was well acquainted with the disease!
The best description of Absence Seizures comes in The Brothers Karamazov. The patient is Smerdyakov
I shall quote from the translation by Constance Garnett, the most wonderful description of the illness
Lets take the example of a patient (27/Lady) who has come to you with a history of weakness of lower limbs since the past 1 week, that has progressed over that week
How To Find Patterns (and personalities?!) in Diseases to make a Diagnosis.
See this video, and think about it for a while.
Think about it and make your observations.
For the sake of this discussion, let us cut to the chase. I will give you the diagnosis first, and together we will reverse engineer the case.
This gentleman has a pure motor weakness, that localises to the muscle. The final diagnosis Inclusion Body Myositis (IBM), a type of Inflammatory Myositis.