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MODULE 8:
NERVOUS TISSUE
PART 5 OF 7
Looking back, a year of creeping foot numbness she explained away — “bad shoes,” “standing too long.” Pre-dates the crash. A slow, sensory-predominant pattern hiding in plain sight.
Slide 1 Transcript
PATIENT CHART
STINA
THIS PART
Age 35
PRESENTING WITH
Numbness, tingling, and a hot stripe of pain down her left leg, slowly creeping, symmetric foot numbness
DIAGNOSIS
Anti-MAG peripheral neuropathy
DRUGS ORDERED
Rituximab
CHART CLUES
COLLECTED AS YOU GO
Radiating Leg Pain & Numbness After a ‘Clear’ Crash
Symmetric Loss of Light-Touch & Vibration
Slowed Nerve Conduction
Synapse Intact — the Fault Is Upstream
Anti-MAG Antibodies
A Map Pointing at Two Nerve Roots
Anti-MAG, Sensory-Predominant Peripheral Neuropathy
Put your money down: Numbness that came first — coincidence?
The numbness pre-dated the crash by a year. Was the accident ever really the cause?
Pick the answer you believe now. We’ll come back to it later!
The Numbness That Began Before the Crash
Once Stina started paying attention, the timeline rearranged itself. The numbness hadn’t begun with the crash at all. For a year before it, her feet had felt subtly off — she’d blamed bad shoes, long shifts on hard floors, getting older. It crept up slowly and evenly from both feet, more numbness than weakness, more nuisance than alarm. She had explained it away a hundred small times. The crash didn’t create the problem; it just turned up the volume on something that had been fraying quietly for a long while.
When the Insulation Frays
Lose the myelin, lose the leap — and the signal falls behind.
Slide 2 Transcript
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Fill in the Blanks: Fill in what fraying myelin does to the signal.
Anti-MAG Antibodies
The immune system turns on the very wrap it should protect.
Slide 3 Transcript
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Multiple Choice: Which protein do Stina’s own antibodies attack?
How Anti-MAG Loosens the Insulation
Here is the mechanism. Recall MAG, the protein anchoring the innermost wrap of peripheral myelin to the axon. In anti-MAG neuropathy, the immune system makes antibodies against MAG; those antibodies attack that innermost wrap and loosen it, so the myelin no longer hugs the axon tightly. With the insulation compromised, saltatory conductionThe rapid transmission of impulses in myelinated axons by jumping between nodes of Ranvier. falters and signals slow — and because the longest sensory nervesNerves that carry signals from sensory receptors to the CNS. to the feet are hit first and hardest, the result is a slowly progressive, symmetric, sensory-predominant numbness. That is Stina’s pattern exactly: both feet, creeping upward, sensation more than strength.
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Slide 4 Transcript
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Slide 5 Transcript
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The Same Fire, Now Reaching Her Nerves
Anti-MAG neuropathy is antibody-driven, and in a patient with lifelong autoinflammation, chronic immune activation is the soil such autoantibodies grow in. The fraying insulation is not an accident of the crash — it is the same systemic fire, now reaching her nerves.
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Slide 6 Transcript
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Slide 7 Transcript
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FINDING!
Anti-MAG Antibodies — Her Own Immune System Stripping Myelin
A slowly progressive, symmetric, sensory-predominant numbness that pre-dates the crash — driven by anti-MAG antibodies loosening the innermost peripheral myelin. New evidence rewrites the story: the accident unmasked the timeline, it didn’t cause the disease. This ties her neuropathy to the chronic inflammation running the whole course.
Confirm or refute your bet:
The numbness pre-dated the crash by a year. Was the accident ever really the cause?
Slide 8 Transcript
NEXT PART
If we know which nerves are numb, we can read a map of the body to find exactly where the damage points. Next: the dermatomeA specific area of skin supplied by a single spinal nerve. that traces Stina’s loss straight to a disc.
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List of terms
- saltatory conduction
- sensory nerves
- dermatome
- development