The Wind-Up Protocol — A Stable Baseline in Healthy Nervous Systems
Short placeholder: identical repeated pinpricks, flat pain rating in healthy controls.
- Pinprick / von Frey: Stimulus type (placeholder caption)
- 1 Hz: Repetition rate (placeholder caption)
- ±0.3 / 10: Healthy rating drift (placeholder caption)
- ~10 sec: Test duration (placeholder caption)
What the test measures
Placeholder: same stimulus, repeated, tracks perceived pain over time.
Why healthy responses stay flat
Placeholder: normal dorsal horn gain control prevents amplification.
Stimulus One in Fibromyalgia — Indistinguishable From Healthy
Short placeholder: the first hit looks identical between groups, that is the trap.
- ~2.8 / 10: FM rating, stimulus 1 (placeholder caption)
- ~2.6 / 10: Healthy rating, stimulus 1 (placeholder caption)
- ~12%: NMDA activation (placeholder caption)
- 100% baseline: Threshold (placeholder caption)
Why single stimuli mislead
Placeholder: one pinprick cannot reveal sensitization, repetition can.
Setting up the comparison
Placeholder: same applicator, same force, same rate, both groups.
Temporal Summation — Repeats Two and Three Amplify the Signal
Short placeholder: NMDA receptors unblock, each repeat feels bigger.
- ~4.4 / 10: FM rating, stimulus 3 (placeholder caption)
- ~31%: NMDA activation (placeholder caption)
- Relieved: Mg2+ block (placeholder caption)
- ~13%: Threshold drop (placeholder caption)
NMDA receptor unblocking
Placeholder: depolarization removes magnesium block, calcium floods in.
Wide-dynamic-range neuron output
Placeholder: neuron firing rate climbs with each identical input.
Later Repeats — Pain Rating Outpaces Stimulus Intensity
Short placeholder: by repeat seven, rating is far above what force alone predicts.
- ~8.5 / 10: FM rating, stimulus 7 (placeholder caption)
- ~69%: NMDA activation (placeholder caption)
- ~61%: Pain threshold (placeholder caption)
- ~2.7 / 10: Healthy rating, stimulus 7 (placeholder caption)
Threshold lowering
Placeholder: less input now needed to trigger the same pain.
Clinical relevance
Placeholder: mirrors widespread spontaneous pain reported in fibromyalgia.
Flat vs Escalating — Objective Evidence of Central Sensitization
Short placeholder: two curves, one test, a measurable diagnostic signature.
- ~10 / 10: FM rating, stimulus 10 (placeholder caption)
- ~2.6 / 10: Healthy rating, stimulus 10 (placeholder caption)
- ~7.4 pts: Curve separation (placeholder caption)
- ~41%: Threshold, stimulus 10 (placeholder caption)
Reading the dual-line chart
Placeholder: flat line healthy, rising line fibromyalgia wind-up.
Bedside diagnostic value
Placeholder: simple, low-cost, objective marker of sensitization.