Two Pedals

Time To Read

2–3 minutes

Date Last Modified

11

CHART CLUE

Three specialists, three “unrelated” problems: a neurogenic bladder that ignores Stina’s commands, electric jolts of face pain, and a high-frequency hearing loss creeping in early. Read together — autonomic instability, a demyelinating cranial neuralgia, and inflammatory sensorineural hearing loss — they are one systemic disease, FMF, touching nearly the whole nervous system.

Stina used to describe a flare as feeling “floored” — heart pounding, mouth dry, a wired-but-exhausted buzz, as if her body were braced for a threat that never came. In calmer stretches the opposite ruled: a sluggish, heavy, “shut-down” feeling. She didn’t have a word for it, but she was describing the two halves of her autonomic nervous system fighting for the wheel.

The ANS works like a car with two pedals. The sympathetic division is the accelerator — “fight or flight.” It speeds the heart, dilates the pupils and airways, mobilizes energy, and diverts blood to muscle; anatomically its nerves emerge from the thoracic and lumbar spinal cord (thoracolumbar). The parasympathetic division is the brake — “rest and digest.” It slows the heart, constricts pupils, and stimulates digestion and bladder emptying; its nerves emerge from the brainstem and sacral cord (craniosacral), including the wide-ranging vagus nerve. Most organs receive dual innervation from both divisions, and health is a moving balance between them — accelerator and brake trading control moment to moment. In dysautonomia that balance breaks: a “revved” flare is the accelerator stuck down, the brake unable to answer. Stina’s contradictory feelings were two pedals out of sync.

From Stina’s chart: Stina’s flares come with a “revved” feeling — pounding heart, dry mouth, wide pupils — that doesn’t match the moment. This page names the pedal that’s stuck down.

Two pedals are only as good as the signals that work them. Next: the chemical messengers and receptors that let each division speak — and how inflammation can scramble the message.

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The Bladder That Won’t Listen

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Chemical Messengers

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