Walk across a lawn once and nothing changes.
Walk the same line a hundred times and you’ve made a path. Now it’s the easiest way to go. Your feet take it without asking.
Your nervous system works the same way. And that’s the key to understanding a lot of chronic pain.
Every time a pain signal travels from your body to your brain, it leaves a trace. Nerves that fire together get better at firing together. The connection gets stronger. Faster. Louder.
This is called neurosensitisation, or central sensitisation. The system hasn’t broken. It has learned.
It learned that this signal matters. So it stopped waiting for permission.
Here’s what that looks like from the inside.
Pain that outlasts the injury by months or years. Pain that spreads beyond where it started. A gentle touch that hurts (allodynia). A small hurt that feels enormous (hyperalgesia). Fatigue, poor sleep, a body that feels permanently on edge.
People are often told their scans look fine. They are, in a sense. The problem isn’t in the tissue anymore. It’s in the path.
Think of it like microphone feedback.
A whisper goes into the mic. The speaker plays it back. The mic picks it up again, slightly louder. Round and round, until a whisper becomes a screech.
Nobody fixes feedback by yelling at the speaker. You change the loop.
Two ways to interrupt the loop
Most chronic pain treatments try to turn down the input. Rest the joint. Numb the area. Block the nerve at the source.
But when the loop itself is the problem, it makes sense to target the loop. Two treatments are drawing attention because that’s precisely what they try to do.
Stellate ganglion block
The stellate ganglion is a bundle of sympathetic nerves at the base of the neck. The sympathetic system is your threat response: heart rate, alertness, blood flow, readiness to fight or flee.
In many people with sensitised pain, that system is stuck on. And a stressed nervous system amplifies pain signals, which creates more stress. Another feedback loop.
A stellate ganglion block delivers local anaesthetic to that nerve bundle, guided by ultrasound or imaging. It’s been used for decades for conditions like complex regional pain syndrome, where sympathetic activity appears to drive the pain. It’s also been studied for PTSD, with a 2020 randomised trial in JAMA Psychiatry showing a meaningful benefit over a sham procedure.
What it offers is a pause. Quiet the sympathetic amplifier, and the whole system gets a chance to settle.
Some people get lasting relief, some need repeat blocks, some don’t respond. It’s a tool, not a guarantee.
Ketamine infusions
Ketamine goes after the path itself.
Sensitisation relies heavily on NMDA receptors, the machinery that lets nerve connections strengthen with repetition. It’s how the path in the grass gets worn in. Ketamine blocks those receptors.
Given as a low dose, supervised infusion, ketamine may help reverse some of that amplification. There’s also evidence it creates a temporary window of neuroplasticity, a period where the brain is more open to forming new patterns and letting old ones fade.
It’s used for conditions like CRPS, neuropathic pain, nervous system sensitisation. Benefits may last months but it is not for everyone. Side effects are real, including nausea, blood pressure changes, dissociation and potential effects on the liver and bladder with repeated use. It needs proper medical oversight.
The part that matters most
A worn path doesn’t disappear just because you stop walking on it for a day.
It fades when you walk somewhere else, again and again.
That’s the real opportunity with both of these treatments. They don’t erase sensitisation. They open a window where the volume is lower and the system is more flexible. What you do with that window counts.
Graded movement. Pain education. Sleep. Therapy that addresses fear and trauma. A care team that sees the whole picture. These are the new paths. The procedure just makes them easier to start walking.
A different question
For years the question was: where is the damage?
For sensitised pain, a better question might be: what has the nervous system learned, and how do we help it learn something else?
That’s a hopeful question. Because anything learned can be relearned.
If this sounds familiar, talk to our Pain Specialists about whether your pain has a sensitisation component and whether options like stellate ganglion block or ketamine infusion fits your situation.
The path was made one step at a time. So is the new one.