A rhizotomy is a procedure that deliberately damages specific nerve fibers to stop them from sending pain or spasticity signals to the brain. It’s used when chronic pain or muscle tightness hasn’t responded to other treatments, and it works by interrupting communication along targeted nerve roots. The term covers several different techniques, from heat-based nerve ablation to surgical cutting, depending on the condition being treated.
How a Rhizotomy Works
Nerves carry signals between your body and brain. When a nerve root becomes a source of chronic pain or drives excessive muscle tightness, a rhizotomy selectively damages that nerve fiber so it can no longer transmit those signals. Think of it as disconnecting a specific wire in a circuit. The surrounding nerves continue functioning normally, but the problematic one is taken offline.
This can be done through heat, chemical injection, physical compression, or surgical cutting. The method depends on which nerve is involved, what condition is being treated, and how permanent the results need to be. Some techniques are minimally invasive and performed through a needle, while others require open surgery under general anesthesia.
Types of Rhizotomy
Radiofrequency Ablation
This is the most common type for spinal pain. A specialized needle is guided to the target nerve using imaging, and the tip generates heat to create a small, controlled burn on the nerve. The procedure is done through the skin without a surgical incision, typically with local anesthesia and sedation. It’s most often used on the medial branch nerves that supply the facet joints of the spine, making it a go-to option for chronic neck and back pain caused by facet joint arthritis or degeneration.
Chemical Rhizotomy (Glycerol Injection)
In this approach, a small amount of glycerol is injected near the nerve root to chemically damage the pain-transmitting fibers. It’s primarily used for trigeminal neuralgia, a condition causing severe facial pain. The patient sits upright during the procedure so the glycerol pools around the correct nerve branch, then stays in that position for about an hour afterward.
Balloon Compression
Also used for trigeminal neuralgia, this technique involves threading a tiny balloon catheter through a needle to the nerve. The balloon is inflated for roughly 1.5 to 3 minutes, physically compressing the nerve fibers enough to disrupt pain signaling. This one requires general anesthesia because the compression itself would be painful.
Selective Dorsal Rhizotomy (SDR)
SDR is a distinct surgical procedure used primarily in children with cerebral palsy. Rather than targeting pain, it reduces spasticity, the constant muscle tightness that interferes with movement. A neurosurgeon identifies and cuts specific sensory nerve rootlets in the lower spine that are driving the abnormal muscle tone, while preserving the ones that function normally. This is open surgery and represents a significantly larger undertaking than the needle-based techniques.
Conditions Treated by Rhizotomy
Chronic Back and Neck Pain
Facet joint pain is one of the most frequent reasons people undergo radiofrequency rhizotomy. The facet joints are small joints along the spine that can become arthritic or inflamed, causing persistent pain that doesn’t respond to physical therapy, medications, or injections. Endoscopic rhizotomy, a newer variation that uses a small camera for direct visualization, provides pain relief in up to 80% of patients with this type of back pain and offers longer pain-free periods than traditional radiofrequency ablation.
Trigeminal Neuralgia
Trigeminal neuralgia causes sudden, severe jolts of facial pain that can be triggered by everyday actions like chewing or touching your face. When medications stop working, rhizotomy is one of the primary options. A 15-year follow-up study of 154 patients treated with radiofrequency rhizotomy found that 99% achieved initial pain relief after the procedure. Over time, about 25% experienced pain recurrence within 14 years, though the degree of recurrence depended heavily on how thoroughly the nerve was treated. Patients with more complete nerve disruption had a median pain-free period exceeding 15 years, while those with milder treatment stayed pain-free for a median of about 32 months.
Spasticity in Cerebral Palsy
SDR targets children with bilateral spastic cerebral palsy, typically between ages 5 and 7, who have moderate movement ability. The ideal candidates have adequate underlying strength and motor control that’s being masked by spasticity. For children who can walk, the primary goal is improving gait. For those who can’t, the focus shifts to making daily care easier and improving comfort. Beyond immediate symptom relief, SDR can change the long-term trajectory of the condition by preventing growth-related complications like contractures and bone deformities that develop when muscles stay chronically tight.
Patient selection is thorough. Centers evaluate children through physical examination, brain imaging, and 3D gait analysis. Some also use trial botulinum toxin injections to gauge how the child responds when spasticity is temporarily reduced. Families are assessed for realistic expectations and the capacity to commit to intensive post-surgical rehabilitation.
How You Qualify for a Rhizotomy
For spinal pain, you don’t go straight to rhizotomy. The standard pathway requires a diagnostic nerve block first, called a medial branch block. A doctor injects a small amount of local anesthetic near the suspected nerve to temporarily numb it. If your pain drops by more than 50%, that confirms the nerve is the source, and you’re considered a candidate for rhizotomy. International consensus guidelines recommend medial branch blocks over joint injections as the screening test because they’re more predictive of a good outcome from the actual procedure.
Some guidelines advocate for a single diagnostic block, while others recommend repeating it twice with a higher pain-relief threshold of 75% before proceeding. The logic is straightforward: the more confidently the pain source is confirmed beforehand, the better the results of the rhizotomy itself.
Patients on blood-thinning medications are generally advised against the procedure due to bleeding risk. Those with spinal hardware from previous surgeries, like pedicle screws, present a challenge because the metal can interfere with imaging guidance and potentially conduct heat from the ablation tool to surrounding tissue.
How Long Pain Relief Lasts
Rhizotomy provides real but not always permanent relief. Nerves can regenerate over time, and the underlying condition causing pain doesn’t go away. For radiofrequency ablation of spinal nerves, pain relief commonly lasts months to a couple of years before the nerve regrows and symptoms gradually return. The procedure can be repeated.
For trigeminal neuralgia, duration varies widely. In patients without other neurological conditions, more thorough nerve disruption extends relief dramatically, from under 3 years with mild treatment to over 15 years with more aggressive ablation. In patients who also have multiple sclerosis, outcomes are less durable. Studies in that population show average pain-free periods of about 23 to 26 months, with recurrence rates between 45% and 60%. This is partly because MS creates new areas of nerve damage in the brain that can reactivate pain pathways even after the peripheral nerve has been treated.
Risks and Side Effects
The most expected side effect is some degree of numbness or altered sensation in the area supplied by the treated nerve. This is essentially built into the procedure: you’re disrupting a nerve, so reduced sensation in that zone is the trade-off for pain relief.
The more concerning complication is called deafferentation pain, a new type of chronic discomfort that develops in the area where sensation was lost. After trigeminal rhizotomy, persistent uncomfortable sensations in the numbed zone develop in 5% to 15% of patients. These can take weeks or months to fully appear. For spinal rhizotomy, the rate is lower, under 4%, and tends to be worst right after surgery and improve over time rather than building gradually.
More selective techniques that target only the pain-carrying fibers while sparing touch sensation produce these complications at much lower rates. Temporary soreness at the procedure site, brief increases in pain, and minor swelling are common in the first few days but resolve quickly.
Recovery After Rhizotomy
Recovery looks very different depending on the type. Needle-based procedures like radiofrequency ablation are outpatient. You go home the same day, may have some local soreness for a week or two, and can typically return to normal activities within days. Pain relief sometimes takes a couple of weeks to fully set in as the treated nerve tissue breaks down.
Selective dorsal rhizotomy in children is a much larger recovery commitment. Physical therapy may be recommended up to 5 times per week after surgery. The intensity and duration depend on the child’s movement abilities before and after the procedure. Effective rehabilitation requires 30 to 45 minutes of daily practice focused on the specific motor skills the child wants to improve, with the child actively attempting the movements themselves rather than being passively moved. Families should expect months of dedicated rehabilitation, and the child’s long-term functional gains depend heavily on this commitment.