Months of Sciatic Leg Pain, Resolved by a Single L5 Nerve Root Block
Case Study Series
Patient Case Report • Sciatica • L5 Nerve Root Block • Fluoroscopic Guidance
Months of persistent sciatic leg pain — resolved completely by a single targeted nerve root block
How a fluoroscopy-guided right L5 nerve root block gave a 40-year-old woman, navigating a complex surgical history, complete and lasting relief from sciatic leg pain — after just one procedure
6 mo
Of persistent right-sided leg pain
1
Nerve root block needed
4 wks
To follow-up assessment
✓
Complete resolution
Emma R. — Aged 40
Persistent right-sided sciatic leg pain • Background of previous spinal surgery • Referred by her spinal surgery team • Complete resolution after a single injection
Right L5 radiculopathySpondylolisthesis with foraminal stenosisPrevious spinal surgeryComplete resolution post-injection
The Presentation
Persistent right-sided sciatic pain, intrusive but not disabling
Emma, a 40-year-old woman, was referred to PainSpa for consideration of a right L5 nerve root block after several months of persistent right-sided leg pain. Her pain radiated from the right buttock along the outer aspect of the leg as far as the ankle, though not typically into the foot, and was not accompanied by any pins-and-needles or other sensory disturbance.
She described the pain as sharp and ‘insistent’ — a quality she found genuinely difficult to ignore, even though its intensity varied considerably from day to day. Physical activity was the clearest aggravating factor: standing, walking and exercise consistently made things worse, while gentle movement was generally well tolerated. Her leg never gave way, she had no significant back pain, and there were no bladder or bowel symptoms to suggest any more concerning pathology.
Emma’s spine had a significant surgical history, and this added a layer of complexity to her presentation. She was referred to Dr Krishna for consideration of an image-guided right L5 nerve root block — a treatment her spinal surgery team felt was appropriate to try before considering any further surgical options.
Clinical Background
A longstanding spine, a new pattern of pain
Emma had undergone spinal surgery in the past, and this surgical history meant that any new intervention needed to be planned with particular care and precision.
Imaging confirmed the cause of her current symptoms: a spondylolisthesis at L4/5 with associated foraminal narrowing on the right side, compromising the right L5 nerve root. This corresponded closely with her pain pattern — a textbook L5 distribution running from the buttock to the outer leg and ankle. With conservative measures including physiotherapy and core strengthening already tried, and surgical revision not the preferred route at this stage, an image-guided nerve root block was a reasonable and appropriately conservative next step.
Understanding why a problem at the L5 nerve root produces leg pain in this specific pattern — and why a precisely targeted injection can be so effective — requires a brief look at the underlying anatomy and mechanism.
Understanding L5 nerve root pain and nerve root blocks
The L5 nerve root and the leg
The L5 nerve root carries sensory information from the buttock, along the outer thigh and lower leg, as far as the ankle. When this nerve root is compressed or irritated as it exits the spine, pain is typically felt along this exact distribution.
Spondylolisthesis and foraminal stenosis
Spondylolisthesis occurs when one vertebra slips forward relative to the one below it. This can narrow the foramen — the bony tunnel through which a nerve root exits the spine — compressing or irritating the nerve as it passes through.
The diagnostic-therapeutic block
A fluoroscopy-guided injection of local anaesthetic and steroid around the affected nerve root serves two purposes: confirming that this nerve root is the source of the pain, and, in many patients, providing meaningful and sometimes lasting relief.
Why image guidance matters
Performing the injection under real-time fluoroscopic (X-ray) guidance allows the needle and the spread of contrast and medication to be visualised directly, maximising accuracy and minimising the risk of complications.
Symptom Assessment
A clear, single-level nerve root pattern
Emma’s symptoms mapped consistently onto a single nerve root level. Her pain was unilateral, well-localised to a specific distribution, and notably free of the red-flag features that would raise concern about more serious pathology.
Pain quality
The defining sensory profile
Sharp, ‘insistent’ pain • Right buttock to outer leg and ankle • Not extending into the foot • No pins-and-needles or numbness
Aggravating & relieving factors
What made it better or worse
Worse with standing, walking and exercise • Gentle activity well tolerated • Variable day-to-day intensity • No sense of the leg giving way
Absence of red flags
What was reassuringly normal
No significant back pain • No bladder or bowel symptoms • No saddle disturbance • Pattern consistent throughout
Background & investigations
Context behind the pain
History of previous spinal surgery • Imaging-confirmed right L4/5 spondylolisthesis • Foraminal stenosis compromising right L5 root • Conservative measures tried first
The defining clinical feature: pain, imaging and anatomy all pointing to one nerve root
Emma’s case was notable for how cleanly her clinical pattern, her imaging findings and the underlying anatomy all converged on a single level — the right L5 nerve root. This kind of concordance is exactly what makes a nerve root block such an attractive option: a precisely targeted injection, guided by imaging, at exactly the level responsible for the pain.
The Treatment Journey
From referral to a single resolving injection
Dr Krishna’s approach combined a thorough assessment of Emma’s complex spinal background with a clear, staged plan: discuss all reasonable options including medication, agree that an image-guided nerve root block was the right next step, and use a single, precisely targeted procedure to settle her symptoms.
Initial Consultation
A detailed assessment of a complex history
Dr Krishna took a detailed history of Emma’s pain pattern and her previous spinal surgery, and reviewed the imaging confirming right L4/5 spondylolisthesis with foraminal narrowing and L5 nerve root compromise. Antineuropathic medication was discussed but, after considering her individual circumstances, deferred for the time being. A right L5 nerve root block under fluoroscopy guidance was agreed as the most appropriate next step.
Expectation-setting
An honest discussion of benefits and limits
Dr Krishna explained that nerve root block injections do not work for everyone, that any benefit may not be sustained, and that a temporary flare-up of symptoms is possible. He was clear that some patients need a further injection for lasting benefit, and that the underlying spinal changes would remain present on imaging regardless of how well the injection worked.
The Procedure
Right L5 nerve root block under fluoroscopy guidance
The injection was performed as a day case, using fluoroscopy (X-ray) guidance with local anaesthetic and steroid. Excellent spread of contrast was achieved around the nerve root, confirming accurate needle placement. There was no anticoagulation to manage and no relevant allergies, and the procedure was well tolerated throughout.
Follow-up Review
Complete resolution at four-week follow-up
At review around four weeks later, Emma reported complete resolution of her pain. She was no longer taking any painkillers and described herself as considerably more functional than before the procedure.
The PainSpa Approach
Four pillars of nerve root pain management at PainSpa
Managing nerve root pain on a background of previous spinal surgery calls for more than a single injection — it calls for careful assessment, precise targeting and an honest conversation about what to expect. Dr Krishna’s approach to Emma’s case reflected a structured model that he applies across his nerve root block practice.
1. Careful assessment of complex histories
Taking time to understand a patient’s full surgical and medical background before planning any new intervention, particularly where previous spinal surgery is involved.
2. Imaging-led, level-specific targeting
Using scan findings to confirm the precise nerve root responsible for symptoms, so that treatment is directed exactly where it is needed.
3. Image-guided precision
Performing every injection under real-time fluoroscopic guidance to maximise accuracy on the targeted nerve root and minimise the risk of complications.
4. Honest, shared decision-making
Realistic discussion of expected benefit, the possibility of a temporary flare-up, and the fact that a nerve root block treats symptoms rather than the underlying structural cause.
When imaging, examination and the pattern of pain all point clearly to a single nerve root, a precisely placed injection can make a profound difference — sometimes resolving symptoms completely with just one procedure. Emma’s case is a good example of how much can be achieved when the diagnosis is right and the treatment is targeted accordingly.
Dr Murli Krishna — Consultant in Pain Medicine, PainSpa
Outcome
Complete resolution at four-week follow-up
At review around four weeks after her right L5 nerve root block, Emma’s progress was striking. The persistent right-sided leg pain that had troubled her for several months had resolved completely.
Key improvements at follow-up
● Complete resolution of right-sided sciatic leg pain — following a single fluoroscopy-guided nerve root block, on a background of several months of persistent symptoms
● No longer requiring any painkillers — full discontinuation of all analgesia at follow-up
● Significant improvement in overall function — a marked change from her level of activity before the procedure
● Procedure well tolerated, with no complications and no flare-up of note
● A clean, single-injection result achieved despite a complex spinal surgical background
It is worth noting that a nerve root block does not address the underlying structural cause — in Emma’s case, the spondylolisthesis and foraminal narrowing remain present on imaging. Should symptoms recur in the future, a repeat injection can be considered, and a strong initial response is generally a good predictor of a similarly good response to any repeat procedure.
Dr Krishna was encouraged by the completeness of Emma’s response. Achieving full resolution of symptoms and a return to normal function from a single, carefully targeted injection is a genuinely good outcome, particularly in a patient whose spinal history added complexity to her care.
Looking Ahead
The next steps in Emma’s ongoing care
The right L5 nerve root block has achieved its primary goal: complete resolution of Emma’s leg pain and a clear improvement in her day-to-day function. The focus now shifts to sustaining this result and monitoring her underlying spinal condition.
Recommended ongoing management plan
PriorityContinue current activity levels, physiotherapy and core strengthening to help maintain the improvement achieved.
OngoingRemain under the shared care of her spinal surgery team for monitoring of the underlying spondylolisthesis and foraminal stenosis.
If neededOption to repeat the nerve root block should symptoms recur; a strong initial response is generally a positive predictor for a repeat procedure.
OpenAn open follow-up appointment remains available with Dr Krishna, allowing Emma to re-engage with specialist input at any point.
Your Specialist
About Dr Murli Krishna
Dr Murli Krishna
Consultant in Pain Medicine — PainSpa
MBBS • FRCA • FFPMRCA • Fellow of the Faculty of Pain Medicine
Dr Krishna is a highly experienced Consultant in Pain Medicine practising at PainSpa’s clinics in Bristol, including Willow Surgery in Downend and the Chesterfield Nuffield Hospital in Clifton. He specialises in the diagnosis and image-guided interventional management of spinal and nerve root pain, including nerve root blocks, facet joint injections and radiofrequency procedures, alongside the wider range of chronic pain conditions.
His approach to nerve root pain is grounded in a detailed assessment of each patient’s full surgical and medical history, precise imaging-guided targeting, and close collaboration with referring spinal surgeons. Every procedure is performed under real-time fluoroscopic or ultrasound guidance, and every plan is built around a frank, realistic conversation about expected benefit and the limits of injection therapy.
Dr Krishna consults in person and via telephone or videolink. Patients interested in exploring nerve root block injections for sciatica or related conditions are encouraged to contact PainSpa to arrange an initial assessment consultation.
Please note: This case study is published for educational and informational purposes. All patient-identifying details — including name, age, occupation and location — have been changed or generalised to protect patient confidentiality. Patient consent to publish has been obtained. Individual results from nerve root block injections vary considerably; these procedures do not guarantee improvement and are not effective for every patient. They are an adjunct to, and not a replacement for, ongoing medical and surgical care. This does not constitute medical advice. Please contact PainSpa to discuss your individual circumstances. For complaints or queries, please write to clinic@painspa.co.uk.
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