Carpal Tunnel Syndrome Treatment London | Private Ultrasound Diagnosis & Injections

Carpal Tunnel Syndrome Explained

Carpal Tunnel Anatomy & Carpal Tunnel Syndrome

The carpal tunnel is an anatomical region located on the palm side of the wrist. It is formed by the wrist bones on the deeper aspect and is enclosed by a thick, broad ligament that attaches to the scaphoid and trapezium bones on the radial (thumb) side, and the pisiform and hamate bones on the ulnar (little finger) side.

Through this tunnel run the tendons of the flexor forearm muscles as well as the median nerve, which supplies motor power to some of the thumb movements and provides sensory sensation to the thumb, index finger, and middle finger.

Carpal Tunnel Symptoms

The location and course of the distal aspect of the median nerve typically delivers sensation to the thumb and adjacent to fingers as well as providing strength and power mainly felt with some movements. 

If significantly inflamed the median nerve may give rise to pain in the palm of the wrist radiating into the thumb muscle bulk and index and middle fingers. In some cases pain may radiate upwards towards the elbow due to compression of the median nerve. 

Typically symptoms are worse overnight as our wrists fall into a flexed position increasing the pressure in the carpal tunnel or with movements involving sustained extension or flexion of the wrist or pressure through the palm side of the wrist and hand.

What Causes Carpal Tunnel?

Carpal tunnel syndrome is a condition in which the median nerve becomes irritated, giving rise to characteristic sensory symptoms and pain in the median nerve distribution of the hand.

Although not every case of carpal tunnel syndrome can be clearly attributed to a specific cause, the primary issue is typically due to pressure changes within the carpal tunnel or compression of the median nerve.

Common contributing factors include:

• Pregnancy (due to fluid retention and hormonal changes)

• Persistent inflammation or thickening of the wrist joint, as seen in inflammatory arthritis or severe osteoarthritis of the wrist or thumb

• Occupational activities involving repetitive weight-bearing through the palm (e.g. using work tools)

Typically, carpal tunnel symptoms are worse overnight, due to increased pressure within the carpal tunnel when the wrist is flexed during sleep.

Carpal Tunnel Diagnosis

Diagnosing carpal tunnel syndrome is best achieved through a combination of:

• Careful history-taking

• Physical examination

• Wearing a wrist brace overnight to prevent the wrist from falling into a prolonged flexed position during sleep can serve as both a therapeutic trial and a way to confirm clinical suspicion. If symptoms improve with bracing, this suggests a local wrist-related issue.

Ultrasound imaging has been validated against diagnostic parameters for carpal tunnel syndrome. Although the median nerve shows anatomical variation between individuals, ultrasound can readily visualise the median nerve within the carpal tunnel in transverse view. The cross-sectional area of the nerve can be measured, which has diagnostic value in carpal tunnel syndrome.

Where necessary, nerve conduction studies can also be requested to confirm the conductivity of the median nerve.

Carpal Tunnel Ultrasound Guided Injections

How is a Carpal Tunnel injection administered?

If a trial of stretching, night-time bracing, and activity modification has failed to relieve symptoms, an ultrasound-guided injection can be administered into the carpal tunnel.

This procedure can be performed with the ultrasound probe placed along the carpal tunnel in a transverse orientation. The needle is visualised advancing from the near side of the probe, passing adjacent to and just deep to the median nerve, and the injectate (steroid) is seen delivered at the correct location.

Alternatively, an out-of-plane technique can be used. In this approach, a centreline is used to align the median nerve next to the centre of the ultrasound image, and the needle is advanced to the correct depth to safely deliver the injection.

What to Do After Your Carpal Tunnel Injection

Needle Path & Post-Injection Pain
Although the carpal tunnel is easily visualized and accessed under ultrasound guidance and is superficial as a structure we will be injecting small amounts of steroid fluid into an already compressed and irritated area. 

This does mean that carpal tunnel syndrome symptoms can increase for several days following a carpal tunnel injection and this pain may be felt immediately after the injection.

It is advisable for patients to have access to a wrist brace during this time in case they suffer any post injection in increase in symptoms.

Wound Care & Infection Risk
Avoid exposing the needle site to public or dirty water (e.g., swimming pools, hot tubs, lakes) for 2–3 days after any ultrasound-guided injection, due to the small infection risk.

Activity Guidance
After a carpal tunnel injection, it is advisable to avoid any significant increase in activity for 10-14 days.
This allows the anti-inflammatory properties of the steroid to work optimally.

Follow-Up
Following a carpal tunnel injection, please contact me immediately if you experience any difficulties.

Other Treatments for Carpal Tunnel Syndrome

Carpal Tunnel Syndrome Splints

Carpal Tunnel Physical Therapy Exercises

Carpal Tunnel | Evidence base

Carpal tunnel syndrome is a compressive neuropathy of the median nerve at the wrist, commonly presenting with nocturnal paraesthesia, hand weakness, and functional impairment. The condition may be transient or progressive, depending on severity and underlying risk factors. Evidence supports a conservative approach in mild to moderate cases, with splinting, activity modification, and targeted therapy as first-line management. Corticosteroid injection into the carpal tunnel has strong evidence for short- to medium-term symptom relief, and can delay or reduce the need for surgery in selected patients. Ultrasound guidance improves the accuracy and safety of injection, allowing real-time visualisation of the median nerve, flexor tendons, and vascular structures, and reduces the risk of intraneural or intravascular injection. Comparative studies suggest US-guided injections may provide superior symptom improvement and lower complication rates compared with landmark-guided techniques, particularly in patients with anatomical variation, diabetes, or recurrent symptoms. Symptom relief is often temporary, and repeat injections should be limited due to diminishing benefit and potential nerve or tendon effects. Surgical decompression remains the definitive treatment for patients with severe, progressive, or refractory symptoms. Overall, ultrasound-guided corticosteroid injection is a well-supported, low-risk intervention for symptom control in carpal tunnel syndrome and is most effective when integrated into a broader management plan.

Questions about your wrist pain?