Carpal tunnel syndrome: what it is, symptoms and treatment
Carpal tunnel syndrome is the most common compression neuropathy. In this guide we explain what it is, why it occurs, how it is diagnosed with electromyography and ultrasound, and what conservative and surgical treatment options we offer at Brain & Spine Barcelona.
Carpal tunnel syndrome causes tingling, numbness and pain in the hand due to compression of the median nerve at the wrist. Detecting and treating it in time prevents permanent loss of sensation and strength. In Barcelona, our peripheral nerve surgery unit assesses each case on an individualised basis.
What is carpal tunnel syndrome?
Carpal tunnel syndrome is the most common entrapment neuropathy. It occurs when the median nerve becomes compressed as it passes through the carpal tunnel, a narrow canal on the palmar side of the wrist. This compression disrupts normal nerve conduction and reduces the nerve's blood supply, causing the characteristic symptoms.
Numbness and tingling usually affect the hand and wrist, although they may also radiate to the forearm or upper arm. It is a treatable condition, but when left without treatment it can cause permanent loss of sensation and muscle weakness.
Anatomy of the carpal tunnel
The carpal tunnel is a rigid conduit formed at its base and sides by the carpal bones and closed at the top by the transverse carpal ligament (also called the flexor retinaculum). Through this space, which cannot expand, run nine finger flexor tendons and the median nerve.
The median nerve is responsible for sensation in the thumb, index finger, middle finger and half the ring finger, and controls some of the muscles that move the thumb. Any process that increases pressure within this enclosed space compresses the nerve against the ligament and triggers the condition.
Causes and risk factors
In many cases there is no single identifiable cause. The syndrome develops when inflammation or increased volume of tissues inside the tunnel raises pressure on the nerve. The main risk factors are:
- Repetitive hand and wrist movements, or prolonged use of vibrating tools.
- Previous wrist injuries or fractures that narrow the canal.
- Hormonal and metabolic factors: pregnancy, hypothyroidism, diabetes and obesity.
- Inflammatory conditions such as rheumatoid arthritis.
- Anatomical predisposition: a naturally narrower carpal tunnel, often hereditary.
- Female sex and middle age, when incidence is higher.
Symptoms
Symptoms usually begin gradually and intermittently. The most common are:
- Tingling, numbness and burning sensation in the thumb, index, middle and half the ring finger.
- Nocturnal worsening that wakes the patient and requires shaking the hand to relieve the discomfort.
- Pain that may radiate towards the forearm.
- A sense of clumsiness or swelling in the hand and difficulty with fine tasks.
- In advanced stages, weakness and atrophy of the thenar muscles with loss of grip strength.
Diagnosis: electromyography and ultrasound
Diagnosis begins with a detailed clinical history and neurological examination including provocative manoeuvres (Tinel's sign and Phalen's test). To confirm it and grade its severity, complementary tests are used:
- Electromyography and nerve conduction studies (EMG): measure the speed at which the median nerve transmits impulses and quantify the degree of involvement. It is the reference test.
- Ultrasound: visualises the median nerve, assesses its thickness and allows ruling out cysts, tenosynovitis or other space-occupying lesions within the tunnel.
- MRI: reserved for selected or atypical cases.
These tests also allow carpal tunnel syndrome to be distinguished from other conditions, such as cervical nerve root compression, which can produce similar symptoms in the hand.
Conservative treatment
In mild and moderate stages, non-surgical treatment is started, especially effective when symptoms have been present for a short time:
- Night splints that keep the wrist in a neutral position and reduce pressure on the nerve.
- Activity modification and workplace ergonomic improvement.
- Anti-inflammatory drugs to manage pain during flares.
- Corticosteroid injections into the tunnel, which can temporarily relieve symptoms.
Surgery: open vs. endoscopic release
When conservative treatment does not control symptoms, or when weakness, atrophy or advanced involvement on electromyography is already present, carpal tunnel release surgery is indicated. The aim is to divide the transverse carpal ligament to decompress the median nerve. It is a day procedure usually performed under local anaesthesia.
Open release
Performed through a small incision in the palm of the hand that provides direct visualisation of the nerve and the ligament. It is a thoroughly validated, safe and reproducible technique.
Endoscopic release
Uses a smaller incision through which a camera is introduced to divide the ligament from the inside. It is generally associated with a somewhat faster functional recovery and less scar discomfort. The choice between the two techniques is made by the surgeon according to each patient's characteristics. You can find out about our surgical techniques and the medical team who perform them.
Recovery after surgery
Relief of nocturnal tingling is usually almost immediate. The superficial wound heals in about two weeks, during which time finger mobilisation is recommended to prevent stiffness. Complete recovery of grip strength and fine sensation is more gradual and may take from six weeks to several months, especially if muscle atrophy was present before the operation.
Early hand rehabilitation and clinical follow-up optimise outcomes. The great majority of patients recover normal function and become symptom-free, with very high success rates when surgery is performed before nerve damage becomes irreversible.
Specialist care in Barcelona
At Brain & Spine Barcelona we assess every case of carpal tunnel syndrome individually, from conservative treatment to surgical release. We see national and international patients at Hospital El Pilar (Balmes 271, Barcelona). Visit our peripheral nerve unit for more information.
Frequently asked questions
Does carpal tunnel syndrome resolve on its own?
In very early stages, mild symptoms may improve with conservative measures such as night splints and activity modification. However, when median nerve compression is moderate or advanced, it rarely resolves spontaneously and usually requires medical or surgical treatment to prevent permanent nerve damage.
How do I know if I have carpal tunnel syndrome and not another condition?
The typical pattern is tingling and numbness in the thumb, index, middle and half the ring finger, which worsens at night or when driving and holding a phone. A definitive diagnosis is confirmed by neurological examination together with electromyography (EMG) and, in selected cases, ultrasound or MRI, which rule out cervical radiculopathy or other neuropathies.
Is carpal tunnel surgery painful or does it require hospitalisation?
Carpal tunnel release is a day procedure performed under local anaesthesia that does not require hospital admission. Most patients report mild discomfort controllable with analgesics during the first few days and go home the same day as the operation.
What is the difference between open and endoscopic surgery?
Both techniques divide the transverse carpal ligament to decompress the median nerve. Open surgery uses a small incision in the palm and provides direct visualisation of the nerve; the endoscopic technique uses a smaller incision and tends to allow a somewhat faster functional recovery. The choice depends on each case and is assessed by the surgeon.
How long is recovery after surgery?
Nocturnal tingling usually improves within a few days. Superficial wound healing takes about two weeks, and grip strength and fine sensation may take from six weeks to several months to normalise, especially if there was muscle atrophy before the operation. Early hand rehabilitation accelerates the process.
Can carpal tunnel syndrome be prevented?
It is not always preventable, as anatomical and hormonal factors play a role, but risk can be reduced with regular breaks during repetitive tasks, adequate workplace ergonomics, avoiding forced wrist positions and managing associated conditions such as diabetes or hypothyroidism.
Can pregnancy cause carpal tunnel syndrome?
Yes. Fluid retention during pregnancy increases pressure inside the carpal tunnel and may cause symptoms, especially in the third trimester. In most cases it is managed conservatively and symptoms resolve in the weeks following delivery.
What happens if I do not treat carpal tunnel syndrome?
Sustained compression of the median nerve can cause permanent loss of sensation, weakness and atrophy of the thenar muscles, as well as difficulties with fine tasks such as doing up buttons or gripping small objects. This is why early consultation is important.
Symptoms of carpal tunnel syndrome?
Our peripheral nerve neurosurgery team in Barcelona can assess your case and guide you on the best treatment, from splints to surgical release.