Detailed consideration of carpal tunnel syndrome: the median nerve in detail


Definition of carpal tunnel syndrome

Carpal tunnel syndrome (CTS) is a compression syndrome of the median nerve in the wrist area.


Carpal tunnel syndrome is the most common peripheral nerve entrapment syndrome. It occurs primarily between the ages of 40 and 70 and can often occur on both sides.

carpal tunnel syndrome median nerve
Examining the hand of a senior patient with carpal tunnel syndrome. Close-up image of senior woman’s wrist.


Carpal tunnel syndrome can be triggered by acute (e.g. injuries) or chronic progressive (e.g. metabolic disorders) nerve compression of the median nerve. The triggering factors include:

Overuse or repetitive activities: Carpal tunnel syndrome is part of the Cumulative Trauma Disorders (CTDs).

Weight gain:

  • Obesity
  • pregnancy
  • Myositis
  • Tumors (fibromas, lipomas)
  • long-term hemodialysis

Degenerative, rheumatic, hormonal and metabolic diseases:

  • Hypothyroidism with myxedema
  • Acromegaly
  • arthritis
  • Tenosynovitis
  • Diabetes mellitus (with diabetic neuropathy)
  • Amyloidosis (e.g. ATTRwt amyloidosis)
  • Mucopolysaccharidosis
  • Trauma
  • Fractures in the wrist area (e.g. radius fracture)
  • Bleeding
  • Edema
  • Hand phlegmon
  • Wrist arthrosis

In some cases the disease also occurs idiopathically. A constitutionally caused narrowing of the carpal tunnel can promote the development of the syndrome.

Causes & Symptoms of CTS

An anatomical bottleneck is a prerequisite for the development of carpal tunnel syndrome, which affects the median nerve in its course below the ligamentum carpi transversum. The clinical symptoms are caused by an increase in volume or edema of the tunnel.

Anatomy of the Median Nerve

see: Carpal Tunnel Graphic

Hofmann-tinzel-sign-Median Nerve
Detailed consideration of carpal tunnel syndrome: the median nerve in detail


Patients with this syndrome suffer from pain and paresthesia in the area supplied by the median nerve. Painful tingling paraesthesias or pinprick-like sensations occur, mainly in the middle and ring fingers, later also in the thumb and index finger, often accompanied by pain in the arm.

Initially, these symptoms often occur in connection with mechanical stress on the hand (e.g. cycling, reading, talking on the phone, knitting, etc.), with the dominant hand often being more severely affected. Pain in the hand and forearm typically also occurs at night (“brachialgia paraesthetica nocturna”).

These symptoms can be relieved by shaking, rubbing, finger movements, arm or hand positions, and cold applications.

As the disease progresses, sensory disturbances occur with increasing numbness, including impairment of the sense of touch (the fingers become numb, fine work is no longer possible).

In advanced stages, chronic nerve compression leads to weakness of the thenar muscles (lateral thenar muscles) and a limitation of grip strength (with difficulty in spreading and rotating the thumb).

Occasionally, vegetative disorders such as skin and nail changes also occur.

carpal tunnel syndrome healing treatment symptoms curpal
Detailed consideration of carpal tunnel syndrome: the median nerve in detail

Concomitant disease

In approximately 16 to 43% of cases, carpal tunnel syndrome is associated with tenosynovitis stenosans (“trigger finger”) or its precursors, which are characterized by morning finger stiffness or painful and incomplete fist formation.


A detailed medical history and clinical examination lead to a diagnosis in most cases.
Inspection and palpation to assess muscle atrophy
Checking surface sensitivity

Motor tests:

  • Restriction of thumb abduction and opposition
  • Bottle test to assess the abductor pollicis brevis muscle

Provocation tests:

  • Hoffmann-Tinel sign
  • Phalen test
  • Carpal compression test (Durkan test)

Online test: Directly on

Further diagnostics are carried out through electrophysiological examinations. Sensory and motor neurographs are effective methods for detecting chronic CTS. A striking finding is a reduced nerve conduction velocity (NCV) of the median nerve in the carpal tunnel, usually due to demyelination. Advanced axon damage can lead to reduced response amplitudes.

Alternatively, the diagnosis can be confirmed by sonography, in which the cross-sectional area of ​​the median nerve above the wrist is measured in the volar transverse section. In carpal tunnel syndrome, it is enlarged due to compression of the nerve.

Differential diagnoses

Nerve root irritation due to degenerative cervical spine changes (cervical radiculopathy of C6 and C7)


Lesions or compression of the median nerve (pronator teres syndrome, thoracic outlet syndrome, scalene syndrome)

Spinal diseases

Non-neurogenic or other diseases (forearm compartment syndrome, polymyalgia, Raynaud’s syndrome, Lyme disease, etc.)

Muscle hypertrophy of the pronator teres muscle or the pronator quadratus muscle, e.g. in athletes or craftsmen


Another treatment alternative is the use of curpal®.

This patented medical device offers a non-surgical solution for carpal tunnel syndrome. Through the mechanically generated pressure on the back of the hand, curpal® stretches the carpal ligament on the palm of the hand, which runs transversely from the ball of the hand to the edge of the hand.

This widens the carpal tunnel and gives the nerve more space. The pressure that caused pain and discomfort subsides. The use of curpal® is an effective method to prevent the progression of carpal tunnel syndrome.

Wearing special wrist supports can also help reduce pressure on the median nerve in the carpal tunnel.

curpal® offers an innovative and gentle alternative to the conventional treatment of carpal tunnel syndrome. It allows patients to relieve their symptoms and improve their quality of life without having to undergo surgery. You can find more information about curpal® and its application on the official website: .


1. German Medical Journal –

2. –


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