Specifics of obstetric paralysis
Injuries to nerve structures of the upper extremities are frequently encountered as birth injuries. Depending on the level of brachial plexus lesion and the involved nerve roots, obstetric paralysis is classified into four main types:
- Upper radicular (also known as Erb-Duchenne paralysis).
- Lower radicular (Dejerine-Klumpke paralysis).
- Total paralysis (total lesion of the entire plexus).
- Mixed type.
The management strategy for such patients directly depends on the clinical picture. If paralytic manifestations are minor, the baseline approach focuses on contracture prevention. In cases of pronounced deficit from birth, physicians' efforts concentrate on comprehensive restoration of plexus function. Conservative measures include proper positioning and limb splinting, mechanotherapy, physiotherapy, and balneotherapy. Regarding surgical intervention, most specialists favor delayed surgery combined with orthopedic correction and soft tissue plastics.
Indications and objectives of conservative treatment
The conservative strategy is applied in two main scenarios: as preparation for surgery (or postoperative rehabilitation) and in injuries where the anatomical continuity of the nerve trunk is preserved. The latter include contusions, various stretches, and compression by hematomas.
The fundamental objectives of non-surgical therapy include:
- Combating scarring: minimizing the volume of scar tissue in the lesion focus so that axons can sprout unhindered from the central nerve segment into the distal one.
- Stimulation of regenerative processes within the nerve fiber itself.
- Maintenance of trophism: improving the functional state of denervated muscle fibers.
- Complication prevention: preventing the development of contractures and severe trophic disorders in the innervation zone.
Complex of conservative measures
Treatment is divided into stages depending on the time elapsed since the injury.
In the acute period, the primary measure is immobilization of the affected segment, which unloads the denervated muscles. Simultaneously, therapeutic massage is prescribed to help relieve edema, normalize local metabolism, and stimulate blood circulation and lymph drainage.
A critical component is physiotherapy. The greatest significance lies in muscle electrical stimulation utilizing elements of active electrogymnastics (when the patient consciously attempts to contract the affected muscle at the moment the current is applied). Additionally, magnetotherapy and electrophoresis with novocaine or iodine preparations are used. In the later chronic period, the focus shifts to thermal procedures (ozokerite, paraffin therapy, special baths) and ultrasound therapy, which further stimulates nerve regeneration.
Pharmacological support is based on vitamin therapy (vitamins B₁, B₆, B₁₂) and the use of drugs such as dibazol and phenatin. A special role is played by Prozerin—a potent anticholinesterase drug indicated from the very first days after injury or surgery.
Surgical nerve repair
If a fresh injury with complete disruption of the anatomical continuity of the trunk is diagnosed, placing a primary nerve suture becomes the optimal choice. The choice of a specific technique depends on the time elapsed since the rupture and the nature of the injury.
One of the basic options is the epineural suture. The procedure requires a strict sequence:
- First, meticulous surgical debridement of the ends of the damaged nerve is performed. The surgeon excises the perineurial remnants, removes damaged axonal segments and hematomas.
- Then fixing sutures are applied. Usually, 5–6 sutures are sufficient, capturing only the outer sheath—the epineurium.
- Critical condition for success: apposition of the nerve trunk ends must occur without the slightest tension or axial twisting.
Briefly: answers to topical questions
Which hand muscles does the median nerve innervate?
The median nerve provides motor innervation to the thenar muscles and part of the lumbrical muscles of the hand.
- Thenar muscles (thenar) — all muscles of this group are innervated, except for the adductor pollicis and the deep head of the flexor pollicis brevis.
- Lumbrical muscles (mm. lumbricales) — the I and II muscles are innervated (the two muscles located on the radial side).
What typical hand deformity occurs with complete damage to the median nerve?
With complete damage to the median nerve, an "ape hand" (or "simian hand") deformity develops. This is due to flattening of the hand, adduction of the thumb, and impaired flexion of the I, II, and partially III digits. When the patient attempts to make a fist, the characteristic "preacher's hand" (or "benediction hand", "obstetrician's hand") sign appears, as the I and II digits do not flex.
Which skin areas of the hand lose sensitivity when the median nerve is damaged?
When the median nerve is damaged, loss of cutaneous sensitivity is localized to the lateral (radial) half of the palm, the skin of the I, II, and III digits, and the radial aspect of the IV digit.
In which anatomical canals does tunnel compression of the median nerve most frequently occur?
Tunnel compression of the median nerve most frequently occurs in two anatomical areas.
- Carpal canal (canalis carpi) — the most frequent site of compression (about 45% of cases), leading to carpal tunnel syndrome.
- Pronator teres region (m. pronator teres) — compression at the level of the upper third of the forearm as the nerve passes through the muscle (pronator syndrome or Seyfarth syndrome).
What specific clinical tests are used to diagnose median nerve injury?
The following tests and signs are used to diagnose median nerve injury:
- De Cu's test — when trying to pull paper between the II and flexed I digit, the I digit does not flex, but is adducted toward the II digit.
- Mill sign — inability to smoothly rotate one thumb around the other with crossed hands.
- Fist clenching test — the I and II digits do not flex.
- Scratch test — inability to scratch the table with the nail of the II digit.
- Tinel's test — provocation of paresthesias by percussion over the proximal edge of the pronator teres.
What surgical methods are used to restore peripheral nerve continuity?
The following methods are used for the surgical treatment of peripheral nerve injuries:
- Primary nerve suture — the optimal method for recent injuries with loss of anatomical continuity.
- Epineural suture — used when the diastase between nerve ends is no more than 2 cm in chronic complete anatomical transection after neurolysis and neuroma resection.
- Microsurgical intrafascicular suture — suturing nerve fascicles under optical magnification.
- Autografting — used for significant diastase or nerve defects greater than 2 cm; the sural nerve is cited as the most successful donor.
- Neurolysis — freeing the nerve from scar tissue while preserving anatomical continuity.
Class and exam questions
Why is immobilization necessary in the acute period of nerve injury?
Immobilization of the injured limb segment is necessary to unload denervated muscles and prevent their overstretching.
What is the golden rule when placing an epineurial suture?
A key condition is that the nerve trunks must be apposed without significant tension or twisting, strictly after meticulous surgical debridement of the ends.
What else to study on this topic
- Technique of perineurial nerve suture
- Surgical tactics in the presence of diastase between nerve ends
- Orthopedic management of neglected obstetric palsies
- Soft tissue plasty techniques in brachial plexus lesions
- Specifics of mechanotherapy in rehabilitation after nerve repair
Master the entire topic in the "Traumatology" course
This is a summary. The course covers everything tested in classes and exams.
- Complete study guide on "Median Nerve Injury" and 812 other subject pages
- Assignments and quizzes after every topic — just like in a colloquium
- AI tutor answers questions on the topic anytime
- 35 video lessons on the subject
Other topics in the section "General Questions of Traumatology and Orthopedics"
Prepared by WhiteCoat Pro faculty in accordance with the medical school curriculum. For educational purposes only.