Introduction
Obstetric brachial plexopathy is a common injury in newborns occurring at the time of birth. It is also called a birth brachial plexus injury and is seen in 0.15 to 3 per 1000 live births globally. Although it shows a spontaneous recovery, there is still a large subtype that requires primary or secondary surgical management for the cure. The first case of obstetric brachial plexopathy was reported in 1764, followed by 1872. Although it was said to be self-regressing in some cases, studies have proved that the recovery rate is comparatively lower than the initially assumed rate. The children need to complete monitoring and receive the earliest treatment for better outcomes.
What Are the Causes of Obstetric Brachial Plexopathy?
The causes of obstetric brachial plexopathy can occur due to complications during two events, one when the baby is in the womb and the other during childbirth. So the causes are:
While the Baby is in the Womb:
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Macrosomia: When the baby is larger than the average weight of more than 4000 grams.
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Breech: Breech is the baby's position at birth with toes facing downwards.
During Birth:
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Gestational Diabetes: When the mother's blood sugar levels are higher during pregnancy.
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Shoulder Dystocia: When the shoulder gets stuck during birth.
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Cephalopelvic Disproportion: When the head of the fetus is larger than the mother's pelvic bone.
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Mothers who have given more stillbirths.
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Prolonged labor time.
What Is a Brachial Plexus?
The brachial plexus is a grouped network of nerves descending from the spine to the neck and shoulder region. The brachial plexus sends signals from the spinal cord to the arm, hand, and shoulder.
How Does Obstetric Brachial Plexopathy Occur?
The injury occurs due to nerve damage during compression in the vertebral column (C5 and C6 vertebrae). The nerve of the brachial plexus exists through the upper cervical vertebrae (spine of the back neck) supplying the shoulder and chest. Compression in these structures during childbirth results in major or minor nerve lesions, which causes deformity in the structure of the newborn. The injuries of obstetric brachial plexopathy can be divided into three types:
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The Upper Injury - It is the most common type of injury involving the C5 and C6 spinal bones. It is also called Erb's palsy, where the arm is seen facing inward with a rotated shoulder. The clinical features are extended elbow, flexed wrist, and fingers.
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The Lower Injury: It is a rear type of injury, seen in only 0.6 percent of cases. This occurs due to a lesion in the lower spinal bones of the neck (C8 to T1). The clinical feature is poor hand grasp.
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Total Nerve Injury - It is the second most common type of injury seen affecting C5 to T1 spinal bones. The clinical feature includes a clawed arm and a weak arm.
What Are the Classifications of Obstetric Brachial Plexopathy?
The classification of obstetric brachial plexopathy can be given under two classifications and they are:
Narakas Classification:
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Group 1 (Duchenne-Erb's palsy): It is the paralysis of the deltoid and biceps.
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Group 2 - It is also called intermediate paralysis and is seen as the paralysis of the deltoid, biceps, wrist, and fingers.
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Group 3 - Total brachial plexus palsy weak extremities without Horner's syndrome.
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Group 4 - Total brachial plexopathy weak extremities with Horner's syndrome.
Waters Classification of Glenohumeral Deformity:
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Type 1 - Less than five degrees in rotation.
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Type 2 - More than five degrees of rotation.
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Type 3 - More than 35 percent of the posterior humeral head (head of the hand).
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Type 4 - The presence of a false bony joint (glenoid).
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Type 5 - Flattened head of the hand joint.
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Type 6 - Shoulder is dislocated posteriorly.
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Type 7 - Growth retardation of the humerus bone.
How Is Obstetric Brachial Plexopathy Seen Clinically?
Some of the clinical features of this condition include:
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Swelling in the shoulder and neck region.
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Uneven eyes.
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Drooping of the eyelids.
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Lack of active movements in the extremities.
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Nerve defects in the limb.
How is Obstetric Brachial Plexopathy Investigated?
Obstetric brachial plexopathy can be investigated using the following methods. They are:
Radiograph (X-Ray) :
X-rays are two-dimensional images used to diagnose a fracture line and examine the fracture lines in the shoulder and hand. It is also used to evaluate adjoining bony deformities.
Magnetic Resonance Imaging (MRI) :
MRI is a type of investigation used to study soft tissue. The MRI scan is used to assess the lesions of the nerve and the extent of nerve injuries.
Ultrasound Scan:
Ultrasound scans are used to examine the functioning of body parts using sound waves. It is used here to examine the bony joints or the head of the humerus bone.
How is Obstetric Brachial Plexopathy Treated?
Although Obstetric brachial plexopathy is self-regressive in a few cases, it does require proper care and management, and that is achieved by treating it in two ways.
Non-Surgical Management: Non-surgical management aims to maintain arm and joint function and muscle strength. This is done by a group of specialists like child specialists, bone surgeons, physiotherapists, occupational therapists, etc. this is achieved by concentrating on stretching the muscles and preventing contraction of the muscles and joints.
Surgical Management: It was created first by Kennady in 1904. The surgical management of obstetric brachial plexopathy is done using microsurgical techniques as it deals with the repair of nerves. The surgery is then followed by repairing soft tissue and bony defects. This procedure is called primary surgical management and is done early in the child's life. Secondary surgical management is done when the child is older. The surgery involves treating the elbow and shoulder deformity.
Conclusion
Obstetric brachial plexopathy is a complex situation occurring in a newborn. The treatment modalities mainly aim to restore the functional efficacy of the child even before growth. Although the plexopathy resolves in a few cases, the other conditions require surgical or non-surgical management with constant monitoring and periodic surgical intervention if needed. But the cases of obstetric brachial plexopathy with proper monitoring and management show a 90 percent of favorable prognosis in patients.
