Erb’s palsy occurs when an injury to the group of nerves that controls the arm causes paralysis symptoms. Erb’s palsy in infants is often caused by complications such as shoulder dystocia during labor, sometimes coupled with medical malpractice or negligence. The nerve damage occurs most frequently when an obstetrician or other medical professional exerts force on the baby that causes the neck to stretch in such a way that the nerves are torn.
The group of nerves that is damaged in Erb’s palsy cases is part of the brachial plexus, which is a group of nerves that controls the shoulder, arm, and hand. Erb Duchenne-palsy is a type of Erb’s palsy that affects the muscles of the elbow and shoulder. Klumpke’s palsy is a type of Erb’s palsy that affects the muscles of the hand and forearm. Erb’s Palsy symptoms may vary depending on the exact location and the severity of the injury. Erb’s palsy generally only affects one arm.
Distinct Erb’s Palsy Symptoms
Erb’s palsy differs from other forms of palsy in that the condition causes weakness and paralysis rather than involuntary muscle movements. The degree of impairment caused by the brachial plexus damage may cause Erb’s palsy to be called by other names. If only part of the arm is affected, it is generally known simply as a brachial plexus injury, rather than Erb’s palsy. Erb’s palsy specifically affects the movement of the upper arm and the rotation of the lower arm, though it may affect the hand in Klumpke’s palsy. In some cases, the eyelid on the opposite side from the affected hand may also droop as a result of the nerve damage in Klumpe’s palsy.
Erb’s Palsy Symptoms Following Birth
Erb’s palsy symptoms that may be noticeable immediately after birth pertain to the way that the baby holds the affected arm. The arm may be limp and bent at the elbow, sometimes with the hand turned outward or backward at an odd angle. Observation may show that the infant is unable to move the arm at the shoulder or that there is limited function and control. Pain, cramping, and muscle stiffness may all be present, which can cause the infant to express more discomfort than normal. A lack of Moro reflex may also be identified by doctors, which is a natural reflex of newborns to thrust the arms out to each side with thumbs flexed when startled.
Symptoms Noticeable Over Time
As the baby develops, some symptoms of Erb’s palsy may become more noticeable. When babies have some degree of motor function in the hand and arm, the strength and grip may be noticeably weaker. The motor and sensory functions in the upper arm may be weak or absent, depending on the degree of injury. Nervous, muscular, and circulatory development may all be considerably delayed in the affected arm. Over time, the muscles in the arm may begin to atrophy.
Erb’s Palsy Complications
Erb’s palsy impairs circulation, which inhibits the body’s ability to regulate temperature and heal. These Erb’s palsy symptoms may be problematic for children, and may result in infections and frostbite if the child is not closely monitored. Most Erb’s palsy symptoms will subside over time either alone or with treatment, but this is not the case if avulsion occurs, which is when the brachial plexus nerves are torn away from the spinal cord. In cases of avulsion, the symptoms of paralysis, numbness, and impairment that characterize Erb’s palsy are permanent.
Erb’s Palsy Diagnosis
Doctors can often diagnose Erb’s palsy in infants by the familiar postural symptoms when doing an examination of the baby. To gauge the extent of the injury, physicians may also order CT scans or MRIs. To test the electrical activity of arm muscles, doctors may use electromyography. As part of the electromyography screening, doctors may also measure the speed of electrical conduction in the nerves to determine how well the nerves are functioning.
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“Erb’s Palsy (Brachial Plexus Birth Palsy).” OrthoInfo. Pediatric Orthopaedic Society of North America, 1 Oct. 2014. Web. 30 Jan. 2015. <http://orthoinfo.aaos.org/topic.cfm?topic=A00077>
“Symptoms of Erbs Palsy.” Erb’s Palsy. ErbsPalsy.org, 1 Jan. 2013. Web. 30 Jan. 2015. <http://erbpalsy.org/symptoms.html>