Erb's point (neurology)

In neurology, Erb's point or the punctum nervosum^[1] is a site at the lateral root of the brachial plexus located 2–3 cm above the clavicle. It is named for Wilhelm Heinrich Erb.^[2] Taken together, there are six types of nerves that meet at this point.

Convergence of nerves

Erb's point is formed by the union of the C5 and C6 nerve roots, which later converge. At the nerve trunk, branches of suprascapular nerves and the nerve to the subclavius also merge. The merged nerve divides into the anterior and posterior division of C5 and C6.

a landmark of the brachial plexus on the upper trunk, located about 1 inch (2.5 cm) above the clavicle at about the level of the sixth cervical vertebra

Clinical significance

Injury to Erb's point is commonly sustained at birth or from a fall onto the shoulder. The nerve roots normally involved are C5 and partly C6. Symptoms include paralysis of the biceps, brachialis, and coracobrachialis (through the musculocutaneous nerve); the brachioradialis (through the radial nerve); and the deltoid (through the axillary nerve). The effect is called "Erb's palsy". Typically, an affected person's arm hangs at the side with the hand rotated medially, like a porter waiting for a tip; hence the colloquial name "porter's tip hand".^[3]

References

1. ^ Anatomy Dissections - LF1 English Parallel
2. ^ synd/942 at Who Named It?
3. ^ Moore, Keith L. Clinically Oriented Anatomy, 2nd ed. Williams & Wilkins: Baltimore, 1985. 658.

See also

• Posterior triangle of the neck

External links

• SUNY Labs 24:st-0600