Radial nerve neuropathy
The radial nerve (n. radialis) is a nerve that is mixed in functions (it is also responsible for movement and sensitivity). The radial nerve is formed mainly from the fibers of C7 - spinal nerves (partly from C5, C6, C8, and Th1), passing first as part of the middle trunk, then the posterior bundle of the brachial plexus.
Diagnostics of the radial nerve neuropathy
Damage to the radial nerve (as a result of surgery, injury, including after injection of the drug, blows and prolonged clamping, bone fractures, and dislocations of the joints) is accompanied by inflammatory changes in it and manifests itself as an impaired motor and sensory function in the area of its innervation on the arm.
The motor fibers of the radial nerve innervate the extensors of the forearm, hand, and fingers, the instep support of the forearm, the abductor thumb muscle, and the muscle involved in flexion of the forearm. The sensory fibers of the radial nerve innervate the skin of the posterior surface of the shoulder, the posterior surface of the forearm, the side of the dorsum of the hand, and partially of the I, II, and sometimes III fingers.
With the defeat of the spinal nerves C7 or the middle trunk of the brachial plexus, the main function of the radial nerve falls out in combination with partial damage to the median nerve, its upper leg. Radial nerve neuropathy at this level manifests itself as a decrease in an inward rotation of the forearm and palmar flexion of the hand. With damage to the posterior bundle of the brachial plexus, the same basic functions of the radial nerve fall out, but in combination with damage to the axillary nerve.
With a high lesion of the radial nerve in the axillary fossa, in the upper third of the shoulder, paralysis of the extensors of the forearm, hand, main phalanges of the fingers, the muscle abducting the thumb of the instep support occurs; the flexion of the forearm is weakened. The reflex from the triceps tendon fades away and the carporadial reflex is somewhat weakened.
Sensitivity falls on the back of the shoulder, forearm, partly the hand, and fingers. The zone of sensory disorders on the hand is often significantly reduced due to the overlap of the zone by the innervation of neighboring nerves. The joint-muscular feeling is not affected. At lower levels of damage, the function of the radial nerve suffers to a limited extent, since the outgoing branches of the radial nerve are preserved above, which makes it easier for a neurologist and neurosurgeon to topically diagnose its damage.
With damage to the radial nerve, very frequently, at the level of the middle third of the shoulder, the function of extension of the forearm and the extensor-ulnar reflex from the triceps is preserved and the sensitivity on the shoulder is not disturbed.
With damage to the radial nerve in the lower third of the shoulder, the function of flexion of the forearm and sensitivity on the posterior surface of the forearm may be preserved, since the corresponding branches extend from the main trunk of the nerve higher in the middle third of the shoulder.
With damage to the radial nerve on the forearm, the function of flexion of the forearm is usually preserved; motor disorders with such damage to the radial nerve are limited to lesions of the extensors of the hand and fingers with impaired sensitivity only on the hand. If the radial nerve is damaged even lower, at the level of the middle third of the forearm, motor dysfunctions can be even more limited, while the extension of the hand is preserved, only the extension of the main phalanges of the fingers can suffer.
With damage to the radial nerve, weakness of the extensors of the hand develops, a typical falling or drooping hand arises.
Among the numerous descriptions of samples or tests that determine movement disorders with damage to the radial nerve, one can note:
- inability to extend the hand and fingers
- inability to abduct the thumb
- when spreading the palms together with the palms of the hands with straightened fingers, the fingers of the affected hand are not retracted, and the bent ones "slide" along the palm of a healthy, retracted hand
Treatment of the radial nerve neuropathy
Treatment for neuritis of the radial nerve is selected individually in each case. It includes a set of conservative procedures:
- nerve and muscle stimulation
- vitamins of group "B", "C" and "E"
- homeopathic remedies
- surgical treatment (neurolysis, stitching of the nerve trunk, etc.)