Posts Tagged ‘brachial plexus’

Three Men Receive Bionic Hands Controlled With Their Minds

The outlook used to be pretty bleak for those who had lost movement in their limbs due to severe nerve damage, but over the last year or so, some incredible advances have been made that are restoring shattered hope for many.

The amazing breakthroughs include spinal cord stimulation that allowed paralyzed men to regain some voluntary control of their legs, a brain implant that enabled a quadriplegic man to move his fingers, and a system that allowed a paralyzed woman to control a robotic armusing her thoughts. Science has definitely been on a roll, but this winning streak isn’t showing any signs of slowing down. Now, the world’s first “bionic reconstructions” have been performed on three Austrian men to help them regain hand function. This technique enabled the newly amputated patients to control prosthetic hands using their minds, allowing them to perform various tasks that most people take for granted.

The men that underwent the procedure had all suffered serious nerve damage as a result of car or climbing accidents, which left them with severely impaired hand function. The nerves that suffered injury were those within a network of fibers supplying the skin and muscles of the upper limbs, known as the brachial plexus. As lead researcher Professor Oskar Aszmann explains in a news release, traumatic events that sever these nerves are essentially inner amputations, irreversibly separating the limb from neural control. While it is possible to operate, Aszmann says the techniques are crude and do little to improve hand function. However, his newly developed procedure is quite different, and is proving to be a success.

Before the men could be fitted with their prosthetic hands, the researchers had to do some preliminary surgical work in which leg muscle was grafted into their arms in order to improve signal transmission from the remaining nerves. After a few months, the fibers had successfully innervated the transplanted tissue, meaning it was time to start the next stage: brain training.

Using a series of sensors placed onto the arm, the men slowly began to learn how to activate the muscle. Next, they mastered how to use electrical nerve signals to control a virtual hand, before eventually moving on to a hybrid hand that was affixed to their non-functioning hand. After around nine months of cognitive training, all of the men had their hand amputated and replaced with a robotic prosthesis that, via sensors, responds to electrical impulses in the muscles.

A few months later, the men had significantly improved hand movement control, which was highlighted by a test of function known as the Southampton Hand Assessment Procedure. As reported in The Lancetbefore the procedure, the men scored an average of 9 out of 100, which soared to 65 using the prosthetic. Furthermore, the men reported less pain and a higher quality of life. For the first time since their injuries, they were able to perform avariety of tasks such as picking up objects, slicing food and undoing buttons with both hands.

“So far, bionic reconstruction has only been done in our center in Vienna,” said Aszmann. “However, there are no technical or surgical limitations that would prevent this procedure from being done in centers with similar expertise and resources.”

The above story is adopted from The Lancet and reprinted from materials provided by NewScientist.

The Course of N.ulnaris

A short article on the course of ulnar nerve.

A link to the article: The Course of N.ulnaris – click here

The ulnar nerve (C7, 8, T1) is the continuation of the medial cord of the brachial plexus. It is usually joined in the axilla by fibers from C7. The ulnar nerve is motor to most of the small muscles of the hand, to flexor carpi ulnaris, and to the ulnar half of the flexor digitorum profundus. It provides sensibility to the ulnar aspect of the hand.

The Course of N.radialis

A short article on the course of radial nerve.

A link to the article: The Course of N.radialis – click here

The radial nerve is the direct continuation of the posterior cord (C5-T1) of the brachial plexus. It supplies the muscles of the extensor compartments, the skin overlaying them and the skin over the dorusm od the hand.

The Course of N.medianus

A short article on the course of median nerve.

A link to the article: The Course of N.medianus – click here

The median nerve (C5, 6, 7, 8, T1) is motor to most of the long flexors of the forearm and muscles of the thenar eminence. It supplies sensibility to the skin of the palm, (usually) radial three and half digits, elbow, wrist, and hand joints.

The Innervation of the Upper Limb

I have written this short segment about the innervation of the upper extremity, just as a reference to the nerves, their origin, course and what they innervate.

Link to an article, click here.

The upper extremity receives neural branches from various spinal nerves. Mostly is innervated by Brachial plexus (C5-T1), but also from Cervical plexus (C3-C4) and intercostal nerve.