Amputee feels limb in chest
amputees feel limbs Amputees could 'feel' their lost arms and hands after scientists reconnected the nerves to their chests, according to a report released today.
The researchers say the experiment holds promise for providing sensation in artificial limbs.
They re-routed key nerves, which had once transferred sensation from the hand to the brain, to their chests.
The nerves re-established themselves in the chest muscles over several months.
Over this time, the scientists applied physical pressure, heat and cold, and electrical stimuli to the areas of the nerves.
The patients said they could feel their missing arms and hands.
In some of the testing, the patients could even specify which area on the hand they could feel.
A woman identified as STH pinpointed a strong feeling of the skin stretching and the joint position of her ring finger being extended.
Moreover, the patients consistently distinguished between the sensation of the chest nerves and those of the missing limbs.
The scientists suggest their success in reviving such specific sensation identified with missing limbs could lead to establishing nervous system feedback in prosthetic devices like artificial hands, arms, feet and legs.
"Our results illustrate a method for creating a portal to the sensory pathways of a lost limb," they say in the online edition of the Proceedings of the National Academy of Sciences.
"This work offers the possibility that an amputee may one day be able to feel with an artificial limb as though it was his own."
The researchers tested two volunteer patients: BSD, a 54 year old man who lost his arms at the shoulder due to electrical burns, and STH, a 24 year old woman who underwent a left upper arm amputation after a car accident.
In both, they took the remaining four main nerves that had connected to the hands and transferred them to different areas of the chest, attaching them into the chest muscles.
In BSD, this took place nine months after the injury. Five months later, the report says, when touched on the chest he began registering sensations from the phantom limb.
Depending on the location and the strength of the pressure put on the chest, BSD registered feelings on the palm or backside of the missing hand.
In STH, the transfer of the nerves was made 15 months after her accident. Four months later, she was registering feelings from the lost hand and wrist from the nerves moved to her chest.
The scientists say their results do not show a full recovery of sensation in all four of the nerves, noting there may be limits to a patient's spatial perceptions and ability to handle complex sensations.