Natural Sensory Feedback for Phantom Limb Modulation and Therapy

Phantom limb pain (PLP) is a frequent consequence of amputation, and it is notoriously difficult to treat. Amputation usually follows traumatic injuries or surgery following vascular diseases, diabetes, osteomyelitis or tumours in cases where the loss of the limb is required for the survival of the patient. The loss of a limb or other body parts is usually followed by the sensation that the lost body part is still present and can be felt. These phenomena are called, respectively, phantom awareness and phantom sensation. In 50-80% of amputees neuropathic pain develops in the lost limb also referred to as phantom limb pain (PLP). PLP can be related to a certain position or movement of the phantom limb, and might be elicited or worsened by a range of physical factors (e.g. changes in the weather or pressure on the residual limb) and psychological factors (e.g. emotional stress). It is well known that most treatments available for PLP today, such as pharmacological, surgical, anaesthetic, psychological and other, are ineffective. Today it is believed that phantom limb pain may be related to changes in the cortex of the brain. There is evidence that these changes may be modulated - or even reversed - by providing sensory input to the stump or amputation zone. For example, cortical reorganization and alleviation of phantom limb pain has been observed in amputees following intense use of a hand prosthesis. However, there is no consistent knowledge on which type of peripheral sensory feedback may be effective in affecting the cortical plasticity or on how to best apply the sensory feedback. The aim of the proposed research is to create natural, meaningful sensations through providing sensory feedback (i.e. surface or neural electrical stimulation) and the effectiveness to alleviate phantom limb pain and restore the cortical neuroplastic changes.