Nerve stimulator helps relieve suffering from chronic pain

Development of new neurotechnologies provides non-pharmaceutical alternatives to chronic pain relief.

Imagine never being able to hug your loved ones because of chronic, excruciating pain. This was the case for Joan who suffered severe neuropathic pain for over 6 years after a Schwannoma (a nerve sheath tumour) was removed from around her brachial plexus. The entire right side of her upper body became incredibly sensitive to touch, where even light touch or clothes brushing against her skin could leave her in agonising pain.

After a number of unsuccessful visits to different consultants, Joan met Dr Tacson Fernandez, Clinical Lead for the Neuromodulation Service at the Royal National Orthopaedic Hospital. He identified Joan’s pain as neuropathic and secondary to changes in the brachial plexus, a network of nerves that sends signals from the spinal cord to the shoulder, arm and hand. Dr Fernandez implanted peripheral nerve stimulators which covered the chest wall area of pain. He also implanted a spinal cord stimulator, which covered the entire distribution of the brachial plexus on the painful side and also targeted the facial sensitivity. Within days of the surgery, Joan was able to hug her husband for the first time in 6 years. The pain she experienced for years was finally more manageable.

Dr Fernandez commented, “Neuropathic pain is a severe, debilitating type of nerve pain which is often difficult to manage using conventional treatment options and dramatically affects the quality of life of sufferers. Some effective interventions such as spinal cord stimulators are currently available, but it is vital that more treatments are developed that can effectively target and treat the range of issues that neuropathic pain presents with.”

Neuropathic pain can result from a number of ailments such as multiple sclerosis, spinal cord injury or a stroke. Diabetes, infection, chemotherapy, some surgeries and alcoholism can also result in painful metabolic peripheral neuropathies. The pain is often described as a burning, shooting, electric shock like sensation. This excruciating pain can be triggered by mechanical or thermal stimuli which substantially impairs quality of life.

Regular painkillers such as ibuprofen and paracetamol are generally not effective; specific nerve pain-killers such as anti-epileptics, anti-depressants or opioids are sometimes used but have numerous side effects and might only prove beneficial in one out of four patients.

There is a growing interest in non-pharmaceutical alternatives to manage neuropathic pain. Spinal cord stimulation has been in use for over three decades, is relatively safe, reversible and a cost-effective long-term solution to manage neuropathic pain. Newer high frequency devices also provide paraesthesia-free stimulation. Brain computer interfaces can provide neurofeedback for the treatment of central neuropathic pain following injuries to the spinal cord. Recently, there has also been promising developments in visual feedback therapies which use virtual and augmented reality, optogenetics, transcranial magnetic stimulation techniques etc., to help with pain management for patients with spinal cord injury.

Neurofeedback (NFB) utilises brain computer interface technology that provides analysis and visualisation of brain activity in real time, while the person is engaged in an NFB task. NFB is typically based on electroencephalography (EEG) due to its technical features, size and affordable price.

NFB is a neuromodulatory technique that enables voluntary modulation of brain activity in order to treat neurological conditions, such as attention deficit hyperactivity disorder, insomnia, depression epilepsy and chronic pain. A distinctive feature of this technique is that it actively involves participants in the therapy. It is believed that NFB tunes brain oscillations towards a homeostatic set-point which affords an optimal balance between network flexibility and stability (i.e. self-organising criticality).

Dr Aleksandra Vuckovic from the University of Glasgow has developed an NFB protocol for treatment of Central Neuropathic Pain (CNP). The protocol is based on modulation of brain activity in selected frequency bands, from the motor cortex. A recent study showed that, out of 15 patients, 75% reported statistically significant reduction of pain, and pain relief was clinically significant (larger than 30%) in 53% participants. A half an hour NFB session provided pain relief that lasted from several hours to 2-3 days.

Prolonged use of NFB may modify baseline brain activity in a desired direction. In addition, long term users can learn how to apply NFB mental strategy even without an NFB device (transfer learning) thereby achieving similar effect as with real NFB. Apart from the occasional headache, there are no known side effects of NFB.

The development of new neurotechnologies will help treat the growing number of people who suffer from neuropathic pain. NFB and spinal cord stimulation are some of the technologies that will be discussed at the KTN’s upcoming Neuropathic Pain Biodesign workshop on the 19th September, in Oxford. The aim of the workshop is to bring together key stakeholders to help accelerate the development of new neurotechnologies. This will be the first in a series of workshops, organised by the KTN’s Neurotechnology Special Interest Group, which will cover mood disorders, stroke rehabilitation, dementia and epilepsy.

Register here for the Neuropathic Pain Biodesign workshop.

Join the Neurotechnology Special Interest Group here.

Join the Neurotechnology LinkedIn group here.

For more information about the Neurotechnology Special Interest Group, please contact Charlie Winkworth-Smith.