January 2018

28th January – 4th February

Assisted Technologies for Amputation Pain

Research published this year in the journal Military Medical Research reviewed current assisted technologies for pain in amputees. Recent reports have estimated that there are global increases in amputees, perhaps due to increased trauma survival rates. Two main types of pain affect amputees: residual limb pain (RLP) and phantom limb pain (PLP). RLP refers to pain in the stump where the amputation occurred, whereas PLP refers to pain felt in the missing body part. Both RLP and PLP are associated with increased medical costs, loss of productivity, lower quality of life ratings, relationship strains and psychological burden. They can also affect rehabilitation and prosthesis use.

The prevalence of PLP is estimated to occur in around 51% of amputees.  Although the reasons why are still unknown. Triggers can range from pre-amputation pain, emotional pain, temperature changes and thoughts related to the amputation. RLP, on the other hand, is the physical damage to the bodily tissues, and it is common to see skin diseases such as fungal infections and allergies as a result.

Advances in technology have proven to be beneficial for medical fields and work is being undertaken to develop devices that can provide pain relief in amputees. Pain management can be categorised into medical, non-medical and surgical interventions. Surgical methods are usually ‘last-resort’ treatment options, due to their invasive and often short-lived results. Medical interventions for pain include medications such as anti-depressants, analgesics and opioids. These are popular treatment options, but can leave individuals with considerable side effects and may become less effective overtime. More recent efforts have been focused on non-medical pain management techniques such as exercise therapy, massage, acupuncture, transcutaneous electrical nerve stimulation (TENS) and psychological therapies such as hypnosis and biofeedback.

Assisted technologies for amputees were reviewed in the literature by the researchers. They found that technologies ranged across medical, non-medical and surgical fields and included seven main methods, briefly summarised below:

  1. Electrical nerve block devices
  • High frequency sinusoidal waveforms of 10kHz and up to 10V are applied to areas proximal to the thickening of nerve tissue.
  • Surgery is required to implant the electrode around the nerve but preliminary data is promising.
  • A prototype for a smart patch nerve stimulator that is less invasive is being tested.
  1. TENS unit
  • Sends stimulating pulses across the surface of the skin and along the nerve strands.
  • Works by inhibiting the neurons involved in pain signalling, increasing blood flow and reducing muscle spasms.
  • Shown to be effective in PLP relief.
  1. Elastomeric pumps and catheters
  • Device that can infuse local anaesthesia for pain relief.
  • Can be totally or partially implanted.
  • Problems are that it is surgically invasive, costly and can lead to infection.
  1. Residual limb covers
  • Ultra-thin steel threads woven into linen fabrics.
  • These prevent nerve exposure of nerve endings on the residual limb to external electric and magnetic fields.
  • There is controversial evidence for them.
  1. Laser Systems
  • Ear acupuncture with laser.
  • It is an alternative treatment but one that proposes to exert pain relief through stimulation of the nervous system.
  • Early studies suggest this may be a promising field in pain management.
  1. Myoelectric prostheses
  • An innovative prosthetic device that actually enables feedback between the artificial limb and the brain itself, thus solving the problem of over-stimulation.
  • It works through the use of electronic sensors, which detect minute nerve and muscle activity that is translated to electric motors to control movements of the artificial limb.
  • The technology enables the user to visualise the amputated limb and engage the areas of the brain that are responsible for limb movement.
  • The brain processes transmissions from electrode sites in the artificial limb much like it does with a real limb, reducing phantom pain.
  1. Virtual reality
  • Can be used in conjuncture with biofeedback.
  • The mirror box therapy is the simplest type and it works by visual feedback resulting in an illusion, which causes cortical sensory reorganisation.

Overall, technological use is emerging for pain management with an aim to design minimally invasive devices that can deliver pain relief for extended periods of time with few side effects.

The full journal article can be accessed here.

22nd – 28th January 2018

Physical Health Conditions Associated with PTSD in Military Veterans

Post-traumatic stress disorder (PTSD) is diagnosed in military veterans at a higher frequency to that of the general public due to the increased likelihood of trauma exposure. Those suffering with PTSD have shown greater vulnerabilities to cardiovascular, gastrointestinal, autoimmune and musculoskeletal conditions, with limited explanation. Subthreshold PTSD, which refers to the experiencing of some symptoms following a trauma, but not enough to meet the diagnostic criteria for PTSD, has received less attention with regards to possible associated comorbid conditions.

The importance of examining subthreshold PTSD is high since PTSD is considered a complex condition with multiple factors contributing to its presentation. It will also be beneficial to assess the physical conditions in those with subthreshold PTSD, compared with those who have full diagnostic PTSD, to reveal whether there is an association between physical conditions and PTSD symptom severity.

A study aimed to compare PTSD with subthreshold PTSD was conducted by researchers from the University of Manitoba, Canada, who analysed data from a national survey of 3157 US veterans.

Results revealed that both PTSD and subthreshold PTSD were associated with respiratory disease and sleep disorder. Full PTSD was also associated with osteoporosis and migraine, whereas those with subthreshold PTSD had higher rates of diabetes. These results reveal that even those with subthreshold PTSD experience negative physical conditions perhaps due to trauma-induced alterations within the body’s stress mechanisms that produce inflammatory consequences linked to numerous health conditions. Additionally, the authors speculate that higher diabetes rates amongst subthreshold PTSD, but not full PTSD sufferers, could be due to maladaptive eating habits that are used as coping strategies to reduce stress and therefore PTSD symptoms. The common underlying association between the physical conditions and PTSD symptom clusters was dysphoric arousal, characterised by sleep difficulties, anger and concentration problems.

These findings create awareness around increased risks of physical conditions for not only PTSD sufferers, but also for those individuals who may be below the threshold for PTSD diagnosis yet have experienced negative symptoms following trauma exposure. They also highlight the need for dysphoric arousal to be included in risk models of physical conditions in this population.

The study has been published and can be found here.

1st – 7th January 2018

Listening to your own brainwaves – a promising new treatment for PTSD

Post-traumatic stress disorder (PTSD) is classified as a behavioural disturbance that can develop following a traumatic event.  Symptoms include re-experiencing the event, negative cognition and mood, and heightened arousal.  Military service personnel and veterans suffering from PTSD also show heightened psychosocial risks, such as substance abuse and suicide. Other physiological changes include increased risk levels for cardiovascular and metabolic diseases.

Researchers from the Wake Forest School of Medicine have recently published a study concentrating on the physical components of PTSD, with a focus on the centre of the disorder: the brain. They used the idea that the root to treat PTSD may be due to an imbalance of physiological functioning in the brain and peripheral nervous system. One such model describes how trauma-related hyperarousal may relate to an imbalance in left temporal lobe activity and the dissociative features of PTSD may be attributed to the freeze response driven by the temporal lobe. Therefore, rebalancing maladaptive brain functioning may alleviate some of these PTSD symptoms.

The results of the study seem promising; with robust data indicating that there were improvements to heart rate variability (altered by stress) and PTSD symptomology, including insomnia and depression. However, a small sample size was used in this study so it will be crucial to expand upon the developments to see whether results are beneficial to a wider number of Service Personnel and veterans.

The full article can be downloaded here.

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